// File: contracts/SmartRoute/intf/IDODOV2Proxy01.sol

/*

    Copyright 2020 DODO ZOO.
    SPDX-License-Identifier: Apache-2.0

*/

pragma solidity 0.6.9;


interface IDODOV2Proxy01 {
    function dodoSwapV2ETHToToken(
        address toToken,
        uint256 minReturnAmount,
        address[] memory dodoPairs,
        uint256 directions,
        bool isIncentive,
        uint256 deadLine
    ) external payable returns (uint256 returnAmount);

    function dodoSwapV2TokenToETH(
        address fromToken,
        uint256 fromTokenAmount,
        uint256 minReturnAmount,
        address[] memory dodoPairs,
        uint256 directions,
        bool isIncentive,
        uint256 deadLine
    ) external returns (uint256 returnAmount);

    function dodoSwapV2TokenToToken(
        address fromToken,
        address toToken,
        uint256 fromTokenAmount,
        uint256 minReturnAmount,
        address[] memory dodoPairs,
        uint256 directions,
        bool isIncentive,
        uint256 deadLine
    ) external returns (uint256 returnAmount);

    function createDODOVendingMachine(
        address baseToken,
        address quoteToken,
        uint256 baseInAmount,
        uint256 quoteInAmount,
        uint256 lpFeeRate,
        uint256 i,
        uint256 k,
        bool isOpenTWAP,
        uint256 deadLine
    ) external payable returns (address newVendingMachine, uint256 shares);

    function addDVMLiquidity(
        address dvmAddress,
        uint256 baseInAmount,
        uint256 quoteInAmount,
        uint256 baseMinAmount,
        uint256 quoteMinAmount,
        uint8 flag, //  0 - ERC20, 1 - baseInETH, 2 - quoteInETH
        uint256 deadLine
    )
        external
        payable
        returns (
            uint256 shares,
            uint256 baseAdjustedInAmount,
            uint256 quoteAdjustedInAmount
        );

    function createDODOPrivatePool(
        address baseToken,
        address quoteToken,
        uint256 baseInAmount,
        uint256 quoteInAmount,
        uint256 lpFeeRate,
        uint256 i,
        uint256 k,
        bool isOpenTwap,
        uint256 deadLine
    ) external payable returns (address newPrivatePool);

    function resetDODOPrivatePool(
        address dppAddress,
        uint256[] memory paramList,  //0 - newLpFeeRate, 1 - newI, 2 - newK
        uint256[] memory amountList, //0 - baseInAmount, 1 - quoteInAmount, 2 - baseOutAmount, 3 - quoteOutAmount
        uint8 flag, // 0 - ERC20, 1 - baseInETH, 2 - quoteInETH, 3 - baseOutETH, 4 - quoteOutETH
        uint256 minBaseReserve,
        uint256 minQuoteReserve,
        uint256 deadLine
    ) external payable;

    function createCrowdPooling(
        address baseToken,
        address quoteToken,
        uint256 baseInAmount,
        uint256[] memory timeLine,
        uint256[] memory valueList,
        bool isOpenTWAP,
        uint256 deadLine
    ) external payable returns (address payable newCrowdPooling);

    function bid(
        address cpAddress,
        uint256 quoteAmount,
        uint8 flag, // 0 - ERC20, 1 - quoteInETH
        uint256 deadLine
    ) external payable;

    function addLiquidityToV1(
        address pair,
        uint256 baseAmount,
        uint256 quoteAmount,
        uint256 baseMinShares,
        uint256 quoteMinShares,
        uint8 flag, // 0 erc20 Out  1 baseInETH  2 quoteInETH 
        uint256 deadLine
    ) external payable returns(uint256, uint256);

    function dodoSwapV1(
        address fromToken,
        address toToken,
        uint256 fromTokenAmount,
        uint256 minReturnAmount,
        address[] memory dodoPairs,
        uint256 directions,
        bool isIncentive,
        uint256 deadLine
    ) external payable returns (uint256 returnAmount);

    function externalSwap(
        address fromToken,
        address toToken,
        address approveTarget,
        address to,
        uint256 fromTokenAmount,
        uint256 minReturnAmount,
        bytes memory callDataConcat,
        bool isIncentive,
        uint256 deadLine
    ) external payable returns (uint256 returnAmount);

    function mixSwap(
        address fromToken,
        address toToken,
        uint256 fromTokenAmount,
        uint256 minReturnAmount,
        address[] memory mixAdapters,
        address[] memory mixPairs,
        address[] memory assetTo,
        uint256 directions,
        bool isIncentive,
        uint256 deadLine
    ) external payable returns (uint256 returnAmount);

}

// File: contracts/SmartRoute/intf/IDODOV2.sol


interface IDODOV2 {

    //========== Common ==================

    function sellBase(address to) external returns (uint256 receiveQuoteAmount);

    function sellQuote(address to) external returns (uint256 receiveBaseAmount);

    function getVaultReserve() external view returns (uint256 baseReserve, uint256 quoteReserve);

    function _BASE_TOKEN_() external view returns (address);

    function _QUOTE_TOKEN_() external view returns (address);

    function getPMMStateForCall() external view returns (
            uint256 i,
            uint256 K,
            uint256 B,
            uint256 Q,
            uint256 B0,
            uint256 Q0,
            uint256 R
    );

    function getUserFeeRate(address user) external view returns (uint256 lpFeeRate, uint256 mtFeeRate);

    
    function getDODOPoolBidirection(address token0, address token1) external view returns (address[] memory, address[] memory);

    //========== DODOVendingMachine ========
    
    function createDODOVendingMachine(
        address baseToken,
        address quoteToken,
        uint256 lpFeeRate,
        uint256 i,
        uint256 k,
        bool isOpenTWAP
    ) external returns (address newVendingMachine);
    
    function buyShares(address to) external returns (uint256,uint256,uint256);


    //========== DODOPrivatePool ===========

    function createDODOPrivatePool() external returns (address newPrivatePool);

    function initDODOPrivatePool(
        address dppAddress,
        address creator,
        address baseToken,
        address quoteToken,
        uint256 lpFeeRate,
        uint256 k,
        uint256 i,
        bool isOpenTwap
    ) external;

    function reset(
        address operator,
        uint256 newLpFeeRate,
        uint256 newI,
        uint256 newK,
        uint256 baseOutAmount,
        uint256 quoteOutAmount,
        uint256 minBaseReserve,
        uint256 minQuoteReserve
    ) external returns (bool); 


    function _OWNER_() external returns (address);
    
    //========== CrowdPooling ===========

    function createCrowdPooling() external returns (address payable newCrowdPooling);

    function initCrowdPooling(
        address cpAddress,
        address creator,
        address baseToken,
        address quoteToken,
        uint256[] memory timeLine,
        uint256[] memory valueList,
        bool isOpenTWAP
    ) external;

    function bid(address to) external;
}

// File: contracts/SmartRoute/intf/IDODOV1.sol


interface IDODOV1 {
    function init(
        address owner,
        address supervisor,
        address maintainer,
        address baseToken,
        address quoteToken,
        address oracle,
        uint256 lpFeeRate,
        uint256 mtFeeRate,
        uint256 k,
        uint256 gasPriceLimit
    ) external;

    function transferOwnership(address newOwner) external;

    function claimOwnership() external;

    function sellBaseToken(
        uint256 amount,
        uint256 minReceiveQuote,
        bytes calldata data
    ) external returns (uint256);

    function buyBaseToken(
        uint256 amount,
        uint256 maxPayQuote,
        bytes calldata data
    ) external returns (uint256);

    function querySellBaseToken(uint256 amount) external view returns (uint256 receiveQuote);

    function queryBuyBaseToken(uint256 amount) external view returns (uint256 payQuote);

    function depositBaseTo(address to, uint256 amount) external returns (uint256);

    function withdrawBase(uint256 amount) external returns (uint256);

    function withdrawAllBase() external returns (uint256);

    function depositQuoteTo(address to, uint256 amount) external returns (uint256);

    function withdrawQuote(uint256 amount) external returns (uint256);

    function withdrawAllQuote() external returns (uint256);

    function _BASE_CAPITAL_TOKEN_() external returns (address);

    function _QUOTE_CAPITAL_TOKEN_() external returns (address);

    function _BASE_TOKEN_() external view returns (address);

    function _QUOTE_TOKEN_() external view returns (address);

    function _R_STATUS_() external view returns (uint8);

    function _QUOTE_BALANCE_() external view returns (uint256);

    function _BASE_BALANCE_() external view returns (uint256);

    function _K_() external view returns (uint256);

    function _MT_FEE_RATE_() external view returns (uint256);

    function _LP_FEE_RATE_() external view returns (uint256);

    function getExpectedTarget() external view returns (uint256 baseTarget, uint256 quoteTarget);

    function getOraclePrice() external view returns (uint256);

    function getMidPrice() external view returns (uint256 midPrice); 
}

// File: contracts/intf/IDODOApprove.sol


interface IDODOApprove {
    function claimTokens(address token,address who,address dest,uint256 amount) external;
    function getDODOProxy() external view returns (address);
}

// File: contracts/lib/InitializableOwnable.sol


/**
 * @title Ownable
 * @author DODO Breeder
 *
 * @notice Ownership related functions
 */
contract InitializableOwnable {
    address public _OWNER_;
    address public _NEW_OWNER_;
    bool internal _INITIALIZED_;

    // ============ Events ============

    event OwnershipTransferPrepared(address indexed previousOwner, address indexed newOwner);

    event OwnershipTransferred(address indexed previousOwner, address indexed newOwner);

    // ============ Modifiers ============

    modifier notInitialized() {
        require(!_INITIALIZED_, "DODO_INITIALIZED");
        _;
    }

    modifier onlyOwner() {
        require(msg.sender == _OWNER_, "NOT_OWNER");
        _;
    }

    // ============ Functions ============

    function initOwner(address newOwner) public notInitialized {
        _INITIALIZED_ = true;
        _OWNER_ = newOwner;
    }

    function transferOwnership(address newOwner) public onlyOwner {
        emit OwnershipTransferPrepared(_OWNER_, newOwner);
        _NEW_OWNER_ = newOwner;
    }

    function claimOwnership() public {
        require(msg.sender == _NEW_OWNER_, "INVALID_CLAIM");
        emit OwnershipTransferred(_OWNER_, _NEW_OWNER_);
        _OWNER_ = _NEW_OWNER_;
        _NEW_OWNER_ = address(0);
    }
}

// File: contracts/SmartRoute/DODOApproveProxy.sol




interface IDODOApproveProxy {
    function isAllowedProxy(address _proxy) external view returns (bool);
    function claimTokens(address token,address who,address dest,uint256 amount) external;
}

/**
 * @title DODOApproveProxy
 * @author DODO Breeder
 *
 * @notice Allow different version dodoproxy to claim from DODOApprove
 */
contract DODOApproveProxy is InitializableOwnable {
    
    // ============ Storage ============
    uint256 private constant _TIMELOCK_DURATION_ = 3 days;
    mapping (address => bool) public _IS_ALLOWED_PROXY_;
    uint256 public _TIMELOCK_;
    address public _PENDING_ADD_DODO_PROXY_;
    address public immutable _DODO_APPROVE_;

    // ============ Modifiers ============
    modifier notLocked() {
        require(
            _TIMELOCK_ <= block.timestamp,
            "SetProxy is timelocked"
        );
        _;
    }

    constructor(address dodoApporve) public {
        _DODO_APPROVE_ = dodoApporve;
    }

    function init(address owner, address[] memory proxies) external {
        initOwner(owner);
        for(uint i = 0; i < proxies.length; i++) 
            _IS_ALLOWED_PROXY_[proxies[i]] = true;
    }

    function unlockAddProxy(address newDodoProxy) public onlyOwner {
        _TIMELOCK_ = block.timestamp + _TIMELOCK_DURATION_;
        _PENDING_ADD_DODO_PROXY_ = newDodoProxy;
    }

    function lockAddProxy() public onlyOwner {
       _PENDING_ADD_DODO_PROXY_ = address(0);
       _TIMELOCK_ = 0;
    }


    function addDODOProxy() external onlyOwner notLocked() {
        _IS_ALLOWED_PROXY_[_PENDING_ADD_DODO_PROXY_] = true;
        lockAddProxy();
    }

    function removeDODOProxy (address oldDodoProxy) public onlyOwner {
        _IS_ALLOWED_PROXY_[oldDodoProxy] = false;
    }
    
    function claimTokens(
        address token,
        address who,
        address dest,
        uint256 amount
    ) external {
        require(_IS_ALLOWED_PROXY_[msg.sender], "DODOApproveProxy:Access restricted");
        IDODOApprove(_DODO_APPROVE_).claimTokens(
            token,
            who,
            dest,
            amount
        );
    }

    function isAllowedProxy(address _proxy) external view returns (bool) {
        return _IS_ALLOWED_PROXY_[_proxy];
    }
}

// File: contracts/lib/SafeMath.sol



/**
 * @title SafeMath
 * @author DODO Breeder
 *
 * @notice Math operations with safety checks that revert on error
 */
library SafeMath {
    function mul(uint256 a, uint256 b) internal pure returns (uint256) {
        if (a == 0) {
            return 0;
        }

        uint256 c = a * b;
        require(c / a == b, "MUL_ERROR");

        return c;
    }

    function div(uint256 a, uint256 b) internal pure returns (uint256) {
        require(b > 0, "DIVIDING_ERROR");
        return a / b;
    }

    function divCeil(uint256 a, uint256 b) internal pure returns (uint256) {
        uint256 quotient = div(a, b);
        uint256 remainder = a - quotient * b;
        if (remainder > 0) {
            return quotient + 1;
        } else {
            return quotient;
        }
    }

    function sub(uint256 a, uint256 b) internal pure returns (uint256) {
        require(b <= a, "SUB_ERROR");
        return a - b;
    }

    function add(uint256 a, uint256 b) internal pure returns (uint256) {
        uint256 c = a + b;
        require(c >= a, "ADD_ERROR");
        return c;
    }

    function sqrt(uint256 x) internal pure returns (uint256 y) {
        uint256 z = x / 2 + 1;
        y = x;
        while (z < y) {
            y = z;
            z = (x / z + z) / 2;
        }
    }
}

// File: contracts/lib/DecimalMath.sol



/**
 * @title DecimalMath
 * @author DODO Breeder
 *
 * @notice Functions for fixed point number with 18 decimals
 */
library DecimalMath {
    using SafeMath for uint256;

    uint256 internal constant ONE = 10**18;
    uint256 internal constant ONE2 = 10**36;

    function mulFloor(uint256 target, uint256 d) internal pure returns (uint256) {
        return target.mul(d) / (10**18);
    }

    function mulCeil(uint256 target, uint256 d) internal pure returns (uint256) {
        return target.mul(d).divCeil(10**18);
    }

    function divFloor(uint256 target, uint256 d) internal pure returns (uint256) {
        return target.mul(10**18).div(d);
    }

    function divCeil(uint256 target, uint256 d) internal pure returns (uint256) {
        return target.mul(10**18).divCeil(d);
    }

    function reciprocalFloor(uint256 target) internal pure returns (uint256) {
        return uint256(10**36).div(target);
    }

    function reciprocalCeil(uint256 target) internal pure returns (uint256) {
        return uint256(10**36).divCeil(target);
    }
}

// File: contracts/SmartRoute/helper/DODOSellHelper.sol




// import {DODOMath} from "../lib/DODOMath.sol";

interface IDODOSellHelper {
    function querySellQuoteToken(address dodo, uint256 amount) external view returns (uint256);
    
    function querySellBaseToken(address dodo, uint256 amount) external view returns (uint256);
}

library DODOMath {
    using SafeMath for uint256;

    /*
        Integrate dodo curve fron V1 to V2
        require V0>=V1>=V2>0
        res = (1-k)i(V1-V2)+ikV0*V0(1/V2-1/V1)
        let V1-V2=delta
        res = i*delta*(1-k+k(V0^2/V1/V2))
    */
    function _GeneralIntegrate(
        uint256 V0,
        uint256 V1,
        uint256 V2,
        uint256 i,
        uint256 k
    ) internal pure returns (uint256) {
        uint256 fairAmount = DecimalMath.mulFloor(i, V1.sub(V2)); // i*delta
        uint256 V0V0V1V2 = DecimalMath.divCeil(V0.mul(V0).div(V1), V2);
        uint256 penalty = DecimalMath.mulFloor(k, V0V0V1V2); // k(V0^2/V1/V2)
        return DecimalMath.mulFloor(fairAmount, DecimalMath.ONE.sub(k).add(penalty));
    }

    /*
        The same with integration expression above, we have:
        i*deltaB = (Q2-Q1)*(1-k+kQ0^2/Q1/Q2)
        Given Q1 and deltaB, solve Q2
        This is a quadratic function and the standard version is
        aQ2^2 + bQ2 + c = 0, where
        a=1-k
        -b=(1-k)Q1-kQ0^2/Q1+i*deltaB
        c=-kQ0^2
        and Q2=(-b+sqrt(b^2+4(1-k)kQ0^2))/2(1-k)
        note: another root is negative, abondan
        if deltaBSig=true, then Q2>Q1
        if deltaBSig=false, then Q2<Q1
    */
    function _SolveQuadraticFunctionForTrade(
        uint256 Q0,
        uint256 Q1,
        uint256 ideltaB,
        bool deltaBSig,
        uint256 k
    ) internal pure returns (uint256) {
        // calculate -b value and sig
        // -b = (1-k)Q1-kQ0^2/Q1+i*deltaB
        uint256 kQ02Q1 = DecimalMath.mulFloor(k, Q0).mul(Q0).div(Q1); // kQ0^2/Q1
        uint256 b = DecimalMath.mulFloor(DecimalMath.ONE.sub(k), Q1); // (1-k)Q1
        bool minusbSig = true;
        if (deltaBSig) {
            b = b.add(ideltaB); // (1-k)Q1+i*deltaB
        } else {
            kQ02Q1 = kQ02Q1.add(ideltaB); // i*deltaB+kQ0^2/Q1
        }
        if (b >= kQ02Q1) {
            b = b.sub(kQ02Q1);
            minusbSig = true;
        } else {
            b = kQ02Q1.sub(b);
            minusbSig = false;
        }

        // calculate sqrt
        uint256 squareRoot = DecimalMath.mulFloor(
            DecimalMath.ONE.sub(k).mul(4),
            DecimalMath.mulFloor(k, Q0).mul(Q0)
        ); // 4(1-k)kQ0^2
        squareRoot = b.mul(b).add(squareRoot).sqrt(); // sqrt(b*b+4(1-k)kQ0*Q0)

        // final res
        uint256 denominator = DecimalMath.ONE.sub(k).mul(2); // 2(1-k)
        uint256 numerator;
        if (minusbSig) {
            numerator = b.add(squareRoot);
        } else {
            numerator = squareRoot.sub(b);
        }

        if (deltaBSig) {
            return DecimalMath.divFloor(numerator, denominator);
        } else {
            return DecimalMath.divCeil(numerator, denominator);
        }
    }

    /*
        Start from the integration function
        i*deltaB = (Q2-Q1)*(1-k+kQ0^2/Q1/Q2)
        Assume Q2=Q0, Given Q1 and deltaB, solve Q0
        let fairAmount = i*deltaB
    */
    function _SolveQuadraticFunctionForTarget(
        uint256 V1,
        uint256 k,
        uint256 fairAmount
    ) internal pure returns (uint256 V0) {
        // V0 = V1+V1*(sqrt-1)/2k
        uint256 sqrt = DecimalMath.divCeil(DecimalMath.mulFloor(k, fairAmount).mul(4), V1);
        sqrt = sqrt.add(DecimalMath.ONE).mul(DecimalMath.ONE).sqrt();
        uint256 premium = DecimalMath.divCeil(sqrt.sub(DecimalMath.ONE), k.mul(2));
        // V0 is greater than or equal to V1 according to the solution
        return DecimalMath.mulFloor(V1, DecimalMath.ONE.add(premium));
    }
}

contract DODOSellHelper {
    using SafeMath for uint256;

    enum RStatus {ONE, ABOVE_ONE, BELOW_ONE}

    uint256 constant ONE = 10**18;

    struct DODOState {
        uint256 oraclePrice;
        uint256 K;
        uint256 B;
        uint256 Q;
        uint256 baseTarget;
        uint256 quoteTarget;
        RStatus rStatus;
    }

    function querySellBaseToken(address dodo, uint256 amount) public view returns (uint256) {
        return IDODOV1(dodo).querySellBaseToken(amount);
    }

    function querySellQuoteToken(address dodo, uint256 amount) public view returns (uint256) {
        DODOState memory state;
        (state.baseTarget, state.quoteTarget) = IDODOV1(dodo).getExpectedTarget();
        state.rStatus = RStatus(IDODOV1(dodo)._R_STATUS_());
        state.oraclePrice = IDODOV1(dodo).getOraclePrice();
        state.Q = IDODOV1(dodo)._QUOTE_BALANCE_();
        state.B = IDODOV1(dodo)._BASE_BALANCE_();
        state.K = IDODOV1(dodo)._K_();

        uint256 boughtAmount;
        // Determine the status (RStatus) and calculate the amount
        // based on the state
        if (state.rStatus == RStatus.ONE) {
            boughtAmount = _ROneSellQuoteToken(amount, state);
        } else if (state.rStatus == RStatus.ABOVE_ONE) {
            boughtAmount = _RAboveSellQuoteToken(amount, state);
        } else {
            uint256 backOneBase = state.B.sub(state.baseTarget);
            uint256 backOneQuote = state.quoteTarget.sub(state.Q);
            if (amount <= backOneQuote) {
                boughtAmount = _RBelowSellQuoteToken(amount, state);
            } else {
                boughtAmount = backOneBase.add(
                    _ROneSellQuoteToken(amount.sub(backOneQuote), state)
                );
            }
        }
        // Calculate fees
        return
            DecimalMath.divFloor(
                boughtAmount,
                DecimalMath.ONE.add(IDODOV1(dodo)._MT_FEE_RATE_()).add(
                    IDODOV1(dodo)._LP_FEE_RATE_()
                )
            );
    }

    function _ROneSellQuoteToken(uint256 amount, DODOState memory state)
        internal
        pure
        returns (uint256 receiveBaseToken)
    {
        uint256 i = DecimalMath.divFloor(ONE, state.oraclePrice);
        uint256 B2 = DODOMath._SolveQuadraticFunctionForTrade(
            state.baseTarget,
            state.baseTarget,
            DecimalMath.mulFloor(i, amount),
            false,
            state.K
        );
        return state.baseTarget.sub(B2);
    }

    function _RAboveSellQuoteToken(uint256 amount, DODOState memory state)
        internal
        pure
        returns (uint256 receieBaseToken)
    {
        uint256 i = DecimalMath.divFloor(ONE, state.oraclePrice);
        uint256 B2 = DODOMath._SolveQuadraticFunctionForTrade(
            state.baseTarget,
            state.B,
            DecimalMath.mulFloor(i, amount),
            false,
            state.K
        );
        return state.B.sub(B2);
    }

    function _RBelowSellQuoteToken(uint256 amount, DODOState memory state)
        internal
        pure
        returns (uint256 receiveBaseToken)
    {
        uint256 Q1 = state.Q.add(amount);
        uint256 i = DecimalMath.divFloor(ONE, state.oraclePrice);
        return DODOMath._GeneralIntegrate(state.quoteTarget, Q1, state.Q, i, state.K);
    }
}

// File: contracts/intf/IERC20.sol

/**
 * @dev Interface of the ERC20 standard as defined in the EIP.
 */
interface IERC20 {
    /**
     * @dev Returns the amount of tokens in existence.
     */
    function totalSupply() external view returns (uint256);

    function decimals() external view returns (uint8);

    function name() external view returns (string memory);

    function symbol() external view returns (string memory);

    /**
     * @dev Returns the amount of tokens owned by `account`.
     */
    function balanceOf(address account) external view returns (uint256);

    /**
     * @dev Moves `amount` tokens from the caller's account to `recipient`.
     *
     * Returns a boolean value indicating whether the operation succeeded.
     *
     * Emits a {Transfer} event.
     */
    function transfer(address recipient, uint256 amount) external returns (bool);

    /**
     * @dev Returns the remaining number of tokens that `spender` will be
     * allowed to spend on behalf of `owner` through {transferFrom}. This is
     * zero by default.
     *
     * This value changes when {approve} or {transferFrom} are called.
     */
    function allowance(address owner, address spender) external view returns (uint256);

    /**
     * @dev Sets `amount` as the allowance of `spender` over the caller's tokens.
     *
     * Returns a boolean value indicating whether the operation succeeded.
     *
     * IMPORTANT: Beware that changing an allowance with this method brings the risk
     * that someone may use both the old and the new allowance by unfortunate
     * transaction ordering. One possible solution to mitigate this race
     * condition is to first reduce the spender's allowance to 0 and set the
     * desired value afterwards:
     * https://github.com/ethereum/EIPs/issues/20#issuecomment-263524729
     *
     * Emits an {Approval} event.
     */
    function approve(address spender, uint256 amount) external returns (bool);

    /**
     * @dev Moves `amount` tokens from `sender` to `recipient` using the
     * allowance mechanism. `amount` is then deducted from the caller's
     * allowance.
     *
     * Returns a boolean value indicating whether the operation succeeded.
     *
     * Emits a {Transfer} event.
     */
    function transferFrom(
        address sender,
        address recipient,
        uint256 amount
    ) external returns (bool);
}

// File: contracts/intf/IWETH.sol



interface IWETH {
    function totalSupply() external view returns (uint256);

    function balanceOf(address account) external view returns (uint256);

    function transfer(address recipient, uint256 amount) external returns (bool);

    function allowance(address owner, address spender) external view returns (uint256);

    function approve(address spender, uint256 amount) external returns (bool);

    function transferFrom(
        address src,
        address dst,
        uint256 wad
    ) external returns (bool);

    function deposit() external payable;

    function withdraw(uint256 wad) external;
}

// File: contracts/SmartRoute/intf/IUni.sol

interface IUni {
    function swapExactTokensForTokens(
        uint amountIn,
        uint amountOutMin,
        address[] calldata path,
        address to,
        uint deadline
    ) external returns (uint[] memory amounts);

    function swap(uint amount0Out, uint amount1Out, address to, bytes calldata data) external;

    function getReserves() external view returns (uint112 reserve0, uint112 reserve1, uint32 blockTimestampLast);

    function token0() external view returns (address);
    
    function token1() external view returns (address);
}

// File: contracts/SmartRoute/intf/IChi.sol


interface IChi {
    function freeUpTo(uint256 value) external returns (uint256);
}

// File: contracts/lib/SafeERC20.sol




/**
 * @title SafeERC20
 * @dev Wrappers around ERC20 operations that throw on failure (when the token
 * contract returns false). Tokens that return no value (and instead revert or
 * throw on failure) are also supported, non-reverting calls are assumed to be
 * successful.
 * To use this library you can add a `using SafeERC20 for ERC20;` statement to your contract,
 * which allows you to call the safe operations as `token.safeTransfer(...)`, etc.
 */
library SafeERC20 {
    using SafeMath for uint256;

    function safeTransfer(
        IERC20 token,
        address to,
        uint256 value
    ) internal {
        _callOptionalReturn(token, abi.encodeWithSelector(token.transfer.selector, to, value));
    }

    function safeTransferFrom(
        IERC20 token,
        address from,
        address to,
        uint256 value
    ) internal {
        _callOptionalReturn(
            token,
            abi.encodeWithSelector(token.transferFrom.selector, from, to, value)
        );
    }

    function safeApprove(
        IERC20 token,
        address spender,
        uint256 value
    ) internal {
        // safeApprove should only be called when setting an initial allowance,
        // or when resetting it to zero. To increase and decrease it, use
        // 'safeIncreaseAllowance' and 'safeDecreaseAllowance'
        // solhint-disable-next-line max-line-length
        require(
            (value == 0) || (token.allowance(address(this), spender) == 0),
            "SafeERC20: approve from non-zero to non-zero allowance"
        );
        _callOptionalReturn(token, abi.encodeWithSelector(token.approve.selector, spender, value));
    }

    /**
     * @dev Imitates a Solidity high-level call (i.e. a regular function call to a contract), relaxing the requirement
     * on the return value: the return value is optional (but if data is returned, it must not be false).
     * @param token The token targeted by the call.
     * @param data The call data (encoded using abi.encode or one of its variants).
     */
    function _callOptionalReturn(IERC20 token, bytes memory data) private {
        // We need to perform a low level call here, to bypass Solidity's return data size checking mechanism, since
        // we're implementing it ourselves.

        // A Solidity high level call has three parts:
        //  1. The target address is checked to verify it contains contract code
        //  2. The call itself is made, and success asserted
        //  3. The return value is decoded, which in turn checks the size of the returned data.
        // solhint-disable-next-line max-line-length

        // solhint-disable-next-line avoid-low-level-calls
        (bool success, bytes memory returndata) = address(token).call(data);
        require(success, "SafeERC20: low-level call failed");

        if (returndata.length > 0) {
            // Return data is optional
            // solhint-disable-next-line max-line-length
            require(abi.decode(returndata, (bool)), "SafeERC20: ERC20 operation did not succeed");
        }
    }
}

// File: contracts/SmartRoute/lib/UniversalERC20.sol





library UniversalERC20 {
    using SafeMath for uint256;
    using SafeERC20 for IERC20;

    IERC20 private constant ETH_ADDRESS = IERC20(0xEeeeeEeeeEeEeeEeEeEeeEEEeeeeEeeeeeeeEEeE);

    function universalTransfer(
        IERC20 token,
        address payable to,
        uint256 amount
    ) internal {
        if (amount > 0) {
            if (isETH(token)) {
                to.transfer(amount);
            } else {
                token.safeTransfer(to, amount);
            }
        }
    }

    function universalApproveMax(
        IERC20 token,
        address to,
        uint256 amount
    ) internal {
        uint256 allowance = token.allowance(address(this), to);
        if (allowance < amount) {
            if (allowance > 0) {
                token.safeApprove(to, 0);
            }
            token.safeApprove(to, uint256(-1));
        }
    }

    function universalBalanceOf(IERC20 token, address who) internal view returns (uint256) {
        if (isETH(token)) {
            return who.balance;
        } else {
            return token.balanceOf(who);
        }
    }

    function tokenBalanceOf(IERC20 token, address who) internal view returns (uint256) {
        return token.balanceOf(who);
    }

    function isETH(IERC20 token) internal pure returns (bool) {
        return token == ETH_ADDRESS;
    }
}

// File: contracts/lib/ReentrancyGuard.sol


/**
 * @title ReentrancyGuard
 * @author DODO Breeder
 *
 * @notice Protect functions from Reentrancy Attack
 */
contract ReentrancyGuard {
    // https://solidity.readthedocs.io/en/latest/control-structures.html?highlight=zero-state#scoping-and-declarations
    // zero-state of _ENTERED_ is false
    bool private _ENTERED_;

    modifier preventReentrant() {
        require(!_ENTERED_, "REENTRANT");
        _ENTERED_ = true;
        _;
        _ENTERED_ = false;
    }
}

// File: contracts/DODOToken/DODOIncentive.sol




interface IDODOIncentive {
    function triggerIncentive(
        address fromToken,
        address toToken,
        address assetTo
    ) external;
}

/**
 * @title DODOIncentive
 * @author DODO Breeder
 *
 * @notice Trade Incentive in DODO platform
 */
contract DODOIncentive is InitializableOwnable {
    using SafeMath for uint256;
    using SafeERC20 for IERC20;

    // ============ Storage ============
    address public immutable _DODO_TOKEN_;
    address public _DODO_PROXY_;
    uint256 public dodoPerBlock;
    uint256 public defaultRate = 10;
    mapping(address => uint256) public boosts;

    uint32 public lastRewardBlock;
    uint112 public totalReward;
    uint112 public totalDistribution;

    // ============ Events ============

    event SetBoost(address token, uint256 boostRate);
    event SetNewProxy(address dodoProxy);
    event SetPerReward(uint256 dodoPerBlock);
    event SetDefaultRate(uint256 defaultRate);
    event Incentive(address user, uint256 reward);

    constructor(address _dodoToken) public {
        _DODO_TOKEN_ = _dodoToken;
    }

    // ============ Ownable ============

    function changeBoost(address _token, uint256 _boostRate) public onlyOwner {
        require(_token != address(0));
        require(_boostRate + defaultRate <= 1000);
        boosts[_token] = _boostRate;
        emit SetBoost(_token, _boostRate);
    }

    function changePerReward(uint256 _dodoPerBlock) public onlyOwner {
        _updateTotalReward();
        dodoPerBlock = _dodoPerBlock;
        emit SetPerReward(dodoPerBlock);
    }

    function changeDefaultRate(uint256 _defaultRate) public onlyOwner {
        defaultRate = _defaultRate;
        emit SetDefaultRate(defaultRate);
    }

    function changeDODOProxy(address _dodoProxy) public onlyOwner {
        _DODO_PROXY_ = _dodoProxy;
        emit SetNewProxy(_DODO_PROXY_);
    }

    function emptyReward(address assetTo) public onlyOwner {
        uint256 balance = IERC20(_DODO_TOKEN_).balanceOf(address(this));
        IERC20(_DODO_TOKEN_).transfer(assetTo, balance);
    }

    // ============ Incentive  function ============

    function triggerIncentive(
        address fromToken,
        address toToken,
        address assetTo
    ) external {
        require(msg.sender == _DODO_PROXY_, "DODOIncentive:Access restricted");

        uint256 curTotalDistribution = totalDistribution;
        uint256 fromRate = boosts[fromToken];
        uint256 toRate = boosts[toToken];
        uint256 rate = (fromRate >= toRate ? fromRate : toRate) + defaultRate;
        require(rate <= 1000, "RATE_INVALID");
        
        uint256 _totalReward = _getTotalReward();
        uint256 reward = ((_totalReward - curTotalDistribution) * rate) / 1000;
        uint256 _totalDistribution = curTotalDistribution + reward;

        _update(_totalReward, _totalDistribution);
        if (reward != 0) {
            IERC20(_DODO_TOKEN_).transfer(assetTo, reward);
            emit Incentive(assetTo, reward);
        }
    }

    function _updateTotalReward() internal {
        uint256 _totalReward = _getTotalReward();
        require(_totalReward < uint112(-1), "OVERFLOW");
        totalReward = uint112(_totalReward);
        lastRewardBlock = uint32(block.number);
    }

    function _update(uint256 _totalReward, uint256 _totalDistribution) internal {
        require(
            _totalReward < uint112(-1) && _totalDistribution < uint112(-1) && block.number < uint32(-1),
            "OVERFLOW"
        );
        lastRewardBlock = uint32(block.number);
        totalReward = uint112(_totalReward);
        totalDistribution = uint112(_totalDistribution);
    }

    function _getTotalReward() internal view returns (uint256) {
        if (lastRewardBlock == 0) {
            return totalReward;
        } else {
            return totalReward + (block.number - lastRewardBlock) * dodoPerBlock;
        }
    }

    // ============= Helper function ===============

    function incentiveStatus(address fromToken, address toToken)
        external
        view
        returns (
            uint256 reward,
            uint256 baseRate,
            uint256 totalRate,
            uint256 curTotalReward,
            uint256 perBlockReward
        )
    {
        baseRate = defaultRate;
        uint256 fromRate = boosts[fromToken];
        uint256 toRate = boosts[toToken];
        totalRate = (fromRate >= toRate ? fromRate : toRate) + defaultRate;
        uint256 _totalReward = _getTotalReward();
        reward = ((_totalReward - totalDistribution) * totalRate) / 1000;
        curTotalReward = _totalReward - totalDistribution;
        perBlockReward = dodoPerBlock;
    }
}

// File: contracts/SmartRoute/intf/IDODOAdapter.sol


interface IDODOAdapter {
    
    function sellBase(address to, address pool) external;

    function sellQuote(address to, address pool) external;
}

// File: contracts/SmartRoute/DODOV2Proxy02.sol
















/**
 * @title DODOV2Proxy02
 * @author DODO Breeder
 *
 * @notice Entrance of trading in DODO platform
 */
contract DODOV2Proxy02 is IDODOV2Proxy01, ReentrancyGuard, InitializableOwnable {
    using SafeMath for uint256;
    using UniversalERC20 for IERC20;

    // ============ Storage ============

    address constant _ETH_ADDRESS_ = 0xEeeeeEeeeEeEeeEeEeEeeEEEeeeeEeeeeeeeEEeE;
    address public immutable _WETH_;
    address public immutable _DODO_APPROVE_PROXY_;
    address public immutable _DODO_SELL_HELPER_;
    address public immutable _DVM_FACTORY_;
    address public immutable _DPP_FACTORY_;
    address public immutable _CP_FACTORY_;
    address public immutable _DODO_INCENTIVE_;
    address public immutable _CHI_TOKEN_;
    uint256 public _GAS_DODO_MAX_RETURN_ = 0;
    uint256 public _GAS_EXTERNAL_RETURN_ = 0;
    mapping (address => bool) public isWhiteListed;

    // ============ Events ============

    event OrderHistory(
        address fromToken,
        address toToken,
        address sender,
        uint256 fromAmount,
        uint256 returnAmount
    );

    // ============ Modifiers ============

    modifier judgeExpired(uint256 deadLine) {
        require(deadLine >= block.timestamp, "DODOV2Proxy02: EXPIRED");
        _;
    }

    fallback() external payable {}

    receive() external payable {}

    constructor(
        address dvmFactory,
        address dppFactory,
        address cpFactory,
        address payable weth,
        address dodoApproveProxy,
        address dodoSellHelper,
        address chiToken,
        address dodoIncentive
    ) public {
        _DVM_FACTORY_ = dvmFactory;
        _DPP_FACTORY_ = dppFactory;
        _CP_FACTORY_ = cpFactory;
        _WETH_ = weth;
        _DODO_APPROVE_PROXY_ = dodoApproveProxy;
        _DODO_SELL_HELPER_ = dodoSellHelper;
        _CHI_TOKEN_ = chiToken;
        _DODO_INCENTIVE_ = dodoIncentive;
    }

    function addWhiteList (address contractAddr) public onlyOwner {
        isWhiteListed[contractAddr] = true;
    }

    function removeWhiteList (address contractAddr) public onlyOwner {
        isWhiteListed[contractAddr] = false;
    }

    function updateGasReturn(uint256 newDodoGasReturn, uint256 newExternalGasReturn) public onlyOwner {
        _GAS_DODO_MAX_RETURN_ = newDodoGasReturn;
        _GAS_EXTERNAL_RETURN_ = newExternalGasReturn;
    }

    // ============ DVM Functions (create & add liquidity) ============

    function createDODOVendingMachine(
        address baseToken,
        address quoteToken,
        uint256 baseInAmount,
        uint256 quoteInAmount,
        uint256 lpFeeRate,
        uint256 i,
        uint256 k,
        bool isOpenTWAP,
        uint256 deadLine
    )
        external
        override
        payable
        preventReentrant
        judgeExpired(deadLine)
        returns (address newVendingMachine, uint256 shares)
    {
        {
            address _baseToken = baseToken == _ETH_ADDRESS_ ? _WETH_ : baseToken;
            address _quoteToken = quoteToken == _ETH_ADDRESS_ ? _WETH_ : quoteToken;
            newVendingMachine = IDODOV2(_DVM_FACTORY_).createDODOVendingMachine(
                _baseToken,
                _quoteToken,
                lpFeeRate,
                i,
                k,
                isOpenTWAP
            );
        }

        {
            address _baseToken = baseToken;
            address _quoteToken = quoteToken;
            _deposit(
                msg.sender,
                newVendingMachine,
                _baseToken,
                baseInAmount,
                _baseToken == _ETH_ADDRESS_
            );
            _deposit(
                msg.sender,
                newVendingMachine,
                _quoteToken,
                quoteInAmount,
                _quoteToken == _ETH_ADDRESS_
            );
        }

        (shares, , ) = IDODOV2(newVendingMachine).buyShares(msg.sender);
    }

    function addDVMLiquidity(
        address dvmAddress,
        uint256 baseInAmount,
        uint256 quoteInAmount,
        uint256 baseMinAmount,
        uint256 quoteMinAmount,
        uint8 flag, // 0 - ERC20, 1 - baseInETH, 2 - quoteInETH
        uint256 deadLine
    )
        external
        override
        payable
        preventReentrant
        judgeExpired(deadLine)
        returns (
            uint256 shares,
            uint256 baseAdjustedInAmount,
            uint256 quoteAdjustedInAmount
        )
    {
        address _dvm = dvmAddress;
        (baseAdjustedInAmount, quoteAdjustedInAmount) = _addDVMLiquidity(
            _dvm,
            baseInAmount,
            quoteInAmount
        );
        require(
            baseAdjustedInAmount >= baseMinAmount && quoteAdjustedInAmount >= quoteMinAmount,
            "DODOV2Proxy02: deposit amount is not enough"
        );

        _deposit(msg.sender, _dvm, IDODOV2(_dvm)._BASE_TOKEN_(), baseAdjustedInAmount, flag == 1);
        _deposit(msg.sender, _dvm, IDODOV2(_dvm)._QUOTE_TOKEN_(), quoteAdjustedInAmount, flag == 2);
        
        (shares, , ) = IDODOV2(_dvm).buyShares(msg.sender);
        // refund dust eth
        if (flag == 1 && msg.value > baseAdjustedInAmount) msg.sender.transfer(msg.value - baseAdjustedInAmount);
        if (flag == 2 && msg.value > quoteAdjustedInAmount) msg.sender.transfer(msg.value - quoteAdjustedInAmount);
    }

    function _addDVMLiquidity(
        address dvmAddress,
        uint256 baseInAmount,
        uint256 quoteInAmount
    ) internal view returns (uint256 baseAdjustedInAmount, uint256 quoteAdjustedInAmount) {
        (uint256 baseReserve, uint256 quoteReserve) = IDODOV2(dvmAddress).getVaultReserve();
        if (quoteReserve == 0 && baseReserve == 0) {
            baseAdjustedInAmount = baseInAmount;
            quoteAdjustedInAmount = quoteInAmount;
        }
        if (quoteReserve == 0 && baseReserve > 0) {
            baseAdjustedInAmount = baseInAmount;
            quoteAdjustedInAmount = 0;
        }
        if (quoteReserve > 0 && baseReserve > 0) {
            uint256 baseIncreaseRatio = DecimalMath.divFloor(baseInAmount, baseReserve);
            uint256 quoteIncreaseRatio = DecimalMath.divFloor(quoteInAmount, quoteReserve);
            if (baseIncreaseRatio <= quoteIncreaseRatio) {
                baseAdjustedInAmount = baseInAmount;
                quoteAdjustedInAmount = DecimalMath.mulFloor(quoteReserve, baseIncreaseRatio);
            } else {
                quoteAdjustedInAmount = quoteInAmount;
                baseAdjustedInAmount = DecimalMath.mulFloor(baseReserve, quoteIncreaseRatio);
            }
        }
    }

    // ============ DPP Functions (create & reset) ============

    function createDODOPrivatePool(
        address baseToken,
        address quoteToken,
        uint256 baseInAmount,
        uint256 quoteInAmount,
        uint256 lpFeeRate,
        uint256 i,
        uint256 k,
        bool isOpenTwap,
        uint256 deadLine
    )
        external
        override
        payable
        preventReentrant
        judgeExpired(deadLine)
        returns (address newPrivatePool)
    {
        newPrivatePool = IDODOV2(_DPP_FACTORY_).createDODOPrivatePool();

        address _baseToken = baseToken;
        address _quoteToken = quoteToken;
        _deposit(msg.sender, newPrivatePool, _baseToken, baseInAmount, _baseToken == _ETH_ADDRESS_);
        _deposit(
            msg.sender,
            newPrivatePool,
            _quoteToken,
            quoteInAmount,
            _quoteToken == _ETH_ADDRESS_
        );

        if (_baseToken == _ETH_ADDRESS_) _baseToken = _WETH_;
        if (_quoteToken == _ETH_ADDRESS_) _quoteToken = _WETH_;

        IDODOV2(_DPP_FACTORY_).initDODOPrivatePool(
            newPrivatePool,
            msg.sender,
            _baseToken,
            _quoteToken,
            lpFeeRate,
            k,
            i,
            isOpenTwap
        );
    }

    function resetDODOPrivatePool(
        address dppAddress,
        uint256[] memory paramList,  //0 - newLpFeeRate, 1 - newI, 2 - newK
        uint256[] memory amountList, //0 - baseInAmount, 1 - quoteInAmount, 2 - baseOutAmount, 3- quoteOutAmount
        uint8 flag, // 0 - ERC20, 1 - baseInETH, 2 - quoteInETH, 3 - baseOutETH, 4 - quoteOutETH
        uint256 minBaseReserve,
        uint256 minQuoteReserve,
        uint256 deadLine
    ) external override payable preventReentrant judgeExpired(deadLine) {
        _deposit(
            msg.sender,
            dppAddress,
            IDODOV2(dppAddress)._BASE_TOKEN_(),
            amountList[0],
            flag == 1
        );
        _deposit(
            msg.sender,
            dppAddress,
            IDODOV2(dppAddress)._QUOTE_TOKEN_(),
            amountList[1],
            flag == 2
        );

        require(IDODOV2(IDODOV2(dppAddress)._OWNER_()).reset(
            msg.sender,
            paramList[0],
            paramList[1],
            paramList[2],
            amountList[2],
            amountList[3],
            minBaseReserve,
            minQuoteReserve
        ), "Reset Failed");

        _withdraw(msg.sender, IDODOV2(dppAddress)._BASE_TOKEN_(), amountList[2], flag == 3);
        _withdraw(msg.sender, IDODOV2(dppAddress)._QUOTE_TOKEN_(), amountList[3], flag == 4);
    }

    // ============ Swap ============

    function dodoSwapV2ETHToToken(
        address toToken,
        uint256 minReturnAmount,
        address[] memory dodoPairs,
        uint256 directions,
        bool isIncentive,
        uint256 deadLine
    )
        external
        override
        payable
        judgeExpired(deadLine)
        returns (uint256 returnAmount)
    {
        require(dodoPairs.length > 0, "DODOV2Proxy02: PAIRS_EMPTY");
        require(minReturnAmount > 0, "DODOV2Proxy02: RETURN_AMOUNT_ZERO");
        uint256 originGas = gasleft();
        
        uint256 originToTokenBalance = IERC20(toToken).balanceOf(msg.sender);
        IWETH(_WETH_).deposit{value: msg.value}();
        IWETH(_WETH_).transfer(dodoPairs[0], msg.value);

        for (uint256 i = 0; i < dodoPairs.length; i++) {
            if (i == dodoPairs.length - 1) {
                if (directions & 1 == 0) {
                    IDODOV2(dodoPairs[i]).sellBase(msg.sender);
                } else {
                    IDODOV2(dodoPairs[i]).sellQuote(msg.sender);
                }
            } else {
                if (directions & 1 == 0) {
                    IDODOV2(dodoPairs[i]).sellBase(dodoPairs[i + 1]);
                } else {
                    IDODOV2(dodoPairs[i]).sellQuote(dodoPairs[i + 1]);
                }
            }
            directions = directions >> 1;
        }

        returnAmount = IERC20(toToken).balanceOf(msg.sender).sub(originToTokenBalance);
        require(returnAmount >= minReturnAmount, "DODOV2Proxy02: Return amount is not enough");

        _dodoGasReturn(originGas);

        _execIncentive(isIncentive, _ETH_ADDRESS_, toToken);

        emit OrderHistory(
            _ETH_ADDRESS_,
            toToken,
            msg.sender,
            msg.value,
            returnAmount
        );
    }

    function dodoSwapV2TokenToETH(
        address fromToken,
        uint256 fromTokenAmount,
        uint256 minReturnAmount,
        address[] memory dodoPairs,
        uint256 directions,
        bool isIncentive,
        uint256 deadLine
    )
        external
        override
        judgeExpired(deadLine)
        returns (uint256 returnAmount)
    {
        require(dodoPairs.length > 0, "DODOV2Proxy02: PAIRS_EMPTY");
        require(minReturnAmount > 0, "DODOV2Proxy02: RETURN_AMOUNT_ZERO");
        uint256 originGas = gasleft();
        
        IDODOApproveProxy(_DODO_APPROVE_PROXY_).claimTokens(fromToken, msg.sender, dodoPairs[0], fromTokenAmount);

        for (uint256 i = 0; i < dodoPairs.length; i++) {
            if (i == dodoPairs.length - 1) {
                if (directions & 1 == 0) {
                    IDODOV2(dodoPairs[i]).sellBase(address(this));
                } else {
                    IDODOV2(dodoPairs[i]).sellQuote(address(this));
                }
            } else {
                if (directions & 1 == 0) {
                    IDODOV2(dodoPairs[i]).sellBase(dodoPairs[i + 1]);
                } else {
                    IDODOV2(dodoPairs[i]).sellQuote(dodoPairs[i + 1]);
                }
            }
            directions = directions >> 1;
        }
        returnAmount = IWETH(_WETH_).balanceOf(address(this));
        require(returnAmount >= minReturnAmount, "DODOV2Proxy02: Return amount is not enough");
        IWETH(_WETH_).withdraw(returnAmount);
        msg.sender.transfer(returnAmount);

        _dodoGasReturn(originGas);

        _execIncentive(isIncentive, fromToken, _ETH_ADDRESS_);

        emit OrderHistory(
            fromToken,
            _ETH_ADDRESS_,
            msg.sender,
            fromTokenAmount,
            returnAmount
        );
    }

    function dodoSwapV2TokenToToken(
        address fromToken,
        address toToken,
        uint256 fromTokenAmount,
        uint256 minReturnAmount,
        address[] memory dodoPairs,
        uint256 directions,
        bool isIncentive,
        uint256 deadLine
    )
        external
        override
        judgeExpired(deadLine)
        returns (uint256 returnAmount)
    {
        require(dodoPairs.length > 0, "DODOV2Proxy02: PAIRS_EMPTY");
        require(minReturnAmount > 0, "DODOV2Proxy02: RETURN_AMOUNT_ZERO");
        uint256 originGas = gasleft();

        uint256 originToTokenBalance = IERC20(toToken).balanceOf(msg.sender);
        IDODOApproveProxy(_DODO_APPROVE_PROXY_).claimTokens(fromToken, msg.sender, dodoPairs[0], fromTokenAmount);

        for (uint256 i = 0; i < dodoPairs.length; i++) {
            if (i == dodoPairs.length - 1) {
                if (directions & 1 == 0) {
                    IDODOV2(dodoPairs[i]).sellBase(msg.sender);
                } else {
                    IDODOV2(dodoPairs[i]).sellQuote(msg.sender);
                }
            } else {
                if (directions& 1 == 0) {
                    IDODOV2(dodoPairs[i]).sellBase(dodoPairs[i + 1]);
                } else {
                    IDODOV2(dodoPairs[i]).sellQuote(dodoPairs[i + 1]);
                }
            }
            directions = directions >> 1;
        }
        returnAmount = IERC20(toToken).balanceOf(msg.sender).sub(originToTokenBalance);
        require(returnAmount >= minReturnAmount, "DODOV2Proxy02: Return amount is not enough");
        
        _dodoGasReturn(originGas);

        _execIncentive(isIncentive, fromToken, toToken);

        emit OrderHistory(
            fromToken,
            toToken,
            msg.sender,
            fromTokenAmount,
            returnAmount
        );
    }

    function externalSwap(
        address fromToken,
        address toToken,
        address approveTarget,
        address swapTarget,
        uint256 fromTokenAmount,
        uint256 minReturnAmount,
        bytes memory callDataConcat,
        bool isIncentive,
        uint256 deadLine
    )
        external
        override
        payable
        judgeExpired(deadLine)
        returns (uint256 returnAmount)
    {
        require(minReturnAmount > 0, "DODOV2Proxy02: RETURN_AMOUNT_ZERO");
        require(fromToken != _CHI_TOKEN_, "DODOV2Proxy02: NOT_SUPPORT_SELL_CHI");
        require(toToken != _CHI_TOKEN_, "DODOV2Proxy02: NOT_SUPPORT_BUY_CHI");
        
        uint256 toTokenOriginBalance = IERC20(toToken).universalBalanceOf(msg.sender);
        if (fromToken != _ETH_ADDRESS_) {
            IDODOApproveProxy(_DODO_APPROVE_PROXY_).claimTokens(
                fromToken,
                msg.sender,
                address(this),
                fromTokenAmount
            );
            IERC20(fromToken).universalApproveMax(approveTarget, fromTokenAmount);
        }

        require(isWhiteListed[swapTarget], "DODOV2Proxy02: Not Whitelist Contract");
        (bool success, ) = swapTarget.call{value: fromToken == _ETH_ADDRESS_ ? msg.value : 0}(callDataConcat);

        require(success, "DODOV2Proxy02: External Swap execution Failed");

        IERC20(toToken).universalTransfer(
            msg.sender,
            IERC20(toToken).universalBalanceOf(address(this))
        );

        returnAmount = IERC20(toToken).universalBalanceOf(msg.sender).sub(toTokenOriginBalance);
        require(returnAmount >= minReturnAmount, "DODOV2Proxy02: Return amount is not enough");

        _externalGasReturn();

        _execIncentive(isIncentive, fromToken, toToken);

        emit OrderHistory(
            fromToken,
            toToken,
            msg.sender,
            fromTokenAmount,
            returnAmount
        );
    }

    function dodoSwapV1(
        address fromToken,
        address toToken,
        uint256 fromTokenAmount,
        uint256 minReturnAmount,
        address[] memory dodoPairs,
        uint256 directions,
        bool isIncentive,
        uint256 deadLine
    )
        external
        override
        payable
        judgeExpired(deadLine)
        returns (uint256 returnAmount)
    {
        require(dodoPairs.length > 0, "DODOV2Proxy02: PAIRS_EMPTY");
        require(minReturnAmount > 0, "DODOV2Proxy02: RETURN_AMOUNT_ZERO");
        require(fromToken != _CHI_TOKEN_, "DODOV2Proxy02: NOT_SUPPORT_SELL_CHI");
        require(toToken != _CHI_TOKEN_, "DODOV2Proxy02: NOT_SUPPORT_BUY_CHI");
        
        uint256 originGas = gasleft();

        address _fromToken = fromToken;
        address _toToken = toToken;
        
        _deposit(msg.sender, address(this), _fromToken, fromTokenAmount, _fromToken == _ETH_ADDRESS_);

        for (uint256 i = 0; i < dodoPairs.length; i++) {
            address curDodoPair = dodoPairs[i];
            if (directions & 1 == 0) {
                address curDodoBase = IDODOV1(curDodoPair)._BASE_TOKEN_();
                require(curDodoBase != _CHI_TOKEN_, "DODOV2Proxy02: NOT_SUPPORT_CHI");
                uint256 curAmountIn = IERC20(curDodoBase).balanceOf(address(this));
                IERC20(curDodoBase).universalApproveMax(curDodoPair, curAmountIn);
                IDODOV1(curDodoPair).sellBaseToken(curAmountIn, 0, "");
            } else {
                address curDodoQuote = IDODOV1(curDodoPair)._QUOTE_TOKEN_();
                require(curDodoQuote != _CHI_TOKEN_, "DODOV2Proxy02: NOT_SUPPORT_CHI");
                uint256 curAmountIn = IERC20(curDodoQuote).balanceOf(address(this));
                IERC20(curDodoQuote).universalApproveMax(curDodoPair, curAmountIn);
                uint256 canBuyBaseAmount = IDODOSellHelper(_DODO_SELL_HELPER_).querySellQuoteToken(
                    curDodoPair,
                    curAmountIn
                );
                IDODOV1(curDodoPair).buyBaseToken(canBuyBaseAmount, curAmountIn, "");
            }
            directions = directions >> 1;
        }

        
        if (_toToken == _ETH_ADDRESS_) {
            returnAmount = IWETH(_WETH_).balanceOf(address(this));
            IWETH(_WETH_).withdraw(returnAmount);
        } else {
            returnAmount = IERC20(_toToken).tokenBalanceOf(address(this));
        }
        
        require(returnAmount >= minReturnAmount, "DODOV2Proxy02: Return amount is not enough");
        IERC20(_toToken).universalTransfer(msg.sender, returnAmount);

        _dodoGasReturn(originGas);

        _execIncentive(isIncentive, _fromToken, _toToken);

        emit OrderHistory(_fromToken, _toToken, msg.sender, fromTokenAmount, returnAmount);
    }


    function mixSwap(
        address fromToken,
        address toToken,
        uint256 fromTokenAmount,
        uint256 minReturnAmount,
        address[] memory mixAdapters,
        address[] memory mixPairs,
        address[] memory assetTo,
        uint256 directions,
        bool isIncentive,
        uint256 deadLine
    ) external override payable judgeExpired(deadLine) returns (uint256 returnAmount) {
        require(mixPairs.length > 0, "DODOV2Proxy02: PAIRS_EMPTY");
        require(mixPairs.length == mixAdapters.length, "DODOV2Proxy02: PAIR_ADAPTER_NOT_MATCH");
        require(mixPairs.length == assetTo.length - 1, "DODOV2Proxy02: PAIR_ASSETTO_NOT_MATCH");
        require(minReturnAmount > 0, "DODOV2Proxy02: RETURN_AMOUNT_ZERO");

        address _fromToken = fromToken;
        address _toToken = toToken;
        uint256 _fromTokenAmount = fromTokenAmount;

        require(_fromToken != _CHI_TOKEN_, "DODOV2Proxy02: NOT_SUPPORT_SELL_CHI");
        require(_toToken != _CHI_TOKEN_, "DODOV2Proxy02: NOT_SUPPORT_BUY_CHI");
        
        uint256 originGas = gasleft();
        uint256 toTokenOriginBalance = IERC20(_toToken).universalBalanceOf(msg.sender);
        
        _deposit(msg.sender, assetTo[0], _fromToken, _fromTokenAmount, _fromToken == _ETH_ADDRESS_);

        for (uint256 i = 0; i < mixPairs.length; i++) {
            if (directions & 1 == 0) {
                IDODOAdapter(mixAdapters[i]).sellBase(assetTo[i + 1],mixPairs[i]);
            } else {
                IDODOAdapter(mixAdapters[i]).sellQuote(assetTo[i + 1],mixPairs[i]);
            }
            directions = directions >> 1;
        }

        if(_toToken == _ETH_ADDRESS_) {
            returnAmount = IWETH(_WETH_).balanceOf(address(this));
            IWETH(_WETH_).withdraw(returnAmount);
            msg.sender.transfer(returnAmount);
        }else {
            returnAmount = IERC20(_toToken).tokenBalanceOf(msg.sender).sub(toTokenOriginBalance);
        }

        require(returnAmount >= minReturnAmount, "DODOV2Proxy02: Return amount is not enough");
        
        _dodoGasReturn(originGas);

        _execIncentive(isIncentive, _fromToken, _toToken);

        emit OrderHistory(
            _fromToken,
            _toToken,
            msg.sender,
            _fromTokenAmount,
            returnAmount
        );
    }

    //============ CrowdPooling Functions (create & bid) ============

    function createCrowdPooling(
        address baseToken,
        address quoteToken,
        uint256 baseInAmount,
        uint256[] memory timeLine,
        uint256[] memory valueList,
        bool isOpenTWAP,
        uint256 deadLine
    ) external override payable preventReentrant judgeExpired(deadLine) returns (address payable newCrowdPooling) {
        address _baseToken = baseToken;
        address _quoteToken = quoteToken == _ETH_ADDRESS_ ? _WETH_ : quoteToken;
        
        newCrowdPooling = IDODOV2(_CP_FACTORY_).createCrowdPooling();

        _deposit(
            msg.sender,
            newCrowdPooling,
            _baseToken,
            baseInAmount,
            false
        );

        newCrowdPooling.transfer(msg.value);

        IDODOV2(_CP_FACTORY_).initCrowdPooling(
            newCrowdPooling,
            msg.sender,
            _baseToken,
            _quoteToken,
            timeLine,
            valueList,
            isOpenTWAP
        );
    }

    function bid(
        address cpAddress,
        uint256 quoteAmount,
        uint8 flag, // 0 - ERC20, 1 - quoteInETH
        uint256 deadLine
    ) external override payable preventReentrant judgeExpired(deadLine) {
        _deposit(msg.sender, cpAddress, IDODOV2(cpAddress)._QUOTE_TOKEN_(), quoteAmount, flag == 1);
        IDODOV2(cpAddress).bid(msg.sender);
    }


    function addLiquidityToV1(
        address pair,
        uint256 baseAmount,
        uint256 quoteAmount,
        uint256 baseMinShares,
        uint256 quoteMinShares,
        uint8 flag, // 0 erc20 In  1 baseInETH  2 quoteIn ETH 
        uint256 deadLine
    ) external override payable preventReentrant judgeExpired(deadLine) returns(uint256 baseShares, uint256 quoteShares) {
        address _baseToken = IDODOV1(pair)._BASE_TOKEN_();
        address _quoteToken = IDODOV1(pair)._QUOTE_TOKEN_();
        
        _deposit(msg.sender, address(this), _baseToken, baseAmount, flag == 1);
        _deposit(msg.sender, address(this), _quoteToken, quoteAmount, flag == 2);

        
        if(baseAmount > 0) {
            IERC20(_baseToken).universalApproveMax(pair, baseAmount);
            baseShares = IDODOV1(pair).depositBaseTo(msg.sender, baseAmount);
        }
        if(quoteAmount > 0) {
            IERC20(_quoteToken).universalApproveMax(pair, quoteAmount);
            quoteShares = IDODOV1(pair).depositQuoteTo(msg.sender, quoteAmount);
        }

        require(baseShares >= baseMinShares && quoteShares >= quoteMinShares,"DODOV2Proxy02: Return DLP is not enough");
    }
    

    function _deposit(
        address from,
        address to,
        address token,
        uint256 amount,
        bool isETH
    ) internal {
        if (isETH) {
            if (amount > 0) {
                IWETH(_WETH_).deposit{value: amount}();
                if (to != address(this)) SafeERC20.safeTransfer(IERC20(_WETH_), to, amount);
            }
        } else {
            IDODOApproveProxy(_DODO_APPROVE_PROXY_).claimTokens(token, from, to, amount);
        }
    }

    function _withdraw(
        address payable to,
        address token,
        uint256 amount,
        bool isETH
    ) internal {
        if (isETH) {
            if (amount > 0) {
                IWETH(_WETH_).withdraw(amount);
                to.transfer(amount);
            }
        } else {
            if (amount > 0) {
                SafeERC20.safeTransfer(IERC20(token), to, amount);
            }
        }
    }

    function _dodoGasReturn(uint256 originGas) internal {
        uint256 _gasDodoMaxReturn = _GAS_DODO_MAX_RETURN_;
        if(_gasDodoMaxReturn > 0) {
            uint256 calcGasTokenBurn = originGas.sub(gasleft()) / 65000;
            uint256 gasTokenBurn = calcGasTokenBurn > _gasDodoMaxReturn ? _gasDodoMaxReturn : calcGasTokenBurn;
            if(gasTokenBurn >= 3 && gasleft() > 27710 + gasTokenBurn * 6080)
                IChi(_CHI_TOKEN_).freeUpTo(gasTokenBurn);
        }
    }

    function _externalGasReturn() internal {
        uint256 _gasExternalReturn = _GAS_EXTERNAL_RETURN_;
        if(_gasExternalReturn > 0) {
            if(gasleft() > 27710 + _gasExternalReturn * 6080)
                IChi(_CHI_TOKEN_).freeUpTo(_gasExternalReturn);
        }
    }

    function _execIncentive(bool isIncentive, address fromToken,address toToken) internal {
        if(isIncentive && gasleft() > 30000) {
            IDODOIncentive(_DODO_INCENTIVE_).triggerIncentive(fromToken, toToken, msg.sender);
        }
    }

}

// File: contracts/intf/IDODOApprove.sol

/*

    Copyright 2020 DODO ZOO.
    SPDX-License-Identifier: Apache-2.0

*/

pragma solidity 0.6.9;
pragma experimental ABIEncoderV2;

interface IDODOApprove {
    function claimTokens(address token,address who,address dest,uint256 amount) external;
    function getDODOProxy() external view returns (address);
}

// File: contracts/lib/InitializableOwnable.sol


/**
 * @title Ownable
 * @author DODO Breeder
 *
 * @notice Ownership related functions
 */
contract InitializableOwnable {
    address public _OWNER_;
    address public _NEW_OWNER_;
    bool internal _INITIALIZED_;

    // ============ Events ============

    event OwnershipTransferPrepared(address indexed previousOwner, address indexed newOwner);

    event OwnershipTransferred(address indexed previousOwner, address indexed newOwner);

    // ============ Modifiers ============

    modifier notInitialized() {
        require(!_INITIALIZED_, "DODO_INITIALIZED");
        _;
    }

    modifier onlyOwner() {
        require(msg.sender == _OWNER_, "NOT_OWNER");
        _;
    }

    // ============ Functions ============

    function initOwner(address newOwner) public notInitialized {
        _INITIALIZED_ = true;
        _OWNER_ = newOwner;
    }

    function transferOwnership(address newOwner) public onlyOwner {
        emit OwnershipTransferPrepared(_OWNER_, newOwner);
        _NEW_OWNER_ = newOwner;
    }

    function claimOwnership() public {
        require(msg.sender == _NEW_OWNER_, "INVALID_CLAIM");
        emit OwnershipTransferred(_OWNER_, _NEW_OWNER_);
        _OWNER_ = _NEW_OWNER_;
        _NEW_OWNER_ = address(0);
    }
}

// File: contracts/SmartRoute/DODOApproveProxy.sol




interface IDODOApproveProxy {
    function isAllowedProxy(address _proxy) external view returns (bool);
    function claimTokens(address token,address who,address dest,uint256 amount) external;
}

/**
 * @title DODOApproveProxy
 * @author DODO Breeder
 *
 * @notice Allow different version dodoproxy to claim from DODOApprove
 */
contract DODOApproveProxy is InitializableOwnable {
    
    // ============ Storage ============
    uint256 private constant _TIMELOCK_DURATION_ = 3 days;
    mapping (address => bool) public _IS_ALLOWED_PROXY_;
    uint256 public _TIMELOCK_;
    address public _PENDING_ADD_DODO_PROXY_;
    address public immutable _DODO_APPROVE_;

    // ============ Modifiers ============
    modifier notLocked() {
        require(
            _TIMELOCK_ <= block.timestamp,
            "SetProxy is timelocked"
        );
        _;
    }

    constructor(address dodoApporve) public {
        _DODO_APPROVE_ = dodoApporve;
    }

    function init(address owner, address[] memory proxies) external {
        initOwner(owner);
        for(uint i = 0; i < proxies.length; i++) 
            _IS_ALLOWED_PROXY_[proxies[i]] = true;
    }

    function unlockAddProxy(address newDodoProxy) public onlyOwner {
        _TIMELOCK_ = block.timestamp + _TIMELOCK_DURATION_;
        _PENDING_ADD_DODO_PROXY_ = newDodoProxy;
    }

    function lockAddProxy() public onlyOwner {
       _PENDING_ADD_DODO_PROXY_ = address(0);
       _TIMELOCK_ = 0;
    }


    function addDODOProxy() external onlyOwner notLocked() {
        _IS_ALLOWED_PROXY_[_PENDING_ADD_DODO_PROXY_] = true;
        lockAddProxy();
    }

    function removeDODOProxy (address oldDodoProxy) public onlyOwner {
        _IS_ALLOWED_PROXY_[oldDodoProxy] = false;
    }
    
    function claimTokens(
        address token,
        address who,
        address dest,
        uint256 amount
    ) external {
        require(_IS_ALLOWED_PROXY_[msg.sender], "DODOApproveProxy:Access restricted");
        IDODOApprove(_DODO_APPROVE_).claimTokens(
            token,
            who,
            dest,
            amount
        );
    }

    function isAllowedProxy(address _proxy) external view returns (bool) {
        return _IS_ALLOWED_PROXY_[_proxy];
    }
}

// File: contracts/intf/IERC20.sol

// This is a file copied from https://github.com/OpenZeppelin/openzeppelin-contracts/blob/master/contracts/token/ERC20/IERC20.sol

pragma solidity 0.6.9;

/**
 * @dev Interface of the ERC20 standard as defined in the EIP.
 */
interface IERC20 {
    /**
     * @dev Returns the amount of tokens in existence.
     */
    function totalSupply() external view returns (uint256);

    function decimals() external view returns (uint8);

    function name() external view returns (string memory);

    function symbol() external view returns (string memory);

    /**
     * @dev Returns the amount of tokens owned by `account`.
     */
    function balanceOf(address account) external view returns (uint256);

    /**
     * @dev Moves `amount` tokens from the caller's account to `recipient`.
     *
     * Returns a boolean value indicating whether the operation succeeded.
     *
     * Emits a {Transfer} event.
     */
    function transfer(address recipient, uint256 amount) external returns (bool);

    /**
     * @dev Returns the remaining number of tokens that `spender` will be
     * allowed to spend on behalf of `owner` through {transferFrom}. This is
     * zero by default.
     *
     * This value changes when {approve} or {transferFrom} are called.
     */
    function allowance(address owner, address spender) external view returns (uint256);

    /**
     * @dev Sets `amount` as the allowance of `spender` over the caller's tokens.
     *
     * Returns a boolean value indicating whether the operation succeeded.
     *
     * IMPORTANT: Beware that changing an allowance with this method brings the risk
     * that someone may use both the old and the new allowance by unfortunate
     * transaction ordering. One possible solution to mitigate this race
     * condition is to first reduce the spender's allowance to 0 and set the
     * desired value afterwards:
     * https://github.com/ethereum/EIPs/issues/20#issuecomment-263524729
     *
     * Emits an {Approval} event.
     */
    function approve(address spender, uint256 amount) external returns (bool);

    /**
     * @dev Moves `amount` tokens from `sender` to `recipient` using the
     * allowance mechanism. `amount` is then deducted from the caller's
     * allowance.
     *
     * Returns a boolean value indicating whether the operation succeeded.
     *
     * Emits a {Transfer} event.
     */
    function transferFrom(
        address sender,
        address recipient,
        uint256 amount
    ) external returns (bool);
}

// File: contracts/lib/SafeMath.sol

/*

    Copyright 2020 DODO ZOO.

*/



/**
 * @title SafeMath
 * @author DODO Breeder
 *
 * @notice Math operations with safety checks that revert on error
 */
library SafeMath {
    function mul(uint256 a, uint256 b) internal pure returns (uint256) {
        if (a == 0) {
            return 0;
        }

        uint256 c = a * b;
        require(c / a == b, "MUL_ERROR");

        return c;
    }

    function div(uint256 a, uint256 b) internal pure returns (uint256) {
        require(b > 0, "DIVIDING_ERROR");
        return a / b;
    }

    function divCeil(uint256 a, uint256 b) internal pure returns (uint256) {
        uint256 quotient = div(a, b);
        uint256 remainder = a - quotient * b;
        if (remainder > 0) {
            return quotient + 1;
        } else {
            return quotient;
        }
    }

    function sub(uint256 a, uint256 b) internal pure returns (uint256) {
        require(b <= a, "SUB_ERROR");
        return a - b;
    }

    function add(uint256 a, uint256 b) internal pure returns (uint256) {
        uint256 c = a + b;
        require(c >= a, "ADD_ERROR");
        return c;
    }

    function sqrt(uint256 x) internal pure returns (uint256 y) {
        uint256 z = x / 2 + 1;
        y = x;
        while (z < y) {
            y = z;
            z = (x / z + z) / 2;
        }
    }
}

// File: contracts/lib/SafeERC20.sol

/*

    Copyright 2020 DODO ZOO.
    This is a simplified version of OpenZepplin's SafeERC20 library

*/





/**
 * @title SafeERC20
 * @dev Wrappers around ERC20 operations that throw on failure (when the token
 * contract returns false). Tokens that return no value (and instead revert or
 * throw on failure) are also supported, non-reverting calls are assumed to be
 * successful.
 * To use this library you can add a `using SafeERC20 for ERC20;` statement to your contract,
 * which allows you to call the safe operations as `token.safeTransfer(...)`, etc.
 */
library SafeERC20 {
    using SafeMath for uint256;

    function safeTransfer(
        IERC20 token,
        address to,
        uint256 value
    ) internal {
        _callOptionalReturn(token, abi.encodeWithSelector(token.transfer.selector, to, value));
    }

    function safeTransferFrom(
        IERC20 token,
        address from,
        address to,
        uint256 value
    ) internal {
        _callOptionalReturn(
            token,
            abi.encodeWithSelector(token.transferFrom.selector, from, to, value)
        );
    }

    function safeApprove(
        IERC20 token,
        address spender,
        uint256 value
    ) internal {
        // safeApprove should only be called when setting an initial allowance,
        // or when resetting it to zero. To increase and decrease it, use
        // 'safeIncreaseAllowance' and 'safeDecreaseAllowance'
        // solhint-disable-next-line max-line-length
        require(
            (value == 0) || (token.allowance(address(this), spender) == 0),
            "SafeERC20: approve from non-zero to non-zero allowance"
        );
        _callOptionalReturn(token, abi.encodeWithSelector(token.approve.selector, spender, value));
    }

    /**
     * @dev Imitates a Solidity high-level call (i.e. a regular function call to a contract), relaxing the requirement
     * on the return value: the return value is optional (but if data is returned, it must not be false).
     * @param token The token targeted by the call.
     * @param data The call data (encoded using abi.encode or one of its variants).
     */
    function _callOptionalReturn(IERC20 token, bytes memory data) private {
        // We need to perform a low level call here, to bypass Solidity's return data size checking mechanism, since
        // we're implementing it ourselves.

        // A Solidity high level call has three parts:
        //  1. The target address is checked to verify it contains contract code
        //  2. The call itself is made, and success asserted
        //  3. The return value is decoded, which in turn checks the size of the returned data.
        // solhint-disable-next-line max-line-length

        // solhint-disable-next-line avoid-low-level-calls
        (bool success, bytes memory returndata) = address(token).call(data);
        require(success, "SafeERC20: low-level call failed");

        if (returndata.length > 0) {
            // Return data is optional
            // solhint-disable-next-line max-line-length
            require(abi.decode(returndata, (bool)), "SafeERC20: ERC20 operation did not succeed");
        }
    }
}

// File: contracts/lib/InitializableOwnable.sol

/*

    Copyright 2020 DODO ZOO.

*/


/**
 * @title Ownable
 * @author DODO Breeder
 *
 * @notice Ownership related functions
 */
contract InitializableOwnable {
    address public _OWNER_;
    address public _NEW_OWNER_;
    bool internal _INITIALIZED_;

    // ============ Events ============

    event OwnershipTransferPrepared(address indexed previousOwner, address indexed newOwner);

    event OwnershipTransferred(address indexed previousOwner, address indexed newOwner);

    // ============ Modifiers ============

    modifier notInitialized() {
        require(!_INITIALIZED_, "DODO_INITIALIZED");
        _;
    }

    modifier onlyOwner() {
        require(msg.sender == _OWNER_, "NOT_OWNER");
        _;
    }

    // ============ Functions ============

    function initOwner(address newOwner) public notInitialized {
        _INITIALIZED_ = true;
        _OWNER_ = newOwner;
    }

    function transferOwnership(address newOwner) public onlyOwner {
        emit OwnershipTransferPrepared(_OWNER_, newOwner);
        _NEW_OWNER_ = newOwner;
    }

    function claimOwnership() public {
        require(msg.sender == _NEW_OWNER_, "INVALID_CLAIM");
        emit OwnershipTransferred(_OWNER_, _NEW_OWNER_);
        _OWNER_ = _NEW_OWNER_;
        _NEW_OWNER_ = address(0);
    }
}

// File: contracts/SmartRoute/DODOApprove.sol

/*

    Copyright 2020 DODO ZOO.

*/






/**
 * @title DODOApprove
 * @author DODO Breeder
 *
 * @notice Handle authorizations in DODO platform
 */
contract DODOApprove is InitializableOwnable {
    using SafeERC20 for IERC20;
    
    // ============ Storage ============
    uint256 private constant _TIMELOCK_DURATION_ = 3 days;
    uint256 private constant _TIMELOCK_EMERGENCY_DURATION_ = 24 hours;
    uint256 public _TIMELOCK_;
    address public _PENDING_DODO_PROXY_;
    address public _DODO_PROXY_;

    // ============ Events ============

    event SetDODOProxy(address indexed oldProxy, address indexed newProxy);

    
    // ============ Modifiers ============
    modifier notLocked() {
        require(
            _TIMELOCK_ <= block.timestamp,
            "SetProxy is timelocked"
        );
        _;
    }

    function init(address owner, address initProxyAddress) external {
        initOwner(owner);
        _DODO_PROXY_ = initProxyAddress;
    }

    function unlockSetProxy(address newDodoProxy) public onlyOwner {
        if(_DODO_PROXY_ == address(0))
            _TIMELOCK_ = block.timestamp + _TIMELOCK_EMERGENCY_DURATION_;
        else
            _TIMELOCK_ = block.timestamp + _TIMELOCK_DURATION_;
        _PENDING_DODO_PROXY_ = newDodoProxy;
    }


    function lockSetProxy() public onlyOwner {
       _PENDING_DODO_PROXY_ = address(0);
       _TIMELOCK_ = 0;
    }


    function setDODOProxy() external onlyOwner notLocked() {
        emit SetDODOProxy(_DODO_PROXY_, _PENDING_DODO_PROXY_);
        _DODO_PROXY_ = _PENDING_DODO_PROXY_;
        lockSetProxy();
    }


    function claimTokens(
        address token,
        address who,
        address dest,
        uint256 amount
    ) external {
        require(msg.sender == _DODO_PROXY_, "DODOApprove:Access restricted");
        if (amount > 0) {
            IERC20(token).safeTransferFrom(who, dest, amount);
        }
    }

    function getDODOProxy() public view returns (address) {
        return _DODO_PROXY_;
    }
}

/*

    Copyright 2020 DODO ZOO.
    SPDX-License-Identifier: Apache-2.0

*/

pragma solidity 0.6.9;
pragma experimental ABIEncoderV2;


/**
 * @title SafeMath
 * @author DODO Breeder
 *
 * @notice Math operations with safety checks that revert on error
 */
library SafeMath {
    function mul(uint256 a, uint256 b) internal pure returns (uint256) {
        if (a == 0) {
            return 0;
        }

        uint256 c = a * b;
        require(c / a == b, "MUL_ERROR");

        return c;
    }

    function div(uint256 a, uint256 b) internal pure returns (uint256) {
        require(b > 0, "DIVIDING_ERROR");
        return a / b;
    }

    function divCeil(uint256 a, uint256 b) internal pure returns (uint256) {
        uint256 quotient = div(a, b);
        uint256 remainder = a - quotient * b;
        if (remainder > 0) {
            return quotient + 1;
        } else {
            return quotient;
        }
    }

    function sub(uint256 a, uint256 b) internal pure returns (uint256) {
        require(b <= a, "SUB_ERROR");
        return a - b;
    }

    function add(uint256 a, uint256 b) internal pure returns (uint256) {
        uint256 c = a + b;
        require(c >= a, "ADD_ERROR");
        return c;
    }

    function sqrt(uint256 x) internal pure returns (uint256 y) {
        uint256 z = x / 2 + 1;
        y = x;
        while (z < y) {
            y = z;
            z = (x / z + z) / 2;
        }
    }
}


// File: contracts/token/DODOToken.sol

/*

    Copyright 2020 DODO ZOO.

*/

/**
 * @title DODO Token
 * @author DODO Breeder
 */
contract DODOToken {
    using SafeMath for uint256;

    string public symbol = "DODO";
    string public name = "DODO bird";

    uint256 public decimals = 18;
    uint256 public totalSupply = 1000000000 * 10**18; // 1 Billion

    mapping(address => uint256) internal balances;
    mapping(address => mapping(address => uint256)) internal allowed;

    // ============ Events ============

    event Transfer(address indexed from, address indexed to, uint256 amount);

    event Approval(address indexed owner, address indexed spender, uint256 amount);

    // ============ Functions ============

    constructor() public {
        balances[msg.sender] = totalSupply;
    }

    /**
     * @dev transfer token for a specified address
     * @param to The address to transfer to.
     * @param amount The amount to be transferred.
     */
    function transfer(address to, uint256 amount) public returns (bool) {
        require(amount <= balances[msg.sender], "BALANCE_NOT_ENOUGH");

        balances[msg.sender] = balances[msg.sender].sub(amount);
        balances[to] = balances[to].add(amount);
        emit Transfer(msg.sender, to, amount);
        return true;
    }

    /**
     * @dev Gets the balance of the specified address.
     * @param owner The address to query the the balance of.
     * @return balance An uint256 representing the amount owned by the passed address.
     */
    function balanceOf(address owner) external view returns (uint256 balance) {
        return balances[owner];
    }

    /**
     * @dev Transfer tokens from one address to another
     * @param from address The address which you want to send tokens from
     * @param to address The address which you want to transfer to
     * @param amount uint256 the amount of tokens to be transferred
     */
    function transferFrom(
        address from,
        address to,
        uint256 amount
    ) public returns (bool) {
        require(amount <= balances[from], "BALANCE_NOT_ENOUGH");
        require(amount <= allowed[from][msg.sender], "ALLOWANCE_NOT_ENOUGH");

        balances[from] = balances[from].sub(amount);
        balances[to] = balances[to].add(amount);
        allowed[from][msg.sender] = allowed[from][msg.sender].sub(amount);
        emit Transfer(from, to, amount);
        return true;
    }

    /**
     * @dev Approve the passed address to spend the specified amount of tokens on behalf of msg.sender.
     * @param spender The address which will spend the funds.
     * @param amount The amount of tokens to be spent.
     */
    function approve(address spender, uint256 amount) public returns (bool) {
        allowed[msg.sender][spender] = amount;
        emit Approval(msg.sender, spender, amount);
        return true;
    }

    /**
     * @dev Function to check the amount of tokens that an owner allowed to a spender.
     * @param owner address The address which owns the funds.
     * @param spender address The address which will spend the funds.
     * @return A uint256 specifying the amount of tokens still available for the spender.
     */
    function allowance(address owner, address spender) public view returns (uint256) {
        return allowed[owner][spender];
    }
}

/*

    Copyright 2020 DODO ZOO.
    SPDX-License-Identifier: Apache-2.0

*/

pragma solidity 0.6.9;
pragma experimental ABIEncoderV2;

library Types {
    enum RStatus {ONE, ABOVE_ONE, BELOW_ONE}
}

// File: contracts/intf/IERC20.sol

// This is a file copied from https://github.com/OpenZeppelin/openzeppelin-contracts/blob/master/contracts/token/ERC20/IERC20.sol

/**
 * @dev Interface of the ERC20 standard as defined in the EIP.
 */
interface IERC20 {
    /**
     * @dev Returns the amount of tokens in existence.
     */
    function totalSupply() external view returns (uint256);

    function decimals() external view returns (uint8);

    function name() external view returns (string memory);

    /**
     * @dev Returns the amount of tokens owned by `account`.
     */
    function balanceOf(address account) external view returns (uint256);

    /**
     * @dev Moves `amount` tokens from the caller's account to `recipient`.
     *
     * Returns a boolean value indicating whether the operation succeeded.
     *
     * Emits a {Transfer} event.
     */
    function transfer(address recipient, uint256 amount) external returns (bool);

    /**
     * @dev Returns the remaining number of tokens that `spender` will be
     * allowed to spend on behalf of `owner` through {transferFrom}. This is
     * zero by default.
     *
     * This value changes when {approve} or {transferFrom} are called.
     */
    function allowance(address owner, address spender) external view returns (uint256);

    /**
     * @dev Sets `amount` as the allowance of `spender` over the caller's tokens.
     *
     * Returns a boolean value indicating whether the operation succeeded.
     *
     * IMPORTANT: Beware that changing an allowance with this method brings the risk
     * that someone may use both the old and the new allowance by unfortunate
     * transaction ordering. One possible solution to mitigate this race
     * condition is to first reduce the spender's allowance to 0 and set the
     * desired value afterwards:
     * https://github.com/ethereum/EIPs/issues/20#issuecomment-263524729
     *
     * Emits an {Approval} event.
     */
    function approve(address spender, uint256 amount) external returns (bool);

    /**
     * @dev Moves `amount` tokens from `sender` to `recipient` using the
     * allowance mechanism. `amount` is then deducted from the caller's
     * allowance.
     *
     * Returns a boolean value indicating whether the operation succeeded.
     *
     * Emits a {Transfer} event.
     */
    function transferFrom(
        address sender,
        address recipient,
        uint256 amount
    ) external returns (bool);
}

// File: contracts/lib/InitializableOwnable.sol

/*

    Copyright 2020 DODO ZOO.

*/

/**
 * @title Ownable
 * @author DODO Breeder
 *
 * @notice Ownership related functions
 */
contract InitializableOwnable {
    address public _OWNER_;
    address public _NEW_OWNER_;

    // ============ Events ============

    event OwnershipTransferPrepared(address indexed previousOwner, address indexed newOwner);

    event OwnershipTransferred(address indexed previousOwner, address indexed newOwner);

    // ============ Modifiers ============

    modifier onlyOwner() {
        require(msg.sender == _OWNER_, "NOT_OWNER");
        _;
    }

    // ============ Functions ============

    function transferOwnership(address newOwner) external onlyOwner {
        require(newOwner != address(0), "INVALID_OWNER");
        emit OwnershipTransferPrepared(_OWNER_, newOwner);
        _NEW_OWNER_ = newOwner;
    }

    function claimOwnership() external {
        require(msg.sender == _NEW_OWNER_, "INVALID_CLAIM");
        emit OwnershipTransferred(_OWNER_, _NEW_OWNER_);
        _OWNER_ = _NEW_OWNER_;
        _NEW_OWNER_ = address(0);
    }
}

// File: contracts/lib/SafeMath.sol

/*

    Copyright 2020 DODO ZOO.

*/

/**
 * @title SafeMath
 * @author DODO Breeder
 *
 * @notice Math operations with safety checks that revert on error
 */
library SafeMath {
    function mul(uint256 a, uint256 b) internal pure returns (uint256) {
        if (a == 0) {
            return 0;
        }

        uint256 c = a * b;
        require(c / a == b, "MUL_ERROR");

        return c;
    }

    function div(uint256 a, uint256 b) internal pure returns (uint256) {
        require(b > 0, "DIVIDING_ERROR");
        return a / b;
    }

    function divCeil(uint256 a, uint256 b) internal pure returns (uint256) {
        uint256 quotient = div(a, b);
        uint256 remainder = a - quotient * b;
        if (remainder > 0) {
            return quotient + 1;
        } else {
            return quotient;
        }
    }

    function sub(uint256 a, uint256 b) internal pure returns (uint256) {
        require(b <= a, "SUB_ERROR");
        return a - b;
    }

    function add(uint256 a, uint256 b) internal pure returns (uint256) {
        uint256 c = a + b;
        require(c >= a, "ADD_ERROR");
        return c;
    }

    function sqrt(uint256 x) internal pure returns (uint256 y) {
        uint256 z = x / 2 + 1;
        y = x;
        while (z < y) {
            y = z;
            z = (x / z + z) / 2;
        }
    }
}

// File: contracts/lib/DecimalMath.sol

/*

    Copyright 2020 DODO ZOO.

*/

/**
 * @title DecimalMath
 * @author DODO Breeder
 *
 * @notice Functions for fixed point number with 18 decimals
 */
library DecimalMath {
    using SafeMath for uint256;

    uint256 constant ONE = 10**18;

    function mul(uint256 target, uint256 d) internal pure returns (uint256) {
        return target.mul(d) / ONE;
    }

    function divFloor(uint256 target, uint256 d) internal pure returns (uint256) {
        return target.mul(ONE).div(d);
    }

    function divCeil(uint256 target, uint256 d) internal pure returns (uint256) {
        return target.mul(ONE).divCeil(d);
    }
}

// File: contracts/lib/ReentrancyGuard.sol

/*

    Copyright 2020 DODO ZOO.

*/

/**
 * @title ReentrancyGuard
 * @author DODO Breeder
 *
 * @notice Protect functions from Reentrancy Attack
 */
contract ReentrancyGuard {
    // https://solidity.readthedocs.io/en/latest/control-structures.html?highlight=zero-state#scoping-and-declarations
    // zero-state of _ENTERED_ is false
    bool private _ENTERED_;

    modifier preventReentrant() {
        require(!_ENTERED_, "REENTRANT");
        _ENTERED_ = true;
        _;
        _ENTERED_ = false;
    }
}

// File: contracts/intf/IOracle.sol

/*

    Copyright 2020 DODO ZOO.

*/

interface IOracle {
    function getPrice() external view returns (uint256);
}

// File: contracts/intf/IDODOLpToken.sol

/*

    Copyright 2020 DODO ZOO.

*/

interface IDODOLpToken {
    function mint(address user, uint256 value) external;

    function burn(address user, uint256 value) external;

    function balanceOf(address owner) external view returns (uint256);

    function totalSupply() external view returns (uint256);
}

// File: contracts/impl/Storage.sol

/*

    Copyright 2020 DODO ZOO.

*/

/**
 * @title Storage
 * @author DODO Breeder
 *
 * @notice Local Variables
 */
contract Storage is InitializableOwnable, ReentrancyGuard {
    using SafeMath for uint256;

    // ============ Variables for Control ============

    bool internal _INITIALIZED_;
    bool public _CLOSED_;
    bool public _DEPOSIT_QUOTE_ALLOWED_;
    bool public _DEPOSIT_BASE_ALLOWED_;
    bool public _TRADE_ALLOWED_;
    uint256 public _GAS_PRICE_LIMIT_;

    // ============ Core Address ============

    address public _SUPERVISOR_; // could freeze system in emergency
    address public _MAINTAINER_; // collect maintainer fee to buy food for DODO

    address public _BASE_TOKEN_;
    address public _QUOTE_TOKEN_;
    address public _ORACLE_;

    // ============ Variables for PMM Algorithm ============

    uint256 public _LP_FEE_RATE_;
    uint256 public _MT_FEE_RATE_;
    uint256 public _K_;

    Types.RStatus public _R_STATUS_;
    uint256 public _TARGET_BASE_TOKEN_AMOUNT_;
    uint256 public _TARGET_QUOTE_TOKEN_AMOUNT_;
    uint256 public _BASE_BALANCE_;
    uint256 public _QUOTE_BALANCE_;

    address public _BASE_CAPITAL_TOKEN_;
    address public _QUOTE_CAPITAL_TOKEN_;

    // ============ Variables for Final Settlement ============

    uint256 public _BASE_CAPITAL_RECEIVE_QUOTE_;
    uint256 public _QUOTE_CAPITAL_RECEIVE_BASE_;
    mapping(address => bool) public _CLAIMED_;

    // ============ Modifiers ============

    modifier onlySupervisorOrOwner() {
        require(msg.sender == _SUPERVISOR_ || msg.sender == _OWNER_, "NOT_SUPERVISOR_OR_OWNER");
        _;
    }

    modifier notClosed() {
        require(!_CLOSED_, "DODO_CLOSED");
        _;
    }

    // ============ Helper Functions ============

    function _checkDODOParameters() internal view returns (uint256) {
        require(_K_ < DecimalMath.ONE, "K>=1");
        require(_K_ > 0, "K=0");
        require(_LP_FEE_RATE_.add(_MT_FEE_RATE_) < DecimalMath.ONE, "FEE_RATE>=1");
    }

    function getOraclePrice() public view returns (uint256) {
        return IOracle(_ORACLE_).getPrice();
    }

    function getBaseCapitalBalanceOf(address lp) public view returns (uint256) {
        return IDODOLpToken(_BASE_CAPITAL_TOKEN_).balanceOf(lp);
    }

    function getTotalBaseCapital() public view returns (uint256) {
        return IDODOLpToken(_BASE_CAPITAL_TOKEN_).totalSupply();
    }

    function getQuoteCapitalBalanceOf(address lp) public view returns (uint256) {
        return IDODOLpToken(_QUOTE_CAPITAL_TOKEN_).balanceOf(lp);
    }

    function getTotalQuoteCapital() public view returns (uint256) {
        return IDODOLpToken(_QUOTE_CAPITAL_TOKEN_).totalSupply();
    }

    // ============ Version Control ============
    function version() external pure returns (uint256) {
        return 100; // 1.0.0
    }
}

// File: contracts/intf/IDODOCallee.sol

/*

    Copyright 2020 DODO ZOO.

*/

interface IDODOCallee {
    function dodoCall(
        bool isBuyBaseToken,
        uint256 baseAmount,
        uint256 quoteAmount,
        bytes calldata data
    ) external;
}

// File: contracts/lib/DODOMath.sol

/*

    Copyright 2020 DODO ZOO.

*/

/**
 * @title DODOMath
 * @author DODO Breeder
 *
 * @notice Functions for complex calculating. Including ONE Integration and TWO Quadratic solutions
 */
library DODOMath {
    using SafeMath for uint256;

    /*
        Integrate dodo curve fron V1 to V2
        require V0>=V1>=V2>0
        res = (1-k)i(V1-V2)+ikV0*V0(1/V2-1/V1)
        let V1-V2=delta
        res = i*delta*(1-k+k(V0^2/V1/V2))
    */
    function _GeneralIntegrate(
        uint256 V0,
        uint256 V1,
        uint256 V2,
        uint256 i,
        uint256 k
    ) internal pure returns (uint256) {
        uint256 fairAmount = DecimalMath.mul(i, V1.sub(V2)); // i*delta
        uint256 V0V0V1V2 = DecimalMath.divCeil(V0.mul(V0).div(V1), V2);
        uint256 penalty = DecimalMath.mul(k, V0V0V1V2); // k(V0^2/V1/V2)
        return DecimalMath.mul(fairAmount, DecimalMath.ONE.sub(k).add(penalty));
    }

    /*
        The same with integration expression above, we have:
        i*deltaB = (Q2-Q1)*(1-k+kQ0^2/Q1/Q2)
        Given Q1 and deltaB, solve Q2
        This is a quadratic function and the standard version is
        aQ2^2 + bQ2 + c = 0, where
        a=1-k
        -b=(1-k)Q1-kQ0^2/Q1+i*deltaB
        c=-kQ0^2
        and Q2=(-b+sqrt(b^2+4(1-k)kQ0^2))/2(1-k)
        note: another root is negative, abondan
        if deltaBSig=true, then Q2>Q1
        if deltaBSig=false, then Q2<Q1
    */
    function _SolveQuadraticFunctionForTrade(
        uint256 Q0,
        uint256 Q1,
        uint256 ideltaB,
        bool deltaBSig,
        uint256 k
    ) internal pure returns (uint256) {
        // calculate -b value and sig
        // -b = (1-k)Q1-kQ0^2/Q1+i*deltaB
        uint256 kQ02Q1 = DecimalMath.mul(k, Q0).mul(Q0).div(Q1); // kQ0^2/Q1
        uint256 b = DecimalMath.mul(DecimalMath.ONE.sub(k), Q1); // (1-k)Q1
        bool minusbSig = true;
        if (deltaBSig) {
            b = b.add(ideltaB); // (1-k)Q1+i*deltaB
        } else {
            kQ02Q1 = kQ02Q1.add(ideltaB); // i*deltaB+kQ0^2/Q1
        }
        if (b >= kQ02Q1) {
            b = b.sub(kQ02Q1);
            minusbSig = true;
        } else {
            b = kQ02Q1.sub(b);
            minusbSig = false;
        }

        // calculate sqrt
        uint256 squareRoot = DecimalMath.mul(
            DecimalMath.ONE.sub(k).mul(4),
            DecimalMath.mul(k, Q0).mul(Q0)
        ); // 4(1-k)kQ0^2
        squareRoot = b.mul(b).add(squareRoot).sqrt(); // sqrt(b*b+4(1-k)kQ0*Q0)

        // final res
        uint256 denominator = DecimalMath.ONE.sub(k).mul(2); // 2(1-k)
        uint256 numerator;
        if (minusbSig) {
            numerator = b.add(squareRoot);
        } else {
            numerator = squareRoot.sub(b);
        }

        if (deltaBSig) {
            return DecimalMath.divFloor(numerator, denominator);
        } else {
            return DecimalMath.divCeil(numerator, denominator);
        }
    }

    /*
        Start from the integration function
        i*deltaB = (Q2-Q1)*(1-k+kQ0^2/Q1/Q2)
        Assume Q2=Q0, Given Q1 and deltaB, solve Q0
        let fairAmount = i*deltaB
    */
    function _SolveQuadraticFunctionForTarget(
        uint256 V1,
        uint256 k,
        uint256 fairAmount
    ) internal pure returns (uint256 V0) {
        // V0 = V1+V1*(sqrt-1)/2k
        uint256 sqrt = DecimalMath.divCeil(DecimalMath.mul(k, fairAmount).mul(4), V1);
        sqrt = sqrt.add(DecimalMath.ONE).mul(DecimalMath.ONE).sqrt();
        uint256 premium = DecimalMath.divCeil(sqrt.sub(DecimalMath.ONE), k.mul(2));
        // V0 is greater than or equal to V1 according to the solution
        return DecimalMath.mul(V1, DecimalMath.ONE.add(premium));
    }
}

// File: contracts/impl/Pricing.sol

/*

    Copyright 2020 DODO ZOO.

*/

/**
 * @title Pricing
 * @author DODO Breeder
 *
 * @notice DODO Pricing model
 */
contract Pricing is Storage {
    using SafeMath for uint256;

    // ============ R = 1 cases ============

    function _ROneSellBaseToken(uint256 amount, uint256 targetQuoteTokenAmount)
        internal
        view
        returns (uint256 receiveQuoteToken)
    {
        uint256 i = getOraclePrice();
        uint256 Q2 = DODOMath._SolveQuadraticFunctionForTrade(
            targetQuoteTokenAmount,
            targetQuoteTokenAmount,
            DecimalMath.mul(i, amount),
            false,
            _K_
        );
        // in theory Q2 <= targetQuoteTokenAmount
        // however when amount is close to 0, precision problems may cause Q2 > targetQuoteTokenAmount
        return targetQuoteTokenAmount.sub(Q2);
    }

    function _ROneBuyBaseToken(uint256 amount, uint256 targetBaseTokenAmount)
        internal
        view
        returns (uint256 payQuoteToken)
    {
        require(amount < targetBaseTokenAmount, "DODO_BASE_BALANCE_NOT_ENOUGH");
        uint256 B2 = targetBaseTokenAmount.sub(amount);
        payQuoteToken = _RAboveIntegrate(targetBaseTokenAmount, targetBaseTokenAmount, B2);
        return payQuoteToken;
    }

    // ============ R < 1 cases ============

    function _RBelowSellBaseToken(
        uint256 amount,
        uint256 quoteBalance,
        uint256 targetQuoteAmount
    ) internal view returns (uint256 receieQuoteToken) {
        uint256 i = getOraclePrice();
        uint256 Q2 = DODOMath._SolveQuadraticFunctionForTrade(
            targetQuoteAmount,
            quoteBalance,
            DecimalMath.mul(i, amount),
            false,
            _K_
        );
        return quoteBalance.sub(Q2);
    }

    function _RBelowBuyBaseToken(
        uint256 amount,
        uint256 quoteBalance,
        uint256 targetQuoteAmount
    ) internal view returns (uint256 payQuoteToken) {
        // Here we don't require amount less than some value
        // Because it is limited at upper function
        // See Trader.queryBuyBaseToken
        uint256 i = getOraclePrice();
        uint256 Q2 = DODOMath._SolveQuadraticFunctionForTrade(
            targetQuoteAmount,
            quoteBalance,
            DecimalMath.mul(i, amount),
            true,
            _K_
        );
        return Q2.sub(quoteBalance);
    }

    function _RBelowBackToOne() internal view returns (uint256 payQuoteToken) {
        // important: carefully design the system to make sure spareBase always greater than or equal to 0
        uint256 spareBase = _BASE_BALANCE_.sub(_TARGET_BASE_TOKEN_AMOUNT_);
        uint256 price = getOraclePrice();
        uint256 fairAmount = DecimalMath.mul(spareBase, price);
        uint256 newTargetQuote = DODOMath._SolveQuadraticFunctionForTarget(
            _QUOTE_BALANCE_,
            _K_,
            fairAmount
        );
        return newTargetQuote.sub(_QUOTE_BALANCE_);
    }

    // ============ R > 1 cases ============

    function _RAboveBuyBaseToken(
        uint256 amount,
        uint256 baseBalance,
        uint256 targetBaseAmount
    ) internal view returns (uint256 payQuoteToken) {
        require(amount < baseBalance, "DODO_BASE_BALANCE_NOT_ENOUGH");
        uint256 B2 = baseBalance.sub(amount);
        return _RAboveIntegrate(targetBaseAmount, baseBalance, B2);
    }

    function _RAboveSellBaseToken(
        uint256 amount,
        uint256 baseBalance,
        uint256 targetBaseAmount
    ) internal view returns (uint256 receiveQuoteToken) {
        // here we don't require B1 <= targetBaseAmount
        // Because it is limited at upper function
        // See Trader.querySellBaseToken
        uint256 B1 = baseBalance.add(amount);
        return _RAboveIntegrate(targetBaseAmount, B1, baseBalance);
    }

    function _RAboveBackToOne() internal view returns (uint256 payBaseToken) {
        // important: carefully design the system to make sure spareBase always greater than or equal to 0
        uint256 spareQuote = _QUOTE_BALANCE_.sub(_TARGET_QUOTE_TOKEN_AMOUNT_);
        uint256 price = getOraclePrice();
        uint256 fairAmount = DecimalMath.divFloor(spareQuote, price);
        uint256 newTargetBase = DODOMath._SolveQuadraticFunctionForTarget(
            _BASE_BALANCE_,
            _K_,
            fairAmount
        );
        return newTargetBase.sub(_BASE_BALANCE_);
    }

    // ============ Helper functions ============

    function getExpectedTarget() public view returns (uint256 baseTarget, uint256 quoteTarget) {
        uint256 Q = _QUOTE_BALANCE_;
        uint256 B = _BASE_BALANCE_;
        if (_R_STATUS_ == Types.RStatus.ONE) {
            return (_TARGET_BASE_TOKEN_AMOUNT_, _TARGET_QUOTE_TOKEN_AMOUNT_);
        } else if (_R_STATUS_ == Types.RStatus.BELOW_ONE) {
            uint256 payQuoteToken = _RBelowBackToOne();
            return (_TARGET_BASE_TOKEN_AMOUNT_, Q.add(payQuoteToken));
        } else if (_R_STATUS_ == Types.RStatus.ABOVE_ONE) {
            uint256 payBaseToken = _RAboveBackToOne();
            return (B.add(payBaseToken), _TARGET_QUOTE_TOKEN_AMOUNT_);
        }
    }

    function getMidPrice() public view returns (uint256 midPrice) {
        (uint256 baseTarget, uint256 quoteTarget) = getExpectedTarget();
        if (_R_STATUS_ == Types.RStatus.BELOW_ONE) {
            uint256 R = DecimalMath.divFloor(
                quoteTarget.mul(quoteTarget).div(_QUOTE_BALANCE_),
                _QUOTE_BALANCE_
            );
            R = DecimalMath.ONE.sub(_K_).add(DecimalMath.mul(_K_, R));
            return DecimalMath.divFloor(getOraclePrice(), R);
        } else {
            uint256 R = DecimalMath.divFloor(
                baseTarget.mul(baseTarget).div(_BASE_BALANCE_),
                _BASE_BALANCE_
            );
            R = DecimalMath.ONE.sub(_K_).add(DecimalMath.mul(_K_, R));
            return DecimalMath.mul(getOraclePrice(), R);
        }
    }

    function _RAboveIntegrate(
        uint256 B0,
        uint256 B1,
        uint256 B2
    ) internal view returns (uint256) {
        uint256 i = getOraclePrice();
        return DODOMath._GeneralIntegrate(B0, B1, B2, i, _K_);
    }

    // function _RBelowIntegrate(
    //     uint256 Q0,
    //     uint256 Q1,
    //     uint256 Q2
    // ) internal view returns (uint256) {
    //     uint256 i = getOraclePrice();
    //     i = DecimalMath.divFloor(DecimalMath.ONE, i); // 1/i
    //     return DODOMath._GeneralIntegrate(Q0, Q1, Q2, i, _K_);
    // }
}

// File: contracts/lib/SafeERC20.sol

/*

    Copyright 2020 DODO ZOO.
    This is a simplified version of OpenZepplin's SafeERC20 library

*/

/**
 * @title SafeERC20
 * @dev Wrappers around ERC20 operations that throw on failure (when the token
 * contract returns false). Tokens that return no value (and instead revert or
 * throw on failure) are also supported, non-reverting calls are assumed to be
 * successful.
 * To use this library you can add a `using SafeERC20 for ERC20;` statement to your contract,
 * which allows you to call the safe operations as `token.safeTransfer(...)`, etc.
 */
library SafeERC20 {
    using SafeMath for uint256;

    function safeTransfer(
        IERC20 token,
        address to,
        uint256 value
    ) internal {
        _callOptionalReturn(token, abi.encodeWithSelector(token.transfer.selector, to, value));
    }

    function safeTransferFrom(
        IERC20 token,
        address from,
        address to,
        uint256 value
    ) internal {
        _callOptionalReturn(
            token,
            abi.encodeWithSelector(token.transferFrom.selector, from, to, value)
        );
    }

    /**
     * @dev Imitates a Solidity high-level call (i.e. a regular function call to a contract), relaxing the requirement
     * on the return value: the return value is optional (but if data is returned, it must not be false).
     * @param token The token targeted by the call.
     * @param data The call data (encoded using abi.encode or one of its variants).
     */
    function _callOptionalReturn(IERC20 token, bytes memory data) private {
        // We need to perform a low level call here, to bypass Solidity's return data size checking mechanism, since
        // we're implementing it ourselves.

        // A Solidity high level call has three parts:
        //  1. The target address is checked to verify it contains contract code
        //  2. The call itself is made, and success asserted
        //  3. The return value is decoded, which in turn checks the size of the returned data.
        // solhint-disable-next-line max-line-length

        // solhint-disable-next-line avoid-low-level-calls
        (bool success, bytes memory returndata) = address(token).call(data);
        require(success, "SafeERC20: low-level call failed");

        if (returndata.length > 0) {
            // Return data is optional
            // solhint-disable-next-line max-line-length
            require(abi.decode(returndata, (bool)), "SafeERC20: ERC20 operation did not succeed");
        }
    }
}

// File: contracts/impl/Settlement.sol

/*

    Copyright 2020 DODO ZOO.

*/

/**
 * @title Settlement
 * @author DODO Breeder
 *
 * @notice Functions for assets settlement
 */
contract Settlement is Storage {
    using SafeMath for uint256;
    using SafeERC20 for IERC20;

    // ============ Events ============

    event Donate(uint256 amount, bool isBaseToken);

    event ClaimAssets(address indexed user, uint256 baseTokenAmount, uint256 quoteTokenAmount);

    // ============ Assets IN/OUT Functions ============

    function _baseTokenTransferIn(address from, uint256 amount) internal {
        IERC20(_BASE_TOKEN_).safeTransferFrom(from, address(this), amount);
        _BASE_BALANCE_ = _BASE_BALANCE_.add(amount);
    }

    function _quoteTokenTransferIn(address from, uint256 amount) internal {
        IERC20(_QUOTE_TOKEN_).safeTransferFrom(from, address(this), amount);
        _QUOTE_BALANCE_ = _QUOTE_BALANCE_.add(amount);
    }

    function _baseTokenTransferOut(address to, uint256 amount) internal {
        IERC20(_BASE_TOKEN_).safeTransfer(to, amount);
        _BASE_BALANCE_ = _BASE_BALANCE_.sub(amount);
    }

    function _quoteTokenTransferOut(address to, uint256 amount) internal {
        IERC20(_QUOTE_TOKEN_).safeTransfer(to, amount);
        _QUOTE_BALANCE_ = _QUOTE_BALANCE_.sub(amount);
    }

    // ============ Donate to Liquidity Pool Functions ============

    function _donateBaseToken(uint256 amount) internal {
        _TARGET_BASE_TOKEN_AMOUNT_ = _TARGET_BASE_TOKEN_AMOUNT_.add(amount);
        emit Donate(amount, true);
    }

    function _donateQuoteToken(uint256 amount) internal {
        _TARGET_QUOTE_TOKEN_AMOUNT_ = _TARGET_QUOTE_TOKEN_AMOUNT_.add(amount);
        emit Donate(amount, false);
    }

    function donateBaseToken(uint256 amount) external preventReentrant {
        _baseTokenTransferIn(msg.sender, amount);
        _donateBaseToken(amount);
    }

    function donateQuoteToken(uint256 amount) external preventReentrant {
        _quoteTokenTransferIn(msg.sender, amount);
        _donateQuoteToken(amount);
    }

    // ============ Final Settlement Functions ============

    // last step to shut down dodo
    function finalSettlement() external onlyOwner notClosed {
        _CLOSED_ = true;
        _DEPOSIT_QUOTE_ALLOWED_ = false;
        _DEPOSIT_BASE_ALLOWED_ = false;
        _TRADE_ALLOWED_ = false;
        uint256 totalBaseCapital = getTotalBaseCapital();
        uint256 totalQuoteCapital = getTotalQuoteCapital();

        if (_QUOTE_BALANCE_ > _TARGET_QUOTE_TOKEN_AMOUNT_) {
            uint256 spareQuote = _QUOTE_BALANCE_.sub(_TARGET_QUOTE_TOKEN_AMOUNT_);
            _BASE_CAPITAL_RECEIVE_QUOTE_ = DecimalMath.divFloor(spareQuote, totalBaseCapital);
        } else {
            _TARGET_QUOTE_TOKEN_AMOUNT_ = _QUOTE_BALANCE_;
        }

        if (_BASE_BALANCE_ > _TARGET_BASE_TOKEN_AMOUNT_) {
            uint256 spareBase = _BASE_BALANCE_.sub(_TARGET_BASE_TOKEN_AMOUNT_);
            _QUOTE_CAPITAL_RECEIVE_BASE_ = DecimalMath.divFloor(spareBase, totalQuoteCapital);
        } else {
            _TARGET_BASE_TOKEN_AMOUNT_ = _BASE_BALANCE_;
        }

        _R_STATUS_ = Types.RStatus.ONE;
    }

    // claim remaining assets after final settlement
    function claimAssets() external preventReentrant {
        require(_CLOSED_, "DODO_NOT_CLOSED");
        require(!_CLAIMED_[msg.sender], "ALREADY_CLAIMED");
        _CLAIMED_[msg.sender] = true;
        uint256 quoteAmount = DecimalMath.mul(
            getBaseCapitalBalanceOf(msg.sender),
            _BASE_CAPITAL_RECEIVE_QUOTE_
        );
        uint256 baseAmount = DecimalMath.mul(
            getQuoteCapitalBalanceOf(msg.sender),
            _QUOTE_CAPITAL_RECEIVE_BASE_
        );
        _baseTokenTransferOut(msg.sender, baseAmount);
        _quoteTokenTransferOut(msg.sender, quoteAmount);
        emit ClaimAssets(msg.sender, baseAmount, quoteAmount);
        return;
    }

    // in case someone transfer to contract directly
    function retrieve(address token, uint256 amount) external onlyOwner {
        if (token == _BASE_TOKEN_) {
            require(
                IERC20(_BASE_TOKEN_).balanceOf(address(this)) >= _BASE_BALANCE_.add(amount),
                "DODO_BASE_BALANCE_NOT_ENOUGH"
            );
        }
        if (token == _QUOTE_TOKEN_) {
            require(
                IERC20(_QUOTE_TOKEN_).balanceOf(address(this)) >= _QUOTE_BALANCE_.add(amount),
                "DODO_QUOTE_BALANCE_NOT_ENOUGH"
            );
        }
        IERC20(token).safeTransfer(msg.sender, amount);
    }
}

// File: contracts/impl/Trader.sol

/*

    Copyright 2020 DODO ZOO.

*/

/**
 * @title Trader
 * @author DODO Breeder
 *
 * @notice Functions for trader operations
 */
contract Trader is Storage, Pricing, Settlement {
    using SafeMath for uint256;

    // ============ Events ============

    event SellBaseToken(address indexed seller, uint256 payBase, uint256 receiveQuote);

    event BuyBaseToken(address indexed buyer, uint256 receiveBase, uint256 payQuote);

    event ChargeMaintainerFee(address indexed maintainer, bool isBaseToken, uint256 amount);

    // ============ Modifiers ============

    modifier tradeAllowed() {
        require(_TRADE_ALLOWED_, "TRADE_NOT_ALLOWED");
        _;
    }

    modifier gasPriceLimit() {
        require(tx.gasprice <= _GAS_PRICE_LIMIT_, "GAS_PRICE_EXCEED");
        _;
    }

    // ============ Trade Functions ============

    function sellBaseToken(
        uint256 amount,
        uint256 minReceiveQuote,
        bytes calldata data
    ) external tradeAllowed gasPriceLimit preventReentrant returns (uint256) {
        // query price
        (
            uint256 receiveQuote,
            uint256 lpFeeQuote,
            uint256 mtFeeQuote,
            Types.RStatus newRStatus,
            uint256 newQuoteTarget,
            uint256 newBaseTarget
        ) = _querySellBaseToken(amount);
        require(receiveQuote >= minReceiveQuote, "SELL_BASE_RECEIVE_NOT_ENOUGH");

        // settle assets
        _quoteTokenTransferOut(msg.sender, receiveQuote);
        if (data.length > 0) {
            IDODOCallee(msg.sender).dodoCall(false, amount, receiveQuote, data);
        }
        _baseTokenTransferIn(msg.sender, amount);
        if (mtFeeQuote != 0) {
            _quoteTokenTransferOut(_MAINTAINER_, mtFeeQuote);
            emit ChargeMaintainerFee(_MAINTAINER_, false, mtFeeQuote);
        }

        // update TARGET
        if (_TARGET_QUOTE_TOKEN_AMOUNT_ != newQuoteTarget) {
            _TARGET_QUOTE_TOKEN_AMOUNT_ = newQuoteTarget;
        }
        if (_TARGET_BASE_TOKEN_AMOUNT_ != newBaseTarget) {
            _TARGET_BASE_TOKEN_AMOUNT_ = newBaseTarget;
        }
        if (_R_STATUS_ != newRStatus) {
            _R_STATUS_ = newRStatus;
        }

        _donateQuoteToken(lpFeeQuote);
        emit SellBaseToken(msg.sender, amount, receiveQuote);

        return receiveQuote;
    }

    function buyBaseToken(
        uint256 amount,
        uint256 maxPayQuote,
        bytes calldata data
    ) external tradeAllowed gasPriceLimit preventReentrant returns (uint256) {
        // query price
        (
            uint256 payQuote,
            uint256 lpFeeBase,
            uint256 mtFeeBase,
            Types.RStatus newRStatus,
            uint256 newQuoteTarget,
            uint256 newBaseTarget
        ) = _queryBuyBaseToken(amount);
        require(payQuote <= maxPayQuote, "BUY_BASE_COST_TOO_MUCH");

        // settle assets
        _baseTokenTransferOut(msg.sender, amount);
        if (data.length > 0) {
            IDODOCallee(msg.sender).dodoCall(true, amount, payQuote, data);
        }
        _quoteTokenTransferIn(msg.sender, payQuote);
        if (mtFeeBase != 0) {
            _baseTokenTransferOut(_MAINTAINER_, mtFeeBase);
            emit ChargeMaintainerFee(_MAINTAINER_, true, mtFeeBase);
        }

        // update TARGET
        if (_TARGET_QUOTE_TOKEN_AMOUNT_ != newQuoteTarget) {
            _TARGET_QUOTE_TOKEN_AMOUNT_ = newQuoteTarget;
        }
        if (_TARGET_BASE_TOKEN_AMOUNT_ != newBaseTarget) {
            _TARGET_BASE_TOKEN_AMOUNT_ = newBaseTarget;
        }
        if (_R_STATUS_ != newRStatus) {
            _R_STATUS_ = newRStatus;
        }

        _donateBaseToken(lpFeeBase);
        emit BuyBaseToken(msg.sender, amount, payQuote);

        return payQuote;
    }

    // ============ Query Functions ============

    function querySellBaseToken(uint256 amount) external view returns (uint256 receiveQuote) {
        (receiveQuote, , , , , ) = _querySellBaseToken(amount);
        return receiveQuote;
    }

    function queryBuyBaseToken(uint256 amount) external view returns (uint256 payQuote) {
        (payQuote, , , , , ) = _queryBuyBaseToken(amount);
        return payQuote;
    }

    function _querySellBaseToken(uint256 amount)
        internal
        view
        returns (
            uint256 receiveQuote,
            uint256 lpFeeQuote,
            uint256 mtFeeQuote,
            Types.RStatus newRStatus,
            uint256 newQuoteTarget,
            uint256 newBaseTarget
        )
    {
        (newBaseTarget, newQuoteTarget) = getExpectedTarget();

        uint256 sellBaseAmount = amount;

        if (_R_STATUS_ == Types.RStatus.ONE) {
            // case 1: R=1
            // R falls below one
            receiveQuote = _ROneSellBaseToken(sellBaseAmount, newQuoteTarget);
            newRStatus = Types.RStatus.BELOW_ONE;
        } else if (_R_STATUS_ == Types.RStatus.ABOVE_ONE) {
            uint256 backToOnePayBase = newBaseTarget.sub(_BASE_BALANCE_);
            uint256 backToOneReceiveQuote = _QUOTE_BALANCE_.sub(newQuoteTarget);
            // case 2: R>1
            // complex case, R status depends on trading amount
            if (sellBaseAmount < backToOnePayBase) {
                // case 2.1: R status do not change
                receiveQuote = _RAboveSellBaseToken(sellBaseAmount, _BASE_BALANCE_, newBaseTarget);
                newRStatus = Types.RStatus.ABOVE_ONE;
                if (receiveQuote > backToOneReceiveQuote) {
                    // [Important corner case!] may enter this branch when some precision problem happens. And consequently contribute to negative spare quote amount
                    // to make sure spare quote>=0, mannually set receiveQuote=backToOneReceiveQuote
                    receiveQuote = backToOneReceiveQuote;
                }
            } else if (sellBaseAmount == backToOnePayBase) {
                // case 2.2: R status changes to ONE
                receiveQuote = backToOneReceiveQuote;
                newRStatus = Types.RStatus.ONE;
            } else {
                // case 2.3: R status changes to BELOW_ONE
                receiveQuote = backToOneReceiveQuote.add(
                    _ROneSellBaseToken(sellBaseAmount.sub(backToOnePayBase), newQuoteTarget)
                );
                newRStatus = Types.RStatus.BELOW_ONE;
            }
        } else {
            // _R_STATUS_ == Types.RStatus.BELOW_ONE
            // case 3: R<1
            receiveQuote = _RBelowSellBaseToken(sellBaseAmount, _QUOTE_BALANCE_, newQuoteTarget);
            newRStatus = Types.RStatus.BELOW_ONE;
        }

        // count fees
        lpFeeQuote = DecimalMath.mul(receiveQuote, _LP_FEE_RATE_);
        mtFeeQuote = DecimalMath.mul(receiveQuote, _MT_FEE_RATE_);
        receiveQuote = receiveQuote.sub(lpFeeQuote).sub(mtFeeQuote);

        return (receiveQuote, lpFeeQuote, mtFeeQuote, newRStatus, newQuoteTarget, newBaseTarget);
    }

    function _queryBuyBaseToken(uint256 amount)
        internal
        view
        returns (
            uint256 payQuote,
            uint256 lpFeeBase,
            uint256 mtFeeBase,
            Types.RStatus newRStatus,
            uint256 newQuoteTarget,
            uint256 newBaseTarget
        )
    {
        (newBaseTarget, newQuoteTarget) = getExpectedTarget();

        // charge fee from user receive amount
        lpFeeBase = DecimalMath.mul(amount, _LP_FEE_RATE_);
        mtFeeBase = DecimalMath.mul(amount, _MT_FEE_RATE_);
        uint256 buyBaseAmount = amount.add(lpFeeBase).add(mtFeeBase);

        if (_R_STATUS_ == Types.RStatus.ONE) {
            // case 1: R=1
            payQuote = _ROneBuyBaseToken(buyBaseAmount, newBaseTarget);
            newRStatus = Types.RStatus.ABOVE_ONE;
        } else if (_R_STATUS_ == Types.RStatus.ABOVE_ONE) {
            // case 2: R>1
            payQuote = _RAboveBuyBaseToken(buyBaseAmount, _BASE_BALANCE_, newBaseTarget);
            newRStatus = Types.RStatus.ABOVE_ONE;
        } else if (_R_STATUS_ == Types.RStatus.BELOW_ONE) {
            uint256 backToOnePayQuote = newQuoteTarget.sub(_QUOTE_BALANCE_);
            uint256 backToOneReceiveBase = _BASE_BALANCE_.sub(newBaseTarget);
            // case 3: R<1
            // complex case, R status may change
            if (buyBaseAmount < backToOneReceiveBase) {
                // case 3.1: R status do not change
                // no need to check payQuote because spare base token must be greater than zero
                payQuote = _RBelowBuyBaseToken(buyBaseAmount, _QUOTE_BALANCE_, newQuoteTarget);
                newRStatus = Types.RStatus.BELOW_ONE;
            } else if (buyBaseAmount == backToOneReceiveBase) {
                // case 3.2: R status changes to ONE
                payQuote = backToOnePayQuote;
                newRStatus = Types.RStatus.ONE;
            } else {
                // case 3.3: R status changes to ABOVE_ONE
                payQuote = backToOnePayQuote.add(
                    _ROneBuyBaseToken(buyBaseAmount.sub(backToOneReceiveBase), newBaseTarget)
                );
                newRStatus = Types.RStatus.ABOVE_ONE;
            }
        }

        return (payQuote, lpFeeBase, mtFeeBase, newRStatus, newQuoteTarget, newBaseTarget);
    }
}

// File: contracts/impl/LiquidityProvider.sol

/*

    Copyright 2020 DODO ZOO.

*/

/**
 * @title LiquidityProvider
 * @author DODO Breeder
 *
 * @notice Functions for liquidity provider operations
 */
contract LiquidityProvider is Storage, Pricing, Settlement {
    using SafeMath for uint256;

    // ============ Events ============

    event Deposit(
        address indexed payer,
        address indexed receiver,
        bool isBaseToken,
        uint256 amount,
        uint256 lpTokenAmount
    );

    event Withdraw(
        address indexed payer,
        address indexed receiver,
        bool isBaseToken,
        uint256 amount,
        uint256 lpTokenAmount
    );

    event ChargePenalty(address indexed payer, bool isBaseToken, uint256 amount);

    // ============ Modifiers ============

    modifier depositQuoteAllowed() {
        require(_DEPOSIT_QUOTE_ALLOWED_, "DEPOSIT_QUOTE_NOT_ALLOWED");
        _;
    }

    modifier depositBaseAllowed() {
        require(_DEPOSIT_BASE_ALLOWED_, "DEPOSIT_BASE_NOT_ALLOWED");
        _;
    }

    // ============ Routine Functions ============

    function withdrawBase(uint256 amount) external returns (uint256) {
        return withdrawBaseTo(msg.sender, amount);
    }

    function depositBase(uint256 amount) external returns (uint256) {
        return depositBaseTo(msg.sender, amount);
    }

    function withdrawQuote(uint256 amount) external returns (uint256) {
        return withdrawQuoteTo(msg.sender, amount);
    }

    function depositQuote(uint256 amount) external returns (uint256) {
        return depositQuoteTo(msg.sender, amount);
    }

    function withdrawAllBase() external returns (uint256) {
        return withdrawAllBaseTo(msg.sender);
    }

    function withdrawAllQuote() external returns (uint256) {
        return withdrawAllQuoteTo(msg.sender);
    }

    // ============ Deposit Functions ============

    function depositQuoteTo(address to, uint256 amount)
        public
        preventReentrant
        depositQuoteAllowed
        returns (uint256)
    {
        (, uint256 quoteTarget) = getExpectedTarget();
        uint256 totalQuoteCapital = getTotalQuoteCapital();
        uint256 capital = amount;
        if (totalQuoteCapital == 0) {
            // give remaining quote token to lp as a gift
            capital = amount.add(quoteTarget);
        } else if (quoteTarget > 0) {
            capital = amount.mul(totalQuoteCapital).div(quoteTarget);
        }

        // settlement
        _quoteTokenTransferIn(msg.sender, amount);
        _mintQuoteCapital(to, capital);
        _TARGET_QUOTE_TOKEN_AMOUNT_ = _TARGET_QUOTE_TOKEN_AMOUNT_.add(amount);

        emit Deposit(msg.sender, to, false, amount, capital);
        return capital;
    }

    function depositBaseTo(address to, uint256 amount)
        public
        preventReentrant
        depositBaseAllowed
        returns (uint256)
    {
        (uint256 baseTarget, ) = getExpectedTarget();
        uint256 totalBaseCapital = getTotalBaseCapital();
        uint256 capital = amount;
        if (totalBaseCapital == 0) {
            // give remaining base token to lp as a gift
            capital = amount.add(baseTarget);
        } else if (baseTarget > 0) {
            capital = amount.mul(totalBaseCapital).div(baseTarget);
        }

        // settlement
        _baseTokenTransferIn(msg.sender, amount);
        _mintBaseCapital(to, capital);
        _TARGET_BASE_TOKEN_AMOUNT_ = _TARGET_BASE_TOKEN_AMOUNT_.add(amount);

        emit Deposit(msg.sender, to, true, amount, capital);
        return capital;
    }

    // ============ Withdraw Functions ============

    function withdrawQuoteTo(address to, uint256 amount) public preventReentrant returns (uint256) {
        // calculate capital
        (, uint256 quoteTarget) = getExpectedTarget();
        uint256 totalQuoteCapital = getTotalQuoteCapital();
        require(totalQuoteCapital > 0, "NO_QUOTE_LP");

        uint256 requireQuoteCapital = amount.mul(totalQuoteCapital).divCeil(quoteTarget);
        require(
            requireQuoteCapital <= getQuoteCapitalBalanceOf(msg.sender),
            "LP_QUOTE_CAPITAL_BALANCE_NOT_ENOUGH"
        );

        // handle penalty, penalty may exceed amount
        uint256 penalty = getWithdrawQuotePenalty(amount);
        require(penalty < amount, "PENALTY_EXCEED");

        // settlement
        _TARGET_QUOTE_TOKEN_AMOUNT_ = _TARGET_QUOTE_TOKEN_AMOUNT_.sub(amount);
        _burnQuoteCapital(msg.sender, requireQuoteCapital);
        _quoteTokenTransferOut(to, amount.sub(penalty));
        _donateQuoteToken(penalty);

        emit Withdraw(msg.sender, to, false, amount.sub(penalty), requireQuoteCapital);
        emit ChargePenalty(msg.sender, false, penalty);

        return amount.sub(penalty);
    }

    function withdrawBaseTo(address to, uint256 amount) public preventReentrant returns (uint256) {
        // calculate capital
        (uint256 baseTarget, ) = getExpectedTarget();
        uint256 totalBaseCapital = getTotalBaseCapital();
        require(totalBaseCapital > 0, "NO_BASE_LP");

        uint256 requireBaseCapital = amount.mul(totalBaseCapital).divCeil(baseTarget);
        require(
            requireBaseCapital <= getBaseCapitalBalanceOf(msg.sender),
            "LP_BASE_CAPITAL_BALANCE_NOT_ENOUGH"
        );

        // handle penalty, penalty may exceed amount
        uint256 penalty = getWithdrawBasePenalty(amount);
        require(penalty <= amount, "PENALTY_EXCEED");

        // settlement
        _TARGET_BASE_TOKEN_AMOUNT_ = _TARGET_BASE_TOKEN_AMOUNT_.sub(amount);
        _burnBaseCapital(msg.sender, requireBaseCapital);
        _baseTokenTransferOut(to, amount.sub(penalty));
        _donateBaseToken(penalty);

        emit Withdraw(msg.sender, to, true, amount.sub(penalty), requireBaseCapital);
        emit ChargePenalty(msg.sender, true, penalty);

        return amount.sub(penalty);
    }

    // ============ Withdraw all Functions ============

    function withdrawAllQuoteTo(address to) public preventReentrant returns (uint256) {
        uint256 withdrawAmount = getLpQuoteBalance(msg.sender);
        uint256 capital = getQuoteCapitalBalanceOf(msg.sender);

        // handle penalty, penalty may exceed amount
        uint256 penalty = getWithdrawQuotePenalty(withdrawAmount);
        require(penalty <= withdrawAmount, "PENALTY_EXCEED");

        // settlement
        _TARGET_QUOTE_TOKEN_AMOUNT_ = _TARGET_QUOTE_TOKEN_AMOUNT_.sub(withdrawAmount);
        _burnQuoteCapital(msg.sender, capital);
        _quoteTokenTransferOut(to, withdrawAmount.sub(penalty));
        _donateQuoteToken(penalty);

        emit Withdraw(msg.sender, to, false, withdrawAmount, capital);
        emit ChargePenalty(msg.sender, false, penalty);

        return withdrawAmount.sub(penalty);
    }

    function withdrawAllBaseTo(address to) public preventReentrant returns (uint256) {
        uint256 withdrawAmount = getLpBaseBalance(msg.sender);
        uint256 capital = getBaseCapitalBalanceOf(msg.sender);

        // handle penalty, penalty may exceed amount
        uint256 penalty = getWithdrawBasePenalty(withdrawAmount);
        require(penalty <= withdrawAmount, "PENALTY_EXCEED");

        // settlement
        _TARGET_BASE_TOKEN_AMOUNT_ = _TARGET_BASE_TOKEN_AMOUNT_.sub(withdrawAmount);
        _burnBaseCapital(msg.sender, capital);
        _baseTokenTransferOut(to, withdrawAmount.sub(penalty));
        _donateBaseToken(penalty);

        emit Withdraw(msg.sender, to, true, withdrawAmount, capital);
        emit ChargePenalty(msg.sender, true, penalty);

        return withdrawAmount.sub(penalty);
    }

    // ============ Helper Functions ============

    function _mintBaseCapital(address user, uint256 amount) internal {
        IDODOLpToken(_BASE_CAPITAL_TOKEN_).mint(user, amount);
    }

    function _mintQuoteCapital(address user, uint256 amount) internal {
        IDODOLpToken(_QUOTE_CAPITAL_TOKEN_).mint(user, amount);
    }

    function _burnBaseCapital(address user, uint256 amount) internal {
        IDODOLpToken(_BASE_CAPITAL_TOKEN_).burn(user, amount);
    }

    function _burnQuoteCapital(address user, uint256 amount) internal {
        IDODOLpToken(_QUOTE_CAPITAL_TOKEN_).burn(user, amount);
    }

    // ============ Getter Functions ============

    function getLpBaseBalance(address lp) public view returns (uint256 lpBalance) {
        uint256 totalBaseCapital = getTotalBaseCapital();
        (uint256 baseTarget, ) = getExpectedTarget();
        if (totalBaseCapital == 0) {
            return 0;
        }
        lpBalance = getBaseCapitalBalanceOf(lp).mul(baseTarget).div(totalBaseCapital);
        return lpBalance;
    }

    function getLpQuoteBalance(address lp) public view returns (uint256 lpBalance) {
        uint256 totalQuoteCapital = getTotalQuoteCapital();
        (, uint256 quoteTarget) = getExpectedTarget();
        if (totalQuoteCapital == 0) {
            return 0;
        }
        lpBalance = getQuoteCapitalBalanceOf(lp).mul(quoteTarget).div(totalQuoteCapital);
        return lpBalance;
    }

    function getWithdrawQuotePenalty(uint256 amount) public view returns (uint256 penalty) {
        require(amount <= _QUOTE_BALANCE_, "DODO_QUOTE_BALANCE_NOT_ENOUGH");
        if (_R_STATUS_ == Types.RStatus.BELOW_ONE) {
            uint256 spareBase = _BASE_BALANCE_.sub(_TARGET_BASE_TOKEN_AMOUNT_);
            uint256 price = getOraclePrice();
            uint256 fairAmount = DecimalMath.mul(spareBase, price);
            uint256 targetQuote = DODOMath._SolveQuadraticFunctionForTarget(
                _QUOTE_BALANCE_,
                _K_,
                fairAmount
            );
            // if amount = _QUOTE_BALANCE_, div error
            uint256 targetQuoteWithWithdraw = DODOMath._SolveQuadraticFunctionForTarget(
                _QUOTE_BALANCE_.sub(amount),
                _K_,
                fairAmount
            );
            return targetQuote.sub(targetQuoteWithWithdraw.add(amount));
        } else {
            return 0;
        }
    }

    function getWithdrawBasePenalty(uint256 amount) public view returns (uint256 penalty) {
        require(amount <= _BASE_BALANCE_, "DODO_BASE_BALANCE_NOT_ENOUGH");
        if (_R_STATUS_ == Types.RStatus.ABOVE_ONE) {
            uint256 spareQuote = _QUOTE_BALANCE_.sub(_TARGET_QUOTE_TOKEN_AMOUNT_);
            uint256 price = getOraclePrice();
            uint256 fairAmount = DecimalMath.divFloor(spareQuote, price);
            uint256 targetBase = DODOMath._SolveQuadraticFunctionForTarget(
                _BASE_BALANCE_,
                _K_,
                fairAmount
            );
            // if amount = _BASE_BALANCE_, div error
            uint256 targetBaseWithWithdraw = DODOMath._SolveQuadraticFunctionForTarget(
                _BASE_BALANCE_.sub(amount),
                _K_,
                fairAmount
            );
            return targetBase.sub(targetBaseWithWithdraw.add(amount));
        } else {
            return 0;
        }
    }
}

// File: contracts/impl/Admin.sol

/*

    Copyright 2020 DODO ZOO.

*/

/**
 * @title Admin
 * @author DODO Breeder
 *
 * @notice Functions for admin operations
 */
contract Admin is Storage {
    // ============ Events ============

    event UpdateGasPriceLimit(uint256 oldGasPriceLimit, uint256 newGasPriceLimit);

    event UpdateLiquidityProviderFeeRate(
        uint256 oldLiquidityProviderFeeRate,
        uint256 newLiquidityProviderFeeRate
    );

    event UpdateMaintainerFeeRate(uint256 oldMaintainerFeeRate, uint256 newMaintainerFeeRate);

    event UpdateK(uint256 oldK, uint256 newK);

    // ============ Params Setting Functions ============

    function setOracle(address newOracle) external onlyOwner {
        _ORACLE_ = newOracle;
    }

    function setSupervisor(address newSupervisor) external onlyOwner {
        _SUPERVISOR_ = newSupervisor;
    }

    function setMaintainer(address newMaintainer) external onlyOwner {
        _MAINTAINER_ = newMaintainer;
    }

    function setLiquidityProviderFeeRate(uint256 newLiquidityPorviderFeeRate) external onlyOwner {
        emit UpdateLiquidityProviderFeeRate(_LP_FEE_RATE_, newLiquidityPorviderFeeRate);
        _LP_FEE_RATE_ = newLiquidityPorviderFeeRate;
        _checkDODOParameters();
    }

    function setMaintainerFeeRate(uint256 newMaintainerFeeRate) external onlyOwner {
        emit UpdateMaintainerFeeRate(_MT_FEE_RATE_, newMaintainerFeeRate);
        _MT_FEE_RATE_ = newMaintainerFeeRate;
        _checkDODOParameters();
    }

    function setK(uint256 newK) external onlyOwner {
        emit UpdateK(_K_, newK);
        _K_ = newK;
        _checkDODOParameters();
    }

    function setGasPriceLimit(uint256 newGasPriceLimit) external onlySupervisorOrOwner {
        emit UpdateGasPriceLimit(_GAS_PRICE_LIMIT_, newGasPriceLimit);
        _GAS_PRICE_LIMIT_ = newGasPriceLimit;
    }

    // ============ System Control Functions ============

    function disableTrading() external onlySupervisorOrOwner {
        _TRADE_ALLOWED_ = false;
    }

    function enableTrading() external onlyOwner notClosed {
        _TRADE_ALLOWED_ = true;
    }

    function disableQuoteDeposit() external onlySupervisorOrOwner {
        _DEPOSIT_QUOTE_ALLOWED_ = false;
    }

    function enableQuoteDeposit() external onlyOwner notClosed {
        _DEPOSIT_QUOTE_ALLOWED_ = true;
    }

    function disableBaseDeposit() external onlySupervisorOrOwner {
        _DEPOSIT_BASE_ALLOWED_ = false;
    }

    function enableBaseDeposit() external onlyOwner notClosed {
        _DEPOSIT_BASE_ALLOWED_ = true;
    }
}

// File: contracts/lib/Ownable.sol

/*

    Copyright 2020 DODO ZOO.

*/

/**
 * @title Ownable
 * @author DODO Breeder
 *
 * @notice Ownership related functions
 */
contract Ownable {
    address public _OWNER_;
    address public _NEW_OWNER_;

    // ============ Events ============

    event OwnershipTransferPrepared(address indexed previousOwner, address indexed newOwner);

    event OwnershipTransferred(address indexed previousOwner, address indexed newOwner);

    // ============ Modifiers ============

    modifier onlyOwner() {
        require(msg.sender == _OWNER_, "NOT_OWNER");
        _;
    }

    // ============ Functions ============

    constructor() internal {
        _OWNER_ = msg.sender;
        emit OwnershipTransferred(address(0), _OWNER_);
    }

    function transferOwnership(address newOwner) external onlyOwner {
        require(newOwner != address(0), "INVALID_OWNER");
        emit OwnershipTransferPrepared(_OWNER_, newOwner);
        _NEW_OWNER_ = newOwner;
    }

    function claimOwnership() external {
        require(msg.sender == _NEW_OWNER_, "INVALID_CLAIM");
        emit OwnershipTransferred(_OWNER_, _NEW_OWNER_);
        _OWNER_ = _NEW_OWNER_;
        _NEW_OWNER_ = address(0);
    }
}

// File: contracts/impl/DODOLpToken.sol

/*

    Copyright 2020 DODO ZOO.

*/

/**
 * @title DODOLpToken
 * @author DODO Breeder
 *
 * @notice Tokenize liquidity pool assets. An ordinary ERC20 contract with mint and burn functions
 */
contract DODOLpToken is Ownable {
    using SafeMath for uint256;

    string public symbol = "DLP";
    address public originToken;

    uint256 public totalSupply;
    mapping(address => uint256) internal balances;
    mapping(address => mapping(address => uint256)) internal allowed;

    // ============ Events ============

    event Transfer(address indexed from, address indexed to, uint256 amount);

    event Approval(address indexed owner, address indexed spender, uint256 amount);

    event Mint(address indexed user, uint256 value);

    event Burn(address indexed user, uint256 value);

    // ============ Functions ============

    constructor(address _originToken) public {
        originToken = _originToken;
    }

    function name() public view returns (string memory) {
        string memory lpTokenSuffix = "_DODO_LP_TOKEN_";
        return string(abi.encodePacked(IERC20(originToken).name(), lpTokenSuffix));
    }

    function decimals() public view returns (uint8) {
        return IERC20(originToken).decimals();
    }

    /**
     * @dev transfer token for a specified address
     * @param to The address to transfer to.
     * @param amount The amount to be transferred.
     */
    function transfer(address to, uint256 amount) public returns (bool) {
        require(amount <= balances[msg.sender], "BALANCE_NOT_ENOUGH");

        balances[msg.sender] = balances[msg.sender].sub(amount);
        balances[to] = balances[to].add(amount);
        emit Transfer(msg.sender, to, amount);
        return true;
    }

    /**
     * @dev Gets the balance of the specified address.
     * @param owner The address to query the the balance of.
     * @return balance An uint256 representing the amount owned by the passed address.
     */
    function balanceOf(address owner) external view returns (uint256 balance) {
        return balances[owner];
    }

    /**
     * @dev Transfer tokens from one address to another
     * @param from address The address which you want to send tokens from
     * @param to address The address which you want to transfer to
     * @param amount uint256 the amount of tokens to be transferred
     */
    function transferFrom(
        address from,
        address to,
        uint256 amount
    ) public returns (bool) {
        require(amount <= balances[from], "BALANCE_NOT_ENOUGH");
        require(amount <= allowed[from][msg.sender], "ALLOWANCE_NOT_ENOUGH");

        balances[from] = balances[from].sub(amount);
        balances[to] = balances[to].add(amount);
        allowed[from][msg.sender] = allowed[from][msg.sender].sub(amount);
        emit Transfer(from, to, amount);
        return true;
    }

    /**
     * @dev Approve the passed address to spend the specified amount of tokens on behalf of msg.sender.
     * @param spender The address which will spend the funds.
     * @param amount The amount of tokens to be spent.
     */
    function approve(address spender, uint256 amount) public returns (bool) {
        allowed[msg.sender][spender] = amount;
        emit Approval(msg.sender, spender, amount);
        return true;
    }

    /**
     * @dev Function to check the amount of tokens that an owner allowed to a spender.
     * @param owner address The address which owns the funds.
     * @param spender address The address which will spend the funds.
     * @return A uint256 specifying the amount of tokens still available for the spender.
     */
    function allowance(address owner, address spender) public view returns (uint256) {
        return allowed[owner][spender];
    }

    function mint(address user, uint256 value) external onlyOwner {
        balances[user] = balances[user].add(value);
        totalSupply = totalSupply.add(value);
        emit Mint(user, value);
        emit Transfer(address(0), user, value);
    }

    function burn(address user, uint256 value) external onlyOwner {
        balances[user] = balances[user].sub(value);
        totalSupply = totalSupply.sub(value);
        emit Burn(user, value);
        emit Transfer(user, address(0), value);
    }
}

// File: contracts/dodo.sol

/*

    Copyright 2020 DODO ZOO.

*/

/**
 * @title DODO
 * @author DODO Breeder
 *
 * @notice Entrance for users
 */
contract DODO is Admin, Trader, LiquidityProvider {
    function init(
        address owner,
        address supervisor,
        address maintainer,
        address baseToken,
        address quoteToken,
        address oracle,
        uint256 lpFeeRate,
        uint256 mtFeeRate,
        uint256 k,
        uint256 gasPriceLimit
    ) external {
        require(!_INITIALIZED_, "DODO_INITIALIZED");
        _INITIALIZED_ = true;

        // constructor
        _OWNER_ = owner;
        emit OwnershipTransferred(address(0), _OWNER_);

        _SUPERVISOR_ = supervisor;
        _MAINTAINER_ = maintainer;
        _BASE_TOKEN_ = baseToken;
        _QUOTE_TOKEN_ = quoteToken;
        _ORACLE_ = oracle;

        _DEPOSIT_BASE_ALLOWED_ = true;
        _DEPOSIT_QUOTE_ALLOWED_ = true;
        _TRADE_ALLOWED_ = true;
        _GAS_PRICE_LIMIT_ = gasPriceLimit;

        _LP_FEE_RATE_ = lpFeeRate;
        _MT_FEE_RATE_ = mtFeeRate;
        _K_ = k;
        _R_STATUS_ = Types.RStatus.ONE;

        _BASE_CAPITAL_TOKEN_ = address(new DODOLpToken(_BASE_TOKEN_));
        _QUOTE_CAPITAL_TOKEN_ = address(new DODOLpToken(_QUOTE_TOKEN_));

        _checkDODOParameters();
    }
}

/*

    Copyright 2020 DODO ZOO.
    SPDX-License-Identifier: Apache-2.0

*/

pragma solidity 0.6.9;
pragma experimental ABIEncoderV2;

library Types {
    enum RStatus {ONE, ABOVE_ONE, BELOW_ONE}
}

// File: contracts/intf/IERC20.sol

// This is a file copied from https://github.com/OpenZeppelin/openzeppelin-contracts/blob/master/contracts/token/ERC20/IERC20.sol

/**
 * @dev Interface of the ERC20 standard as defined in the EIP.
 */
interface IERC20 {
    /**
     * @dev Returns the amount of tokens in existence.
     */
    function totalSupply() external view returns (uint256);

    function decimals() external view returns (uint8);

    function name() external view returns (string memory);

    /**
     * @dev Returns the amount of tokens owned by `account`.
     */
    function balanceOf(address account) external view returns (uint256);

    /**
     * @dev Moves `amount` tokens from the caller's account to `recipient`.
     *
     * Returns a boolean value indicating whether the operation succeeded.
     *
     * Emits a {Transfer} event.
     */
    function transfer(address recipient, uint256 amount) external returns (bool);

    /**
     * @dev Returns the remaining number of tokens that `spender` will be
     * allowed to spend on behalf of `owner` through {transferFrom}. This is
     * zero by default.
     *
     * This value changes when {approve} or {transferFrom} are called.
     */
    function allowance(address owner, address spender) external view returns (uint256);

    /**
     * @dev Sets `amount` as the allowance of `spender` over the caller's tokens.
     *
     * Returns a boolean value indicating whether the operation succeeded.
     *
     * IMPORTANT: Beware that changing an allowance with this method brings the risk
     * that someone may use both the old and the new allowance by unfortunate
     * transaction ordering. One possible solution to mitigate this race
     * condition is to first reduce the spender's allowance to 0 and set the
     * desired value afterwards:
     * https://github.com/ethereum/EIPs/issues/20#issuecomment-263524729
     *
     * Emits an {Approval} event.
     */
    function approve(address spender, uint256 amount) external returns (bool);

    /**
     * @dev Moves `amount` tokens from `sender` to `recipient` using the
     * allowance mechanism. `amount` is then deducted from the caller's
     * allowance.
     *
     * Returns a boolean value indicating whether the operation succeeded.
     *
     * Emits a {Transfer} event.
     */
    function transferFrom(
        address sender,
        address recipient,
        uint256 amount
    ) external returns (bool);
}

// File: contracts/lib/InitializableOwnable.sol

/*

    Copyright 2020 DODO ZOO.

*/

/**
 * @title Ownable
 * @author DODO Breeder
 *
 * @notice Ownership related functions
 */
contract InitializableOwnable {
    address public _OWNER_;
    address public _NEW_OWNER_;

    // ============ Events ============

    event OwnershipTransferPrepared(address indexed previousOwner, address indexed newOwner);

    event OwnershipTransferred(address indexed previousOwner, address indexed newOwner);

    // ============ Modifiers ============

    modifier onlyOwner() {
        require(msg.sender == _OWNER_, "NOT_OWNER");
        _;
    }

    // ============ Functions ============

    function transferOwnership(address newOwner) external onlyOwner {
        require(newOwner != address(0), "INVALID_OWNER");
        emit OwnershipTransferPrepared(_OWNER_, newOwner);
        _NEW_OWNER_ = newOwner;
    }

    function claimOwnership() external {
        require(msg.sender == _NEW_OWNER_, "INVALID_CLAIM");
        emit OwnershipTransferred(_OWNER_, _NEW_OWNER_);
        _OWNER_ = _NEW_OWNER_;
        _NEW_OWNER_ = address(0);
    }
}

// File: contracts/lib/SafeMath.sol

/*

    Copyright 2020 DODO ZOO.

*/

/**
 * @title SafeMath
 * @author DODO Breeder
 *
 * @notice Math operations with safety checks that revert on error
 */
library SafeMath {
    function mul(uint256 a, uint256 b) internal pure returns (uint256) {
        if (a == 0) {
            return 0;
        }

        uint256 c = a * b;
        require(c / a == b, "MUL_ERROR");

        return c;
    }

    function div(uint256 a, uint256 b) internal pure returns (uint256) {
        require(b > 0, "DIVIDING_ERROR");
        return a / b;
    }

    function divCeil(uint256 a, uint256 b) internal pure returns (uint256) {
        uint256 quotient = div(a, b);
        uint256 remainder = a - quotient * b;
        if (remainder > 0) {
            return quotient + 1;
        } else {
            return quotient;
        }
    }

    function sub(uint256 a, uint256 b) internal pure returns (uint256) {
        require(b <= a, "SUB_ERROR");
        return a - b;
    }

    function add(uint256 a, uint256 b) internal pure returns (uint256) {
        uint256 c = a + b;
        require(c >= a, "ADD_ERROR");
        return c;
    }

    function sqrt(uint256 x) internal pure returns (uint256 y) {
        uint256 z = x / 2 + 1;
        y = x;
        while (z < y) {
            y = z;
            z = (x / z + z) / 2;
        }
    }
}

// File: contracts/lib/DecimalMath.sol

/*

    Copyright 2020 DODO ZOO.

*/

/**
 * @title DecimalMath
 * @author DODO Breeder
 *
 * @notice Functions for fixed point number with 18 decimals
 */
library DecimalMath {
    using SafeMath for uint256;

    uint256 constant ONE = 10**18;

    function mul(uint256 target, uint256 d) internal pure returns (uint256) {
        return target.mul(d) / ONE;
    }

    function divFloor(uint256 target, uint256 d) internal pure returns (uint256) {
        return target.mul(ONE).div(d);
    }

    function divCeil(uint256 target, uint256 d) internal pure returns (uint256) {
        return target.mul(ONE).divCeil(d);
    }
}

// File: contracts/lib/ReentrancyGuard.sol

/*

    Copyright 2020 DODO ZOO.

*/

/**
 * @title ReentrancyGuard
 * @author DODO Breeder
 *
 * @notice Protect functions from Reentrancy Attack
 */
contract ReentrancyGuard {
    // https://solidity.readthedocs.io/en/latest/control-structures.html?highlight=zero-state#scoping-and-declarations
    // zero-state of _ENTERED_ is false
    bool private _ENTERED_;

    modifier preventReentrant() {
        require(!_ENTERED_, "REENTRANT");
        _ENTERED_ = true;
        _;
        _ENTERED_ = false;
    }
}

// File: contracts/intf/IOracle.sol

/*

    Copyright 2020 DODO ZOO.

*/

interface IOracle {
    function getPrice() external view returns (uint256);
}

// File: contracts/intf/IDODOLpToken.sol

/*

    Copyright 2020 DODO ZOO.

*/

interface IDODOLpToken {
    function mint(address user, uint256 value) external;

    function burn(address user, uint256 value) external;

    function balanceOf(address owner) external view returns (uint256);

    function totalSupply() external view returns (uint256);
}

// File: contracts/impl/Storage.sol

/*

    Copyright 2020 DODO ZOO.

*/

/**
 * @title Storage
 * @author DODO Breeder
 *
 * @notice Local Variables
 */
contract Storage is InitializableOwnable, ReentrancyGuard {
    using SafeMath for uint256;

    // ============ Variables for Control ============

    bool internal _INITIALIZED_;
    bool public _CLOSED_;
    bool public _DEPOSIT_QUOTE_ALLOWED_;
    bool public _DEPOSIT_BASE_ALLOWED_;
    bool public _TRADE_ALLOWED_;
    uint256 public _GAS_PRICE_LIMIT_;

    // ============ Core Address ============

    address public _SUPERVISOR_; // could freeze system in emergency
    address public _MAINTAINER_; // collect maintainer fee to buy food for DODO

    address public _BASE_TOKEN_;
    address public _QUOTE_TOKEN_;
    address public _ORACLE_;

    // ============ Variables for PMM Algorithm ============

    uint256 public _LP_FEE_RATE_;
    uint256 public _MT_FEE_RATE_;
    uint256 public _K_;

    Types.RStatus public _R_STATUS_;
    uint256 public _TARGET_BASE_TOKEN_AMOUNT_;
    uint256 public _TARGET_QUOTE_TOKEN_AMOUNT_;
    uint256 public _BASE_BALANCE_;
    uint256 public _QUOTE_BALANCE_;

    address public _BASE_CAPITAL_TOKEN_;
    address public _QUOTE_CAPITAL_TOKEN_;

    // ============ Variables for Final Settlement ============

    uint256 public _BASE_CAPITAL_RECEIVE_QUOTE_;
    uint256 public _QUOTE_CAPITAL_RECEIVE_BASE_;
    mapping(address => bool) public _CLAIMED_;

    // ============ Modifiers ============

    modifier onlySupervisorOrOwner() {
        require(msg.sender == _SUPERVISOR_ || msg.sender == _OWNER_, "NOT_SUPERVISOR_OR_OWNER");
        _;
    }

    modifier notClosed() {
        require(!_CLOSED_, "DODO_CLOSED");
        _;
    }

    // ============ Helper Functions ============

    function _checkDODOParameters() internal view returns (uint256) {
        require(_K_ < DecimalMath.ONE, "K>=1");
        require(_K_ > 0, "K=0");
        require(_LP_FEE_RATE_.add(_MT_FEE_RATE_) < DecimalMath.ONE, "FEE_RATE>=1");
    }

    function getOraclePrice() public view returns (uint256) {
        return IOracle(_ORACLE_).getPrice();
    }

    function getBaseCapitalBalanceOf(address lp) public view returns (uint256) {
        return IDODOLpToken(_BASE_CAPITAL_TOKEN_).balanceOf(lp);
    }

    function getTotalBaseCapital() public view returns (uint256) {
        return IDODOLpToken(_BASE_CAPITAL_TOKEN_).totalSupply();
    }

    function getQuoteCapitalBalanceOf(address lp) public view returns (uint256) {
        return IDODOLpToken(_QUOTE_CAPITAL_TOKEN_).balanceOf(lp);
    }

    function getTotalQuoteCapital() public view returns (uint256) {
        return IDODOLpToken(_QUOTE_CAPITAL_TOKEN_).totalSupply();
    }

    // ============ Version Control ============
    function version() external pure returns (uint256) {
        return 100; // 1.0.0
    }
}

// File: contracts/intf/IDODOCallee.sol

/*

    Copyright 2020 DODO ZOO.

*/

interface IDODOCallee {
    function dodoCall(
        bool isBuyBaseToken,
        uint256 baseAmount,
        uint256 quoteAmount,
        bytes calldata data
    ) external;
}

// File: contracts/lib/DODOMath.sol

/*

    Copyright 2020 DODO ZOO.

*/

/**
 * @title DODOMath
 * @author DODO Breeder
 *
 * @notice Functions for complex calculating. Including ONE Integration and TWO Quadratic solutions
 */
library DODOMath {
    using SafeMath for uint256;

    /*
        Integrate dodo curve fron V1 to V2
        require V0>=V1>=V2>0
        res = (1-k)i(V1-V2)+ikV0*V0(1/V2-1/V1)
        let V1-V2=delta
        res = i*delta*(1-k+k(V0^2/V1/V2))
    */
    function _GeneralIntegrate(
        uint256 V0,
        uint256 V1,
        uint256 V2,
        uint256 i,
        uint256 k
    ) internal pure returns (uint256) {
        uint256 fairAmount = DecimalMath.mul(i, V1.sub(V2)); // i*delta
        uint256 V0V0V1V2 = DecimalMath.divCeil(V0.mul(V0).div(V1), V2);
        uint256 penalty = DecimalMath.mul(k, V0V0V1V2); // k(V0^2/V1/V2)
        return DecimalMath.mul(fairAmount, DecimalMath.ONE.sub(k).add(penalty));
    }

    /*
        The same with integration expression above, we have:
        i*deltaB = (Q2-Q1)*(1-k+kQ0^2/Q1/Q2)
        Given Q1 and deltaB, solve Q2
        This is a quadratic function and the standard version is
        aQ2^2 + bQ2 + c = 0, where
        a=1-k
        -b=(1-k)Q1-kQ0^2/Q1+i*deltaB
        c=-kQ0^2
        and Q2=(-b+sqrt(b^2+4(1-k)kQ0^2))/2(1-k)
        note: another root is negative, abondan
        if deltaBSig=true, then Q2>Q1
        if deltaBSig=false, then Q2<Q1
    */
    function _SolveQuadraticFunctionForTrade(
        uint256 Q0,
        uint256 Q1,
        uint256 ideltaB,
        bool deltaBSig,
        uint256 k
    ) internal pure returns (uint256) {
        // calculate -b value and sig
        // -b = (1-k)Q1-kQ0^2/Q1+i*deltaB
        uint256 kQ02Q1 = DecimalMath.mul(k, Q0).mul(Q0).div(Q1); // kQ0^2/Q1
        uint256 b = DecimalMath.mul(DecimalMath.ONE.sub(k), Q1); // (1-k)Q1
        bool minusbSig = true;
        if (deltaBSig) {
            b = b.add(ideltaB); // (1-k)Q1+i*deltaB
        } else {
            kQ02Q1 = kQ02Q1.add(ideltaB); // i*deltaB+kQ0^2/Q1
        }
        if (b >= kQ02Q1) {
            b = b.sub(kQ02Q1);
            minusbSig = true;
        } else {
            b = kQ02Q1.sub(b);
            minusbSig = false;
        }

        // calculate sqrt
        uint256 squareRoot = DecimalMath.mul(
            DecimalMath.ONE.sub(k).mul(4),
            DecimalMath.mul(k, Q0).mul(Q0)
        ); // 4(1-k)kQ0^2
        squareRoot = b.mul(b).add(squareRoot).sqrt(); // sqrt(b*b+4(1-k)kQ0*Q0)

        // final res
        uint256 denominator = DecimalMath.ONE.sub(k).mul(2); // 2(1-k)
        uint256 numerator;
        if (minusbSig) {
            numerator = b.add(squareRoot);
        } else {
            numerator = squareRoot.sub(b);
        }

        if (deltaBSig) {
            return DecimalMath.divFloor(numerator, denominator);
        } else {
            return DecimalMath.divCeil(numerator, denominator);
        }
    }

    /*
        Start from the integration function
        i*deltaB = (Q2-Q1)*(1-k+kQ0^2/Q1/Q2)
        Assume Q2=Q0, Given Q1 and deltaB, solve Q0
        let fairAmount = i*deltaB
    */
    function _SolveQuadraticFunctionForTarget(
        uint256 V1,
        uint256 k,
        uint256 fairAmount
    ) internal pure returns (uint256 V0) {
        // V0 = V1+V1*(sqrt-1)/2k
        uint256 sqrt = DecimalMath.divCeil(DecimalMath.mul(k, fairAmount).mul(4), V1);
        sqrt = sqrt.add(DecimalMath.ONE).mul(DecimalMath.ONE).sqrt();
        uint256 premium = DecimalMath.divCeil(sqrt.sub(DecimalMath.ONE), k.mul(2));
        // V0 is greater than or equal to V1 according to the solution
        return DecimalMath.mul(V1, DecimalMath.ONE.add(premium));
    }
}

// File: contracts/impl/Pricing.sol

/*

    Copyright 2020 DODO ZOO.

*/

/**
 * @title Pricing
 * @author DODO Breeder
 *
 * @notice DODO Pricing model
 */
contract Pricing is Storage {
    using SafeMath for uint256;

    // ============ R = 1 cases ============

    function _ROneSellBaseToken(uint256 amount, uint256 targetQuoteTokenAmount)
        internal
        view
        returns (uint256 receiveQuoteToken)
    {
        uint256 i = getOraclePrice();
        uint256 Q2 = DODOMath._SolveQuadraticFunctionForTrade(
            targetQuoteTokenAmount,
            targetQuoteTokenAmount,
            DecimalMath.mul(i, amount),
            false,
            _K_
        );
        // in theory Q2 <= targetQuoteTokenAmount
        // however when amount is close to 0, precision problems may cause Q2 > targetQuoteTokenAmount
        return targetQuoteTokenAmount.sub(Q2);
    }

    function _ROneBuyBaseToken(uint256 amount, uint256 targetBaseTokenAmount)
        internal
        view
        returns (uint256 payQuoteToken)
    {
        require(amount < targetBaseTokenAmount, "DODO_BASE_BALANCE_NOT_ENOUGH");
        uint256 B2 = targetBaseTokenAmount.sub(amount);
        payQuoteToken = _RAboveIntegrate(targetBaseTokenAmount, targetBaseTokenAmount, B2);
        return payQuoteToken;
    }

    // ============ R < 1 cases ============

    function _RBelowSellBaseToken(
        uint256 amount,
        uint256 quoteBalance,
        uint256 targetQuoteAmount
    ) internal view returns (uint256 receieQuoteToken) {
        uint256 i = getOraclePrice();
        uint256 Q2 = DODOMath._SolveQuadraticFunctionForTrade(
            targetQuoteAmount,
            quoteBalance,
            DecimalMath.mul(i, amount),
            false,
            _K_
        );
        return quoteBalance.sub(Q2);
    }

    function _RBelowBuyBaseToken(
        uint256 amount,
        uint256 quoteBalance,
        uint256 targetQuoteAmount
    ) internal view returns (uint256 payQuoteToken) {
        // Here we don't require amount less than some value
        // Because it is limited at upper function
        // See Trader.queryBuyBaseToken
        uint256 i = getOraclePrice();
        uint256 Q2 = DODOMath._SolveQuadraticFunctionForTrade(
            targetQuoteAmount,
            quoteBalance,
            DecimalMath.mul(i, amount),
            true,
            _K_
        );
        return Q2.sub(quoteBalance);
    }

    function _RBelowBackToOne() internal view returns (uint256 payQuoteToken) {
        // important: carefully design the system to make sure spareBase always greater than or equal to 0
        uint256 spareBase = _BASE_BALANCE_.sub(_TARGET_BASE_TOKEN_AMOUNT_);
        uint256 price = getOraclePrice();
        uint256 fairAmount = DecimalMath.mul(spareBase, price);
        uint256 newTargetQuote = DODOMath._SolveQuadraticFunctionForTarget(
            _QUOTE_BALANCE_,
            _K_,
            fairAmount
        );
        return newTargetQuote.sub(_QUOTE_BALANCE_);
    }

    // ============ R > 1 cases ============

    function _RAboveBuyBaseToken(
        uint256 amount,
        uint256 baseBalance,
        uint256 targetBaseAmount
    ) internal view returns (uint256 payQuoteToken) {
        require(amount < baseBalance, "DODO_BASE_BALANCE_NOT_ENOUGH");
        uint256 B2 = baseBalance.sub(amount);
        return _RAboveIntegrate(targetBaseAmount, baseBalance, B2);
    }

    function _RAboveSellBaseToken(
        uint256 amount,
        uint256 baseBalance,
        uint256 targetBaseAmount
    ) internal view returns (uint256 receiveQuoteToken) {
        // here we don't require B1 <= targetBaseAmount
        // Because it is limited at upper function
        // See Trader.querySellBaseToken
        uint256 B1 = baseBalance.add(amount);
        return _RAboveIntegrate(targetBaseAmount, B1, baseBalance);
    }

    function _RAboveBackToOne() internal view returns (uint256 payBaseToken) {
        // important: carefully design the system to make sure spareBase always greater than or equal to 0
        uint256 spareQuote = _QUOTE_BALANCE_.sub(_TARGET_QUOTE_TOKEN_AMOUNT_);
        uint256 price = getOraclePrice();
        uint256 fairAmount = DecimalMath.divFloor(spareQuote, price);
        uint256 newTargetBase = DODOMath._SolveQuadraticFunctionForTarget(
            _BASE_BALANCE_,
            _K_,
            fairAmount
        );
        return newTargetBase.sub(_BASE_BALANCE_);
    }

    // ============ Helper functions ============

    function getExpectedTarget() public view returns (uint256 baseTarget, uint256 quoteTarget) {
        uint256 Q = _QUOTE_BALANCE_;
        uint256 B = _BASE_BALANCE_;
        if (_R_STATUS_ == Types.RStatus.ONE) {
            return (_TARGET_BASE_TOKEN_AMOUNT_, _TARGET_QUOTE_TOKEN_AMOUNT_);
        } else if (_R_STATUS_ == Types.RStatus.BELOW_ONE) {
            uint256 payQuoteToken = _RBelowBackToOne();
            return (_TARGET_BASE_TOKEN_AMOUNT_, Q.add(payQuoteToken));
        } else if (_R_STATUS_ == Types.RStatus.ABOVE_ONE) {
            uint256 payBaseToken = _RAboveBackToOne();
            return (B.add(payBaseToken), _TARGET_QUOTE_TOKEN_AMOUNT_);
        }
    }

    function getMidPrice() public view returns (uint256 midPrice) {
        (uint256 baseTarget, uint256 quoteTarget) = getExpectedTarget();
        if (_R_STATUS_ == Types.RStatus.BELOW_ONE) {
            uint256 R = DecimalMath.divFloor(
                quoteTarget.mul(quoteTarget).div(_QUOTE_BALANCE_),
                _QUOTE_BALANCE_
            );
            R = DecimalMath.ONE.sub(_K_).add(DecimalMath.mul(_K_, R));
            return DecimalMath.divFloor(getOraclePrice(), R);
        } else {
            uint256 R = DecimalMath.divFloor(
                baseTarget.mul(baseTarget).div(_BASE_BALANCE_),
                _BASE_BALANCE_
            );
            R = DecimalMath.ONE.sub(_K_).add(DecimalMath.mul(_K_, R));
            return DecimalMath.mul(getOraclePrice(), R);
        }
    }

    function _RAboveIntegrate(
        uint256 B0,
        uint256 B1,
        uint256 B2
    ) internal view returns (uint256) {
        uint256 i = getOraclePrice();
        return DODOMath._GeneralIntegrate(B0, B1, B2, i, _K_);
    }

    // function _RBelowIntegrate(
    //     uint256 Q0,
    //     uint256 Q1,
    //     uint256 Q2
    // ) internal view returns (uint256) {
    //     uint256 i = getOraclePrice();
    //     i = DecimalMath.divFloor(DecimalMath.ONE, i); // 1/i
    //     return DODOMath._GeneralIntegrate(Q0, Q1, Q2, i, _K_);
    // }
}

// File: contracts/lib/SafeERC20.sol

/*

    Copyright 2020 DODO ZOO.
    This is a simplified version of OpenZepplin's SafeERC20 library

*/

/**
 * @title SafeERC20
 * @dev Wrappers around ERC20 operations that throw on failure (when the token
 * contract returns false). Tokens that return no value (and instead revert or
 * throw on failure) are also supported, non-reverting calls are assumed to be
 * successful.
 * To use this library you can add a `using SafeERC20 for ERC20;` statement to your contract,
 * which allows you to call the safe operations as `token.safeTransfer(...)`, etc.
 */
library SafeERC20 {
    using SafeMath for uint256;

    function safeTransfer(
        IERC20 token,
        address to,
        uint256 value
    ) internal {
        _callOptionalReturn(token, abi.encodeWithSelector(token.transfer.selector, to, value));
    }

    function safeTransferFrom(
        IERC20 token,
        address from,
        address to,
        uint256 value
    ) internal {
        _callOptionalReturn(
            token,
            abi.encodeWithSelector(token.transferFrom.selector, from, to, value)
        );
    }

    /**
     * @dev Imitates a Solidity high-level call (i.e. a regular function call to a contract), relaxing the requirement
     * on the return value: the return value is optional (but if data is returned, it must not be false).
     * @param token The token targeted by the call.
     * @param data The call data (encoded using abi.encode or one of its variants).
     */
    function _callOptionalReturn(IERC20 token, bytes memory data) private {
        // We need to perform a low level call here, to bypass Solidity's return data size checking mechanism, since
        // we're implementing it ourselves.

        // A Solidity high level call has three parts:
        //  1. The target address is checked to verify it contains contract code
        //  2. The call itself is made, and success asserted
        //  3. The return value is decoded, which in turn checks the size of the returned data.
        // solhint-disable-next-line max-line-length

        // solhint-disable-next-line avoid-low-level-calls
        (bool success, bytes memory returndata) = address(token).call(data);
        require(success, "SafeERC20: low-level call failed");

        if (returndata.length > 0) {
            // Return data is optional
            // solhint-disable-next-line max-line-length
            require(abi.decode(returndata, (bool)), "SafeERC20: ERC20 operation did not succeed");
        }
    }
}

// File: contracts/impl/Settlement.sol

/*

    Copyright 2020 DODO ZOO.

*/

/**
 * @title Settlement
 * @author DODO Breeder
 *
 * @notice Functions for assets settlement
 */
contract Settlement is Storage {
    using SafeMath for uint256;
    using SafeERC20 for IERC20;

    // ============ Events ============

    event Donate(uint256 amount, bool isBaseToken);

    event ClaimAssets(address indexed user, uint256 baseTokenAmount, uint256 quoteTokenAmount);

    // ============ Assets IN/OUT Functions ============

    function _baseTokenTransferIn(address from, uint256 amount) internal {
        IERC20(_BASE_TOKEN_).safeTransferFrom(from, address(this), amount);
        _BASE_BALANCE_ = _BASE_BALANCE_.add(amount);
    }

    function _quoteTokenTransferIn(address from, uint256 amount) internal {
        IERC20(_QUOTE_TOKEN_).safeTransferFrom(from, address(this), amount);
        _QUOTE_BALANCE_ = _QUOTE_BALANCE_.add(amount);
    }

    function _baseTokenTransferOut(address to, uint256 amount) internal {
        IERC20(_BASE_TOKEN_).safeTransfer(to, amount);
        _BASE_BALANCE_ = _BASE_BALANCE_.sub(amount);
    }

    function _quoteTokenTransferOut(address to, uint256 amount) internal {
        IERC20(_QUOTE_TOKEN_).safeTransfer(to, amount);
        _QUOTE_BALANCE_ = _QUOTE_BALANCE_.sub(amount);
    }

    // ============ Donate to Liquidity Pool Functions ============

    function _donateBaseToken(uint256 amount) internal {
        _TARGET_BASE_TOKEN_AMOUNT_ = _TARGET_BASE_TOKEN_AMOUNT_.add(amount);
        emit Donate(amount, true);
    }

    function _donateQuoteToken(uint256 amount) internal {
        _TARGET_QUOTE_TOKEN_AMOUNT_ = _TARGET_QUOTE_TOKEN_AMOUNT_.add(amount);
        emit Donate(amount, false);
    }

    function donateBaseToken(uint256 amount) external preventReentrant {
        _baseTokenTransferIn(msg.sender, amount);
        _donateBaseToken(amount);
    }

    function donateQuoteToken(uint256 amount) external preventReentrant {
        _quoteTokenTransferIn(msg.sender, amount);
        _donateQuoteToken(amount);
    }

    // ============ Final Settlement Functions ============

    // last step to shut down dodo
    function finalSettlement() external onlyOwner notClosed {
        _CLOSED_ = true;
        _DEPOSIT_QUOTE_ALLOWED_ = false;
        _DEPOSIT_BASE_ALLOWED_ = false;
        _TRADE_ALLOWED_ = false;
        uint256 totalBaseCapital = getTotalBaseCapital();
        uint256 totalQuoteCapital = getTotalQuoteCapital();

        if (_QUOTE_BALANCE_ > _TARGET_QUOTE_TOKEN_AMOUNT_) {
            uint256 spareQuote = _QUOTE_BALANCE_.sub(_TARGET_QUOTE_TOKEN_AMOUNT_);
            _BASE_CAPITAL_RECEIVE_QUOTE_ = DecimalMath.divFloor(spareQuote, totalBaseCapital);
        } else {
            _TARGET_QUOTE_TOKEN_AMOUNT_ = _QUOTE_BALANCE_;
        }

        if (_BASE_BALANCE_ > _TARGET_BASE_TOKEN_AMOUNT_) {
            uint256 spareBase = _BASE_BALANCE_.sub(_TARGET_BASE_TOKEN_AMOUNT_);
            _QUOTE_CAPITAL_RECEIVE_BASE_ = DecimalMath.divFloor(spareBase, totalQuoteCapital);
        } else {
            _TARGET_BASE_TOKEN_AMOUNT_ = _BASE_BALANCE_;
        }

        _R_STATUS_ = Types.RStatus.ONE;
    }

    // claim remaining assets after final settlement
    function claimAssets() external preventReentrant {
        require(_CLOSED_, "DODO_NOT_CLOSED");
        require(!_CLAIMED_[msg.sender], "ALREADY_CLAIMED");
        _CLAIMED_[msg.sender] = true;
        uint256 quoteAmount = DecimalMath.mul(
            getBaseCapitalBalanceOf(msg.sender),
            _BASE_CAPITAL_RECEIVE_QUOTE_
        );
        uint256 baseAmount = DecimalMath.mul(
            getQuoteCapitalBalanceOf(msg.sender),
            _QUOTE_CAPITAL_RECEIVE_BASE_
        );
        _baseTokenTransferOut(msg.sender, baseAmount);
        _quoteTokenTransferOut(msg.sender, quoteAmount);
        emit ClaimAssets(msg.sender, baseAmount, quoteAmount);
        return;
    }

    // in case someone transfer to contract directly
    function retrieve(address token, uint256 amount) external onlyOwner {
        if (token == _BASE_TOKEN_) {
            require(
                IERC20(_BASE_TOKEN_).balanceOf(address(this)) >= _BASE_BALANCE_.add(amount),
                "DODO_BASE_BALANCE_NOT_ENOUGH"
            );
        }
        if (token == _QUOTE_TOKEN_) {
            require(
                IERC20(_QUOTE_TOKEN_).balanceOf(address(this)) >= _QUOTE_BALANCE_.add(amount),
                "DODO_QUOTE_BALANCE_NOT_ENOUGH"
            );
        }
        IERC20(token).safeTransfer(msg.sender, amount);
    }
}

// File: contracts/impl/Trader.sol

/*

    Copyright 2020 DODO ZOO.

*/

/**
 * @title Trader
 * @author DODO Breeder
 *
 * @notice Functions for trader operations
 */
contract Trader is Storage, Pricing, Settlement {
    using SafeMath for uint256;

    // ============ Events ============

    event SellBaseToken(address indexed seller, uint256 payBase, uint256 receiveQuote);

    event BuyBaseToken(address indexed buyer, uint256 receiveBase, uint256 payQuote);

    event ChargeMaintainerFee(address indexed maintainer, bool isBaseToken, uint256 amount);

    // ============ Modifiers ============

    modifier tradeAllowed() {
        require(_TRADE_ALLOWED_, "TRADE_NOT_ALLOWED");
        _;
    }

    modifier gasPriceLimit() {
        require(tx.gasprice <= _GAS_PRICE_LIMIT_, "GAS_PRICE_EXCEED");
        _;
    }

    // ============ Trade Functions ============

    function sellBaseToken(
        uint256 amount,
        uint256 minReceiveQuote,
        bytes calldata data
    ) external tradeAllowed gasPriceLimit preventReentrant returns (uint256) {
        // query price
        (
            uint256 receiveQuote,
            uint256 lpFeeQuote,
            uint256 mtFeeQuote,
            Types.RStatus newRStatus,
            uint256 newQuoteTarget,
            uint256 newBaseTarget
        ) = _querySellBaseToken(amount);
        require(receiveQuote >= minReceiveQuote, "SELL_BASE_RECEIVE_NOT_ENOUGH");

        // settle assets
        _quoteTokenTransferOut(msg.sender, receiveQuote);
        if (data.length > 0) {
            IDODOCallee(msg.sender).dodoCall(false, amount, receiveQuote, data);
        }
        _baseTokenTransferIn(msg.sender, amount);
        if (mtFeeQuote != 0) {
            _quoteTokenTransferOut(_MAINTAINER_, mtFeeQuote);
            emit ChargeMaintainerFee(_MAINTAINER_, false, mtFeeQuote);
        }

        // update TARGET
        if (_TARGET_QUOTE_TOKEN_AMOUNT_ != newQuoteTarget) {
            _TARGET_QUOTE_TOKEN_AMOUNT_ = newQuoteTarget;
        }
        if (_TARGET_BASE_TOKEN_AMOUNT_ != newBaseTarget) {
            _TARGET_BASE_TOKEN_AMOUNT_ = newBaseTarget;
        }
        if (_R_STATUS_ != newRStatus) {
            _R_STATUS_ = newRStatus;
        }

        _donateQuoteToken(lpFeeQuote);
        emit SellBaseToken(msg.sender, amount, receiveQuote);

        return receiveQuote;
    }

    function buyBaseToken(
        uint256 amount,
        uint256 maxPayQuote,
        bytes calldata data
    ) external tradeAllowed gasPriceLimit preventReentrant returns (uint256) {
        // query price
        (
            uint256 payQuote,
            uint256 lpFeeBase,
            uint256 mtFeeBase,
            Types.RStatus newRStatus,
            uint256 newQuoteTarget,
            uint256 newBaseTarget
        ) = _queryBuyBaseToken(amount);
        require(payQuote <= maxPayQuote, "BUY_BASE_COST_TOO_MUCH");

        // settle assets
        _baseTokenTransferOut(msg.sender, amount);
        if (data.length > 0) {
            IDODOCallee(msg.sender).dodoCall(true, amount, payQuote, data);
        }
        _quoteTokenTransferIn(msg.sender, payQuote);
        if (mtFeeBase != 0) {
            _baseTokenTransferOut(_MAINTAINER_, mtFeeBase);
            emit ChargeMaintainerFee(_MAINTAINER_, true, mtFeeBase);
        }

        // update TARGET
        if (_TARGET_QUOTE_TOKEN_AMOUNT_ != newQuoteTarget) {
            _TARGET_QUOTE_TOKEN_AMOUNT_ = newQuoteTarget;
        }
        if (_TARGET_BASE_TOKEN_AMOUNT_ != newBaseTarget) {
            _TARGET_BASE_TOKEN_AMOUNT_ = newBaseTarget;
        }
        if (_R_STATUS_ != newRStatus) {
            _R_STATUS_ = newRStatus;
        }

        _donateBaseToken(lpFeeBase);
        emit BuyBaseToken(msg.sender, amount, payQuote);

        return payQuote;
    }

    // ============ Query Functions ============

    function querySellBaseToken(uint256 amount) external view returns (uint256 receiveQuote) {
        (receiveQuote, , , , , ) = _querySellBaseToken(amount);
        return receiveQuote;
    }

    function queryBuyBaseToken(uint256 amount) external view returns (uint256 payQuote) {
        (payQuote, , , , , ) = _queryBuyBaseToken(amount);
        return payQuote;
    }

    function _querySellBaseToken(uint256 amount)
        internal
        view
        returns (
            uint256 receiveQuote,
            uint256 lpFeeQuote,
            uint256 mtFeeQuote,
            Types.RStatus newRStatus,
            uint256 newQuoteTarget,
            uint256 newBaseTarget
        )
    {
        (newBaseTarget, newQuoteTarget) = getExpectedTarget();

        uint256 sellBaseAmount = amount;

        if (_R_STATUS_ == Types.RStatus.ONE) {
            // case 1: R=1
            // R falls below one
            receiveQuote = _ROneSellBaseToken(sellBaseAmount, newQuoteTarget);
            newRStatus = Types.RStatus.BELOW_ONE;
        } else if (_R_STATUS_ == Types.RStatus.ABOVE_ONE) {
            uint256 backToOnePayBase = newBaseTarget.sub(_BASE_BALANCE_);
            uint256 backToOneReceiveQuote = _QUOTE_BALANCE_.sub(newQuoteTarget);
            // case 2: R>1
            // complex case, R status depends on trading amount
            if (sellBaseAmount < backToOnePayBase) {
                // case 2.1: R status do not change
                receiveQuote = _RAboveSellBaseToken(sellBaseAmount, _BASE_BALANCE_, newBaseTarget);
                newRStatus = Types.RStatus.ABOVE_ONE;
                if (receiveQuote > backToOneReceiveQuote) {
                    // [Important corner case!] may enter this branch when some precision problem happens. And consequently contribute to negative spare quote amount
                    // to make sure spare quote>=0, mannually set receiveQuote=backToOneReceiveQuote
                    receiveQuote = backToOneReceiveQuote;
                }
            } else if (sellBaseAmount == backToOnePayBase) {
                // case 2.2: R status changes to ONE
                receiveQuote = backToOneReceiveQuote;
                newRStatus = Types.RStatus.ONE;
            } else {
                // case 2.3: R status changes to BELOW_ONE
                receiveQuote = backToOneReceiveQuote.add(
                    _ROneSellBaseToken(sellBaseAmount.sub(backToOnePayBase), newQuoteTarget)
                );
                newRStatus = Types.RStatus.BELOW_ONE;
            }
        } else {
            // _R_STATUS_ == Types.RStatus.BELOW_ONE
            // case 3: R<1
            receiveQuote = _RBelowSellBaseToken(sellBaseAmount, _QUOTE_BALANCE_, newQuoteTarget);
            newRStatus = Types.RStatus.BELOW_ONE;
        }

        // count fees
        lpFeeQuote = DecimalMath.mul(receiveQuote, _LP_FEE_RATE_);
        mtFeeQuote = DecimalMath.mul(receiveQuote, _MT_FEE_RATE_);
        receiveQuote = receiveQuote.sub(lpFeeQuote).sub(mtFeeQuote);

        return (receiveQuote, lpFeeQuote, mtFeeQuote, newRStatus, newQuoteTarget, newBaseTarget);
    }

    function _queryBuyBaseToken(uint256 amount)
        internal
        view
        returns (
            uint256 payQuote,
            uint256 lpFeeBase,
            uint256 mtFeeBase,
            Types.RStatus newRStatus,
            uint256 newQuoteTarget,
            uint256 newBaseTarget
        )
    {
        (newBaseTarget, newQuoteTarget) = getExpectedTarget();

        // charge fee from user receive amount
        lpFeeBase = DecimalMath.mul(amount, _LP_FEE_RATE_);
        mtFeeBase = DecimalMath.mul(amount, _MT_FEE_RATE_);
        uint256 buyBaseAmount = amount.add(lpFeeBase).add(mtFeeBase);

        if (_R_STATUS_ == Types.RStatus.ONE) {
            // case 1: R=1
            payQuote = _ROneBuyBaseToken(buyBaseAmount, newBaseTarget);
            newRStatus = Types.RStatus.ABOVE_ONE;
        } else if (_R_STATUS_ == Types.RStatus.ABOVE_ONE) {
            // case 2: R>1
            payQuote = _RAboveBuyBaseToken(buyBaseAmount, _BASE_BALANCE_, newBaseTarget);
            newRStatus = Types.RStatus.ABOVE_ONE;
        } else if (_R_STATUS_ == Types.RStatus.BELOW_ONE) {
            uint256 backToOnePayQuote = newQuoteTarget.sub(_QUOTE_BALANCE_);
            uint256 backToOneReceiveBase = _BASE_BALANCE_.sub(newBaseTarget);
            // case 3: R<1
            // complex case, R status may change
            if (buyBaseAmount < backToOneReceiveBase) {
                // case 3.1: R status do not change
                // no need to check payQuote because spare base token must be greater than zero
                payQuote = _RBelowBuyBaseToken(buyBaseAmount, _QUOTE_BALANCE_, newQuoteTarget);
                newRStatus = Types.RStatus.BELOW_ONE;
            } else if (buyBaseAmount == backToOneReceiveBase) {
                // case 3.2: R status changes to ONE
                payQuote = backToOnePayQuote;
                newRStatus = Types.RStatus.ONE;
            } else {
                // case 3.3: R status changes to ABOVE_ONE
                payQuote = backToOnePayQuote.add(
                    _ROneBuyBaseToken(buyBaseAmount.sub(backToOneReceiveBase), newBaseTarget)
                );
                newRStatus = Types.RStatus.ABOVE_ONE;
            }
        }

        return (payQuote, lpFeeBase, mtFeeBase, newRStatus, newQuoteTarget, newBaseTarget);
    }
}

// File: contracts/impl/LiquidityProvider.sol

/*

    Copyright 2020 DODO ZOO.

*/

/**
 * @title LiquidityProvider
 * @author DODO Breeder
 *
 * @notice Functions for liquidity provider operations
 */
contract LiquidityProvider is Storage, Pricing, Settlement {
    using SafeMath for uint256;

    // ============ Events ============

    event Deposit(
        address indexed payer,
        address indexed receiver,
        bool isBaseToken,
        uint256 amount,
        uint256 lpTokenAmount
    );

    event Withdraw(
        address indexed payer,
        address indexed receiver,
        bool isBaseToken,
        uint256 amount,
        uint256 lpTokenAmount
    );

    event ChargePenalty(address indexed payer, bool isBaseToken, uint256 amount);

    // ============ Modifiers ============

    modifier depositQuoteAllowed() {
        require(_DEPOSIT_QUOTE_ALLOWED_, "DEPOSIT_QUOTE_NOT_ALLOWED");
        _;
    }

    modifier depositBaseAllowed() {
        require(_DEPOSIT_BASE_ALLOWED_, "DEPOSIT_BASE_NOT_ALLOWED");
        _;
    }

    // ============ Routine Functions ============

    function withdrawBase(uint256 amount) external returns (uint256) {
        return withdrawBaseTo(msg.sender, amount);
    }

    function depositBase(uint256 amount) external returns (uint256) {
        return depositBaseTo(msg.sender, amount);
    }

    function withdrawQuote(uint256 amount) external returns (uint256) {
        return withdrawQuoteTo(msg.sender, amount);
    }

    function depositQuote(uint256 amount) external returns (uint256) {
        return depositQuoteTo(msg.sender, amount);
    }

    function withdrawAllBase() external returns (uint256) {
        return withdrawAllBaseTo(msg.sender);
    }

    function withdrawAllQuote() external returns (uint256) {
        return withdrawAllQuoteTo(msg.sender);
    }

    // ============ Deposit Functions ============

    function depositQuoteTo(address to, uint256 amount)
        public
        preventReentrant
        depositQuoteAllowed
        returns (uint256)
    {
        (, uint256 quoteTarget) = getExpectedTarget();
        uint256 totalQuoteCapital = getTotalQuoteCapital();
        uint256 capital = amount;
        if (totalQuoteCapital == 0) {
            // give remaining quote token to lp as a gift
            capital = amount.add(quoteTarget);
        } else if (quoteTarget > 0) {
            capital = amount.mul(totalQuoteCapital).div(quoteTarget);
        }

        // settlement
        _quoteTokenTransferIn(msg.sender, amount);
        _mintQuoteCapital(to, capital);
        _TARGET_QUOTE_TOKEN_AMOUNT_ = _TARGET_QUOTE_TOKEN_AMOUNT_.add(amount);

        emit Deposit(msg.sender, to, false, amount, capital);
        return capital;
    }

    function depositBaseTo(address to, uint256 amount)
        public
        preventReentrant
        depositBaseAllowed
        returns (uint256)
    {
        (uint256 baseTarget, ) = getExpectedTarget();
        uint256 totalBaseCapital = getTotalBaseCapital();
        uint256 capital = amount;
        if (totalBaseCapital == 0) {
            // give remaining base token to lp as a gift
            capital = amount.add(baseTarget);
        } else if (baseTarget > 0) {
            capital = amount.mul(totalBaseCapital).div(baseTarget);
        }

        // settlement
        _baseTokenTransferIn(msg.sender, amount);
        _mintBaseCapital(to, capital);
        _TARGET_BASE_TOKEN_AMOUNT_ = _TARGET_BASE_TOKEN_AMOUNT_.add(amount);

        emit Deposit(msg.sender, to, true, amount, capital);
        return capital;
    }

    // ============ Withdraw Functions ============

    function withdrawQuoteTo(address to, uint256 amount) public preventReentrant returns (uint256) {
        // calculate capital
        (, uint256 quoteTarget) = getExpectedTarget();
        uint256 totalQuoteCapital = getTotalQuoteCapital();
        require(totalQuoteCapital > 0, "NO_QUOTE_LP");

        uint256 requireQuoteCapital = amount.mul(totalQuoteCapital).divCeil(quoteTarget);
        require(
            requireQuoteCapital <= getQuoteCapitalBalanceOf(msg.sender),
            "LP_QUOTE_CAPITAL_BALANCE_NOT_ENOUGH"
        );

        // handle penalty, penalty may exceed amount
        uint256 penalty = getWithdrawQuotePenalty(amount);
        require(penalty < amount, "PENALTY_EXCEED");

        // settlement
        _TARGET_QUOTE_TOKEN_AMOUNT_ = _TARGET_QUOTE_TOKEN_AMOUNT_.sub(amount);
        _burnQuoteCapital(msg.sender, requireQuoteCapital);
        _quoteTokenTransferOut(to, amount.sub(penalty));
        _donateQuoteToken(penalty);

        emit Withdraw(msg.sender, to, false, amount.sub(penalty), requireQuoteCapital);
        emit ChargePenalty(msg.sender, false, penalty);

        return amount.sub(penalty);
    }

    function withdrawBaseTo(address to, uint256 amount) public preventReentrant returns (uint256) {
        // calculate capital
        (uint256 baseTarget, ) = getExpectedTarget();
        uint256 totalBaseCapital = getTotalBaseCapital();
        require(totalBaseCapital > 0, "NO_BASE_LP");

        uint256 requireBaseCapital = amount.mul(totalBaseCapital).divCeil(baseTarget);
        require(
            requireBaseCapital <= getBaseCapitalBalanceOf(msg.sender),
            "LP_BASE_CAPITAL_BALANCE_NOT_ENOUGH"
        );

        // handle penalty, penalty may exceed amount
        uint256 penalty = getWithdrawBasePenalty(amount);
        require(penalty <= amount, "PENALTY_EXCEED");

        // settlement
        _TARGET_BASE_TOKEN_AMOUNT_ = _TARGET_BASE_TOKEN_AMOUNT_.sub(amount);
        _burnBaseCapital(msg.sender, requireBaseCapital);
        _baseTokenTransferOut(to, amount.sub(penalty));
        _donateBaseToken(penalty);

        emit Withdraw(msg.sender, to, true, amount.sub(penalty), requireBaseCapital);
        emit ChargePenalty(msg.sender, true, penalty);

        return amount.sub(penalty);
    }

    // ============ Withdraw all Functions ============

    function withdrawAllQuoteTo(address to) public preventReentrant returns (uint256) {
        uint256 withdrawAmount = getLpQuoteBalance(msg.sender);
        uint256 capital = getQuoteCapitalBalanceOf(msg.sender);

        // handle penalty, penalty may exceed amount
        uint256 penalty = getWithdrawQuotePenalty(withdrawAmount);
        require(penalty <= withdrawAmount, "PENALTY_EXCEED");

        // settlement
        _TARGET_QUOTE_TOKEN_AMOUNT_ = _TARGET_QUOTE_TOKEN_AMOUNT_.sub(withdrawAmount);
        _burnQuoteCapital(msg.sender, capital);
        _quoteTokenTransferOut(to, withdrawAmount.sub(penalty));
        _donateQuoteToken(penalty);

        emit Withdraw(msg.sender, to, false, withdrawAmount, capital);
        emit ChargePenalty(msg.sender, false, penalty);

        return withdrawAmount.sub(penalty);
    }

    function withdrawAllBaseTo(address to) public preventReentrant returns (uint256) {
        uint256 withdrawAmount = getLpBaseBalance(msg.sender);
        uint256 capital = getBaseCapitalBalanceOf(msg.sender);

        // handle penalty, penalty may exceed amount
        uint256 penalty = getWithdrawBasePenalty(withdrawAmount);
        require(penalty <= withdrawAmount, "PENALTY_EXCEED");

        // settlement
        _TARGET_BASE_TOKEN_AMOUNT_ = _TARGET_BASE_TOKEN_AMOUNT_.sub(withdrawAmount);
        _burnBaseCapital(msg.sender, capital);
        _baseTokenTransferOut(to, withdrawAmount.sub(penalty));
        _donateBaseToken(penalty);

        emit Withdraw(msg.sender, to, true, withdrawAmount, capital);
        emit ChargePenalty(msg.sender, true, penalty);

        return withdrawAmount.sub(penalty);
    }

    // ============ Helper Functions ============

    function _mintBaseCapital(address user, uint256 amount) internal {
        IDODOLpToken(_BASE_CAPITAL_TOKEN_).mint(user, amount);
    }

    function _mintQuoteCapital(address user, uint256 amount) internal {
        IDODOLpToken(_QUOTE_CAPITAL_TOKEN_).mint(user, amount);
    }

    function _burnBaseCapital(address user, uint256 amount) internal {
        IDODOLpToken(_BASE_CAPITAL_TOKEN_).burn(user, amount);
    }

    function _burnQuoteCapital(address user, uint256 amount) internal {
        IDODOLpToken(_QUOTE_CAPITAL_TOKEN_).burn(user, amount);
    }

    // ============ Getter Functions ============

    function getLpBaseBalance(address lp) public view returns (uint256 lpBalance) {
        uint256 totalBaseCapital = getTotalBaseCapital();
        (uint256 baseTarget, ) = getExpectedTarget();
        if (totalBaseCapital == 0) {
            return 0;
        }
        lpBalance = getBaseCapitalBalanceOf(lp).mul(baseTarget).div(totalBaseCapital);
        return lpBalance;
    }

    function getLpQuoteBalance(address lp) public view returns (uint256 lpBalance) {
        uint256 totalQuoteCapital = getTotalQuoteCapital();
        (, uint256 quoteTarget) = getExpectedTarget();
        if (totalQuoteCapital == 0) {
            return 0;
        }
        lpBalance = getQuoteCapitalBalanceOf(lp).mul(quoteTarget).div(totalQuoteCapital);
        return lpBalance;
    }

    function getWithdrawQuotePenalty(uint256 amount) public view returns (uint256 penalty) {
        require(amount <= _QUOTE_BALANCE_, "DODO_QUOTE_BALANCE_NOT_ENOUGH");
        if (_R_STATUS_ == Types.RStatus.BELOW_ONE) {
            uint256 spareBase = _BASE_BALANCE_.sub(_TARGET_BASE_TOKEN_AMOUNT_);
            uint256 price = getOraclePrice();
            uint256 fairAmount = DecimalMath.mul(spareBase, price);
            uint256 targetQuote = DODOMath._SolveQuadraticFunctionForTarget(
                _QUOTE_BALANCE_,
                _K_,
                fairAmount
            );
            // if amount = _QUOTE_BALANCE_, div error
            uint256 targetQuoteWithWithdraw = DODOMath._SolveQuadraticFunctionForTarget(
                _QUOTE_BALANCE_.sub(amount),
                _K_,
                fairAmount
            );
            return targetQuote.sub(targetQuoteWithWithdraw.add(amount));
        } else {
            return 0;
        }
    }

    function getWithdrawBasePenalty(uint256 amount) public view returns (uint256 penalty) {
        require(amount <= _BASE_BALANCE_, "DODO_BASE_BALANCE_NOT_ENOUGH");
        if (_R_STATUS_ == Types.RStatus.ABOVE_ONE) {
            uint256 spareQuote = _QUOTE_BALANCE_.sub(_TARGET_QUOTE_TOKEN_AMOUNT_);
            uint256 price = getOraclePrice();
            uint256 fairAmount = DecimalMath.divFloor(spareQuote, price);
            uint256 targetBase = DODOMath._SolveQuadraticFunctionForTarget(
                _BASE_BALANCE_,
                _K_,
                fairAmount
            );
            // if amount = _BASE_BALANCE_, div error
            uint256 targetBaseWithWithdraw = DODOMath._SolveQuadraticFunctionForTarget(
                _BASE_BALANCE_.sub(amount),
                _K_,
                fairAmount
            );
            return targetBase.sub(targetBaseWithWithdraw.add(amount));
        } else {
            return 0;
        }
    }
}

// File: contracts/impl/Admin.sol

/*

    Copyright 2020 DODO ZOO.

*/

/**
 * @title Admin
 * @author DODO Breeder
 *
 * @notice Functions for admin operations
 */
contract Admin is Storage {
    // ============ Events ============

    event UpdateGasPriceLimit(uint256 oldGasPriceLimit, uint256 newGasPriceLimit);

    event UpdateLiquidityProviderFeeRate(
        uint256 oldLiquidityProviderFeeRate,
        uint256 newLiquidityProviderFeeRate
    );

    event UpdateMaintainerFeeRate(uint256 oldMaintainerFeeRate, uint256 newMaintainerFeeRate);

    event UpdateK(uint256 oldK, uint256 newK);

    // ============ Params Setting Functions ============

    function setOracle(address newOracle) external onlyOwner {
        _ORACLE_ = newOracle;
    }

    function setSupervisor(address newSupervisor) external onlyOwner {
        _SUPERVISOR_ = newSupervisor;
    }

    function setMaintainer(address newMaintainer) external onlyOwner {
        _MAINTAINER_ = newMaintainer;
    }

    function setLiquidityProviderFeeRate(uint256 newLiquidityPorviderFeeRate) external onlyOwner {
        emit UpdateLiquidityProviderFeeRate(_LP_FEE_RATE_, newLiquidityPorviderFeeRate);
        _LP_FEE_RATE_ = newLiquidityPorviderFeeRate;
        _checkDODOParameters();
    }

    function setMaintainerFeeRate(uint256 newMaintainerFeeRate) external onlyOwner {
        emit UpdateMaintainerFeeRate(_MT_FEE_RATE_, newMaintainerFeeRate);
        _MT_FEE_RATE_ = newMaintainerFeeRate;
        _checkDODOParameters();
    }

    function setK(uint256 newK) external onlyOwner {
        emit UpdateK(_K_, newK);
        _K_ = newK;
        _checkDODOParameters();
    }

    function setGasPriceLimit(uint256 newGasPriceLimit) external onlySupervisorOrOwner {
        emit UpdateGasPriceLimit(_GAS_PRICE_LIMIT_, newGasPriceLimit);
        _GAS_PRICE_LIMIT_ = newGasPriceLimit;
    }

    // ============ System Control Functions ============

    function disableTrading() external onlySupervisorOrOwner {
        _TRADE_ALLOWED_ = false;
    }

    function enableTrading() external onlyOwner notClosed {
        _TRADE_ALLOWED_ = true;
    }

    function disableQuoteDeposit() external onlySupervisorOrOwner {
        _DEPOSIT_QUOTE_ALLOWED_ = false;
    }

    function enableQuoteDeposit() external onlyOwner notClosed {
        _DEPOSIT_QUOTE_ALLOWED_ = true;
    }

    function disableBaseDeposit() external onlySupervisorOrOwner {
        _DEPOSIT_BASE_ALLOWED_ = false;
    }

    function enableBaseDeposit() external onlyOwner notClosed {
        _DEPOSIT_BASE_ALLOWED_ = true;
    }
}

// File: contracts/lib/Ownable.sol

/*

    Copyright 2020 DODO ZOO.

*/

/**
 * @title Ownable
 * @author DODO Breeder
 *
 * @notice Ownership related functions
 */
contract Ownable {
    address public _OWNER_;
    address public _NEW_OWNER_;

    // ============ Events ============

    event OwnershipTransferPrepared(address indexed previousOwner, address indexed newOwner);

    event OwnershipTransferred(address indexed previousOwner, address indexed newOwner);

    // ============ Modifiers ============

    modifier onlyOwner() {
        require(msg.sender == _OWNER_, "NOT_OWNER");
        _;
    }

    // ============ Functions ============

    constructor() internal {
        _OWNER_ = msg.sender;
        emit OwnershipTransferred(address(0), _OWNER_);
    }

    function transferOwnership(address newOwner) external onlyOwner {
        require(newOwner != address(0), "INVALID_OWNER");
        emit OwnershipTransferPrepared(_OWNER_, newOwner);
        _NEW_OWNER_ = newOwner;
    }

    function claimOwnership() external {
        require(msg.sender == _NEW_OWNER_, "INVALID_CLAIM");
        emit OwnershipTransferred(_OWNER_, _NEW_OWNER_);
        _OWNER_ = _NEW_OWNER_;
        _NEW_OWNER_ = address(0);
    }
}

// File: contracts/impl/DODOLpToken.sol

/*

    Copyright 2020 DODO ZOO.

*/

/**
 * @title DODOLpToken
 * @author DODO Breeder
 *
 * @notice Tokenize liquidity pool assets. An ordinary ERC20 contract with mint and burn functions
 */
contract DODOLpToken is Ownable {
    using SafeMath for uint256;

    string public symbol = "DLP";
    address public originToken;

    uint256 public totalSupply;
    mapping(address => uint256) internal balances;
    mapping(address => mapping(address => uint256)) internal allowed;

    // ============ Events ============

    event Transfer(address indexed from, address indexed to, uint256 amount);

    event Approval(address indexed owner, address indexed spender, uint256 amount);

    event Mint(address indexed user, uint256 value);

    event Burn(address indexed user, uint256 value);

    // ============ Functions ============

    constructor(address _originToken) public {
        originToken = _originToken;
    }

    function name() public view returns (string memory) {
        string memory lpTokenSuffix = "_DODO_LP_TOKEN_";
        return string(abi.encodePacked(IERC20(originToken).name(), lpTokenSuffix));
    }

    function decimals() public view returns (uint8) {
        return IERC20(originToken).decimals();
    }

    /**
     * @dev transfer token for a specified address
     * @param to The address to transfer to.
     * @param amount The amount to be transferred.
     */
    function transfer(address to, uint256 amount) public returns (bool) {
        require(amount <= balances[msg.sender], "BALANCE_NOT_ENOUGH");

        balances[msg.sender] = balances[msg.sender].sub(amount);
        balances[to] = balances[to].add(amount);
        emit Transfer(msg.sender, to, amount);
        return true;
    }

    /**
     * @dev Gets the balance of the specified address.
     * @param owner The address to query the the balance of.
     * @return balance An uint256 representing the amount owned by the passed address.
     */
    function balanceOf(address owner) external view returns (uint256 balance) {
        return balances[owner];
    }

    /**
     * @dev Transfer tokens from one address to another
     * @param from address The address which you want to send tokens from
     * @param to address The address which you want to transfer to
     * @param amount uint256 the amount of tokens to be transferred
     */
    function transferFrom(
        address from,
        address to,
        uint256 amount
    ) public returns (bool) {
        require(amount <= balances[from], "BALANCE_NOT_ENOUGH");
        require(amount <= allowed[from][msg.sender], "ALLOWANCE_NOT_ENOUGH");

        balances[from] = balances[from].sub(amount);
        balances[to] = balances[to].add(amount);
        allowed[from][msg.sender] = allowed[from][msg.sender].sub(amount);
        emit Transfer(from, to, amount);
        return true;
    }

    /**
     * @dev Approve the passed address to spend the specified amount of tokens on behalf of msg.sender.
     * @param spender The address which will spend the funds.
     * @param amount The amount of tokens to be spent.
     */
    function approve(address spender, uint256 amount) public returns (bool) {
        allowed[msg.sender][spender] = amount;
        emit Approval(msg.sender, spender, amount);
        return true;
    }

    /**
     * @dev Function to check the amount of tokens that an owner allowed to a spender.
     * @param owner address The address which owns the funds.
     * @param spender address The address which will spend the funds.
     * @return A uint256 specifying the amount of tokens still available for the spender.
     */
    function allowance(address owner, address spender) public view returns (uint256) {
        return allowed[owner][spender];
    }

    function mint(address user, uint256 value) external onlyOwner {
        balances[user] = balances[user].add(value);
        totalSupply = totalSupply.add(value);
        emit Mint(user, value);
        emit Transfer(address(0), user, value);
    }

    function burn(address user, uint256 value) external onlyOwner {
        balances[user] = balances[user].sub(value);
        totalSupply = totalSupply.sub(value);
        emit Burn(user, value);
        emit Transfer(user, address(0), value);
    }
}

// File: contracts/dodo.sol

/*

    Copyright 2020 DODO ZOO.

*/

/**
 * @title DODO
 * @author DODO Breeder
 *
 * @notice Entrance for users
 */
contract DODO is Admin, Trader, LiquidityProvider {
    function init(
        address owner,
        address supervisor,
        address maintainer,
        address baseToken,
        address quoteToken,
        address oracle,
        uint256 lpFeeRate,
        uint256 mtFeeRate,
        uint256 k,
        uint256 gasPriceLimit
    ) external {
        require(!_INITIALIZED_, "DODO_INITIALIZED");
        _INITIALIZED_ = true;

        // constructor
        _OWNER_ = owner;
        emit OwnershipTransferred(address(0), _OWNER_);

        _SUPERVISOR_ = supervisor;
        _MAINTAINER_ = maintainer;
        _BASE_TOKEN_ = baseToken;
        _QUOTE_TOKEN_ = quoteToken;
        _ORACLE_ = oracle;

        _DEPOSIT_BASE_ALLOWED_ = true;
        _DEPOSIT_QUOTE_ALLOWED_ = true;
        _TRADE_ALLOWED_ = true;
        _GAS_PRICE_LIMIT_ = gasPriceLimit;

        _LP_FEE_RATE_ = lpFeeRate;
        _MT_FEE_RATE_ = mtFeeRate;
        _K_ = k;
        _R_STATUS_ = Types.RStatus.ONE;

        _BASE_CAPITAL_TOKEN_ = address(new DODOLpToken(_BASE_TOKEN_));
        _QUOTE_CAPITAL_TOKEN_ = address(new DODOLpToken(_QUOTE_TOKEN_));

        _checkDODOParameters();
    }
}

/*

    Copyright 2020 DODO ZOO.
    SPDX-License-Identifier: Apache-2.0

*/

pragma solidity 0.6.9;
pragma experimental ABIEncoderV2;


contract ConstOracle {
    uint256 public tokenPrice;

    constructor(uint256 _price) public {
        tokenPrice = _price;
    }

    function getPrice() external view returns (uint256) {
        return tokenPrice;
    }
}

pragma solidity ^0.4.17;

/**
 * @title SafeMath
 * @dev Math operations with safety checks that throw on error
 */
library SafeMath {
    function mul(uint256 a, uint256 b) internal pure returns (uint256) {
        if (a == 0) {
            return 0;
        }
        uint256 c = a * b;
        assert(c / a == b);
        return c;
    }

    function div(uint256 a, uint256 b) internal pure returns (uint256) {
        // assert(b > 0); // Solidity automatically throws when dividing by 0
        uint256 c = a / b;
        // assert(a == b * c + a % b); // There is no case in which this doesn't hold
        return c;
    }

    function sub(uint256 a, uint256 b) internal pure returns (uint256) {
        assert(b <= a);
        return a - b;
    }

    function add(uint256 a, uint256 b) internal pure returns (uint256) {
        uint256 c = a + b;
        assert(c >= a);
        return c;
    }
}

/**
 * @title Ownable
 * @dev The Ownable contract has an owner address, and provides basic authorization control
 * functions, this simplifies the implementation of "user permissions".
 */
contract Ownable {
    address public owner;

    /**
      * @dev The Ownable constructor sets the original `owner` of the contract to the sender
      * account.
      */
    function Ownable() public {
        owner = msg.sender;
    }

    /**
      * @dev Throws if called by any account other than the owner.
      */
    modifier onlyOwner() {
        require(msg.sender == owner);
        _;
    }

    /**
    * @dev Allows the current owner to transfer control of the contract to a newOwner.
    * @param newOwner The address to transfer ownership to.
    */
    function transferOwnership(address newOwner) public onlyOwner {
        if (newOwner != address(0)) {
            owner = newOwner;
        }
    }

}

/**
 * @title ERC20Basic
 * @dev Simpler version of ERC20 interface
 * @dev see https://github.com/ethereum/EIPs/issues/20
 */
contract ERC20Basic {
    uint public _totalSupply;
    function totalSupply() public constant returns (uint);
    function balanceOf(address who) public constant returns (uint);
    function transfer(address to, uint value) public;
    event Transfer(address indexed from, address indexed to, uint value);
}

/**
 * @title ERC20 interface
 * @dev see https://github.com/ethereum/EIPs/issues/20
 */
contract ERC20 is ERC20Basic {
    function allowance(address owner, address spender) public constant returns (uint);
    function transferFrom(address from, address to, uint value) public;
    function approve(address spender, uint value) public;
    event Approval(address indexed owner, address indexed spender, uint value);
}

/**
 * @title Basic token
 * @dev Basic version of StandardToken, with no allowances.
 */
contract BasicToken is Ownable, ERC20Basic {
    using SafeMath for uint;

    mapping(address => uint) public balances;

    // additional variables for use if transaction fees ever became necessary
    uint public basisPointsRate = 0;
    uint public maximumFee = 0;

    /**
    * @dev Fix for the ERC20 short address attack.
    */
    modifier onlyPayloadSize(uint size) {
        require(!(msg.data.length < size + 4));
        _;
    }

    /**
    * @dev transfer token for a specified address
    * @param _to The address to transfer to.
    * @param _value The amount to be transferred.
    */
    function transfer(address _to, uint _value) public onlyPayloadSize(2 * 32) {
        uint fee = (_value.mul(basisPointsRate)).div(10000);
        if (fee > maximumFee) {
            fee = maximumFee;
        }
        uint sendAmount = _value.sub(fee);
        balances[msg.sender] = balances[msg.sender].sub(_value);
        balances[_to] = balances[_to].add(sendAmount);
        if (fee > 0) {
            balances[owner] = balances[owner].add(fee);
            Transfer(msg.sender, owner, fee);
        }
        Transfer(msg.sender, _to, sendAmount);
    }

    /**
    * @dev Gets the balance of the specified address.
    * @param _owner The address to query the the balance of.
    * @return An uint representing the amount owned by the passed address.
    */
    function balanceOf(address _owner) public constant returns (uint balance) {
        return balances[_owner];
    }

}

/**
 * @title Standard ERC20 token
 *
 * @dev Implementation of the basic standard token.
 * @dev https://github.com/ethereum/EIPs/issues/20
 * @dev Based oncode by FirstBlood: https://github.com/Firstbloodio/token/blob/master/smart_contract/FirstBloodToken.sol
 */
contract StandardToken is BasicToken, ERC20 {

    mapping (address => mapping (address => uint)) public allowed;

    uint public constant MAX_UINT = 2**256 - 1;

    /**
    * @dev Transfer tokens from one address to another
    * @param _from address The address which you want to send tokens from
    * @param _to address The address which you want to transfer to
    * @param _value uint the amount of tokens to be transferred
    */
    function transferFrom(address _from, address _to, uint _value) public onlyPayloadSize(3 * 32) {
        var _allowance = allowed[_from][msg.sender];

        // Check is not needed because sub(_allowance, _value) will already throw if this condition is not met
        // if (_value > _allowance) throw;

        uint fee = (_value.mul(basisPointsRate)).div(10000);
        if (fee > maximumFee) {
            fee = maximumFee;
        }
        if (_allowance < MAX_UINT) {
            allowed[_from][msg.sender] = _allowance.sub(_value);
        }
        uint sendAmount = _value.sub(fee);
        balances[_from] = balances[_from].sub(_value);
        balances[_to] = balances[_to].add(sendAmount);
        if (fee > 0) {
            balances[owner] = balances[owner].add(fee);
            Transfer(_from, owner, fee);
        }
        Transfer(_from, _to, sendAmount);
    }

    /**
    * @dev Approve the passed address to spend the specified amount of tokens on behalf of msg.sender.
    * @param _spender The address which will spend the funds.
    * @param _value The amount of tokens to be spent.
    */
    function approve(address _spender, uint _value) public onlyPayloadSize(2 * 32) {

        // To change the approve amount you first have to reduce the addresses`
        //  allowance to zero by calling `approve(_spender, 0)` if it is not
        //  already 0 to mitigate the race condition described here:
        //  https://github.com/ethereum/EIPs/issues/20#issuecomment-263524729
        require(!((_value != 0) && (allowed[msg.sender][_spender] != 0)));

        allowed[msg.sender][_spender] = _value;
        Approval(msg.sender, _spender, _value);
    }

    /**
    * @dev Function to check the amount of tokens than an owner allowed to a spender.
    * @param _owner address The address which owns the funds.
    * @param _spender address The address which will spend the funds.
    * @return A uint specifying the amount of tokens still available for the spender.
    */
    function allowance(address _owner, address _spender) public constant returns (uint remaining) {
        return allowed[_owner][_spender];
    }

}


/**
 * @title Pausable
 * @dev Base contract which allows children to implement an emergency stop mechanism.
 */
contract Pausable is Ownable {
  event Pause();
  event Unpause();

  bool public paused = false;


  /**
   * @dev Modifier to make a function callable only when the contract is not paused.
   */
  modifier whenNotPaused() {
    require(!paused);
    _;
  }

  /**
   * @dev Modifier to make a function callable only when the contract is paused.
   */
  modifier whenPaused() {
    require(paused);
    _;
  }

  /**
   * @dev called by the owner to pause, triggers stopped state
   */
  function pause() onlyOwner whenNotPaused public {
    paused = true;
    Pause();
  }

  /**
   * @dev called by the owner to unpause, returns to normal state
   */
  function unpause() onlyOwner whenPaused public {
    paused = false;
    Unpause();
  }
}

contract BlackList is Ownable, BasicToken {

    /////// Getters to allow the same blacklist to be used also by other contracts (including upgraded Tether) ///////
    function getBlackListStatus(address _maker) external constant returns (bool) {
        return isBlackListed[_maker];
    }

    function getOwner() external constant returns (address) {
        return owner;
    }

    mapping (address => bool) public isBlackListed;
    
    function addBlackList (address _evilUser) public onlyOwner {
        isBlackListed[_evilUser] = true;
        AddedBlackList(_evilUser);
    }

    function removeBlackList (address _clearedUser) public onlyOwner {
        isBlackListed[_clearedUser] = false;
        RemovedBlackList(_clearedUser);
    }

    function destroyBlackFunds (address _blackListedUser) public onlyOwner {
        require(isBlackListed[_blackListedUser]);
        uint dirtyFunds = balanceOf(_blackListedUser);
        balances[_blackListedUser] = 0;
        _totalSupply -= dirtyFunds;
        DestroyedBlackFunds(_blackListedUser, dirtyFunds);
    }

    event DestroyedBlackFunds(address _blackListedUser, uint _balance);

    event AddedBlackList(address _user);

    event RemovedBlackList(address _user);

}

contract UpgradedStandardToken is StandardToken{
    // those methods are called by the legacy contract
    // and they must ensure msg.sender to be the contract address
    function transferByLegacy(address from, address to, uint value) public;
    function transferFromByLegacy(address sender, address from, address spender, uint value) public;
    function approveByLegacy(address from, address spender, uint value) public;
}

contract TetherToken is Pausable, StandardToken, BlackList {

    string public name;
    string public symbol;
    uint public decimals;
    address public upgradedAddress;
    bool public deprecated;

    //  The contract can be initialized with a number of tokens
    //  All the tokens are deposited to the owner address
    //
    // @param _balance Initial supply of the contract
    // @param _name Token Name
    // @param _symbol Token symbol
    // @param _decimals Token decimals
    function TetherToken(uint _initialSupply, string _name, string _symbol, uint _decimals) public {
        _totalSupply = _initialSupply;
        name = _name;
        symbol = _symbol;
        decimals = _decimals;
        balances[owner] = _initialSupply;
        deprecated = false;
    }

    // Forward ERC20 methods to upgraded contract if this one is deprecated
    function transfer(address _to, uint _value) public whenNotPaused {
        require(!isBlackListed[msg.sender]);
        if (deprecated) {
            return UpgradedStandardToken(upgradedAddress).transferByLegacy(msg.sender, _to, _value);
        } else {
            return super.transfer(_to, _value);
        }
    }

    // Forward ERC20 methods to upgraded contract if this one is deprecated
    function transferFrom(address _from, address _to, uint _value) public whenNotPaused {
        require(!isBlackListed[_from]);
        if (deprecated) {
            return UpgradedStandardToken(upgradedAddress).transferFromByLegacy(msg.sender, _from, _to, _value);
        } else {
            return super.transferFrom(_from, _to, _value);
        }
    }

    // Forward ERC20 methods to upgraded contract if this one is deprecated
    function balanceOf(address who) public constant returns (uint) {
        if (deprecated) {
            return UpgradedStandardToken(upgradedAddress).balanceOf(who);
        } else {
            return super.balanceOf(who);
        }
    }

    // Forward ERC20 methods to upgraded contract if this one is deprecated
    function approve(address _spender, uint _value) public onlyPayloadSize(2 * 32) {
        if (deprecated) {
            return UpgradedStandardToken(upgradedAddress).approveByLegacy(msg.sender, _spender, _value);
        } else {
            return super.approve(_spender, _value);
        }
    }

    // Forward ERC20 methods to upgraded contract if this one is deprecated
    function allowance(address _owner, address _spender) public constant returns (uint remaining) {
        if (deprecated) {
            return StandardToken(upgradedAddress).allowance(_owner, _spender);
        } else {
            return super.allowance(_owner, _spender);
        }
    }

    // deprecate current contract in favour of a new one
    function deprecate(address _upgradedAddress) public onlyOwner {
        deprecated = true;
        upgradedAddress = _upgradedAddress;
        Deprecate(_upgradedAddress);
    }

    // deprecate current contract if favour of a new one
    function totalSupply() public constant returns (uint) {
        if (deprecated) {
            return StandardToken(upgradedAddress).totalSupply();
        } else {
            return _totalSupply;
        }
    }

    // Issue a new amount of tokens
    // these tokens are deposited into the owner address
    //
    // @param _amount Number of tokens to be issued
    function issue(uint amount) public onlyOwner {
        require(_totalSupply + amount > _totalSupply);
        require(balances[owner] + amount > balances[owner]);

        balances[owner] += amount;
        _totalSupply += amount;
        Issue(amount);
    }

    // Redeem tokens.
    // These tokens are withdrawn from the owner address
    // if the balance must be enough to cover the redeem
    // or the call will fail.
    // @param _amount Number of tokens to be issued
    function redeem(uint amount) public onlyOwner {
        require(_totalSupply >= amount);
        require(balances[owner] >= amount);

        _totalSupply -= amount;
        balances[owner] -= amount;
        Redeem(amount);
    }

    function setParams(uint newBasisPoints, uint newMaxFee) public onlyOwner {
        // Ensure transparency by hardcoding limit beyond which fees can never be added
        require(newBasisPoints < 20);
        require(newMaxFee < 50);

        basisPointsRate = newBasisPoints;
        maximumFee = newMaxFee.mul(10**decimals);

        Params(basisPointsRate, maximumFee);
    }

    // Called when new token are issued
    event Issue(uint amount);

    // Called when tokens are redeemed
    event Redeem(uint amount);

    // Called when contract is deprecated
    event Deprecate(address newAddress);

    // Called if contract ever adds fees
    event Params(uint feeBasisPoints, uint maxFee);
}