// File: contracts/ElvantisFeeReceiver.sol



// SPDX-License-Identifier: MIT

pragma solidity ^0.8.0;

import "@openzeppelin/contracts/token/ERC20/IERC20.sol";
import "@openzeppelin/contracts/access/Ownable.sol";
import './interfaces/IElvantisFeeReceiver.sol';
import './interfaces/IDEXRouter.sol';

// This contract will only be used for Elvantis Token
contract ElvantisFeeReceiver is Ownable, IElvantisFeeReceiver {
    IERC20 public elvantis;
    IDEXRouter public router;
    address public feeRecipient;

    bool public swapEnabled = true;
    uint256 public swapThreshold = 1 ether;
    
    event FeeRecipientUpdated(address indexed feeRecipient);
    event RouterUpdated(address indexed router);
    event SwapUpdated(bool indexed enabled);
    event SwapThresholdUpdated(uint256 indexed threshold);

    modifier onlyElvantis {
        require(msg.sender == address(elvantis), "ElvantisFeeReceiver: Only Elvantis!");
        _;
    }

    constructor(address _elvantis, address _router, address _owner) {
        require(_elvantis != address(0) && _router != address(0) && _owner != address(0), "ElvantisFeeReceiver: zero address");

        elvantis = IERC20(_elvantis);
        router = IDEXRouter(_router);
        transferOwnership(_owner);
    }

    function onFeeReceived(address token, uint256 amount) external override onlyElvantis {
        if(token != address(0)) {
            address recipient = swapEnabled ? address(this) : feeRecipient;
            elvantis.transferFrom(address(elvantis), recipient, amount);
            _swapTokensForETH();
        }
    }

    function _swapTokensForETH() private {
        uint256 amount = elvantis.balanceOf(address(this));
        if(amount > swapThreshold) {
            address[] memory path = new address[](2);
            path[0] = address(elvantis);
            path[1] = router.WETH();

            elvantis.approve(address(router), amount);
            
            router.swapExactTokensForETHSupportingFeeOnTransferTokens(
                amount,
                0,
                path,
                feeRecipient,
                block.timestamp
            );
        }
    }
    
    function setFeeRecipient(address _feeRecipient) onlyOwner external {
        require(_feeRecipient != address(0), "ElvantisFeeReceiver: _feeRecipient is a zero address");
        feeRecipient = _feeRecipient;
        emit FeeRecipientUpdated(_feeRecipient);
    }

    function setRouter(IDEXRouter _router) onlyOwner external {
        require(address(_router) != address(0), "ElvantisFeeReceiver: _router is a zero address");
        router = _router;
        emit RouterUpdated(address(_router));
    }

    function setSwapEnabled(bool _enabled) onlyOwner external {
        swapEnabled = _enabled;
        emit SwapUpdated(_enabled);
    }

    function setSwapThreshold(uint256 _threshold) onlyOwner external {
        swapThreshold = _threshold;
        emit SwapThresholdUpdated(_threshold);
    }

    function drainAccidentallySentTokens(IERC20 token, address recipient, uint256 amount) onlyOwner external {
        token.transfer(recipient, amount);
    }
}
// File: @openzeppelin/contracts/token/ERC20/IERC20.sol



// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts v4.4.1 (token/ERC20/IERC20.sol)

pragma solidity ^0.8.0;

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

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

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

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

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

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

    /**
     * @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);
}

// File: @openzeppelin/contracts/access/Ownable.sol



// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts v4.4.1 (access/Ownable.sol)

pragma solidity ^0.8.0;

import "../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.
 *
 * By default, the owner account will be the one that deploys the contract. 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;

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

    /**
     * @dev Initializes the contract setting the deployer as the initial owner.
     */
    constructor() {
        _transferOwnership(_msgSender());
    }

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

    /**
     * @dev Throws if called by any account other than the owner.
     */
    modifier onlyOwner() {
        require(owner() == _msgSender(), "Ownable: caller is not the owner");
        _;
    }

    /**
     * @dev Leaves the contract without owner. It will not be possible to call
     * `onlyOwner` functions anymore. Can only be called by the current owner.
     *
     * NOTE: Renouncing ownership will leave the contract without an owner,
     * thereby removing 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 {
        require(newOwner != address(0), "Ownable: new owner is the zero address");
        _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);
    }
}

// File: contracts/interfaces/IElvantisFeeReceiver.sol



// SPDX-License-Identifier: MIT

pragma solidity ^0.8.0;

interface IElvantisFeeReceiver {
    function onFeeReceived(address token, uint256 amount) external;
}

// File: contracts/interfaces/IDEXRouter.sol



// SPDX-License-Identifier: MIT

pragma solidity ^0.8.0;

interface IDEXRouter {
    function WETH() external pure returns (address);

    function swapExactTokensForETHSupportingFeeOnTransferTokens(
        uint256 amountIn,
        uint256 amountOutMin,
        address[] calldata path,
        address to,
        uint256 deadline
    ) external;
} 

// File: @openzeppelin/contracts/utils/Context.sol



// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts v4.4.1 (utils/Context.sol)

pragma solidity ^0.8.0;

/**
 * @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;
    }
}