Cryo Explorer Ethereum Mainnet

// 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 v5.0.1) (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
pragma solidity ^0.8.19;

import "@openzeppelin/contracts/access/Ownable.sol";

/// -----------------------------------------------------------------------
/// Interfaces
/// -----------------------------------------------------------------------
/// @dev Minimal ERC20 interface for transferFrom
interface IERC20 {
    function transferFrom(
        address from,
        address to,
        uint256 amount
    ) external returns (bool);
}

/// @title DCA Forwarder Contract
/// @notice Enables pull-based ERC20 transfers from user wallets to arbitrary destinations
///         for automated Dollar-Cost Averaging (DCA) strategies. Users give one-time
///         infinite allowance; then this contract pulls tokens as needed.
contract DCAForwarder is Ownable {
    /// -----------------------------------------------------------------------
    /// Errors
    /// -----------------------------------------------------------------------
    /// @notice Thrown when a zero address is provided
    error DCAForwarder_ZeroAddress();
    /// @notice Thrown when a zero amount is provided
    error DCAForwarder_ZeroAmount();
    /// @notice Thrown when ERC20 transferFrom fails
    error DCAForwarder_TransferFailed();

    /// -----------------------------------------------------------------------
    /// Events
    /// -----------------------------------------------------------------------
    /// @notice Emitted when funds are pulled and forwarded
    /// @param user    The address of the user from whose balance tokens were pulled
    /// @param token   The ERC20 token contract address transferred
    /// @param dest    The destination address receiving the tokens
    /// @param amount  The exact amount of tokens transferred
    event FundsPulled(
        address indexed user,
        address indexed token,
        address indexed dest,
        uint256 amount
    );

    /// -----------------------------------------------------------------------
    /// Constructor
    /// -----------------------------------------------------------------------
    /// @notice Initializes the contract and sets the deployer as the owner
    constructor() Ownable(msg.sender) {
        // Ownable constructor sets msg.sender as owner
    }

    /// -----------------------------------------------------------------------
    /// Public Functions (onlyOwner)
    /// -----------------------------------------------------------------------

    /// @notice Pulls `amount` of `token` from `user` and forwards it to `dest`
    /// @dev Requires user has previously approved this contract for at least `amount`
    /// @param token   The ERC20 token contract address
    /// @param user    The token holder's address
    /// @param dest    The recipient address (e.g., swap provider)
    /// @param amount  The number of tokens to transfer
    function pullAndForward(
        address token,
        address user,
        address dest,
        uint256 amount
    ) external onlyOwner {
        if (user == address(0) || dest == address(0))
            revert DCAForwarder_ZeroAddress();
        if (amount == 0) revert DCAForwarder_ZeroAmount();

        if (!IERC20(token).transferFrom(user, dest, amount))
            revert DCAForwarder_TransferFailed();

        emit FundsPulled(user, token, dest, amount);
    }
}