Contract Source Code:

// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v5.0.0) (access/Ownable.sol)

pragma solidity ^0.8.20;

import {Context} from "../utils/Context.sol";

/**
 * @dev Contract module which provides a basic access control mechanism, where
 * there is an account (an owner) that can be granted exclusive access to
 * specific functions.
 *
 * The initial owner is set to the address provided by the deployer. This can
 * later be changed with {transferOwnership}.
 *
 * This module is used through inheritance. It will make available the modifier
 * `onlyOwner`, which can be applied to your functions to restrict their use to
 * the owner.
 */
abstract contract Ownable is Context {
    address private _owner;

    /**
     * @dev The caller account is not authorized to perform an operation.
     */
    error OwnableUnauthorizedAccount(address account);

    /**
     * @dev The owner is not a valid owner account. (eg. `address(0)`)
     */
    error OwnableInvalidOwner(address owner);

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

    /**
     * @dev Initializes the contract setting the address provided by the deployer as the initial owner.
     */
    constructor(address initialOwner) {
        if (initialOwner == address(0)) {
            revert OwnableInvalidOwner(address(0));
        }
        _transferOwnership(initialOwner);
    }

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

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

    /**
     * @dev Throws if the sender is not the owner.
     */
    function _checkOwner() internal view virtual {
        if (owner() != _msgSender()) {
            revert OwnableUnauthorizedAccount(_msgSender());
        }
    }

    /**
     * @dev Leaves the contract without owner. It will not be possible to call
     * `onlyOwner` functions. Can only be called by the current owner.
     *
     * NOTE: Renouncing ownership will leave the contract without an owner,
     * thereby disabling any functionality that is only available to the owner.
     */
    function renounceOwnership() public virtual onlyOwner {
        _transferOwnership(address(0));
    }

    /**
     * @dev Transfers ownership of the contract to a new account (`newOwner`).
     * Can only be called by the current owner.
     */
    function transferOwnership(address newOwner) public virtual onlyOwner {
        if (newOwner == address(0)) {
            revert OwnableInvalidOwner(address(0));
        }
        _transferOwnership(newOwner);
    }

    /**
     * @dev Transfers ownership of the contract to a new account (`newOwner`).
     * Internal function without access restriction.
     */
    function _transferOwnership(address newOwner) internal virtual {
        address oldOwner = _owner;
        _owner = newOwner;
        emit OwnershipTransferred(oldOwner, newOwner);
    }
}

// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v5.0.0) (token/ERC20/extensions/IERC20Metadata.sol)

pragma solidity ^0.8.20;

import {IERC20} from "../IERC20.sol";

/**
 * @dev Interface for the optional metadata functions from the ERC20 standard.
 */
interface IERC20Metadata is IERC20 {
    /**
     * @dev Returns the name of the token.
     */
    function name() external view returns (string memory);

    /**
     * @dev Returns the symbol of the token.
     */
    function symbol() external view returns (string memory);

    /**
     * @dev Returns the decimals places of the token.
     */
    function decimals() external view returns (uint8);
}

// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v5.0.0) (token/ERC20/IERC20.sol)

pragma solidity ^0.8.20;

/**
 * @dev Interface of the ERC20 standard as defined in the EIP.
 */
interface IERC20 {
    /**
     * @dev Emitted when `value` tokens are moved from one account (`from`) to
     * another (`to`).
     *
     * Note that `value` may be zero.
     */
    event Transfer(address indexed from, address indexed to, uint256 value);

    /**
     * @dev Emitted when the allowance of a `spender` for an `owner` is set by
     * a call to {approve}. `value` is the new allowance.
     */
    event Approval(address indexed owner, address indexed spender, uint256 value);

    /**
     * @dev Returns the value of tokens in existence.
     */
    function totalSupply() external view returns (uint256);

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

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

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

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

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

// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v5.0.1) (utils/Context.sol)

pragma solidity ^0.8.20;

/**
 * @dev Provides information about the current execution context, including the
 * sender of the transaction and its data. While these are generally available
 * via msg.sender and msg.data, they should not be accessed in such a direct
 * manner, since when dealing with meta-transactions the account sending and
 * paying for execution may not be the actual sender (as far as an application
 * is concerned).
 *
 * This contract is only required for intermediate, library-like contracts.
 */
abstract contract Context {
    function _msgSender() internal view virtual returns (address) {
        return msg.sender;
    }

    function _msgData() internal view virtual returns (bytes calldata) {
        return msg.data;
    }

    function _contextSuffixLength() internal view virtual returns (uint256) {
        return 0;
    }
}

// SPDX-License-Identifier: MIT
// Author: A.P
// Organization: Rare Art
// Development: Kibernacia
// Product: Rare Art Airdrop
// Version: 1.0.0
// Link: https://linktr.ee/rareuniverse
pragma solidity ^0.8.24;

// OpenZeppelin
import {Ownable} from "@openzeppelin/contracts/access/Ownable.sol";
import {IERC20Metadata} from "@openzeppelin/contracts/token/ERC20/extensions/IERC20Metadata.sol";

contract RareArtAirdrop is Ownable {
    /// @notice Stores contract name.
    /// @dev Stores constant string.
    string private constant _name = "R4REDROP";

    /// @notice Stores contract symbol.
    /// @dev Stores constant string.
    string private constant _symbol = "R4REDROP";

    /// @notice Mapping to store balances of tokens assigned to recipients.
    /// @dev Nested mapping where the first key is the token address and the second key is the recipient address.
    mapping(address => mapping(address => uint256)) private _balances;

    // Events
    /**
     * @notice Emitted when an airdrop is assigned to a recipient.
     * @param token The address of the ERC20 token being airdropped.
     * @param recipient The address of the recipient receiving the airdrop.
     * @param amount The amount of tokens assigned to the recipient.
     */
    event AirdropAssigned(
        address indexed token,
        address indexed recipient,
        uint256 amount
    );

    /**
     * @notice Emitted when an airdrop is triggered for a specific token.
     * @param token The address of the ERC20 token being airdropped.
     */
    event AirdropTriggered(address indexed token);

    /**
     * @notice Emitted when a recipient claims their airdropped tokens.
     * @param token The address of the ERC20 token being claimed.
     * @param recipient The address of the recipient claiming the airdrop.
     * @param amount The amount of tokens claimed by the recipient.
     */
    event AirdropClaimed(
        address indexed token,
        address indexed recipient,
        uint256 amount
    );

    // Errors
    /// @notice Error thrown when the recipients and amounts arrays have different lengths.
    error RecipientsAndAmountsMismatch();

    /// @notice Error thrown when there are no tokens available to claim.
    error InsufficientBalanceToClaim();

    /// @notice Error thrown when a token transfer fails.
    error TokenTransferFailed();

    /**
     * @notice Constructor that sets the owner of the contract.
     * @dev The Ownable constructor is called with the deployer's address.
     */
    constructor() Ownable(_msgSender()) {}

    /**
     * @notice Returns the balance of a specific token assigned to an account.
     * @param token The address of the ERC20 token.
     * @param account The address of the account.
     * @return The balance of the specified token assigned to the account.
     */
    function balanceOf(
        address token,
        address account
    ) public view returns (uint256) {
        return _balances[token][account];
    }

    /**
     * @notice Assign airdrop amounts for a specific token to multiple recipients.
     * @dev Only the contract owner can call this function.
     * @param token The address of the ERC20 token.
     * @param recipients The array of recipient addresses.
     * @param amounts The array of token amounts to be assigned to the recipients.
     * @dev Emits an `AirdropAssigned` event for each recipient.
     * @dev Reverts with `RecipientsAndAmountsMismatch` if the lengths of `recipients` and `amounts` are not equal.
     */
    function assign(
        address token,
        address[] calldata recipients,
        uint256[] calldata amounts
    ) external onlyOwner {
        // Validation
        if (recipients.length != amounts.length) {
            revert RecipientsAndAmountsMismatch();
        }

        for (uint256 i = 0; i < recipients.length; i++) {
            // Update
            _balances[token][recipients[i]] += amounts[i];

            // Event
            emit AirdropAssigned(token, recipients[i], amounts[i]);
        }
    }

    /**
     * @notice Trigger the airdrop transaction to distribute tokens to all assigned recipients for a specific token.
     * @dev Only the contract owner can call this function.
     * @param token The address of the ERC20 token.
     * @param recipients The array of recipient addresses who have a balance to claim.
     * @dev Emits an `AirdropTriggered` event after the airdrop is completed.
     * @dev Reverts with `TokenTransferFailed` if any of the token transfers fail.
     */
    function airdrop(
        address token,
        address[] calldata recipients
    ) external onlyOwner {
        // Object
        IERC20Metadata _contract = IERC20Metadata(token);

        for (uint256 i = 0; i < recipients.length; i++) {
            // Parameters
            address recipient = recipients[i];
            uint256 amount = _balances[token][recipient];

            // Validation
            if (amount > 0) {
                // Transfer
                bool status = _contract.transfer(recipient, amount);

                // Validation
                if (!status) {
                    revert TokenTransferFailed();
                }

                // Update
                _balances[token][recipient] = 0;
            }
        }

        emit AirdropTriggered(token);
    }

    /**
     * @notice Allows a user to claim their assigned tokens for a specific token.
     * @dev Only the recipient of the airdrop can call this function.
     * @param token The address of the ERC20 token.
     * @dev Emits an `AirdropClaimed` event after the claim is successful.
     * @dev Reverts with `InsufficientBalanceToClaim` if the caller has no tokens to claim.
     * @dev Reverts with `TokenTransferFailed` if the token transfer fails.
     */
    function claim(address token) external {
        // Parameters
        uint256 amount = _balances[token][_msgSender()];

        // Validation
        if (amount == 0) {
            revert InsufficientBalanceToClaim();
        }

        // Object
        IERC20Metadata _contract = IERC20Metadata(token);

        // Transfer
        bool status = _contract.transfer(_msgSender(), amount);

        // Validation
        if (!status) {
            revert TokenTransferFailed();
        }

        // Update
        _balances[token][_msgSender()] = 0;

        // Event
        emit AirdropClaimed(token, _msgSender(), amount);
    }

    /**
     * @notice Allows the contract owner to withdraw any leftover tokens from the contract.
     * @dev Only the contract owner can call this function.
     * @param token The address of the ERC20 token to withdraw.
     * @param amount The amount of tokens to withdraw.
     * @dev Reverts with `TokenTransferFailed` if the token transfer fails.
     */
    function withdraw(address token, uint256 amount) external onlyOwner {
        // Object
        IERC20Metadata _contract = IERC20Metadata(token);

        // Transfer
        bool status = _contract.transfer(owner(), amount);

        // Validation
        if (!status) {
            revert TokenTransferFailed();
        }
    }

    /**
     * @dev Returns the name of the contract.
     */
    function name() public view virtual returns (string memory) {
        return _name;
    }

    /**
     * @dev Returns the symbol of the contract, usually a shorter version of the
     * name.
     */
    function symbol() public view virtual returns (string memory) {
        return _symbol;
    }

    /**
     * @notice Fallback function to receive ETH.
     * @dev This function allows the contract to receive ETH.
     */
    receive() external payable {}

    /**
     * @notice Fallback function to receive ETH.
     * @dev This function allows the contract to receive ETH.
     */
    fallback() external payable {}
}