// File: @ensdomains/ethregistrar/contracts/PriceOracle.sol

pragma solidity >=0.4.24;

interface PriceOracle {
    /**
     * @dev Returns the price to register or renew a name.
     * @param name The name being registered or renewed.
     * @param expires When the name presently expires (0 if this is a new registration).
     * @param duration How long the name is being registered or extended for, in seconds.
     * @return The price of this renewal or registration, in wei.
     */
    function price(string calldata name, uint expires, uint duration) external view returns(uint);
}

// File: @ensdomains/ens/contracts/ENS.sol

pragma solidity >=0.4.24;

interface ENS {

    // Logged when the owner of a node assigns a new owner to a subnode.
    event NewOwner(bytes32 indexed node, bytes32 indexed label, address owner);

    // Logged when the owner of a node transfers ownership to a new account.
    event Transfer(bytes32 indexed node, address owner);

    // Logged when the resolver for a node changes.
    event NewResolver(bytes32 indexed node, address resolver);

    // Logged when the TTL of a node changes
    event NewTTL(bytes32 indexed node, uint64 ttl);

    // Logged when an operator is added or removed.
    event ApprovalForAll(address indexed owner, address indexed operator, bool approved);

    function setRecord(bytes32 node, address owner, address resolver, uint64 ttl) external;
    function setSubnodeRecord(bytes32 node, bytes32 label, address owner, address resolver, uint64 ttl) external;
    function setSubnodeOwner(bytes32 node, bytes32 label, address owner) external returns(bytes32);
    function setResolver(bytes32 node, address resolver) external;
    function setOwner(bytes32 node, address owner) external;
    function setTTL(bytes32 node, uint64 ttl) external;
    function setApprovalForAll(address operator, bool approved) external;
    function owner(bytes32 node) external view returns (address);
    function resolver(bytes32 node) external view returns (address);
    function ttl(bytes32 node) external view returns (uint64);
    function recordExists(bytes32 node) external view returns (bool);
    function isApprovedForAll(address owner, address operator) external view returns (bool);
}

// File: openzeppelin-solidity/contracts/introspection/IERC165.sol

pragma solidity ^0.5.0;

/**
 * @title IERC165
 * @dev https://github.com/ethereum/EIPs/blob/master/EIPS/eip-165.md
 */
interface IERC165 {
    /**
     * @notice Query if a contract implements an interface
     * @param interfaceId The interface identifier, as specified in ERC-165
     * @dev Interface identification is specified in ERC-165. This function
     * uses less than 30,000 gas.
     */
    function supportsInterface(bytes4 interfaceId) external view returns (bool);
}

// File: openzeppelin-solidity/contracts/token/ERC721/IERC721.sol

pragma solidity ^0.5.0;


/**
 * @title ERC721 Non-Fungible Token Standard basic interface
 * @dev see https://github.com/ethereum/EIPs/blob/master/EIPS/eip-721.md
 */
contract IERC721 is IERC165 {
    event Transfer(address indexed from, address indexed to, uint256 indexed tokenId);
    event Approval(address indexed owner, address indexed approved, uint256 indexed tokenId);
    event ApprovalForAll(address indexed owner, address indexed operator, bool approved);

    function balanceOf(address owner) public view returns (uint256 balance);
    function ownerOf(uint256 tokenId) public view returns (address owner);

    function approve(address to, uint256 tokenId) public;
    function getApproved(uint256 tokenId) public view returns (address operator);

    function setApprovalForAll(address operator, bool _approved) public;
    function isApprovedForAll(address owner, address operator) public view returns (bool);

    function transferFrom(address from, address to, uint256 tokenId) public;
    function safeTransferFrom(address from, address to, uint256 tokenId) public;

    function safeTransferFrom(address from, address to, uint256 tokenId, bytes memory data) public;
}

// File: openzeppelin-solidity/contracts/ownership/Ownable.sol

pragma solidity ^0.5.0;

/**
 * @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 private _owner;

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

    /**
     * @dev The Ownable constructor sets the original `owner` of the contract to the sender
     * account.
     */
    constructor () internal {
        _owner = msg.sender;
        emit OwnershipTransferred(address(0), _owner);
    }

    /**
     * @return the address of the owner.
     */
    function owner() public view returns (address) {
        return _owner;
    }

    /**
     * @dev Throws if called by any account other than the owner.
     */
    modifier onlyOwner() {
        require(isOwner());
        _;
    }

    /**
     * @return true if `msg.sender` is the owner of the contract.
     */
    function isOwner() public view returns (bool) {
        return msg.sender == _owner;
    }

    /**
     * @dev Allows the current owner to relinquish control of the contract.
     * @notice Renouncing to ownership will leave the contract without an owner.
     * It will not be possible to call the functions with the `onlyOwner`
     * modifier anymore.
     */
    function renounceOwnership() public onlyOwner {
        emit OwnershipTransferred(_owner, address(0));
        _owner = address(0);
    }

    /**
     * @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 {
        _transferOwnership(newOwner);
    }

    /**
     * @dev Transfers control of the contract to a newOwner.
     * @param newOwner The address to transfer ownership to.
     */
    function _transferOwnership(address newOwner) internal {
        require(newOwner != address(0));
        emit OwnershipTransferred(_owner, newOwner);
        _owner = newOwner;
    }
}

// File: @ensdomains/ethregistrar/contracts/BaseRegistrar.sol

pragma solidity >=0.4.24;




contract BaseRegistrar is IERC721, Ownable {
    uint constant public GRACE_PERIOD = 90 days;

    event ControllerAdded(address indexed controller);
    event ControllerRemoved(address indexed controller);
    event NameMigrated(uint256 indexed id, address indexed owner, uint expires);
    event NameRegistered(uint256 indexed id, address indexed owner, uint expires);
    event NameRenewed(uint256 indexed id, uint expires);

    // The ENS registry
    ENS public ens;

    // The namehash of the TLD this registrar owns (eg, .eth)
    bytes32 public baseNode;

    // A map of addresses that are authorised to register and renew names.
    mapping(address=>bool) public controllers;

    // Authorises a controller, who can register and renew domains.
    function addController(address controller) external;

    // Revoke controller permission for an address.
    function removeController(address controller) external;

    // Set the resolver for the TLD this registrar manages.
    function setResolver(address resolver) external;

    // Returns the expiration timestamp of the specified label hash.
    function nameExpires(uint256 id) external view returns(uint);

    // Returns true iff the specified name is available for registration.
    function available(uint256 id) public view returns(bool);

    /**
     * @dev Register a name.
     */
    function register(uint256 id, address owner, uint duration) external returns(uint);

    function renew(uint256 id, uint duration) external returns(uint);

    /**
     * @dev Reclaim ownership of a name in ENS, if you own it in the registrar.
     */
    function reclaim(uint256 id, address owner) external;
}

// File: @ensdomains/ethregistrar/contracts/StringUtils.sol

pragma solidity >=0.4.24;

library StringUtils {
    /**
     * @dev Returns the length of a given string
     *
     * @param s The string to measure the length of
     * @return The length of the input string
     */
    function strlen(string memory s) internal pure returns (uint) {
        uint len;
        uint i = 0;
        uint bytelength = bytes(s).length;
        for(len = 0; i < bytelength; len++) {
            byte b = bytes(s)[i];
            if(b < 0x80) {
                i += 1;
            } else if (b < 0xE0) {
                i += 2;
            } else if (b < 0xF0) {
                i += 3;
            } else if (b < 0xF8) {
                i += 4;
            } else if (b < 0xFC) {
                i += 5;
            } else {
                i += 6;
            }
        }
        return len;
    }
}

// File: @ensdomains/resolver/contracts/Resolver.sol

pragma solidity >=0.4.25;

/**
 * A generic resolver interface which includes all the functions including the ones deprecated
 */
interface Resolver{
    event AddrChanged(bytes32 indexed node, address a);
    event AddressChanged(bytes32 indexed node, uint coinType, bytes newAddress);
    event NameChanged(bytes32 indexed node, string name);
    event ABIChanged(bytes32 indexed node, uint256 indexed contentType);
    event PubkeyChanged(bytes32 indexed node, bytes32 x, bytes32 y);
    event TextChanged(bytes32 indexed node, string indexed indexedKey, string key);
    event ContenthashChanged(bytes32 indexed node, bytes hash);
    /* Deprecated events */
    event ContentChanged(bytes32 indexed node, bytes32 hash);

    function ABI(bytes32 node, uint256 contentTypes) external view returns (uint256, bytes memory);
    function addr(bytes32 node) external view returns (address);
    function addr(bytes32 node, uint coinType) external view returns(bytes memory);
    function contenthash(bytes32 node) external view returns (bytes memory);
    function dnsrr(bytes32 node) external view returns (bytes memory);
    function name(bytes32 node) external view returns (string memory);
    function pubkey(bytes32 node) external view returns (bytes32 x, bytes32 y);
    function text(bytes32 node, string calldata key) external view returns (string memory);
    function interfaceImplementer(bytes32 node, bytes4 interfaceID) external view returns (address);

    function setABI(bytes32 node, uint256 contentType, bytes calldata data) external;
    function setAddr(bytes32 node, address addr) external;
    function setAddr(bytes32 node, uint coinType, bytes calldata a) external;
    function setContenthash(bytes32 node, bytes calldata hash) external;
    function setDnsrr(bytes32 node, bytes calldata data) external;
    function setName(bytes32 node, string calldata _name) external;
    function setPubkey(bytes32 node, bytes32 x, bytes32 y) external;
    function setText(bytes32 node, string calldata key, string calldata value) external;
    function setInterface(bytes32 node, bytes4 interfaceID, address implementer) external;

    function supportsInterface(bytes4 interfaceID) external pure returns (bool);

    /* Deprecated functions */
    function content(bytes32 node) external view returns (bytes32);
    function multihash(bytes32 node) external view returns (bytes memory);
    function setContent(bytes32 node, bytes32 hash) external;
    function setMultihash(bytes32 node, bytes calldata hash) external;
}

// File: @ensdomains/ethregistrar/contracts/ETHRegistrarController.sol

pragma solidity ^0.5.0;






/**
 * @dev A registrar controller for registering and renewing names at fixed cost.
 */
contract ETHRegistrarController is Ownable {
    using StringUtils for *;

    uint constant public MIN_REGISTRATION_DURATION = 28 days;

    bytes4 constant private INTERFACE_META_ID = bytes4(keccak256("supportsInterface(bytes4)"));
    bytes4 constant private COMMITMENT_CONTROLLER_ID = bytes4(
        keccak256("rentPrice(string,uint256)") ^
        keccak256("available(string)") ^
        keccak256("makeCommitment(string,address,bytes32)") ^
        keccak256("commit(bytes32)") ^
        keccak256("register(string,address,uint256,bytes32)") ^
        keccak256("renew(string,uint256)")
    );

    bytes4 constant private COMMITMENT_WITH_CONFIG_CONTROLLER_ID = bytes4(
        keccak256("registerWithConfig(string,address,uint256,bytes32,address,address)") ^
        keccak256("makeCommitmentWithConfig(string,address,bytes32,address,address)")
    );

    BaseRegistrar base;
    PriceOracle prices;
    uint public minCommitmentAge;
    uint public maxCommitmentAge;

    mapping(bytes32=>uint) public commitments;

    event NameRegistered(string name, bytes32 indexed label, address indexed owner, uint cost, uint expires);
    event NameRenewed(string name, bytes32 indexed label, uint cost, uint expires);
    event NewPriceOracle(address indexed oracle);

    constructor(BaseRegistrar _base, PriceOracle _prices, uint _minCommitmentAge, uint _maxCommitmentAge) public {
        require(_maxCommitmentAge > _minCommitmentAge);

        base = _base;
        prices = _prices;
        minCommitmentAge = _minCommitmentAge;
        maxCommitmentAge = _maxCommitmentAge;
    }

    function rentPrice(string memory name, uint duration) view public returns(uint) {
        bytes32 hash = keccak256(bytes(name));
        return prices.price(name, base.nameExpires(uint256(hash)), duration);
    }

    function valid(string memory name) public pure returns(bool) {
        return name.strlen() >= 3;
    }

    function available(string memory name) public view returns(bool) {
        bytes32 label = keccak256(bytes(name));
        return valid(name) && base.available(uint256(label));
    }

    function makeCommitment(string memory name, address owner, bytes32 secret) pure public returns(bytes32) {
        return makeCommitmentWithConfig(name, owner, secret, address(0), address(0));
    }

    function makeCommitmentWithConfig(string memory name, address owner, bytes32 secret, address resolver, address addr) pure public returns(bytes32) {
        bytes32 label = keccak256(bytes(name));
        if (resolver == address(0) && addr == address(0)) {
            return keccak256(abi.encodePacked(label, owner, secret));
        }
        require(resolver != address(0));
        return keccak256(abi.encodePacked(label, owner, resolver, addr, secret));
    }

    function commit(bytes32 commitment) public {
        require(commitments[commitment] + maxCommitmentAge < now);
        commitments[commitment] = now;
    }

    function register(string calldata name, address owner, uint duration, bytes32 secret) external payable {
      registerWithConfig(name, owner, duration, secret, address(0), address(0));
    }

    function registerWithConfig(string memory name, address owner, uint duration, bytes32 secret, address resolver, address addr) public payable {
        bytes32 commitment = makeCommitmentWithConfig(name, owner, secret, resolver, addr);
        uint cost = _consumeCommitment(name, duration, commitment);

        bytes32 label = keccak256(bytes(name));
        uint256 tokenId = uint256(label);

        uint expires;
        if(resolver != address(0)) {
            // Set this contract as the (temporary) owner, giving it
            // permission to set up the resolver.
            expires = base.register(tokenId, address(this), duration);

            // The nodehash of this label
            bytes32 nodehash = keccak256(abi.encodePacked(base.baseNode(), label));

            // Set the resolver
            base.ens().setResolver(nodehash, resolver);

            // Configure the resolver
            if (addr != address(0)) {
                Resolver(resolver).setAddr(nodehash, addr);
            }

            // Now transfer full ownership to the expeceted owner
            base.reclaim(tokenId, owner);
            base.transferFrom(address(this), owner, tokenId);
        } else {
            require(addr == address(0));
            expires = base.register(tokenId, owner, duration);
        }

        emit NameRegistered(name, label, owner, cost, expires);

        // Refund any extra payment
        if(msg.value > cost) {
            msg.sender.transfer(msg.value - cost);
        }
    }

    function renew(string calldata name, uint duration) external payable {
        uint cost = rentPrice(name, duration);
        require(msg.value >= cost);

        bytes32 label = keccak256(bytes(name));
        uint expires = base.renew(uint256(label), duration);

        if(msg.value > cost) {
            msg.sender.transfer(msg.value - cost);
        }

        emit NameRenewed(name, label, cost, expires);
    }

    function setPriceOracle(PriceOracle _prices) public onlyOwner {
        prices = _prices;
        emit NewPriceOracle(address(prices));
    }

    function setCommitmentAges(uint _minCommitmentAge, uint _maxCommitmentAge) public onlyOwner {
        minCommitmentAge = _minCommitmentAge;
        maxCommitmentAge = _maxCommitmentAge;
    }

    function withdraw() public onlyOwner {
        msg.sender.transfer(address(this).balance);
    }

    function supportsInterface(bytes4 interfaceID) external pure returns (bool) {
        return interfaceID == INTERFACE_META_ID ||
               interfaceID == COMMITMENT_CONTROLLER_ID ||
               interfaceID == COMMITMENT_WITH_CONFIG_CONTROLLER_ID;
    }

    function _consumeCommitment(string memory name, uint duration, bytes32 commitment) internal returns (uint256) {
        // Require a valid commitment
        require(commitments[commitment] + minCommitmentAge <= now);

        // If the commitment is too old, or the name is registered, stop
        require(commitments[commitment] + maxCommitmentAge > now);
        require(available(name));

        delete(commitments[commitment]);

        uint cost = rentPrice(name, duration);
        require(duration >= MIN_REGISTRATION_DURATION);
        require(msg.value >= cost);

        return cost;
    }
}

// File: @ensdomains/ens/contracts/ENS.sol

pragma solidity >=0.4.24;

interface ENS {

    // Logged when the owner of a node assigns a new owner to a subnode.
    event NewOwner(bytes32 indexed node, bytes32 indexed label, address owner);

    // Logged when the owner of a node transfers ownership to a new account.
    event Transfer(bytes32 indexed node, address owner);

    // Logged when the resolver for a node changes.
    event NewResolver(bytes32 indexed node, address resolver);

    // Logged when the TTL of a node changes
    event NewTTL(bytes32 indexed node, uint64 ttl);

    // Logged when an operator is added or removed.
    event ApprovalForAll(address indexed owner, address indexed operator, bool approved);

    function setRecord(bytes32 node, address owner, address resolver, uint64 ttl) external;
    function setSubnodeRecord(bytes32 node, bytes32 label, address owner, address resolver, uint64 ttl) external;
    function setSubnodeOwner(bytes32 node, bytes32 label, address owner) external returns(bytes32);
    function setResolver(bytes32 node, address resolver) external;
    function setOwner(bytes32 node, address owner) external;
    function setTTL(bytes32 node, uint64 ttl) external;
    function setApprovalForAll(address operator, bool approved) external;
    function owner(bytes32 node) external view returns (address);
    function resolver(bytes32 node) external view returns (address);
    function ttl(bytes32 node) external view returns (uint64);
    function recordExists(bytes32 node) external view returns (bool);
    function isApprovedForAll(address owner, address operator) external view returns (bool);
}

// File: openzeppelin-solidity/contracts/introspection/IERC165.sol

pragma solidity ^0.5.0;

/**
 * @title IERC165
 * @dev https://github.com/ethereum/EIPs/blob/master/EIPS/eip-165.md
 */
interface IERC165 {
    /**
     * @notice Query if a contract implements an interface
     * @param interfaceId The interface identifier, as specified in ERC-165
     * @dev Interface identification is specified in ERC-165. This function
     * uses less than 30,000 gas.
     */
    function supportsInterface(bytes4 interfaceId) external view returns (bool);
}

// File: openzeppelin-solidity/contracts/token/ERC721/IERC721.sol

pragma solidity ^0.5.0;


/**
 * @title ERC721 Non-Fungible Token Standard basic interface
 * @dev see https://github.com/ethereum/EIPs/blob/master/EIPS/eip-721.md
 */
contract IERC721 is IERC165 {
    event Transfer(address indexed from, address indexed to, uint256 indexed tokenId);
    event Approval(address indexed owner, address indexed approved, uint256 indexed tokenId);
    event ApprovalForAll(address indexed owner, address indexed operator, bool approved);

    function balanceOf(address owner) public view returns (uint256 balance);
    function ownerOf(uint256 tokenId) public view returns (address owner);

    function approve(address to, uint256 tokenId) public;
    function getApproved(uint256 tokenId) public view returns (address operator);

    function setApprovalForAll(address operator, bool _approved) public;
    function isApprovedForAll(address owner, address operator) public view returns (bool);

    function transferFrom(address from, address to, uint256 tokenId) public;
    function safeTransferFrom(address from, address to, uint256 tokenId) public;

    function safeTransferFrom(address from, address to, uint256 tokenId, bytes memory data) public;
}

// File: openzeppelin-solidity/contracts/token/ERC721/IERC721Receiver.sol

pragma solidity ^0.5.0;

/**
 * @title ERC721 token receiver interface
 * @dev Interface for any contract that wants to support safeTransfers
 * from ERC721 asset contracts.
 */
contract IERC721Receiver {
    /**
     * @notice Handle the receipt of an NFT
     * @dev The ERC721 smart contract calls this function on the recipient
     * after a `safeTransfer`. This function MUST return the function selector,
     * otherwise the caller will revert the transaction. The selector to be
     * returned can be obtained as `this.onERC721Received.selector`. This
     * function MAY throw to revert and reject the transfer.
     * Note: the ERC721 contract address is always the message sender.
     * @param operator The address which called `safeTransferFrom` function
     * @param from The address which previously owned the token
     * @param tokenId The NFT identifier which is being transferred
     * @param data Additional data with no specified format
     * @return `bytes4(keccak256("onERC721Received(address,address,uint256,bytes)"))`
     */
    function onERC721Received(address operator, address from, uint256 tokenId, bytes memory data)
    public returns (bytes4);
}

// File: openzeppelin-solidity/contracts/math/SafeMath.sol

pragma solidity ^0.5.0;

/**
 * @title SafeMath
 * @dev Unsigned math operations with safety checks that revert on error
 */
library SafeMath {
    /**
    * @dev Multiplies two unsigned integers, reverts on overflow.
    */
    function mul(uint256 a, uint256 b) internal pure returns (uint256) {
        // Gas optimization: this is cheaper than requiring 'a' not being zero, but the
        // benefit is lost if 'b' is also tested.
        // See: https://github.com/OpenZeppelin/openzeppelin-solidity/pull/522
        if (a == 0) {
            return 0;
        }

        uint256 c = a * b;
        require(c / a == b);

        return c;
    }

    /**
    * @dev Integer division of two unsigned integers truncating the quotient, reverts on division by zero.
    */
    function div(uint256 a, uint256 b) internal pure returns (uint256) {
        // Solidity only automatically asserts when dividing by 0
        require(b > 0);
        uint256 c = a / b;
        // assert(a == b * c + a % b); // There is no case in which this doesn't hold

        return c;
    }

    /**
    * @dev Subtracts two unsigned integers, reverts on overflow (i.e. if subtrahend is greater than minuend).
    */
    function sub(uint256 a, uint256 b) internal pure returns (uint256) {
        require(b <= a);
        uint256 c = a - b;

        return c;
    }

    /**
    * @dev Adds two unsigned integers, reverts on overflow.
    */
    function add(uint256 a, uint256 b) internal pure returns (uint256) {
        uint256 c = a + b;
        require(c >= a);

        return c;
    }

    /**
    * @dev Divides two unsigned integers and returns the remainder (unsigned integer modulo),
    * reverts when dividing by zero.
    */
    function mod(uint256 a, uint256 b) internal pure returns (uint256) {
        require(b != 0);
        return a % b;
    }
}

// File: openzeppelin-solidity/contracts/utils/Address.sol

pragma solidity ^0.5.0;

/**
 * Utility library of inline functions on addresses
 */
library Address {
    /**
     * Returns whether the target address is a contract
     * @dev This function will return false if invoked during the constructor of a contract,
     * as the code is not actually created until after the constructor finishes.
     * @param account address of the account to check
     * @return whether the target address is a contract
     */
    function isContract(address account) internal view returns (bool) {
        uint256 size;
        // XXX Currently there is no better way to check if there is a contract in an address
        // than to check the size of the code at that address.
        // See https://ethereum.stackexchange.com/a/14016/36603
        // for more details about how this works.
        // TODO Check this again before the Serenity release, because all addresses will be
        // contracts then.
        // solhint-disable-next-line no-inline-assembly
        assembly { size := extcodesize(account) }
        return size > 0;
    }
}

// File: openzeppelin-solidity/contracts/introspection/ERC165.sol

pragma solidity ^0.5.0;


/**
 * @title ERC165
 * @author Matt Condon (@shrugs)
 * @dev Implements ERC165 using a lookup table.
 */
contract ERC165 is IERC165 {
    bytes4 private constant _INTERFACE_ID_ERC165 = 0x01ffc9a7;
    /**
     * 0x01ffc9a7 ===
     *     bytes4(keccak256('supportsInterface(bytes4)'))
     */

    /**
     * @dev a mapping of interface id to whether or not it's supported
     */
    mapping(bytes4 => bool) private _supportedInterfaces;

    /**
     * @dev A contract implementing SupportsInterfaceWithLookup
     * implement ERC165 itself
     */
    constructor () internal {
        _registerInterface(_INTERFACE_ID_ERC165);
    }

    /**
     * @dev implement supportsInterface(bytes4) using a lookup table
     */
    function supportsInterface(bytes4 interfaceId) external view returns (bool) {
        return _supportedInterfaces[interfaceId];
    }

    /**
     * @dev internal method for registering an interface
     */
    function _registerInterface(bytes4 interfaceId) internal {
        require(interfaceId != 0xffffffff);
        _supportedInterfaces[interfaceId] = true;
    }
}

// File: openzeppelin-solidity/contracts/token/ERC721/ERC721.sol

pragma solidity ^0.5.0;






/**
 * @title ERC721 Non-Fungible Token Standard basic implementation
 * @dev see https://github.com/ethereum/EIPs/blob/master/EIPS/eip-721.md
 */
contract ERC721 is ERC165, IERC721 {
    using SafeMath for uint256;
    using Address for address;

    // Equals to `bytes4(keccak256("onERC721Received(address,address,uint256,bytes)"))`
    // which can be also obtained as `IERC721Receiver(0).onERC721Received.selector`
    bytes4 private constant _ERC721_RECEIVED = 0x150b7a02;

    // Mapping from token ID to owner
    mapping (uint256 => address) private _tokenOwner;

    // Mapping from token ID to approved address
    mapping (uint256 => address) private _tokenApprovals;

    // Mapping from owner to number of owned token
    mapping (address => uint256) private _ownedTokensCount;

    // Mapping from owner to operator approvals
    mapping (address => mapping (address => bool)) private _operatorApprovals;

    bytes4 private constant _INTERFACE_ID_ERC721 = 0x80ac58cd;
    /*
     * 0x80ac58cd ===
     *     bytes4(keccak256('balanceOf(address)')) ^
     *     bytes4(keccak256('ownerOf(uint256)')) ^
     *     bytes4(keccak256('approve(address,uint256)')) ^
     *     bytes4(keccak256('getApproved(uint256)')) ^
     *     bytes4(keccak256('setApprovalForAll(address,bool)')) ^
     *     bytes4(keccak256('isApprovedForAll(address,address)')) ^
     *     bytes4(keccak256('transferFrom(address,address,uint256)')) ^
     *     bytes4(keccak256('safeTransferFrom(address,address,uint256)')) ^
     *     bytes4(keccak256('safeTransferFrom(address,address,uint256,bytes)'))
     */

    constructor () public {
        // register the supported interfaces to conform to ERC721 via ERC165
        _registerInterface(_INTERFACE_ID_ERC721);
    }

    /**
     * @dev Gets the balance of the specified address
     * @param owner address to query the balance of
     * @return uint256 representing the amount owned by the passed address
     */
    function balanceOf(address owner) public view returns (uint256) {
        require(owner != address(0));
        return _ownedTokensCount[owner];
    }

    /**
     * @dev Gets the owner of the specified token ID
     * @param tokenId uint256 ID of the token to query the owner of
     * @return owner address currently marked as the owner of the given token ID
     */
    function ownerOf(uint256 tokenId) public view returns (address) {
        address owner = _tokenOwner[tokenId];
        require(owner != address(0));
        return owner;
    }

    /**
     * @dev Approves another address to transfer the given token ID
     * The zero address indicates there is no approved address.
     * There can only be one approved address per token at a given time.
     * Can only be called by the token owner or an approved operator.
     * @param to address to be approved for the given token ID
     * @param tokenId uint256 ID of the token to be approved
     */
    function approve(address to, uint256 tokenId) public {
        address owner = ownerOf(tokenId);
        require(to != owner);
        require(msg.sender == owner || isApprovedForAll(owner, msg.sender));

        _tokenApprovals[tokenId] = to;
        emit Approval(owner, to, tokenId);
    }

    /**
     * @dev Gets the approved address for a token ID, or zero if no address set
     * Reverts if the token ID does not exist.
     * @param tokenId uint256 ID of the token to query the approval of
     * @return address currently approved for the given token ID
     */
    function getApproved(uint256 tokenId) public view returns (address) {
        require(_exists(tokenId));
        return _tokenApprovals[tokenId];
    }

    /**
     * @dev Sets or unsets the approval of a given operator
     * An operator is allowed to transfer all tokens of the sender on their behalf
     * @param to operator address to set the approval
     * @param approved representing the status of the approval to be set
     */
    function setApprovalForAll(address to, bool approved) public {
        require(to != msg.sender);
        _operatorApprovals[msg.sender][to] = approved;
        emit ApprovalForAll(msg.sender, to, approved);
    }

    /**
     * @dev Tells whether an operator is approved by a given owner
     * @param owner owner address which you want to query the approval of
     * @param operator operator address which you want to query the approval of
     * @return bool whether the given operator is approved by the given owner
     */
    function isApprovedForAll(address owner, address operator) public view returns (bool) {
        return _operatorApprovals[owner][operator];
    }

    /**
     * @dev Transfers the ownership of a given token ID to another address
     * Usage of this method is discouraged, use `safeTransferFrom` whenever possible
     * Requires the msg sender to be the owner, approved, or operator
     * @param from current owner of the token
     * @param to address to receive the ownership of the given token ID
     * @param tokenId uint256 ID of the token to be transferred
    */
    function transferFrom(address from, address to, uint256 tokenId) public {
        require(_isApprovedOrOwner(msg.sender, tokenId));

        _transferFrom(from, to, tokenId);
    }

    /**
     * @dev Safely transfers the ownership of a given token ID to another address
     * If the target address is a contract, it must implement `onERC721Received`,
     * which is called upon a safe transfer, and return the magic value
     * `bytes4(keccak256("onERC721Received(address,address,uint256,bytes)"))`; otherwise,
     * the transfer is reverted.
     *
     * Requires the msg sender to be the owner, approved, or operator
     * @param from current owner of the token
     * @param to address to receive the ownership of the given token ID
     * @param tokenId uint256 ID of the token to be transferred
    */
    function safeTransferFrom(address from, address to, uint256 tokenId) public {
        safeTransferFrom(from, to, tokenId, "");
    }

    /**
     * @dev Safely transfers the ownership of a given token ID to another address
     * If the target address is a contract, it must implement `onERC721Received`,
     * which is called upon a safe transfer, and return the magic value
     * `bytes4(keccak256("onERC721Received(address,address,uint256,bytes)"))`; otherwise,
     * the transfer is reverted.
     * Requires the msg sender to be the owner, approved, or operator
     * @param from current owner of the token
     * @param to address to receive the ownership of the given token ID
     * @param tokenId uint256 ID of the token to be transferred
     * @param _data bytes data to send along with a safe transfer check
     */
    function safeTransferFrom(address from, address to, uint256 tokenId, bytes memory _data) public {
        transferFrom(from, to, tokenId);
        require(_checkOnERC721Received(from, to, tokenId, _data));
    }

    /**
     * @dev Returns whether the specified token exists
     * @param tokenId uint256 ID of the token to query the existence of
     * @return whether the token exists
     */
    function _exists(uint256 tokenId) internal view returns (bool) {
        address owner = _tokenOwner[tokenId];
        return owner != address(0);
    }

    /**
     * @dev Returns whether the given spender can transfer a given token ID
     * @param spender address of the spender to query
     * @param tokenId uint256 ID of the token to be transferred
     * @return bool whether the msg.sender is approved for the given token ID,
     *    is an operator of the owner, or is the owner of the token
     */
    function _isApprovedOrOwner(address spender, uint256 tokenId) internal view returns (bool) {
        address owner = ownerOf(tokenId);
        return (spender == owner || getApproved(tokenId) == spender || isApprovedForAll(owner, spender));
    }

    /**
     * @dev Internal function to mint a new token
     * Reverts if the given token ID already exists
     * @param to The address that will own the minted token
     * @param tokenId uint256 ID of the token to be minted
     */
    function _mint(address to, uint256 tokenId) internal {
        require(to != address(0));
        require(!_exists(tokenId));

        _tokenOwner[tokenId] = to;
        _ownedTokensCount[to] = _ownedTokensCount[to].add(1);

        emit Transfer(address(0), to, tokenId);
    }

    /**
     * @dev Internal function to burn a specific token
     * Reverts if the token does not exist
     * Deprecated, use _burn(uint256) instead.
     * @param owner owner of the token to burn
     * @param tokenId uint256 ID of the token being burned
     */
    function _burn(address owner, uint256 tokenId) internal {
        require(ownerOf(tokenId) == owner);

        _clearApproval(tokenId);

        _ownedTokensCount[owner] = _ownedTokensCount[owner].sub(1);
        _tokenOwner[tokenId] = address(0);

        emit Transfer(owner, address(0), tokenId);
    }

    /**
     * @dev Internal function to burn a specific token
     * Reverts if the token does not exist
     * @param tokenId uint256 ID of the token being burned
     */
    function _burn(uint256 tokenId) internal {
        _burn(ownerOf(tokenId), tokenId);
    }

    /**
     * @dev Internal function to transfer ownership of a given token ID to another address.
     * As opposed to transferFrom, this imposes no restrictions on msg.sender.
     * @param from current owner of the token
     * @param to address to receive the ownership of the given token ID
     * @param tokenId uint256 ID of the token to be transferred
    */
    function _transferFrom(address from, address to, uint256 tokenId) internal {
        require(ownerOf(tokenId) == from);
        require(to != address(0));

        _clearApproval(tokenId);

        _ownedTokensCount[from] = _ownedTokensCount[from].sub(1);
        _ownedTokensCount[to] = _ownedTokensCount[to].add(1);

        _tokenOwner[tokenId] = to;

        emit Transfer(from, to, tokenId);
    }

    /**
     * @dev Internal function to invoke `onERC721Received` on a target address
     * The call is not executed if the target address is not a contract
     * @param from address representing the previous owner of the given token ID
     * @param to target address that will receive the tokens
     * @param tokenId uint256 ID of the token to be transferred
     * @param _data bytes optional data to send along with the call
     * @return whether the call correctly returned the expected magic value
     */
    function _checkOnERC721Received(address from, address to, uint256 tokenId, bytes memory _data)
        internal returns (bool)
    {
        if (!to.isContract()) {
            return true;
        }

        bytes4 retval = IERC721Receiver(to).onERC721Received(msg.sender, from, tokenId, _data);
        return (retval == _ERC721_RECEIVED);
    }

    /**
     * @dev Private function to clear current approval of a given token ID
     * @param tokenId uint256 ID of the token to be transferred
     */
    function _clearApproval(uint256 tokenId) private {
        if (_tokenApprovals[tokenId] != address(0)) {
            _tokenApprovals[tokenId] = address(0);
        }
    }
}

// File: openzeppelin-solidity/contracts/ownership/Ownable.sol

pragma solidity ^0.5.0;

/**
 * @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 private _owner;

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

    /**
     * @dev The Ownable constructor sets the original `owner` of the contract to the sender
     * account.
     */
    constructor () internal {
        _owner = msg.sender;
        emit OwnershipTransferred(address(0), _owner);
    }

    /**
     * @return the address of the owner.
     */
    function owner() public view returns (address) {
        return _owner;
    }

    /**
     * @dev Throws if called by any account other than the owner.
     */
    modifier onlyOwner() {
        require(isOwner());
        _;
    }

    /**
     * @return true if `msg.sender` is the owner of the contract.
     */
    function isOwner() public view returns (bool) {
        return msg.sender == _owner;
    }

    /**
     * @dev Allows the current owner to relinquish control of the contract.
     * @notice Renouncing to ownership will leave the contract without an owner.
     * It will not be possible to call the functions with the `onlyOwner`
     * modifier anymore.
     */
    function renounceOwnership() public onlyOwner {
        emit OwnershipTransferred(_owner, address(0));
        _owner = address(0);
    }

    /**
     * @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 {
        _transferOwnership(newOwner);
    }

    /**
     * @dev Transfers control of the contract to a newOwner.
     * @param newOwner The address to transfer ownership to.
     */
    function _transferOwnership(address newOwner) internal {
        require(newOwner != address(0));
        emit OwnershipTransferred(_owner, newOwner);
        _owner = newOwner;
    }
}

// File: @ensdomains/ethregistrar/contracts/BaseRegistrar.sol

pragma solidity >=0.4.24;




contract BaseRegistrar is IERC721, Ownable {
    uint constant public GRACE_PERIOD = 90 days;

    event ControllerAdded(address indexed controller);
    event ControllerRemoved(address indexed controller);
    event NameMigrated(uint256 indexed id, address indexed owner, uint expires);
    event NameRegistered(uint256 indexed id, address indexed owner, uint expires);
    event NameRenewed(uint256 indexed id, uint expires);

    // The ENS registry
    ENS public ens;

    // The namehash of the TLD this registrar owns (eg, .eth)
    bytes32 public baseNode;

    // A map of addresses that are authorised to register and renew names.
    mapping(address=>bool) public controllers;

    // Authorises a controller, who can register and renew domains.
    function addController(address controller) external;

    // Revoke controller permission for an address.
    function removeController(address controller) external;

    // Set the resolver for the TLD this registrar manages.
    function setResolver(address resolver) external;

    // Returns the expiration timestamp of the specified label hash.
    function nameExpires(uint256 id) external view returns(uint);

    // Returns true iff the specified name is available for registration.
    function available(uint256 id) public view returns(bool);

    /**
     * @dev Register a name.
     */
    function register(uint256 id, address owner, uint duration) external returns(uint);

    function renew(uint256 id, uint duration) external returns(uint);

    /**
     * @dev Reclaim ownership of a name in ENS, if you own it in the registrar.
     */
    function reclaim(uint256 id, address owner) external;
}

// File: @ensdomains/ethregistrar/contracts/BaseRegistrarImplementation.sol

pragma solidity ^0.5.0;




contract BaseRegistrarImplementation is BaseRegistrar, ERC721 {
    // A map of expiry times
    mapping(uint256=>uint) expiries;

    bytes4 constant private INTERFACE_META_ID = bytes4(keccak256("supportsInterface(bytes4)"));
    bytes4 constant private ERC721_ID = bytes4(
        keccak256("balanceOf(address)") ^
        keccak256("ownerOf(uint256)") ^
        keccak256("approve(address,uint256)") ^
        keccak256("getApproved(uint256)") ^
        keccak256("setApprovalForAll(address,bool)") ^
        keccak256("isApprovedForAll(address,address)") ^
        keccak256("transferFrom(address,address,uint256)") ^
        keccak256("safeTransferFrom(address,address,uint256)") ^
        keccak256("safeTransferFrom(address,address,uint256,bytes)")
    );
    bytes4 constant private RECLAIM_ID = bytes4(keccak256("reclaim(uint256,address)"));

    constructor(ENS _ens, bytes32 _baseNode) public {
        ens = _ens;
        baseNode = _baseNode;
    }

    modifier live {
        require(ens.owner(baseNode) == address(this));
        _;
    }

    modifier onlyController {
        require(controllers[msg.sender]);
        _;
    }

    /**
     * @dev Gets the owner of the specified token ID. Names become unowned
     *      when their registration expires.
     * @param tokenId uint256 ID of the token to query the owner of
     * @return address currently marked as the owner of the given token ID
     */
    function ownerOf(uint256 tokenId) public view returns (address) {
        require(expiries[tokenId] > now);
        return super.ownerOf(tokenId);
    }

    // Authorises a controller, who can register and renew domains.
    function addController(address controller) external onlyOwner {
        controllers[controller] = true;
        emit ControllerAdded(controller);
    }

    // Revoke controller permission for an address.
    function removeController(address controller) external onlyOwner {
        controllers[controller] = false;
        emit ControllerRemoved(controller);
    }

    // Set the resolver for the TLD this registrar manages.
    function setResolver(address resolver) external onlyOwner {
        ens.setResolver(baseNode, resolver);
    }

    // Returns the expiration timestamp of the specified id.
    function nameExpires(uint256 id) external view returns(uint) {
        return expiries[id];
    }

    // Returns true iff the specified name is available for registration.
    function available(uint256 id) public view returns(bool) {
        // Not available if it's registered here or in its grace period.
        return expiries[id] + GRACE_PERIOD < now;
    }

    /**
     * @dev Register a name.
     * @param id The token ID (keccak256 of the label).
     * @param owner The address that should own the registration.
     * @param duration Duration in seconds for the registration.
     */
    function register(uint256 id, address owner, uint duration) external returns(uint) {
      return _register(id, owner, duration, true);
    }

    /**
     * @dev Register a name, without modifying the registry.
     * @param id The token ID (keccak256 of the label).
     * @param owner The address that should own the registration.
     * @param duration Duration in seconds for the registration.
     */
    function registerOnly(uint256 id, address owner, uint duration) external returns(uint) {
      return _register(id, owner, duration, false);
    }

    function _register(uint256 id, address owner, uint duration, bool updateRegistry) internal live onlyController returns(uint) {
        require(available(id));
        require(now + duration + GRACE_PERIOD > now + GRACE_PERIOD); // Prevent future overflow

        expiries[id] = now + duration;
        if(_exists(id)) {
            // Name was previously owned, and expired
            _burn(id);
        }
        _mint(owner, id);
        if(updateRegistry) {
            ens.setSubnodeOwner(baseNode, bytes32(id), owner);
        }

        emit NameRegistered(id, owner, now + duration);

        return now + duration;
    }

    function renew(uint256 id, uint duration) external live onlyController returns(uint) {
        require(expiries[id] + GRACE_PERIOD >= now); // Name must be registered here or in grace period
        require(expiries[id] + duration + GRACE_PERIOD > duration + GRACE_PERIOD); // Prevent future overflow

        expiries[id] += duration;
        emit NameRenewed(id, expiries[id]);
        return expiries[id];
    }

    /**
     * @dev Reclaim ownership of a name in ENS, if you own it in the registrar.
     */
    function reclaim(uint256 id, address owner) external live {
        require(_isApprovedOrOwner(msg.sender, id));
        ens.setSubnodeOwner(baseNode, bytes32(id), owner);
    }

    function supportsInterface(bytes4 interfaceID) external view returns (bool) {
        return interfaceID == INTERFACE_META_ID ||
               interfaceID == ERC721_ID ||
               interfaceID == RECLAIM_ID;
    }
}

// File: @ensdomains/ens/contracts/ENS.sol

pragma solidity >=0.4.24;

interface ENS {

    // Logged when the owner of a node assigns a new owner to a subnode.
    event NewOwner(bytes32 indexed node, bytes32 indexed label, address owner);

    // Logged when the owner of a node transfers ownership to a new account.
    event Transfer(bytes32 indexed node, address owner);

    // Logged when the resolver for a node changes.
    event NewResolver(bytes32 indexed node, address resolver);

    // Logged when the TTL of a node changes
    event NewTTL(bytes32 indexed node, uint64 ttl);

    // Logged when an operator is added or removed.
    event ApprovalForAll(address indexed owner, address indexed operator, bool approved);

    function setRecord(bytes32 node, address owner, address resolver, uint64 ttl) external;
    function setSubnodeRecord(bytes32 node, bytes32 label, address owner, address resolver, uint64 ttl) external;
    function setSubnodeOwner(bytes32 node, bytes32 label, address owner) external returns(bytes32);
    function setResolver(bytes32 node, address resolver) external;
    function setOwner(bytes32 node, address owner) external;
    function setTTL(bytes32 node, uint64 ttl) external;
    function setApprovalForAll(address operator, bool approved) external;
    function owner(bytes32 node) external view returns (address);
    function resolver(bytes32 node) external view returns (address);
    function ttl(bytes32 node) external view returns (uint64);
    function recordExists(bytes32 node) external view returns (bool);
    function isApprovedForAll(address owner, address operator) external view returns (bool);
}

// File: @ensdomains/ens/contracts/ENSRegistry.sol

pragma solidity ^0.5.0;


/**
 * The ENS registry contract.
 */
contract ENSRegistry is ENS {

    struct Record {
        address owner;
        address resolver;
        uint64 ttl;
    }

    mapping (bytes32 => Record) records;
    mapping (address => mapping(address => bool)) operators;

    // Permits modifications only by the owner of the specified node.
    modifier authorised(bytes32 node) {
        address owner = records[node].owner;
        require(owner == msg.sender || operators[owner][msg.sender]);
        _;
    }

    /**
     * @dev Constructs a new ENS registrar.
     */
    constructor() public {
        records[0x0].owner = msg.sender;
    }

    /**
     * @dev Sets the record for a node.
     * @param node The node to update.
     * @param owner The address of the new owner.
     * @param resolver The address of the resolver.
     * @param ttl The TTL in seconds.
     */
    function setRecord(bytes32 node, address owner, address resolver, uint64 ttl) external {
        setOwner(node, owner);
        _setResolverAndTTL(node, resolver, ttl);
    }

    /**
     * @dev Sets the record for a subnode.
     * @param node The parent node.
     * @param label The hash of the label specifying the subnode.
     * @param owner The address of the new owner.
     * @param resolver The address of the resolver.
     * @param ttl The TTL in seconds.
     */
    function setSubnodeRecord(bytes32 node, bytes32 label, address owner, address resolver, uint64 ttl) external {
        bytes32 subnode = setSubnodeOwner(node, label, owner);
        _setResolverAndTTL(subnode, resolver, ttl);
    }

    /**
     * @dev Transfers ownership of a node to a new address. May only be called by the current owner of the node.
     * @param node The node to transfer ownership of.
     * @param owner The address of the new owner.
     */
    function setOwner(bytes32 node, address owner) public authorised(node) {
        _setOwner(node, owner);
        emit Transfer(node, owner);
    }

    /**
     * @dev Transfers ownership of a subnode keccak256(node, label) to a new address. May only be called by the owner of the parent node.
     * @param node The parent node.
     * @param label The hash of the label specifying the subnode.
     * @param owner The address of the new owner.
     */
    function setSubnodeOwner(bytes32 node, bytes32 label, address owner) public authorised(node) returns(bytes32) {
        bytes32 subnode = keccak256(abi.encodePacked(node, label));
        _setOwner(subnode, owner);
        emit NewOwner(node, label, owner);
        return subnode;
    }

    /**
     * @dev Sets the resolver address for the specified node.
     * @param node The node to update.
     * @param resolver The address of the resolver.
     */
    function setResolver(bytes32 node, address resolver) public authorised(node) {
        emit NewResolver(node, resolver);
        records[node].resolver = resolver;
    }

    /**
     * @dev Sets the TTL for the specified node.
     * @param node The node to update.
     * @param ttl The TTL in seconds.
     */
    function setTTL(bytes32 node, uint64 ttl) public authorised(node) {
        emit NewTTL(node, ttl);
        records[node].ttl = ttl;
    }

    /**
     * @dev Enable or disable approval for a third party ("operator") to manage
     *  all of `msg.sender`'s ENS records. Emits the ApprovalForAll event.
     * @param operator Address to add to the set of authorized operators.
     * @param approved True if the operator is approved, false to revoke approval.
     */
    function setApprovalForAll(address operator, bool approved) external {
        operators[msg.sender][operator] = approved;
        emit ApprovalForAll(msg.sender, operator, approved);
    }

    /**
     * @dev Returns the address that owns the specified node.
     * @param node The specified node.
     * @return address of the owner.
     */
    function owner(bytes32 node) public view returns (address) {
        address addr = records[node].owner;
        if (addr == address(this)) {
            return address(0x0);
        }

        return addr;
    }

    /**
     * @dev Returns the address of the resolver for the specified node.
     * @param node The specified node.
     * @return address of the resolver.
     */
    function resolver(bytes32 node) public view returns (address) {
        return records[node].resolver;
    }

    /**
     * @dev Returns the TTL of a node, and any records associated with it.
     * @param node The specified node.
     * @return ttl of the node.
     */
    function ttl(bytes32 node) public view returns (uint64) {
        return records[node].ttl;
    }

    /**
     * @dev Returns whether a record has been imported to the registry.
     * @param node The specified node.
     * @return Bool if record exists
     */
    function recordExists(bytes32 node) public view returns (bool) {
        return records[node].owner != address(0x0);
    }

    /**
     * @dev Query if an address is an authorized operator for another address.
     * @param owner The address that owns the records.
     * @param operator The address that acts on behalf of the owner.
     * @return True if `operator` is an approved operator for `owner`, false otherwise.
     */
    function isApprovedForAll(address owner, address operator) external view returns (bool) {
        return operators[owner][operator];
    }

    function _setOwner(bytes32 node, address owner) internal {
        records[node].owner = owner;
    }

    function _setResolverAndTTL(bytes32 node, address resolver, uint64 ttl) internal {
        if(resolver != records[node].resolver) {
            records[node].resolver = resolver;
            emit NewResolver(node, resolver);
        }

        if(ttl != records[node].ttl) {
            records[node].ttl = ttl;
            emit NewTTL(node, ttl);
        }
    }
}

// File: @ensdomains/ens/contracts/ENSRegistryWithFallback.sol

pragma solidity ^0.5.0;



/**
 * The ENS registry contract.
 */
contract ENSRegistryWithFallback is ENSRegistry {

    ENS public old;

    /**
     * @dev Constructs a new ENS registrar.
     */
    constructor(ENS _old) public ENSRegistry() {
        old = _old;
    }

    /**
     * @dev Returns the address of the resolver for the specified node.
     * @param node The specified node.
     * @return address of the resolver.
     */
    function resolver(bytes32 node) public view returns (address) {
        if (!recordExists(node)) {
            return old.resolver(node);
        }

        return super.resolver(node);
    }

    /**
     * @dev Returns the address that owns the specified node.
     * @param node The specified node.
     * @return address of the owner.
     */
    function owner(bytes32 node) public view returns (address) {
        if (!recordExists(node)) {
            return old.owner(node);
        }

        return super.owner(node);
    }

    /**
     * @dev Returns the TTL of a node, and any records associated with it.
     * @param node The specified node.
     * @return ttl of the node.
     */
    function ttl(bytes32 node) public view returns (uint64) {
        if (!recordExists(node)) {
            return old.ttl(node);
        }

        return super.ttl(node);
    }

    function _setOwner(bytes32 node, address owner) internal {
        address addr = owner;
        if (addr == address(0x0)) {
            addr = address(this);
        }

        super._setOwner(node, addr);
    }
}

// File: @ensdomains/ens/contracts/ENS.sol

pragma solidity >=0.4.24;

interface ENS {

    // Logged when the owner of a node assigns a new owner to a subnode.
    event NewOwner(bytes32 indexed node, bytes32 indexed label, address owner);

    // Logged when the owner of a node transfers ownership to a new account.
    event Transfer(bytes32 indexed node, address owner);

    // Logged when the resolver for a node changes.
    event NewResolver(bytes32 indexed node, address resolver);

    // Logged when the TTL of a node changes
    event NewTTL(bytes32 indexed node, uint64 ttl);


    function setSubnodeOwner(bytes32 node, bytes32 label, address owner) external;
    function setResolver(bytes32 node, address resolver) external;
    function setOwner(bytes32 node, address owner) external;
    function setTTL(bytes32 node, uint64 ttl) external;
    function owner(bytes32 node) external view returns (address);
    function resolver(bytes32 node) external view returns (address);
    function ttl(bytes32 node) external view returns (uint64);

}

// File: contracts/ResolverBase.sol

pragma solidity ^0.5.0;

contract ResolverBase {
    bytes4 private constant INTERFACE_META_ID = 0x01ffc9a7;

    function supportsInterface(bytes4 interfaceID) public pure returns(bool) {
        return interfaceID == INTERFACE_META_ID;
    }

    function isAuthorised(bytes32 node) internal view returns(bool);

    modifier authorised(bytes32 node) {
        require(isAuthorised(node));
        _;
    }

    function bytesToAddress(bytes memory b) internal pure returns(address payable a) {
        require(b.length == 20);
        assembly {
            a := div(mload(add(b, 32)), exp(256, 12))
        }
    }

    function addressToBytes(address a) internal pure returns(bytes memory b) {
        b = new bytes(20);
        assembly {
            mstore(add(b, 32), mul(a, exp(256, 12)))
        }
    }
}

// File: contracts/profiles/ABIResolver.sol

pragma solidity ^0.5.0;


contract ABIResolver is ResolverBase {
    bytes4 constant private ABI_INTERFACE_ID = 0x2203ab56;

    event ABIChanged(bytes32 indexed node, uint256 indexed contentType);

    mapping(bytes32=>mapping(uint256=>bytes)) abis;

    /**
     * Sets the ABI associated with an ENS node.
     * Nodes may have one ABI of each content type. To remove an ABI, set it to
     * the empty string.
     * @param node The node to update.
     * @param contentType The content type of the ABI
     * @param data The ABI data.
     */
    function setABI(bytes32 node, uint256 contentType, bytes calldata data) external authorised(node) {
        // Content types must be powers of 2
        require(((contentType - 1) & contentType) == 0);

        abis[node][contentType] = data;
        emit ABIChanged(node, contentType);
    }

    /**
     * Returns the ABI associated with an ENS node.
     * Defined in EIP205.
     * @param node The ENS node to query
     * @param contentTypes A bitwise OR of the ABI formats accepted by the caller.
     * @return contentType The content type of the return value
     * @return data The ABI data
     */
    function ABI(bytes32 node, uint256 contentTypes) external view returns (uint256, bytes memory) {
        mapping(uint256=>bytes) storage abiset = abis[node];

        for (uint256 contentType = 1; contentType <= contentTypes; contentType <<= 1) {
            if ((contentType & contentTypes) != 0 && abiset[contentType].length > 0) {
                return (contentType, abiset[contentType]);
            }
        }

        return (0, bytes(""));
    }

    function supportsInterface(bytes4 interfaceID) public pure returns(bool) {
        return interfaceID == ABI_INTERFACE_ID || super.supportsInterface(interfaceID);
    }
}

// File: contracts/profiles/AddrResolver.sol

pragma solidity ^0.5.0;


contract AddrResolver is ResolverBase {
    bytes4 constant private ADDR_INTERFACE_ID = 0x3b3b57de;
    bytes4 constant private ADDRESS_INTERFACE_ID = 0xf1cb7e06;
    uint constant private COIN_TYPE_ETH = 60;

    event AddrChanged(bytes32 indexed node, address a);
    event AddressChanged(bytes32 indexed node, uint coinType, bytes newAddress);

    mapping(bytes32=>mapping(uint=>bytes)) _addresses;

    /**
     * Sets the address associated with an ENS node.
     * May only be called by the owner of that node in the ENS registry.
     * @param node The node to update.
     * @param a The address to set.
     */
    function setAddr(bytes32 node, address a) external authorised(node) {
        setAddr(node, COIN_TYPE_ETH, addressToBytes(a));
    }

    /**
     * Returns the address associated with an ENS node.
     * @param node The ENS node to query.
     * @return The associated address.
     */
    function addr(bytes32 node) public view returns (address payable) {
        bytes memory a = addr(node, COIN_TYPE_ETH);
        if(a.length == 0) {
            return address(0);
        }
        return bytesToAddress(a);
    }

    function setAddr(bytes32 node, uint coinType, bytes memory a) public authorised(node) {
        emit AddressChanged(node, coinType, a);
        if(coinType == COIN_TYPE_ETH) {
            emit AddrChanged(node, bytesToAddress(a));
        }
        _addresses[node][coinType] = a;
    }

    function addr(bytes32 node, uint coinType) public view returns(bytes memory) {
        return _addresses[node][coinType];
    }

    function supportsInterface(bytes4 interfaceID) public pure returns(bool) {
        return interfaceID == ADDR_INTERFACE_ID || interfaceID == ADDRESS_INTERFACE_ID || super.supportsInterface(interfaceID);
    }
}

// File: contracts/profiles/ContentHashResolver.sol

pragma solidity ^0.5.0;


contract ContentHashResolver is ResolverBase {
    bytes4 constant private CONTENT_HASH_INTERFACE_ID = 0xbc1c58d1;

    event ContenthashChanged(bytes32 indexed node, bytes hash);

    mapping(bytes32=>bytes) hashes;

    /**
     * Sets the contenthash associated with an ENS node.
     * May only be called by the owner of that node in the ENS registry.
     * @param node The node to update.
     * @param hash The contenthash to set
     */
    function setContenthash(bytes32 node, bytes calldata hash) external authorised(node) {
        hashes[node] = hash;
        emit ContenthashChanged(node, hash);
    }

    /**
     * Returns the contenthash associated with an ENS node.
     * @param node The ENS node to query.
     * @return The associated contenthash.
     */
    function contenthash(bytes32 node) external view returns (bytes memory) {
        return hashes[node];
    }

    function supportsInterface(bytes4 interfaceID) public pure returns(bool) {
        return interfaceID == CONTENT_HASH_INTERFACE_ID || super.supportsInterface(interfaceID);
    }
}

// File: @ensdomains/dnssec-oracle/contracts/BytesUtils.sol

pragma solidity >0.4.23;

library BytesUtils {
    /*
    * @dev Returns the keccak-256 hash of a byte range.
    * @param self The byte string to hash.
    * @param offset The position to start hashing at.
    * @param len The number of bytes to hash.
    * @return The hash of the byte range.
    */
    function keccak(bytes memory self, uint offset, uint len) internal pure returns (bytes32 ret) {
        require(offset + len <= self.length);
        assembly {
            ret := keccak256(add(add(self, 32), offset), len)
        }
    }


    /*
    * @dev Returns a positive number if `other` comes lexicographically after
    *      `self`, a negative number if it comes before, or zero if the
    *      contents of the two bytes are equal.
    * @param self The first bytes to compare.
    * @param other The second bytes to compare.
    * @return The result of the comparison.
    */
    function compare(bytes memory self, bytes memory other) internal pure returns (int) {
        return compare(self, 0, self.length, other, 0, other.length);
    }

    /*
    * @dev Returns a positive number if `other` comes lexicographically after
    *      `self`, a negative number if it comes before, or zero if the
    *      contents of the two bytes are equal. Comparison is done per-rune,
    *      on unicode codepoints.
    * @param self The first bytes to compare.
    * @param offset The offset of self.
    * @param len    The length of self.
    * @param other The second bytes to compare.
    * @param otheroffset The offset of the other string.
    * @param otherlen    The length of the other string.
    * @return The result of the comparison.
    */
    function compare(bytes memory self, uint offset, uint len, bytes memory other, uint otheroffset, uint otherlen) internal pure returns (int) {
        uint shortest = len;
        if (otherlen < len)
        shortest = otherlen;

        uint selfptr;
        uint otherptr;

        assembly {
            selfptr := add(self, add(offset, 32))
            otherptr := add(other, add(otheroffset, 32))
        }
        for (uint idx = 0; idx < shortest; idx += 32) {
            uint a;
            uint b;
            assembly {
                a := mload(selfptr)
                b := mload(otherptr)
            }
            if (a != b) {
                // Mask out irrelevant bytes and check again
                uint mask;
                if (shortest > 32) {
                    mask = uint256(- 1); // aka 0xffffff....
                } else {
                    mask = ~(2 ** (8 * (32 - shortest + idx)) - 1);
                }
                uint diff = (a & mask) - (b & mask);
                if (diff != 0)
                return int(diff);
            }
            selfptr += 32;
            otherptr += 32;
        }

        return int(len) - int(otherlen);
    }

    /*
    * @dev Returns true if the two byte ranges are equal.
    * @param self The first byte range to compare.
    * @param offset The offset into the first byte range.
    * @param other The second byte range to compare.
    * @param otherOffset The offset into the second byte range.
    * @param len The number of bytes to compare
    * @return True if the byte ranges are equal, false otherwise.
    */
    function equals(bytes memory self, uint offset, bytes memory other, uint otherOffset, uint len) internal pure returns (bool) {
        return keccak(self, offset, len) == keccak(other, otherOffset, len);
    }

    /*
    * @dev Returns true if the two byte ranges are equal with offsets.
    * @param self The first byte range to compare.
    * @param offset The offset into the first byte range.
    * @param other The second byte range to compare.
    * @param otherOffset The offset into the second byte range.
    * @return True if the byte ranges are equal, false otherwise.
    */
    function equals(bytes memory self, uint offset, bytes memory other, uint otherOffset) internal pure returns (bool) {
        return keccak(self, offset, self.length - offset) == keccak(other, otherOffset, other.length - otherOffset);
    }

    /*
    * @dev Compares a range of 'self' to all of 'other' and returns True iff
    *      they are equal.
    * @param self The first byte range to compare.
    * @param offset The offset into the first byte range.
    * @param other The second byte range to compare.
    * @return True if the byte ranges are equal, false otherwise.
    */
    function equals(bytes memory self, uint offset, bytes memory other) internal pure returns (bool) {
        return self.length >= offset + other.length && equals(self, offset, other, 0, other.length);
    }

    /*
    * @dev Returns true if the two byte ranges are equal.
    * @param self The first byte range to compare.
    * @param other The second byte range to compare.
    * @return True if the byte ranges are equal, false otherwise.
    */
    function equals(bytes memory self, bytes memory other) internal pure returns(bool) {
        return self.length == other.length && equals(self, 0, other, 0, self.length);
    }

    /*
    * @dev Returns the 8-bit number at the specified index of self.
    * @param self The byte string.
    * @param idx The index into the bytes
    * @return The specified 8 bits of the string, interpreted as an integer.
    */
    function readUint8(bytes memory self, uint idx) internal pure returns (uint8 ret) {
        return uint8(self[idx]);
    }

    /*
    * @dev Returns the 16-bit number at the specified index of self.
    * @param self The byte string.
    * @param idx The index into the bytes
    * @return The specified 16 bits of the string, interpreted as an integer.
    */
    function readUint16(bytes memory self, uint idx) internal pure returns (uint16 ret) {
        require(idx + 2 <= self.length);
        assembly {
            ret := and(mload(add(add(self, 2), idx)), 0xFFFF)
        }
    }

    /*
    * @dev Returns the 32-bit number at the specified index of self.
    * @param self The byte string.
    * @param idx The index into the bytes
    * @return The specified 32 bits of the string, interpreted as an integer.
    */
    function readUint32(bytes memory self, uint idx) internal pure returns (uint32 ret) {
        require(idx + 4 <= self.length);
        assembly {
            ret := and(mload(add(add(self, 4), idx)), 0xFFFFFFFF)
        }
    }

    /*
    * @dev Returns the 32 byte value at the specified index of self.
    * @param self The byte string.
    * @param idx The index into the bytes
    * @return The specified 32 bytes of the string.
    */
    function readBytes32(bytes memory self, uint idx) internal pure returns (bytes32 ret) {
        require(idx + 32 <= self.length);
        assembly {
            ret := mload(add(add(self, 32), idx))
        }
    }

    /*
    * @dev Returns the 32 byte value at the specified index of self.
    * @param self The byte string.
    * @param idx The index into the bytes
    * @return The specified 32 bytes of the string.
    */
    function readBytes20(bytes memory self, uint idx) internal pure returns (bytes20 ret) {
        require(idx + 20 <= self.length);
        assembly {
            ret := and(mload(add(add(self, 32), idx)), 0xFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFF000000000000000000000000)
        }
    }

    /*
    * @dev Returns the n byte value at the specified index of self.
    * @param self The byte string.
    * @param idx The index into the bytes.
    * @param len The number of bytes.
    * @return The specified 32 bytes of the string.
    */
    function readBytesN(bytes memory self, uint idx, uint len) internal pure returns (bytes32 ret) {
        require(len <= 32);
        require(idx + len <= self.length);
        assembly {
            let mask := not(sub(exp(256, sub(32, len)), 1))
            ret := and(mload(add(add(self, 32), idx)),  mask)
        }
    }

    function memcpy(uint dest, uint src, uint len) private pure {
        // Copy word-length chunks while possible
        for (; len >= 32; len -= 32) {
            assembly {
                mstore(dest, mload(src))
            }
            dest += 32;
            src += 32;
        }

        // Copy remaining bytes
        uint mask = 256 ** (32 - len) - 1;
        assembly {
            let srcpart := and(mload(src), not(mask))
            let destpart := and(mload(dest), mask)
            mstore(dest, or(destpart, srcpart))
        }
    }

    /*
    * @dev Copies a substring into a new byte string.
    * @param self The byte string to copy from.
    * @param offset The offset to start copying at.
    * @param len The number of bytes to copy.
    */
    function substring(bytes memory self, uint offset, uint len) internal pure returns(bytes memory) {
        require(offset + len <= self.length);

        bytes memory ret = new bytes(len);
        uint dest;
        uint src;

        assembly {
            dest := add(ret, 32)
            src := add(add(self, 32), offset)
        }
        memcpy(dest, src, len);

        return ret;
    }

    // Maps characters from 0x30 to 0x7A to their base32 values.
    // 0xFF represents invalid characters in that range.
    bytes constant base32HexTable = hex'00010203040506070809FFFFFFFFFFFFFF0A0B0C0D0E0F101112131415161718191A1B1C1D1E1FFFFFFFFFFFFFFFFFFFFF0A0B0C0D0E0F101112131415161718191A1B1C1D1E1F';

    /**
     * @dev Decodes unpadded base32 data of up to one word in length.
     * @param self The data to decode.
     * @param off Offset into the string to start at.
     * @param len Number of characters to decode.
     * @return The decoded data, left aligned.
     */
    function base32HexDecodeWord(bytes memory self, uint off, uint len) internal pure returns(bytes32) {
        require(len <= 52);

        uint ret = 0;
        uint8 decoded;
        for(uint i = 0; i < len; i++) {
            bytes1 char = self[off + i];
            require(char >= 0x30 && char <= 0x7A);
            decoded = uint8(base32HexTable[uint(uint8(char)) - 0x30]);
            require(decoded <= 0x20);
            if(i == len - 1) {
                break;
            }
            ret = (ret << 5) | decoded;
        }

        uint bitlen = len * 5;
        if(len % 8 == 0) {
            // Multiple of 8 characters, no padding
            ret = (ret << 5) | decoded;
        } else if(len % 8 == 2) {
            // Two extra characters - 1 byte
            ret = (ret << 3) | (decoded >> 2);
            bitlen -= 2;
        } else if(len % 8 == 4) {
            // Four extra characters - 2 bytes
            ret = (ret << 1) | (decoded >> 4);
            bitlen -= 4;
        } else if(len % 8 == 5) {
            // Five extra characters - 3 bytes
            ret = (ret << 4) | (decoded >> 1);
            bitlen -= 1;
        } else if(len % 8 == 7) {
            // Seven extra characters - 4 bytes
            ret = (ret << 2) | (decoded >> 3);
            bitlen -= 3;
        } else {
            revert();
        }

        return bytes32(ret << (256 - bitlen));
    }
}

// File: @ensdomains/buffer/contracts/Buffer.sol

pragma solidity >0.4.18;

/**
* @dev A library for working with mutable byte buffers in Solidity.
*
* Byte buffers are mutable and expandable, and provide a variety of primitives
* for writing to them. At any time you can fetch a bytes object containing the
* current contents of the buffer. The bytes object should not be stored between
* operations, as it may change due to resizing of the buffer.
*/
library Buffer {
    /**
    * @dev Represents a mutable buffer. Buffers have a current value (buf) and
    *      a capacity. The capacity may be longer than the current value, in
    *      which case it can be extended without the need to allocate more memory.
    */
    struct buffer {
        bytes buf;
        uint capacity;
    }

    /**
    * @dev Initializes a buffer with an initial capacity.
    * @param buf The buffer to initialize.
    * @param capacity The number of bytes of space to allocate the buffer.
    * @return The buffer, for chaining.
    */
    function init(buffer memory buf, uint capacity) internal pure returns(buffer memory) {
        if (capacity % 32 != 0) {
            capacity += 32 - (capacity % 32);
        }
        // Allocate space for the buffer data
        buf.capacity = capacity;
        assembly {
            let ptr := mload(0x40)
            mstore(buf, ptr)
            mstore(ptr, 0)
            mstore(0x40, add(32, add(ptr, capacity)))
        }
        return buf;
    }

    /**
    * @dev Initializes a new buffer from an existing bytes object.
    *      Changes to the buffer may mutate the original value.
    * @param b The bytes object to initialize the buffer with.
    * @return A new buffer.
    */
    function fromBytes(bytes memory b) internal pure returns(buffer memory) {
        buffer memory buf;
        buf.buf = b;
        buf.capacity = b.length;
        return buf;
    }

    function resize(buffer memory buf, uint capacity) private pure {
        bytes memory oldbuf = buf.buf;
        init(buf, capacity);
        append(buf, oldbuf);
    }

    function max(uint a, uint b) private pure returns(uint) {
        if (a > b) {
            return a;
        }
        return b;
    }

    /**
    * @dev Sets buffer length to 0.
    * @param buf The buffer to truncate.
    * @return The original buffer, for chaining..
    */
    function truncate(buffer memory buf) internal pure returns (buffer memory) {
        assembly {
            let bufptr := mload(buf)
            mstore(bufptr, 0)
        }
        return buf;
    }

    /**
    * @dev Writes a byte string to a buffer. Resizes if doing so would exceed
    *      the capacity of the buffer.
    * @param buf The buffer to append to.
    * @param off The start offset to write to.
    * @param data The data to append.
    * @param len The number of bytes to copy.
    * @return The original buffer, for chaining.
    */
    function write(buffer memory buf, uint off, bytes memory data, uint len) internal pure returns(buffer memory) {
        require(len <= data.length);

        if (off + len > buf.capacity) {
            resize(buf, max(buf.capacity, len + off) * 2);
        }

        uint dest;
        uint src;
        assembly {
            // Memory address of the buffer data
            let bufptr := mload(buf)
            // Length of existing buffer data
            let buflen := mload(bufptr)
            // Start address = buffer address + offset + sizeof(buffer length)
            dest := add(add(bufptr, 32), off)
            // Update buffer length if we're extending it
            if gt(add(len, off), buflen) {
                mstore(bufptr, add(len, off))
            }
            src := add(data, 32)
        }

        // Copy word-length chunks while possible
        for (; len >= 32; len -= 32) {
            assembly {
                mstore(dest, mload(src))
            }
            dest += 32;
            src += 32;
        }

        // Copy remaining bytes
        uint mask = 256 ** (32 - len) - 1;
        assembly {
            let srcpart := and(mload(src), not(mask))
            let destpart := and(mload(dest), mask)
            mstore(dest, or(destpart, srcpart))
        }

        return buf;
    }

    /**
    * @dev Appends a byte string to a buffer. Resizes if doing so would exceed
    *      the capacity of the buffer.
    * @param buf The buffer to append to.
    * @param data The data to append.
    * @param len The number of bytes to copy.
    * @return The original buffer, for chaining.
    */
    function append(buffer memory buf, bytes memory data, uint len) internal pure returns (buffer memory) {
        return write(buf, buf.buf.length, data, len);
    }

    /**
    * @dev Appends a byte string to a buffer. Resizes if doing so would exceed
    *      the capacity of the buffer.
    * @param buf The buffer to append to.
    * @param data The data to append.
    * @return The original buffer, for chaining.
    */
    function append(buffer memory buf, bytes memory data) internal pure returns (buffer memory) {
        return write(buf, buf.buf.length, data, data.length);
    }

    /**
    * @dev Writes a byte to the buffer. Resizes if doing so would exceed the
    *      capacity of the buffer.
    * @param buf The buffer to append to.
    * @param off The offset to write the byte at.
    * @param data The data to append.
    * @return The original buffer, for chaining.
    */
    function writeUint8(buffer memory buf, uint off, uint8 data) internal pure returns(buffer memory) {
        if (off >= buf.capacity) {
            resize(buf, buf.capacity * 2);
        }

        assembly {
            // Memory address of the buffer data
            let bufptr := mload(buf)
            // Length of existing buffer data
            let buflen := mload(bufptr)
            // Address = buffer address + sizeof(buffer length) + off
            let dest := add(add(bufptr, off), 32)
            mstore8(dest, data)
            // Update buffer length if we extended it
            if eq(off, buflen) {
                mstore(bufptr, add(buflen, 1))
            }
        }
        return buf;
    }

    /**
    * @dev Appends a byte to the buffer. Resizes if doing so would exceed the
    *      capacity of the buffer.
    * @param buf The buffer to append to.
    * @param data The data to append.
    * @return The original buffer, for chaining.
    */
    function appendUint8(buffer memory buf, uint8 data) internal pure returns(buffer memory) {
        return writeUint8(buf, buf.buf.length, data);
    }

    /**
    * @dev Writes up to 32 bytes to the buffer. Resizes if doing so would
    *      exceed the capacity of the buffer.
    * @param buf The buffer to append to.
    * @param off The offset to write at.
    * @param data The data to append.
    * @param len The number of bytes to write (left-aligned).
    * @return The original buffer, for chaining.
    */
    function write(buffer memory buf, uint off, bytes32 data, uint len) private pure returns(buffer memory) {
        if (len + off > buf.capacity) {
            resize(buf, (len + off) * 2);
        }

        uint mask = 256 ** len - 1;
        // Right-align data
        data = data >> (8 * (32 - len));
        assembly {
            // Memory address of the buffer data
            let bufptr := mload(buf)
            // Address = buffer address + sizeof(buffer length) + off + len
            let dest := add(add(bufptr, off), len)
            mstore(dest, or(and(mload(dest), not(mask)), data))
            // Update buffer length if we extended it
            if gt(add(off, len), mload(bufptr)) {
                mstore(bufptr, add(off, len))
            }
        }
        return buf;
    }

    /**
    * @dev Writes a bytes20 to the buffer. Resizes if doing so would exceed the
    *      capacity of the buffer.
    * @param buf The buffer to append to.
    * @param off The offset to write at.
    * @param data The data to append.
    * @return The original buffer, for chaining.
    */
    function writeBytes20(buffer memory buf, uint off, bytes20 data) internal pure returns (buffer memory) {
        return write(buf, off, bytes32(data), 20);
    }

    /**
    * @dev Appends a bytes20 to the buffer. Resizes if doing so would exceed
    *      the capacity of the buffer.
    * @param buf The buffer to append to.
    * @param data The data to append.
    * @return The original buffer, for chhaining.
    */
    function appendBytes20(buffer memory buf, bytes20 data) internal pure returns (buffer memory) {
        return write(buf, buf.buf.length, bytes32(data), 20);
    }

    /**
    * @dev Appends a bytes32 to the buffer. Resizes if doing so would exceed
    *      the capacity of the buffer.
    * @param buf The buffer to append to.
    * @param data The data to append.
    * @return The original buffer, for chaining.
    */
    function appendBytes32(buffer memory buf, bytes32 data) internal pure returns (buffer memory) {
        return write(buf, buf.buf.length, data, 32);
    }

    /**
    * @dev Writes an integer to the buffer. Resizes if doing so would exceed
    *      the capacity of the buffer.
    * @param buf The buffer to append to.
    * @param off The offset to write at.
    * @param data The data to append.
    * @param len The number of bytes to write (right-aligned).
    * @return The original buffer, for chaining.
    */
    function writeInt(buffer memory buf, uint off, uint data, uint len) private pure returns(buffer memory) {
        if (len + off > buf.capacity) {
            resize(buf, (len + off) * 2);
        }

        uint mask = 256 ** len - 1;
        assembly {
            // Memory address of the buffer data
            let bufptr := mload(buf)
            // Address = buffer address + off + sizeof(buffer length) + len
            let dest := add(add(bufptr, off), len)
            mstore(dest, or(and(mload(dest), not(mask)), data))
            // Update buffer length if we extended it
            if gt(add(off, len), mload(bufptr)) {
                mstore(bufptr, add(off, len))
            }
        }
        return buf;
    }

    /**
     * @dev Appends a byte to the end of the buffer. Resizes if doing so would
     * exceed the capacity of the buffer.
     * @param buf The buffer to append to.
     * @param data The data to append.
     * @return The original buffer.
     */
    function appendInt(buffer memory buf, uint data, uint len) internal pure returns(buffer memory) {
        return writeInt(buf, buf.buf.length, data, len);
    }
}

// File: @ensdomains/dnssec-oracle/contracts/RRUtils.sol

pragma solidity >0.4.23;



/**
* @dev RRUtils is a library that provides utilities for parsing DNS resource records.
*/
library RRUtils {
    using BytesUtils for *;
    using Buffer for *;

    /**
    * @dev Returns the number of bytes in the DNS name at 'offset' in 'self'.
    * @param self The byte array to read a name from.
    * @param offset The offset to start reading at.
    * @return The length of the DNS name at 'offset', in bytes.
    */
    function nameLength(bytes memory self, uint offset) internal pure returns(uint) {
        uint idx = offset;
        while (true) {
            assert(idx < self.length);
            uint labelLen = self.readUint8(idx);
            idx += labelLen + 1;
            if (labelLen == 0) {
                break;
            }
        }
        return idx - offset;
    }

    /**
    * @dev Returns a DNS format name at the specified offset of self.
    * @param self The byte array to read a name from.
    * @param offset The offset to start reading at.
    * @return The name.
    */
    function readName(bytes memory self, uint offset) internal pure returns(bytes memory ret) {
        uint len = nameLength(self, offset);
        return self.substring(offset, len);
    }

    /**
    * @dev Returns the number of labels in the DNS name at 'offset' in 'self'.
    * @param self The byte array to read a name from.
    * @param offset The offset to start reading at.
    * @return The number of labels in the DNS name at 'offset', in bytes.
    */
    function labelCount(bytes memory self, uint offset) internal pure returns(uint) {
        uint count = 0;
        while (true) {
            assert(offset < self.length);
            uint labelLen = self.readUint8(offset);
            offset += labelLen + 1;
            if (labelLen == 0) {
                break;
            }
            count += 1;
        }
        return count;
    }

    /**
    * @dev An iterator over resource records.
    */
    struct RRIterator {
        bytes data;
        uint offset;
        uint16 dnstype;
        uint16 class;
        uint32 ttl;
        uint rdataOffset;
        uint nextOffset;
    }

    /**
    * @dev Begins iterating over resource records.
    * @param self The byte string to read from.
    * @param offset The offset to start reading at.
    * @return An iterator object.
    */
    function iterateRRs(bytes memory self, uint offset) internal pure returns (RRIterator memory ret) {
        ret.data = self;
        ret.nextOffset = offset;
        next(ret);
    }

    /**
    * @dev Returns true iff there are more RRs to iterate.
    * @param iter The iterator to check.
    * @return True iff the iterator has finished.
    */
    function done(RRIterator memory iter) internal pure returns(bool) {
        return iter.offset >= iter.data.length;
    }

    /**
    * @dev Moves the iterator to the next resource record.
    * @param iter The iterator to advance.
    */
    function next(RRIterator memory iter) internal pure {
        iter.offset = iter.nextOffset;
        if (iter.offset >= iter.data.length) {
            return;
        }

        // Skip the name
        uint off = iter.offset + nameLength(iter.data, iter.offset);

        // Read type, class, and ttl
        iter.dnstype = iter.data.readUint16(off);
        off += 2;
        iter.class = iter.data.readUint16(off);
        off += 2;
        iter.ttl = iter.data.readUint32(off);
        off += 4;

        // Read the rdata
        uint rdataLength = iter.data.readUint16(off);
        off += 2;
        iter.rdataOffset = off;
        iter.nextOffset = off + rdataLength;
    }

    /**
    * @dev Returns the name of the current record.
    * @param iter The iterator.
    * @return A new bytes object containing the owner name from the RR.
    */
    function name(RRIterator memory iter) internal pure returns(bytes memory) {
        return iter.data.substring(iter.offset, nameLength(iter.data, iter.offset));
    }

    /**
    * @dev Returns the rdata portion of the current record.
    * @param iter The iterator.
    * @return A new bytes object containing the RR's RDATA.
    */
    function rdata(RRIterator memory iter) internal pure returns(bytes memory) {
        return iter.data.substring(iter.rdataOffset, iter.nextOffset - iter.rdataOffset);
    }

    /**
    * @dev Checks if a given RR type exists in a type bitmap.
    * @param self The byte string to read the type bitmap from.
    * @param offset The offset to start reading at.
    * @param rrtype The RR type to check for.
    * @return True if the type is found in the bitmap, false otherwise.
    */
    function checkTypeBitmap(bytes memory self, uint offset, uint16 rrtype) internal pure returns (bool) {
        uint8 typeWindow = uint8(rrtype >> 8);
        uint8 windowByte = uint8((rrtype & 0xff) / 8);
        uint8 windowBitmask = uint8(uint8(1) << (uint8(7) - uint8(rrtype & 0x7)));
        for (uint off = offset; off < self.length;) {
            uint8 window = self.readUint8(off);
            uint8 len = self.readUint8(off + 1);
            if (typeWindow < window) {
                // We've gone past our window; it's not here.
                return false;
            } else if (typeWindow == window) {
                // Check this type bitmap
                if (len * 8 <= windowByte) {
                    // Our type is past the end of the bitmap
                    return false;
                }
                return (self.readUint8(off + windowByte + 2) & windowBitmask) != 0;
            } else {
                // Skip this type bitmap
                off += len + 2;
            }
        }

        return false;
    }

    function compareNames(bytes memory self, bytes memory other) internal pure returns (int) {
        if (self.equals(other)) {
            return 0;
        }

        uint off;
        uint otheroff;
        uint prevoff;
        uint otherprevoff;
        uint counts = labelCount(self, 0);
        uint othercounts = labelCount(other, 0);

        // Keep removing labels from the front of the name until both names are equal length
        while (counts > othercounts) {
            prevoff = off;
            off = progress(self, off);
            counts--;
        }

        while (othercounts > counts) {
            otherprevoff = otheroff;
            otheroff = progress(other, otheroff);
            othercounts--;
        }

        // Compare the last nonequal labels to each other
        while (counts > 0 && !self.equals(off, other, otheroff)) {
            prevoff = off;
            off = progress(self, off);
            otherprevoff = otheroff;
            otheroff = progress(other, otheroff);
            counts -= 1;
        }

        if (off == 0) {
            return -1;
        }
        if(otheroff == 0) {
            return 1;
        }

        return self.compare(prevoff + 1, self.readUint8(prevoff), other, otherprevoff + 1, other.readUint8(otherprevoff));
    }

    function progress(bytes memory body, uint off) internal pure returns(uint) {
        return off + 1 + body.readUint8(off);
    }
}

// File: contracts/profiles/DNSResolver.sol

pragma solidity ^0.5.0;



contract DNSResolver is ResolverBase {
    using RRUtils for *;
    using BytesUtils for bytes;

    bytes4 constant private DNS_RECORD_INTERFACE_ID = 0xa8fa5682;

    // DNSRecordChanged is emitted whenever a given node/name/resource's RRSET is updated.
    event DNSRecordChanged(bytes32 indexed node, bytes name, uint16 resource, bytes record);
    // DNSRecordDeleted is emitted whenever a given node/name/resource's RRSET is deleted.
    event DNSRecordDeleted(bytes32 indexed node, bytes name, uint16 resource);
    // DNSZoneCleared is emitted whenever a given node's zone information is cleared.
    event DNSZoneCleared(bytes32 indexed node);

    // Version the mapping for each zone.  This allows users who have lost
    // track of their entries to effectively delete an entire zone by bumping
    // the version number.
    // node => version
    mapping(bytes32=>uint256) private versions;

    // The records themselves.  Stored as binary RRSETs
    // node => version => name => resource => data
    mapping(bytes32=>mapping(uint256=>mapping(bytes32=>mapping(uint16=>bytes)))) private records;

    // Count of number of entries for a given name.  Required for DNS resolvers
    // when resolving wildcards.
    // node => version => name => number of records
    mapping(bytes32=>mapping(uint256=>mapping(bytes32=>uint16))) private nameEntriesCount;

    /**
     * Set one or more DNS records.  Records are supplied in wire-format.
     * Records with the same node/name/resource must be supplied one after the
     * other to ensure the data is updated correctly. For example, if the data
     * was supplied:
     *     a.example.com IN A 1.2.3.4
     *     a.example.com IN A 5.6.7.8
     *     www.example.com IN CNAME a.example.com.
     * then this would store the two A records for a.example.com correctly as a
     * single RRSET, however if the data was supplied:
     *     a.example.com IN A 1.2.3.4
     *     www.example.com IN CNAME a.example.com.
     *     a.example.com IN A 5.6.7.8
     * then this would store the first A record, the CNAME, then the second A
     * record which would overwrite the first.
     *
     * @param node the namehash of the node for which to set the records
     * @param data the DNS wire format records to set
     */
    function setDNSRecords(bytes32 node, bytes calldata data) external authorised(node) {
        uint16 resource = 0;
        uint256 offset = 0;
        bytes memory name;
        bytes memory value;
        bytes32 nameHash;
        // Iterate over the data to add the resource records
        for (RRUtils.RRIterator memory iter = data.iterateRRs(0); !iter.done(); iter.next()) {
            if (resource == 0) {
                resource = iter.dnstype;
                name = iter.name();
                nameHash = keccak256(abi.encodePacked(name));
                value = bytes(iter.rdata());
            } else {
                bytes memory newName = iter.name();
                if (resource != iter.dnstype || !name.equals(newName)) {
                    setDNSRRSet(node, name, resource, data, offset, iter.offset - offset, value.length == 0);
                    resource = iter.dnstype;
                    offset = iter.offset;
                    name = newName;
                    nameHash = keccak256(name);
                    value = bytes(iter.rdata());
                }
            }
        }
        if (name.length > 0) {
            setDNSRRSet(node, name, resource, data, offset, data.length - offset, value.length == 0);
        }
    }

    /**
     * Obtain a DNS record.
     * @param node the namehash of the node for which to fetch the record
     * @param name the keccak-256 hash of the fully-qualified name for which to fetch the record
     * @param resource the ID of the resource as per https://en.wikipedia.org/wiki/List_of_DNS_record_types
     * @return the DNS record in wire format if present, otherwise empty
     */
    function dnsRecord(bytes32 node, bytes32 name, uint16 resource) public view returns (bytes memory) {
        return records[node][versions[node]][name][resource];
    }

    /**
     * Check if a given node has records.
     * @param node the namehash of the node for which to check the records
     * @param name the namehash of the node for which to check the records
     */
    function hasDNSRecords(bytes32 node, bytes32 name) public view returns (bool) {
        return (nameEntriesCount[node][versions[node]][name] != 0);
    }

    /**
     * Clear all information for a DNS zone.
     * @param node the namehash of the node for which to clear the zone
     */
    function clearDNSZone(bytes32 node) public authorised(node) {
        versions[node]++;
        emit DNSZoneCleared(node);
    }

    function supportsInterface(bytes4 interfaceID) public pure returns(bool) {
        return interfaceID == DNS_RECORD_INTERFACE_ID || super.supportsInterface(interfaceID);
    }

    function setDNSRRSet(
        bytes32 node,
        bytes memory name,
        uint16 resource,
        bytes memory data,
        uint256 offset,
        uint256 size,
        bool deleteRecord) private
    {
        uint256 version = versions[node];
        bytes32 nameHash = keccak256(name);
        bytes memory rrData = data.substring(offset, size);
        if (deleteRecord) {
            if (records[node][version][nameHash][resource].length != 0) {
                nameEntriesCount[node][version][nameHash]--;
            }
            delete(records[node][version][nameHash][resource]);
            emit DNSRecordDeleted(node, name, resource);
        } else {
            if (records[node][version][nameHash][resource].length == 0) {
                nameEntriesCount[node][version][nameHash]++;
            }
            records[node][version][nameHash][resource] = rrData;
            emit DNSRecordChanged(node, name, resource, rrData);
        }
    }
}

// File: contracts/profiles/InterfaceResolver.sol

pragma solidity ^0.5.0;



contract InterfaceResolver is ResolverBase, AddrResolver {
    bytes4 constant private INTERFACE_INTERFACE_ID = bytes4(keccak256("interfaceImplementer(bytes32,bytes4)"));
    bytes4 private constant INTERFACE_META_ID = 0x01ffc9a7;

    event InterfaceChanged(bytes32 indexed node, bytes4 indexed interfaceID, address implementer);

    mapping(bytes32=>mapping(bytes4=>address)) interfaces;

    /**
     * Sets an interface associated with a name.
     * Setting the address to 0 restores the default behaviour of querying the contract at `addr()` for interface support.
     * @param node The node to update.
     * @param interfaceID The EIP 168 interface ID.
     * @param implementer The address of a contract that implements this interface for this node.
     */
    function setInterface(bytes32 node, bytes4 interfaceID, address implementer) external authorised(node) {
        interfaces[node][interfaceID] = implementer;
        emit InterfaceChanged(node, interfaceID, implementer);
    }

    /**
     * Returns the address of a contract that implements the specified interface for this name.
     * If an implementer has not been set for this interfaceID and name, the resolver will query
     * the contract at `addr()`. If `addr()` is set, a contract exists at that address, and that
     * contract implements EIP168 and returns `true` for the specified interfaceID, its address
     * will be returned.
     * @param node The ENS node to query.
     * @param interfaceID The EIP 168 interface ID to check for.
     * @return The address that implements this interface, or 0 if the interface is unsupported.
     */
    function interfaceImplementer(bytes32 node, bytes4 interfaceID) external view returns (address) {
        address implementer = interfaces[node][interfaceID];
        if(implementer != address(0)) {
            return implementer;
        }

        address a = addr(node);
        if(a == address(0)) {
            return address(0);
        }

        (bool success, bytes memory returnData) = a.staticcall(abi.encodeWithSignature("supportsInterface(bytes4)", INTERFACE_META_ID));
        if(!success || returnData.length < 32 || returnData[31] == 0) {
            // EIP 168 not supported by target
            return address(0);
        }

        (success, returnData) = a.staticcall(abi.encodeWithSignature("supportsInterface(bytes4)", interfaceID));
        if(!success || returnData.length < 32 || returnData[31] == 0) {
            // Specified interface not supported by target
            return address(0);
        }

        return a;
    }

    function supportsInterface(bytes4 interfaceID) public pure returns(bool) {
        return interfaceID == INTERFACE_INTERFACE_ID || super.supportsInterface(interfaceID);
    }
}

// File: contracts/profiles/NameResolver.sol

pragma solidity ^0.5.0;


contract NameResolver is ResolverBase {
    bytes4 constant private NAME_INTERFACE_ID = 0x691f3431;

    event NameChanged(bytes32 indexed node, string name);

    mapping(bytes32=>string) names;

    /**
     * Sets the name associated with an ENS node, for reverse records.
     * May only be called by the owner of that node in the ENS registry.
     * @param node The node to update.
     * @param name The name to set.
     */
    function setName(bytes32 node, string calldata name) external authorised(node) {
        names[node] = name;
        emit NameChanged(node, name);
    }

    /**
     * Returns the name associated with an ENS node, for reverse records.
     * Defined in EIP181.
     * @param node The ENS node to query.
     * @return The associated name.
     */
    function name(bytes32 node) external view returns (string memory) {
        return names[node];
    }

    function supportsInterface(bytes4 interfaceID) public pure returns(bool) {
        return interfaceID == NAME_INTERFACE_ID || super.supportsInterface(interfaceID);
    }
}

// File: contracts/profiles/PubkeyResolver.sol

pragma solidity ^0.5.0;


contract PubkeyResolver is ResolverBase {
    bytes4 constant private PUBKEY_INTERFACE_ID = 0xc8690233;

    event PubkeyChanged(bytes32 indexed node, bytes32 x, bytes32 y);

    struct PublicKey {
        bytes32 x;
        bytes32 y;
    }

    mapping(bytes32=>PublicKey) pubkeys;

    /**
     * Sets the SECP256k1 public key associated with an ENS node.
     * @param node The ENS node to query
     * @param x the X coordinate of the curve point for the public key.
     * @param y the Y coordinate of the curve point for the public key.
     */
    function setPubkey(bytes32 node, bytes32 x, bytes32 y) external authorised(node) {
        pubkeys[node] = PublicKey(x, y);
        emit PubkeyChanged(node, x, y);
    }

    /**
     * Returns the SECP256k1 public key associated with an ENS node.
     * Defined in EIP 619.
     * @param node The ENS node to query
     * @return x, y the X and Y coordinates of the curve point for the public key.
     */
    function pubkey(bytes32 node) external view returns (bytes32 x, bytes32 y) {
        return (pubkeys[node].x, pubkeys[node].y);
    }

    function supportsInterface(bytes4 interfaceID) public pure returns(bool) {
        return interfaceID == PUBKEY_INTERFACE_ID || super.supportsInterface(interfaceID);
    }
}

// File: contracts/profiles/TextResolver.sol

pragma solidity ^0.5.0;


contract TextResolver is ResolverBase {
    bytes4 constant private TEXT_INTERFACE_ID = 0x59d1d43c;

    event TextChanged(bytes32 indexed node, string indexed indexedKey, string key);

    mapping(bytes32=>mapping(string=>string)) texts;

    /**
     * Sets the text data associated with an ENS node and key.
     * May only be called by the owner of that node in the ENS registry.
     * @param node The node to update.
     * @param key The key to set.
     * @param value The text data value to set.
     */
    function setText(bytes32 node, string calldata key, string calldata value) external authorised(node) {
        texts[node][key] = value;
        emit TextChanged(node, key, key);
    }

    /**
     * Returns the text data associated with an ENS node and key.
     * @param node The ENS node to query.
     * @param key The text data key to query.
     * @return The associated text data.
     */
    function text(bytes32 node, string calldata key) external view returns (string memory) {
        return texts[node][key];
    }

    function supportsInterface(bytes4 interfaceID) public pure returns(bool) {
        return interfaceID == TEXT_INTERFACE_ID || super.supportsInterface(interfaceID);
    }
}

// File: contracts/PublicResolver.sol

pragma solidity ^0.5.0;
pragma experimental ABIEncoderV2;










/**
 * A simple resolver anyone can use; only allows the owner of a node to set its
 * address.
 */
contract PublicResolver is ABIResolver, AddrResolver, ContentHashResolver, DNSResolver, InterfaceResolver, NameResolver, PubkeyResolver, TextResolver {
    ENS ens;

    /**
     * A mapping of authorisations. An address that is authorised for a name
     * may make any changes to the name that the owner could, but may not update
     * the set of authorisations.
     * (node, owner, caller) => isAuthorised
     */
    mapping(bytes32=>mapping(address=>mapping(address=>bool))) public authorisations;

    event AuthorisationChanged(bytes32 indexed node, address indexed owner, address indexed target, bool isAuthorised);

    constructor(ENS _ens) public {
        ens = _ens;
    }

    /**
     * @dev Sets or clears an authorisation.
     * Authorisations are specific to the caller. Any account can set an authorisation
     * for any name, but the authorisation that is checked will be that of the
     * current owner of a name. Thus, transferring a name effectively clears any
     * existing authorisations, and new authorisations can be set in advance of
     * an ownership transfer if desired.
     *
     * @param node The name to change the authorisation on.
     * @param target The address that is to be authorised or deauthorised.
     * @param isAuthorised True if the address should be authorised, or false if it should be deauthorised.
     */
    function setAuthorisation(bytes32 node, address target, bool isAuthorised) external {
        authorisations[node][msg.sender][target] = isAuthorised;
        emit AuthorisationChanged(node, msg.sender, target, isAuthorised);
    }

    function isAuthorised(bytes32 node) internal view returns(bool) {
        address owner = ens.owner(node);
        return owner == msg.sender || authorisations[node][owner][msg.sender];
    }

    function multicall(bytes[] calldata data) external returns(bytes[] memory results) {
        results = new bytes[](data.length);
        for(uint i = 0; i < data.length; i++) {
            (bool success, bytes memory result) = address(this).delegatecall(data[i]);
            require(success);
            results[i] = result;
        }
        return results;
    }
}

// File: contracts/SafeMath.sol

pragma solidity >=0.4.24;

/**
 * @title SafeMath
 * @dev Unsigned math operations with safety checks that revert on error
 */
library SafeMath {
    /**
    * @dev Multiplies two unsigned integers, reverts on overflow.
    */
    function mul(uint256 a, uint256 b) internal pure returns (uint256) {
        // Gas optimization: this is cheaper than requiring 'a' not being zero, but the
        // benefit is lost if 'b' is also tested.
        // See: https://github.com/OpenZeppelin/openzeppelin-solidity/pull/522
        if (a == 0) {
            return 0;
        }

        uint256 c = a * b;
        require(c / a == b);

        return c;
    }

    /**
    * @dev Integer division of two unsigned integers truncating the quotient, reverts on division by zero.
    */
    function div(uint256 a, uint256 b) internal pure returns (uint256) {
        // Solidity only automatically asserts when dividing by 0
        require(b > 0);
        uint256 c = a / b;
        // assert(a == b * c + a % b); // There is no case in which this doesn't hold

        return c;
    }

    /**
    * @dev Subtracts two unsigned integers, reverts on overflow (i.e. if subtrahend is greater than minuend).
    */
    function sub(uint256 a, uint256 b) internal pure returns (uint256) {
        require(b <= a);
        uint256 c = a - b;

        return c;
    }

    /**
    * @dev Adds two unsigned integers, reverts on overflow.
    */
    function add(uint256 a, uint256 b) internal pure returns (uint256) {
        uint256 c = a + b;
        require(c >= a);

        return c;
    }

    /**
    * @dev Divides two unsigned integers and returns the remainder (unsigned integer modulo),
    * reverts when dividing by zero.
    */
    function mod(uint256 a, uint256 b) internal pure returns (uint256) {
        require(b != 0);
        return a % b;
    }
}

// File: contracts/PriceOracle.sol

pragma solidity >=0.4.24;

interface PriceOracle {
    /**
     * @dev Returns the price to register or renew a name.
     * @param name The name being registered or renewed.
     * @param expires When the name presently expires (0 if this is a new registration).
     * @param duration How long the name is being registered or extended for, in seconds.
     * @return The price of this renewal or registration, in wei.
     */
    function price(string calldata name, uint expires, uint duration) external view returns(uint);
}

// File: contracts/StringUtils.sol

pragma solidity >=0.4.24;

library StringUtils {
    /**
     * @dev Returns the length of a given string
     *
     * @param s The string to measure the length of
     * @return The length of the input string
     */
    function strlen(string memory s) internal pure returns (uint) {
        uint len;
        uint i = 0;
        uint bytelength = bytes(s).length;
        for(len = 0; i < bytelength; len++) {
            byte b = bytes(s)[i];
            if(b < 0x80) {
                i += 1;
            } else if (b < 0xE0) {
                i += 2;
            } else if (b < 0xF0) {
                i += 3;
            } else if (b < 0xF8) {
                i += 4;
            } else if (b < 0xFC) {
                i += 5;
            } else {
                i += 6;
            }
        }
        return len;
    }
}

// File: openzeppelin-solidity/contracts/ownership/Ownable.sol

pragma solidity ^0.5.0;

/**
 * @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 private _owner;

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

    /**
     * @dev The Ownable constructor sets the original `owner` of the contract to the sender
     * account.
     */
    constructor () internal {
        _owner = msg.sender;
        emit OwnershipTransferred(address(0), _owner);
    }

    /**
     * @return the address of the owner.
     */
    function owner() public view returns (address) {
        return _owner;
    }

    /**
     * @dev Throws if called by any account other than the owner.
     */
    modifier onlyOwner() {
        require(isOwner());
        _;
    }

    /**
     * @return true if `msg.sender` is the owner of the contract.
     */
    function isOwner() public view returns (bool) {
        return msg.sender == _owner;
    }

    /**
     * @dev Allows the current owner to relinquish control of the contract.
     * @notice Renouncing to ownership will leave the contract without an owner.
     * It will not be possible to call the functions with the `onlyOwner`
     * modifier anymore.
     */
    function renounceOwnership() public onlyOwner {
        emit OwnershipTransferred(_owner, address(0));
        _owner = address(0);
    }

    /**
     * @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 {
        _transferOwnership(newOwner);
    }

    /**
     * @dev Transfers control of the contract to a newOwner.
     * @param newOwner The address to transfer ownership to.
     */
    function _transferOwnership(address newOwner) internal {
        require(newOwner != address(0));
        emit OwnershipTransferred(_owner, newOwner);
        _owner = newOwner;
    }
}

// File: contracts/StablePriceOracle.sol

pragma solidity >=0.5.0;





interface AggregatorInterface {
  function latestAnswer() external view returns (int256);
}


// StablePriceOracle sets a price in USD, based on an oracle.
contract StablePriceOracle is Ownable, PriceOracle {
    using SafeMath for *;
    using StringUtils for *;

    // Rent in base price units by length. Element 0 is for 1-length names, and so on.
    uint[] public rentPrices;

    // Oracle address
    AggregatorInterface public usdOracle;

    event OracleChanged(address oracle);

    event RentPriceChanged(uint[] prices);

    bytes4 constant private INTERFACE_META_ID = bytes4(keccak256("supportsInterface(bytes4)"));
    bytes4 constant private ORACLE_ID = bytes4(keccak256("price(string,uint256,uint256)") ^ keccak256("premium(string,uint256,uint256)"));

    constructor(AggregatorInterface _usdOracle, uint[] memory _rentPrices) public {
        usdOracle = _usdOracle;
        setPrices(_rentPrices);
    }

    function price(string calldata name, uint expires, uint duration) external view returns(uint) {
        uint len = name.strlen();
        if(len > rentPrices.length) {
            len = rentPrices.length;
        }
        require(len > 0);
        
        uint basePrice = rentPrices[len - 1].mul(duration);
        basePrice = basePrice.add(_premium(name, expires, duration));

        return attoUSDToWei(basePrice);
    }

    /**
     * @dev Sets rent prices.
     * @param _rentPrices The price array. Each element corresponds to a specific
     *                    name length; names longer than the length of the array
     *                    default to the price of the last element. Values are
     *                    in base price units, equal to one attodollar (1e-18
     *                    dollar) each.
     */
    function setPrices(uint[] memory _rentPrices) public onlyOwner {
        rentPrices = _rentPrices;
        emit RentPriceChanged(_rentPrices);
    }

    /**
     * @dev Sets the price oracle address
     * @param _usdOracle The address of the price oracle to use.
     */
    function setOracle(AggregatorInterface _usdOracle) public onlyOwner {
        usdOracle = _usdOracle;
        emit OracleChanged(address(_usdOracle));
    }

    /**
     * @dev Returns the pricing premium in wei.
     */
    function premium(string calldata name, uint expires, uint duration) external view returns(uint) {
        return attoUSDToWei(_premium(name, expires, duration));
    }

    /**
     * @dev Returns the pricing premium in internal base units.
     */
    function _premium(string memory name, uint expires, uint duration) internal view returns(uint) {
        return 0;
    }

    function attoUSDToWei(uint amount) internal view returns(uint) {
        uint ethPrice = uint(usdOracle.latestAnswer());
        return amount.mul(1e8).div(ethPrice);
    }

    function weiToAttoUSD(uint amount) internal view returns(uint) {
        uint ethPrice = uint(usdOracle.latestAnswer());
        return amount.mul(ethPrice).div(1e8);
    }

    function supportsInterface(bytes4 interfaceID) public view returns (bool) {
        return interfaceID == INTERFACE_META_ID || interfaceID == ORACLE_ID;
    }
}

// File: contracts/LinearPremiumPriceOracle.sol

pragma solidity >=0.5.0;



contract LinearPremiumPriceOracle is StablePriceOracle {
    using SafeMath for *;

    uint GRACE_PERIOD = 90 days;

    uint public initialPremium;
    uint public premiumDecreaseRate;

    bytes4 constant private TIME_UNTIL_PREMIUM_ID = bytes4(keccak256("timeUntilPremium(uint,uint"));

    constructor(AggregatorInterface _usdOracle, uint[] memory _rentPrices, uint _initialPremium, uint _premiumDecreaseRate) public
        StablePriceOracle(_usdOracle, _rentPrices)
    {
        initialPremium = _initialPremium;
        premiumDecreaseRate = _premiumDecreaseRate;
    }

    function _premium(string memory name, uint expires, uint /*duration*/) internal view returns(uint) {
        expires = expires.add(GRACE_PERIOD);
        if(expires > now) {
            // No premium for renewals
            return 0;
        }

        // Calculate the discount off the maximum premium
        uint discount = premiumDecreaseRate.mul(now.sub(expires));

        // If we've run out the premium period, return 0.
        if(discount > initialPremium) {
            return 0;
        }
        
        return initialPremium - discount;
    }

    /**
     * @dev Returns the timestamp at which a name with the specified expiry date will have
     *      the specified re-registration price premium.
     * @param expires The timestamp at which the name expires.
     * @param amount The amount, in wei, the caller is willing to pay
     * @return The timestamp at which the premium for this domain will be `amount`.
     */
    function timeUntilPremium(uint expires, uint amount) external view returns(uint) {
        amount = weiToAttoUSD(amount);
        require(amount <= initialPremium);

        expires = expires.add(GRACE_PERIOD);

        uint discount = initialPremium.sub(amount);
        uint duration = discount.div(premiumDecreaseRate);
        return expires.add(duration);
    }

    function supportsInterface(bytes4 interfaceID) public view returns (bool) {
        return (interfaceID == TIME_UNTIL_PREMIUM_ID) || super.supportsInterface(interfaceID);
    }
}

/**
* @dev A library for working with mutable byte buffers in Solidity.
*
* Byte buffers are mutable and expandable, and provide a variety of primitives
* for writing to them. At any time you can fetch a bytes object containing the
* current contents of the buffer. The bytes object should not be stored between
* operations, as it may change due to resizing of the buffer.
*/
library Buffer {
  /**
  * @dev Represents a mutable buffer. Buffers have a current value (buf) and
  *      a capacity. The capacity may be longer than the current value, in
  *      which case it can be extended without the need to allocate more memory.
  */
  struct buffer {
    bytes buf;
    uint capacity;
  }

  /**
  * @dev Initializes a buffer with an initial capacity.
  * @param buf The buffer to initialize.
  * @param capacity The number of bytes of space to allocate the buffer.
  * @return The buffer, for chaining.
  */
  function init(buffer memory buf, uint capacity) internal pure returns(buffer memory) {
    if (capacity % 32 != 0) {
      capacity += 32 - (capacity % 32);
    }
    // Allocate space for the buffer data
    buf.capacity = capacity;
    assembly {
      let ptr := mload(0x40)
      mstore(buf, ptr)
      mstore(ptr, 0)
      mstore(0x40, add(32, add(ptr, capacity)))
    }
    return buf;
  }

  /**
  * @dev Initializes a new buffer from an existing bytes object.
  *      Changes to the buffer may mutate the original value.
  * @param b The bytes object to initialize the buffer with.
  * @return A new buffer.
  */
  function fromBytes(bytes memory b) internal pure returns(buffer memory) {
    buffer memory buf;
    buf.buf = b;
    buf.capacity = b.length;
    return buf;
  }

  function resize(buffer memory buf, uint capacity) private pure {
    bytes memory oldbuf = buf.buf;
    init(buf, capacity);
    append(buf, oldbuf);
  }

  function max(uint a, uint b) private pure returns(uint) {
    if (a > b) {
      return a;
    }
    return b;
  }

  /**
  * @dev Sets buffer length to 0.
  * @param buf The buffer to truncate.
  * @return The original buffer, for chaining..
  */
  function truncate(buffer memory buf) internal pure returns (buffer memory) {
    assembly {
      let bufptr := mload(buf)
      mstore(bufptr, 0)
    }
    return buf;
  }

  /**
  * @dev Writes a byte string to a buffer. Resizes if doing so would exceed
  *      the capacity of the buffer.
  * @param buf The buffer to append to.
  * @param off The start offset to write to.
  * @param data The data to append.
  * @param len The number of bytes to copy.
  * @return The original buffer, for chaining.
  */
  function write(buffer memory buf, uint off, bytes memory data, uint len) internal pure returns(buffer memory) {
    require(len <= data.length);

    if (off + len > buf.capacity) {
      resize(buf, max(buf.capacity, len + off) * 2);
    }

    uint dest;
    uint src;
    assembly {
      // Memory address of the buffer data
      let bufptr := mload(buf)
      // Length of existing buffer data
      let buflen := mload(bufptr)
      // Start address = buffer address + offset + sizeof(buffer length)
      dest := add(add(bufptr, 32), off)
      // Update buffer length if we're extending it
      if gt(add(len, off), buflen) {
        mstore(bufptr, add(len, off))
      }
      src := add(data, 32)
    }

    // Copy word-length chunks while possible
    for (; len >= 32; len -= 32) {
      assembly {
        mstore(dest, mload(src))
      }
      dest += 32;
      src += 32;
    }

    // Copy remaining bytes
    uint mask = 256 ** (32 - len) - 1;
    assembly {
      let srcpart := and(mload(src), not(mask))
      let destpart := and(mload(dest), mask)
      mstore(dest, or(destpart, srcpart))
    }

    return buf;
  }

  /**
  * @dev Appends a byte string to a buffer. Resizes if doing so would exceed
  *      the capacity of the buffer.
  * @param buf The buffer to append to.
  * @param data The data to append.
  * @param len The number of bytes to copy.
  * @return The original buffer, for chaining.
  */
  function append(buffer memory buf, bytes memory data, uint len) internal pure returns (buffer memory) {
    return write(buf, buf.buf.length, data, len);
  }

  /**
  * @dev Appends a byte string to a buffer. Resizes if doing so would exceed
  *      the capacity of the buffer.
  * @param buf The buffer to append to.
  * @param data The data to append.
  * @return The original buffer, for chaining.
  */
  function append(buffer memory buf, bytes memory data) internal pure returns (buffer memory) {
    return write(buf, buf.buf.length, data, data.length);
  }

  /**
  * @dev Writes a byte to the buffer. Resizes if doing so would exceed the
  *      capacity of the buffer.
  * @param buf The buffer to append to.
  * @param off The offset to write the byte at.
  * @param data The data to append.
  * @return The original buffer, for chaining.
  */
  function writeUint8(buffer memory buf, uint off, uint8 data) internal pure returns(buffer memory) {
    if (off >= buf.capacity) {
      resize(buf, buf.capacity * 2);
    }

    assembly {
      // Memory address of the buffer data
      let bufptr := mload(buf)
      // Length of existing buffer data
      let buflen := mload(bufptr)
      // Address = buffer address + sizeof(buffer length) + off
      let dest := add(add(bufptr, off), 32)
      mstore8(dest, data)
      // Update buffer length if we extended it
      if eq(off, buflen) {
        mstore(bufptr, add(buflen, 1))
      }
    }
    return buf;
  }

  /**
  * @dev Appends a byte to the buffer. Resizes if doing so would exceed the
  *      capacity of the buffer.
  * @param buf The buffer to append to.
  * @param data The data to append.
  * @return The original buffer, for chaining.
  */
  function appendUint8(buffer memory buf, uint8 data) internal pure returns(buffer memory) {
    return writeUint8(buf, buf.buf.length, data);
  }

  /**
  * @dev Writes up to 32 bytes to the buffer. Resizes if doing so would
  *      exceed the capacity of the buffer.
  * @param buf The buffer to append to.
  * @param off The offset to write at.
  * @param data The data to append.
  * @param len The number of bytes to write (left-aligned).
  * @return The original buffer, for chaining.
  */
  function write(buffer memory buf, uint off, bytes32 data, uint len) private pure returns(buffer memory) {
    if (len + off > buf.capacity) {
      resize(buf, (len + off) * 2);
    }

    uint mask = 256 ** len - 1;
    // Right-align data
    data = data >> (8 * (32 - len));
    assembly {
      // Memory address of the buffer data
      let bufptr := mload(buf)
      // Address = buffer address + sizeof(buffer length) + off + len
      let dest := add(add(bufptr, off), len)
      mstore(dest, or(and(mload(dest), not(mask)), data))
      // Update buffer length if we extended it
      if gt(add(off, len), mload(bufptr)) {
        mstore(bufptr, add(off, len))
      }
    }
    return buf;
  }

  /**
  * @dev Writes a bytes20 to the buffer. Resizes if doing so would exceed the
  *      capacity of the buffer.
  * @param buf The buffer to append to.
  * @param off The offset to write at.
  * @param data The data to append.
  * @return The original buffer, for chaining.
  */
  function writeBytes20(buffer memory buf, uint off, bytes20 data) internal pure returns (buffer memory) {
    return write(buf, off, bytes32(data), 20);
  }

  /**
  * @dev Appends a bytes20 to the buffer. Resizes if doing so would exceed
  *      the capacity of the buffer.
  * @param buf The buffer to append to.
  * @param data The data to append.
  * @return The original buffer, for chhaining.
  */
  function appendBytes20(buffer memory buf, bytes20 data) internal pure returns (buffer memory) {
    return write(buf, buf.buf.length, bytes32(data), 20);
  }

  /**
  * @dev Appends a bytes32 to the buffer. Resizes if doing so would exceed
  *      the capacity of the buffer.
  * @param buf The buffer to append to.
  * @param data The data to append.
  * @return The original buffer, for chaining.
  */
  function appendBytes32(buffer memory buf, bytes32 data) internal pure returns (buffer memory) {
    return write(buf, buf.buf.length, data, 32);
  }

  /**
  * @dev Writes an integer to the buffer. Resizes if doing so would exceed
  *      the capacity of the buffer.
  * @param buf The buffer to append to.
  * @param off The offset to write at.
  * @param data The data to append.
  * @param len The number of bytes to write (right-aligned).
  * @return The original buffer, for chaining.
  */
  function writeInt(buffer memory buf, uint off, uint data, uint len) private pure returns(buffer memory) {
    if (len + off > buf.capacity) {
      resize(buf, (len + off) * 2);
    }

    uint mask = 256 ** len - 1;
    assembly {
      // Memory address of the buffer data
      let bufptr := mload(buf)
      // Address = buffer address + off + sizeof(buffer length) + len
      let dest := add(add(bufptr, off), len)
      mstore(dest, or(and(mload(dest), not(mask)), data))
      // Update buffer length if we extended it
      if gt(add(off, len), mload(bufptr)) {
        mstore(bufptr, add(off, len))
      }
    }
    return buf;
  }

  /**
   * @dev Appends a byte to the end of the buffer. Resizes if doing so would
   * exceed the capacity of the buffer.
   * @param buf The buffer to append to.
   * @param data The data to append.
   * @return The original buffer.
   */
  function appendInt(buffer memory buf, uint data, uint len) internal pure returns(buffer memory) {
    return writeInt(buf, buf.buf.length, data, len);
  }
}

library CBOR {
  using Buffer for Buffer.buffer;

  uint8 private constant MAJOR_TYPE_INT = 0;
  uint8 private constant MAJOR_TYPE_NEGATIVE_INT = 1;
  uint8 private constant MAJOR_TYPE_BYTES = 2;
  uint8 private constant MAJOR_TYPE_STRING = 3;
  uint8 private constant MAJOR_TYPE_ARRAY = 4;
  uint8 private constant MAJOR_TYPE_MAP = 5;
  uint8 private constant MAJOR_TYPE_CONTENT_FREE = 7;

  function encodeType(Buffer.buffer memory buf, uint8 major, uint value) private pure {
    if(value <= 23) {
      buf.appendUint8(uint8((major << 5) | value));
    } else if(value <= 0xFF) {
      buf.appendUint8(uint8((major << 5) | 24));
      buf.appendInt(value, 1);
    } else if(value <= 0xFFFF) {
      buf.appendUint8(uint8((major << 5) | 25));
      buf.appendInt(value, 2);
    } else if(value <= 0xFFFFFFFF) {
      buf.appendUint8(uint8((major << 5) | 26));
      buf.appendInt(value, 4);
    } else if(value <= 0xFFFFFFFFFFFFFFFF) {
      buf.appendUint8(uint8((major << 5) | 27));
      buf.appendInt(value, 8);
    }
  }

  function encodeIndefiniteLengthType(Buffer.buffer memory buf, uint8 major) private pure {
    buf.appendUint8(uint8((major << 5) | 31));
  }

  function encodeUInt(Buffer.buffer memory buf, uint value) internal pure {
    encodeType(buf, MAJOR_TYPE_INT, value);
  }

  function encodeInt(Buffer.buffer memory buf, int value) internal pure {
    if(value >= 0) {
      encodeType(buf, MAJOR_TYPE_INT, uint(value));
    } else {
      encodeType(buf, MAJOR_TYPE_NEGATIVE_INT, uint(-1 - value));
    }
  }

  function encodeBytes(Buffer.buffer memory buf, bytes value) internal pure {
    encodeType(buf, MAJOR_TYPE_BYTES, value.length);
    buf.append(value);
  }

  function encodeString(Buffer.buffer memory buf, string value) internal pure {
    encodeType(buf, MAJOR_TYPE_STRING, bytes(value).length);
    buf.append(bytes(value));
  }

  function startArray(Buffer.buffer memory buf) internal pure {
    encodeIndefiniteLengthType(buf, MAJOR_TYPE_ARRAY);
  }

  function startMap(Buffer.buffer memory buf) internal pure {
    encodeIndefiniteLengthType(buf, MAJOR_TYPE_MAP);
  }

  function endSequence(Buffer.buffer memory buf) internal pure {
    encodeIndefiniteLengthType(buf, MAJOR_TYPE_CONTENT_FREE);
  }
}

/**
 * @title Library for common Chainlink functions
 * @dev Uses imported CBOR library for encoding to buffer
 */
library Chainlink {
  uint256 internal constant defaultBufferSize = 256; // solhint-disable-line const-name-snakecase

  using CBOR for Buffer.buffer;

  struct Request {
    bytes32 id;
    address callbackAddress;
    bytes4 callbackFunctionId;
    uint256 nonce;
    Buffer.buffer buf;
  }

  /**
   * @notice Initializes a Chainlink request
   * @dev Sets the ID, callback address, and callback function signature on the request
   * @param self The uninitialized request
   * @param _id The Job Specification ID
   * @param _callbackAddress The callback address
   * @param _callbackFunction The callback function signature
   * @return The initialized request
   */
  function initialize(
    Request memory self,
    bytes32 _id,
    address _callbackAddress,
    bytes4 _callbackFunction
  ) internal pure returns (Chainlink.Request memory) {
    Buffer.init(self.buf, defaultBufferSize);
    self.id = _id;
    self.callbackAddress = _callbackAddress;
    self.callbackFunctionId = _callbackFunction;
    return self;
  }

  /**
   * @notice Sets the data for the buffer without encoding CBOR on-chain
   * @dev CBOR can be closed with curly-brackets {} or they can be left off
   * @param self The initialized request
   * @param _data The CBOR data
   */
  function setBuffer(Request memory self, bytes _data)
    internal pure
  {
    Buffer.init(self.buf, _data.length);
    Buffer.append(self.buf, _data);
  }

  /**
   * @notice Adds a string value to the request with a given key name
   * @param self The initialized request
   * @param _key The name of the key
   * @param _value The string value to add
   */
  function add(Request memory self, string _key, string _value)
    internal pure
  {
    self.buf.encodeString(_key);
    self.buf.encodeString(_value);
  }

  /**
   * @notice Adds a bytes value to the request with a given key name
   * @param self The initialized request
   * @param _key The name of the key
   * @param _value The bytes value to add
   */
  function addBytes(Request memory self, string _key, bytes _value)
    internal pure
  {
    self.buf.encodeString(_key);
    self.buf.encodeBytes(_value);
  }

  /**
   * @notice Adds a int256 value to the request with a given key name
   * @param self The initialized request
   * @param _key The name of the key
   * @param _value The int256 value to add
   */
  function addInt(Request memory self, string _key, int256 _value)
    internal pure
  {
    self.buf.encodeString(_key);
    self.buf.encodeInt(_value);
  }

  /**
   * @notice Adds a uint256 value to the request with a given key name
   * @param self The initialized request
   * @param _key The name of the key
   * @param _value The uint256 value to add
   */
  function addUint(Request memory self, string _key, uint256 _value)
    internal pure
  {
    self.buf.encodeString(_key);
    self.buf.encodeUInt(_value);
  }

  /**
   * @notice Adds an array of strings to the request with a given key name
   * @param self The initialized request
   * @param _key The name of the key
   * @param _values The array of string values to add
   */
  function addStringArray(Request memory self, string _key, string[] memory _values)
    internal pure
  {
    self.buf.encodeString(_key);
    self.buf.startArray();
    for (uint256 i = 0; i < _values.length; i++) {
      self.buf.encodeString(_values[i]);
    }
    self.buf.endSequence();
  }
}

interface ENSInterface {

  // Logged when the owner of a node assigns a new owner to a subnode.
  event NewOwner(bytes32 indexed node, bytes32 indexed label, address owner);

  // Logged when the owner of a node transfers ownership to a new account.
  event Transfer(bytes32 indexed node, address owner);

  // Logged when the resolver for a node changes.
  event NewResolver(bytes32 indexed node, address resolver);

  // Logged when the TTL of a node changes
  event NewTTL(bytes32 indexed node, uint64 ttl);


  function setSubnodeOwner(bytes32 node, bytes32 label, address owner) external;
  function setResolver(bytes32 node, address resolver) external;
  function setOwner(bytes32 node, address owner) external;
  function setTTL(bytes32 node, uint64 ttl) external;
  function owner(bytes32 node) external view returns (address);
  function resolver(bytes32 node) external view returns (address);
  function ttl(bytes32 node) external view returns (uint64);

}

interface LinkTokenInterface {
  function allowance(address owner, address spender) external returns (uint256 remaining);
  function approve(address spender, uint256 value) external returns (bool success);
  function balanceOf(address owner) external returns (uint256 balance);
  function decimals() external returns (uint8 decimalPlaces);
  function decreaseApproval(address spender, uint256 addedValue) external returns (bool success);
  function increaseApproval(address spender, uint256 subtractedValue) external;
  function name() external returns (string tokenName);
  function symbol() external returns (string tokenSymbol);
  function totalSupply() external returns (uint256 totalTokensIssued);
  function transfer(address to, uint256 value) external returns (bool success);
  function transferAndCall(address to, uint256 value, bytes data) external returns (bool success);
  function transferFrom(address from, address to, uint256 value) external returns (bool success);
}

interface ChainlinkRequestInterface {
  function oracleRequest(
    address sender,
    uint256 payment,
    bytes32 id,
    address callbackAddress,
    bytes4 callbackFunctionId,
    uint256 nonce,
    uint256 version,
    bytes data
  ) external;

  function cancelOracleRequest(
    bytes32 requestId,
    uint256 payment,
    bytes4 callbackFunctionId,
    uint256 expiration
  ) external;
}

interface PointerInterface {
  function getAddress() external view returns (address);
}


contract ENSResolver {
  function addr(bytes32 node) public view returns (address);
}


/**
 * @title SafeMath
 * @dev Math operations with safety checks that throw on error
 */
library SafeMath {

  /**
  * @dev Multiplies two numbers, throws on overflow.
  */
  function mul(uint256 _a, uint256 _b) internal pure returns (uint256 c) {
    // Gas optimization: this is cheaper than asserting 'a' not being zero, but the
    // benefit is lost if 'b' is also tested.
    // See: https://github.com/OpenZeppelin/openzeppelin-solidity/pull/522
    if (_a == 0) {
      return 0;
    }

    c = _a * _b;
    assert(c / _a == _b);
    return c;
  }

  /**
  * @dev Integer division of two numbers, truncating the quotient.
  */
  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 _a / _b;
  }

  /**
  * @dev Subtracts two numbers, throws on overflow (i.e. if subtrahend is greater than minuend).
  */
  function sub(uint256 _a, uint256 _b) internal pure returns (uint256) {
    assert(_b <= _a);
    return _a - _b;
  }

  /**
  * @dev Adds two numbers, throws on overflow.
  */
  function add(uint256 _a, uint256 _b) internal pure returns (uint256 c) {
    c = _a + _b;
    assert(c >= _a);
    return c;
  }
}

/**
 * @title The ChainlinkClient contract
 * @notice Contract writers can inherit this contract in order to create requests for the
 * Chainlink network
 */
contract ChainlinkClient {
  using Chainlink for Chainlink.Request;
  using SafeMath for uint256;

  uint256 constant internal LINK = 10**18;
  uint256 constant private AMOUNT_OVERRIDE = 0;
  address constant private SENDER_OVERRIDE = 0x0;
  uint256 constant private ARGS_VERSION = 1;
  bytes32 constant private ENS_TOKEN_SUBNAME = keccak256("link");
  bytes32 constant private ENS_ORACLE_SUBNAME = keccak256("oracle");
  address constant private LINK_TOKEN_POINTER = 0xC89bD4E1632D3A43CB03AAAd5262cbe4038Bc571;

  ENSInterface private ens;
  bytes32 private ensNode;
  LinkTokenInterface private link;
  ChainlinkRequestInterface private oracle;
  uint256 private requests = 1;
  mapping(bytes32 => address) private pendingRequests;

  event ChainlinkRequested(bytes32 indexed id);
  event ChainlinkFulfilled(bytes32 indexed id);
  event ChainlinkCancelled(bytes32 indexed id);

  /**
   * @notice Creates a request that can hold additional parameters
   * @param _specId The Job Specification ID that the request will be created for
   * @param _callbackAddress The callback address that the response will be sent to
   * @param _callbackFunctionSignature The callback function signature to use for the callback address
   * @return A Chainlink Request struct in memory
   */
  function buildChainlinkRequest(
    bytes32 _specId,
    address _callbackAddress,
    bytes4 _callbackFunctionSignature
  ) internal pure returns (Chainlink.Request memory) {
    Chainlink.Request memory req;
    return req.initialize(_specId, _callbackAddress, _callbackFunctionSignature);
  }

  /**
   * @notice Creates a Chainlink request to the stored oracle address
   * @dev Calls `chainlinkRequestTo` with the stored oracle address
   * @param _req The initialized Chainlink Request
   * @param _payment The amount of LINK to send for the request
   * @return The request ID
   */
  function sendChainlinkRequest(Chainlink.Request memory _req, uint256 _payment)
    internal
    returns (bytes32)
  {
    return sendChainlinkRequestTo(oracle, _req, _payment);
  }

  /**
   * @notice Creates a Chainlink request to the specified oracle address
   * @dev Generates and stores a request ID, increments the local nonce, and uses `transferAndCall` to
   * send LINK which creates a request on the target oracle contract.
   * Emits ChainlinkRequested event.
   * @param _oracle The address of the oracle for the request
   * @param _req The initialized Chainlink Request
   * @param _payment The amount of LINK to send for the request
   * @return The request ID
   */
  function sendChainlinkRequestTo(address _oracle, Chainlink.Request memory _req, uint256 _payment)
    internal
    returns (bytes32 requestId)
  {
    requestId = keccak256(abi.encodePacked(this, requests));
    _req.nonce = requests;
    pendingRequests[requestId] = _oracle;
    emit ChainlinkRequested(requestId);
    require(link.transferAndCall(_oracle, _payment, encodeRequest(_req)), "unable to transferAndCall to oracle");
    requests += 1;

    return requestId;
  }

  /**
   * @notice Allows a request to be cancelled if it has not been fulfilled
   * @dev Requires keeping track of the expiration value emitted from the oracle contract.
   * Deletes the request from the `pendingRequests` mapping.
   * Emits ChainlinkCancelled event.
   * @param _requestId The request ID
   * @param _payment The amount of LINK sent for the request
   * @param _callbackFunc The callback function specified for the request
   * @param _expiration The time of the expiration for the request
   */
  function cancelChainlinkRequest(
    bytes32 _requestId,
    uint256 _payment,
    bytes4 _callbackFunc,
    uint256 _expiration
  )
    internal
  {
    ChainlinkRequestInterface requested = ChainlinkRequestInterface(pendingRequests[_requestId]);
    delete pendingRequests[_requestId];
    emit ChainlinkCancelled(_requestId);
    requested.cancelOracleRequest(_requestId, _payment, _callbackFunc, _expiration);
  }

  /**
   * @notice Sets the stored oracle address
   * @param _oracle The address of the oracle contract
   */
  function setChainlinkOracle(address _oracle) internal {
    oracle = ChainlinkRequestInterface(_oracle);
  }

  /**
   * @notice Sets the LINK token address
   * @param _link The address of the LINK token contract
   */
  function setChainlinkToken(address _link) internal {
    link = LinkTokenInterface(_link);
  }

  /**
   * @notice Sets the Chainlink token address for the public
   * network as given by the Pointer contract
   */
  function setPublicChainlinkToken() internal {
    setChainlinkToken(PointerInterface(LINK_TOKEN_POINTER).getAddress());
  }

  /**
   * @notice Retrieves the stored address of the LINK token
   * @return The address of the LINK token
   */
  function chainlinkTokenAddress()
    internal
    view
    returns (address)
  {
    return address(link);
  }

  /**
   * @notice Retrieves the stored address of the oracle contract
   * @return The address of the oracle contract
   */
  function chainlinkOracleAddress()
    internal
    view
    returns (address)
  {
    return address(oracle);
  }

  /**
   * @notice Allows for a request which was created on another contract to be fulfilled
   * on this contract
   * @param _oracle The address of the oracle contract that will fulfill the request
   * @param _requestId The request ID used for the response
   */
  function addChainlinkExternalRequest(address _oracle, bytes32 _requestId)
    internal
    notPendingRequest(_requestId)
  {
    pendingRequests[_requestId] = _oracle;
  }

  /**
   * @notice Sets the stored oracle and LINK token contracts with the addresses resolved by ENS
   * @dev Accounts for subnodes having different resolvers
   * @param _ens The address of the ENS contract
   * @param _node The ENS node hash
   */
  function useChainlinkWithENS(address _ens, bytes32 _node)
    internal
  {
    ens = ENSInterface(_ens);
    ensNode = _node;
    bytes32 linkSubnode = keccak256(abi.encodePacked(ensNode, ENS_TOKEN_SUBNAME));
    ENSResolver resolver = ENSResolver(ens.resolver(linkSubnode));
    setChainlinkToken(resolver.addr(linkSubnode));
    updateChainlinkOracleWithENS();
  }

  /**
   * @notice Sets the stored oracle contract with the address resolved by ENS
   * @dev This may be called on its own as long as `useChainlinkWithENS` has been called previously
   */
  function updateChainlinkOracleWithENS()
    internal
  {
    bytes32 oracleSubnode = keccak256(abi.encodePacked(ensNode, ENS_ORACLE_SUBNAME));
    ENSResolver resolver = ENSResolver(ens.resolver(oracleSubnode));
    setChainlinkOracle(resolver.addr(oracleSubnode));
  }

  /**
   * @notice Encodes the request to be sent to the oracle contract
   * @dev The Chainlink node expects values to be in order for the request to be picked up. Order of types
   * will be validated in the oracle contract.
   * @param _req The initialized Chainlink Request
   * @return The bytes payload for the `transferAndCall` method
   */
  function encodeRequest(Chainlink.Request memory _req)
    private
    view
    returns (bytes memory)
  {
    return abi.encodeWithSelector(
      oracle.oracleRequest.selector,
      SENDER_OVERRIDE, // Sender value - overridden by onTokenTransfer by the requesting contract's address
      AMOUNT_OVERRIDE, // Amount value - overridden by onTokenTransfer by the actual amount of LINK sent
      _req.id,
      _req.callbackAddress,
      _req.callbackFunctionId,
      _req.nonce,
      ARGS_VERSION,
      _req.buf.buf);
  }

  /**
   * @notice Ensures that the fulfillment is valid for this contract
   * @dev Use if the contract developer prefers methods instead of modifiers for validation
   * @param _requestId The request ID for fulfillment
   */
  function validateChainlinkCallback(bytes32 _requestId)
    internal
    recordChainlinkFulfillment(_requestId)
    // solhint-disable-next-line no-empty-blocks
  {}

  /**
   * @dev Reverts if the sender is not the oracle of the request.
   * Emits ChainlinkFulfilled event.
   * @param _requestId The request ID for fulfillment
   */
  modifier recordChainlinkFulfillment(bytes32 _requestId) {
    require(msg.sender == pendingRequests[_requestId], "Source must be the oracle of the request");
    delete pendingRequests[_requestId];
    emit ChainlinkFulfilled(_requestId);
    _;
  }

  /**
   * @dev Reverts if the request is already pending
   * @param _requestId The request ID for fulfillment
   */
  modifier notPendingRequest(bytes32 _requestId) {
    require(pendingRequests[_requestId] == address(0), "Request is already pending");
    _;
  }
}

interface AggregatorInterface {
  function latestAnswer() external view returns (int256);
  function latestTimestamp() external view returns (uint256);
  function latestRound() external view returns (uint256);
  function getAnswer(uint256 roundId) external view returns (int256);
  function getTimestamp(uint256 roundId) external view returns (uint256);

  event AnswerUpdated(int256 indexed current, uint256 indexed roundId, uint256 timestamp);
  event NewRound(uint256 indexed roundId, address indexed startedBy);
}

library SignedSafeMath {

  /**
   * @dev Adds two int256s and makes sure the result doesn't overflow. Signed
   * integers aren't supported by the SafeMath library, thus this method
   * @param _a The first number to be added
   * @param _a The second number to be added
   */
  function add(int256 _a, int256 _b)
    internal
    pure
    returns (int256)
  {
    int256 c = _a + _b;
    require((_b >= 0 && c >= _a) || (_b < 0 && c < _a), "SignedSafeMath: addition overflow");

    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;


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


  /**
   * @dev The Ownable constructor sets the original `owner` of the contract to the sender
   * account.
   */
  constructor() 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 relinquish control of the contract.
   * @notice Renouncing to ownership will leave the contract without an owner.
   * It will not be possible to call the functions with the `onlyOwner`
   * modifier anymore.
   */
  function renounceOwnership() public onlyOwner {
    emit OwnershipRenounced(owner);
    owner = address(0);
  }

  /**
   * @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 {
    _transferOwnership(_newOwner);
  }

  /**
   * @dev Transfers control of the contract to a newOwner.
   * @param _newOwner The address to transfer ownership to.
   */
  function _transferOwnership(address _newOwner) internal {
    require(_newOwner != address(0));
    emit OwnershipTransferred(owner, _newOwner);
    owner = _newOwner;
  }
}

/**
 * @title An example Chainlink contract with aggregation
 * @notice Requesters can use this contract as a framework for creating
 * requests to multiple Chainlink nodes and running aggregation
 * as the contract receives answers.
 */
contract Aggregator is AggregatorInterface, ChainlinkClient, Ownable {
  using SignedSafeMath for int256;

  struct Answer {
    uint128 minimumResponses;
    uint128 maxResponses;
    int256[] responses;
  }

  event ResponseReceived(int256 indexed response, uint256 indexed answerId, address indexed sender);

  int256 private currentAnswerValue;
  uint256 private updatedTimestampValue;
  uint256 private latestCompletedAnswer;
  uint128 public paymentAmount;
  uint128 public minimumResponses;
  bytes32[] public jobIds;
  address[] public oracles;

  uint256 private answerCounter = 1;
  mapping(address => bool) public authorizedRequesters;
  mapping(bytes32 => uint256) private requestAnswers;
  mapping(uint256 => Answer) private answers;
  mapping(uint256 => int256) private currentAnswers;
  mapping(uint256 => uint256) private updatedTimestamps;

  uint256 constant private MAX_ORACLE_COUNT = 45;

  /**
   * @notice Deploy with the address of the LINK token and arrays of matching
   * length containing the addresses of the oracles and their corresponding
   * Job IDs.
   * @dev Sets the LinkToken address for the network, addresses of the oracles,
   * and jobIds in storage.
   * @param _link The address of the LINK token
   * @param _paymentAmount the amount of LINK to be sent to each oracle for each request
   * @param _minimumResponses the minimum number of responses
   * before an answer will be calculated
   * @param _oracles An array of oracle addresses
   * @param _jobIds An array of Job IDs
   */
  constructor(
    address _link,
    uint128 _paymentAmount,
    uint128 _minimumResponses,
    address[] _oracles,
    bytes32[] _jobIds
  ) public Ownable() {
    setChainlinkToken(_link);
    updateRequestDetails(_paymentAmount, _minimumResponses, _oracles, _jobIds);
  }

  /**
   * @notice Creates a Chainlink request for each oracle in the oracles array.
   * @dev This example does not include request parameters. Reference any documentation
   * associated with the Job IDs used to determine the required parameters per-request.
   */
  function requestRateUpdate()
    external
    ensureAuthorizedRequester()
  {
    Chainlink.Request memory request;
    bytes32 requestId;
    uint256 oraclePayment = paymentAmount;

    for (uint i = 0; i < oracles.length; i++) {
      request = buildChainlinkRequest(jobIds[i], this, this.chainlinkCallback.selector);
      requestId = sendChainlinkRequestTo(oracles[i], request, oraclePayment);
      requestAnswers[requestId] = answerCounter;
    }
    answers[answerCounter].minimumResponses = minimumResponses;
    answers[answerCounter].maxResponses = uint128(oracles.length);
    answerCounter = answerCounter.add(1);

    emit NewRound(answerCounter, msg.sender);
  }

  /**
   * @notice Receives the answer from the Chainlink node.
   * @dev This function can only be called by the oracle that received the request.
   * @param _clRequestId The Chainlink request ID associated with the answer
   * @param _response The answer provided by the Chainlink node
   */
  function chainlinkCallback(bytes32 _clRequestId, int256 _response)
    external
  {
    validateChainlinkCallback(_clRequestId);

    uint256 answerId = requestAnswers[_clRequestId];
    delete requestAnswers[_clRequestId];

    answers[answerId].responses.push(_response);
    emit ResponseReceived(_response, answerId, msg.sender);
    updateLatestAnswer(answerId);
    deleteAnswer(answerId);
  }

  /**
   * @notice Updates the arrays of oracles and jobIds with new values,
   * overwriting the old values.
   * @dev Arrays are validated to be equal length.
   * @param _paymentAmount the amount of LINK to be sent to each oracle for each request
   * @param _minimumResponses the minimum number of responses
   * before an answer will be calculated
   * @param _oracles An array of oracle addresses
   * @param _jobIds An array of Job IDs
   */
  function updateRequestDetails(
    uint128 _paymentAmount,
    uint128 _minimumResponses,
    address[] _oracles,
    bytes32[] _jobIds
  )
    public
    onlyOwner()
    validateAnswerRequirements(_minimumResponses, _oracles, _jobIds)
  {
    paymentAmount = _paymentAmount;
    minimumResponses = _minimumResponses;
    jobIds = _jobIds;
    oracles = _oracles;
  }

  /**
   * @notice Allows the owner of the contract to withdraw any LINK balance
   * available on the contract.
   * @dev The contract will need to have a LINK balance in order to create requests.
   * @param _recipient The address to receive the LINK tokens
   * @param _amount The amount of LINK to send from the contract
   */
  function transferLINK(address _recipient, uint256 _amount)
    public
    onlyOwner()
  {
    LinkTokenInterface linkToken = LinkTokenInterface(chainlinkTokenAddress());
    require(linkToken.transfer(_recipient, _amount), "LINK transfer failed");
  }

  /**
   * @notice Called by the owner to permission other addresses to generate new
   * requests to oracles.
   * @param _requester the address whose permissions are being set
   * @param _allowed boolean that determines whether the requester is
   * permissioned or not
   */
  function setAuthorization(address _requester, bool _allowed)
    external
    onlyOwner()
  {
    authorizedRequesters[_requester] = _allowed;
  }

  /**
   * @notice Cancels an outstanding Chainlink request.
   * The oracle contract requires the request ID and additional metadata to
   * validate the cancellation. Only old answers can be cancelled.
   * @param _requestId is the identifier for the chainlink request being cancelled
   * @param _payment is the amount of LINK paid to the oracle for the request
   * @param _expiration is the time when the request expires
   */
  function cancelRequest(
    bytes32 _requestId,
    uint256 _payment,
    uint256 _expiration
  )
    external
    ensureAuthorizedRequester()
  {
    uint256 answerId = requestAnswers[_requestId];
    require(answerId < latestCompletedAnswer, "Cannot modify an in-progress answer");

    delete requestAnswers[_requestId];
    answers[answerId].responses.push(0);
    deleteAnswer(answerId);

    cancelChainlinkRequest(
      _requestId,
      _payment,
      this.chainlinkCallback.selector,
      _expiration
    );
  }

  /**
   * @notice Called by the owner to kill the contract. This transfers all LINK
   * balance and ETH balance (if there is any) to the owner.
   */
  function destroy()
    external
    onlyOwner()
  {
    LinkTokenInterface linkToken = LinkTokenInterface(chainlinkTokenAddress());
    transferLINK(owner, linkToken.balanceOf(address(this)));
    selfdestruct(owner);
  }

  /**
   * @dev Performs aggregation of the answers received from the Chainlink nodes.
   * Assumes that at least half the oracles are honest and so can't contol the
   * middle of the ordered responses.
   * @param _answerId The answer ID associated with the group of requests
   */
  function updateLatestAnswer(uint256 _answerId)
    private
    ensureMinResponsesReceived(_answerId)
    ensureOnlyLatestAnswer(_answerId)
  {
    uint256 responseLength = answers[_answerId].responses.length;
    uint256 middleIndex = responseLength.div(2);
    int256 currentAnswerTemp;
    if (responseLength % 2 == 0) {
      int256 median1 = quickselect(answers[_answerId].responses, middleIndex);
      int256 median2 = quickselect(answers[_answerId].responses, middleIndex.add(1)); // quickselect is 1 indexed
      currentAnswerTemp = median1.add(median2) / 2; // signed integers are not supported by SafeMath
    } else {
      currentAnswerTemp = quickselect(answers[_answerId].responses, middleIndex.add(1)); // quickselect is 1 indexed
    }
    currentAnswerValue = currentAnswerTemp;
    latestCompletedAnswer = _answerId;
    updatedTimestampValue = now;
    updatedTimestamps[_answerId] = now;
    currentAnswers[_answerId] = currentAnswerTemp;
    emit AnswerUpdated(currentAnswerTemp, _answerId, now);
  }

  /**
   * @notice get the most recently reported answer
   */
  function latestAnswer()
    external
    view
    returns (int256)
  {
    return currentAnswers[latestCompletedAnswer];
  }

  /**
   * @notice get the last updated at block timestamp
   */
  function latestTimestamp()
    external
    view
    returns (uint256)
  {
    return updatedTimestamps[latestCompletedAnswer];
  }

  /**
   * @notice get past rounds answers
   * @param _roundId the answer number to retrieve the answer for
   */
  function getAnswer(uint256 _roundId)
    external
    view
    returns (int256)
  {
    return currentAnswers[_roundId];
  }

  /**
   * @notice get block timestamp when an answer was last updated
   * @param _roundId the answer number to retrieve the updated timestamp for
   */
  function getTimestamp(uint256 _roundId)
    external
    view
    returns (uint256)
  {
    return updatedTimestamps[_roundId];
  }

  /**
   * @notice get the latest completed round where the answer was updated
   */
  function latestRound() external view returns (uint256) {
    return latestCompletedAnswer;
  }

  /**
   * @dev Returns the kth value of the ordered array
   * See: http://www.cs.yale.edu/homes/aspnes/pinewiki/QuickSelect.html
   * @param _a The list of elements to pull from
   * @param _k The index, 1 based, of the elements you want to pull from when ordered
   */
  function quickselect(int256[] memory _a, uint256 _k)
    private
    pure
    returns (int256)
  {
    int256[] memory a = _a;
    uint256 k = _k;
    uint256 aLen = a.length;
    int256[] memory a1 = new int256[](aLen);
    int256[] memory a2 = new int256[](aLen);
    uint256 a1Len;
    uint256 a2Len;
    int256 pivot;
    uint256 i;

    while (true) {
      pivot = a[aLen.div(2)];
      a1Len = 0;
      a2Len = 0;
      for (i = 0; i < aLen; i++) {
        if (a[i] < pivot) {
          a1[a1Len] = a[i];
          a1Len++;
        } else if (a[i] > pivot) {
          a2[a2Len] = a[i];
          a2Len++;
        }
      }
      if (k <= a1Len) {
        aLen = a1Len;
        (a, a1) = swap(a, a1);
      } else if (k > (aLen.sub(a2Len))) {
        k = k.sub(aLen.sub(a2Len));
        aLen = a2Len;
        (a, a2) = swap(a, a2);
      } else {
        return pivot;
      }
    }
  }

  /**
   * @dev Swaps the pointers to two uint256 arrays in memory
   * @param _a The pointer to the first in memory array
   * @param _b The pointer to the second in memory array
   */
  function swap(int256[] memory _a, int256[] memory _b)
    private
    pure
    returns(int256[] memory, int256[] memory)
  {
    return (_b, _a);
  }

  /**
   * @dev Cleans up the answer record if all responses have been received.
   * @param _answerId The identifier of the answer to be deleted
   */
  function deleteAnswer(uint256 _answerId)
    private
    ensureAllResponsesReceived(_answerId)
  {
    delete answers[_answerId];
  }

  /**
   * @dev Prevents taking an action if the minimum number of responses has not
   * been received for an answer.
   * @param _answerId The the identifier of the answer that keeps track of the responses.
   */
  modifier ensureMinResponsesReceived(uint256 _answerId) {
    if (answers[_answerId].responses.length >= answers[_answerId].minimumResponses) {
      _;
    }
  }

  /**
   * @dev Prevents taking an action if not all responses are received for an answer.
   * @param _answerId The the identifier of the answer that keeps track of the responses.
   */
  modifier ensureAllResponsesReceived(uint256 _answerId) {
    if (answers[_answerId].responses.length == answers[_answerId].maxResponses) {
      _;
    }
  }

  /**
   * @dev Prevents taking an action if a newer answer has been recorded.
   * @param _answerId The current answer's identifier.
   * Answer IDs are in ascending order.
   */
  modifier ensureOnlyLatestAnswer(uint256 _answerId) {
    if (latestCompletedAnswer <= _answerId) {
      _;
    }
  }

  /**
   * @dev Ensures corresponding number of oracles and jobs.
   * @param _oracles The list of oracles.
   * @param _jobIds The list of jobs.
   */
  modifier validateAnswerRequirements(
    uint256 _minimumResponses,
    address[] _oracles,
    bytes32[] _jobIds
  ) {
    require(_oracles.length <= MAX_ORACLE_COUNT, "cannot have more than 45 oracles");
    require(_oracles.length >= _minimumResponses, "must have at least as many oracles as responses");
    require(_oracles.length == _jobIds.length, "must have exactly as many oracles as job IDs");
    _;
  }

  /**
   * @dev Reverts if `msg.sender` is not authorized to make requests.
   */
  modifier ensureAuthorizedRequester() {
    require(authorizedRequesters[msg.sender] || msg.sender == owner, "Not an authorized address for creating requests");
    _;
  }

}