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



// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v4.9.0) (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 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 {
        require(owner() == _msgSender(), "Ownable: caller is not the owner");
    }

    /**
     * @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 {
        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: @openzeppelin/contracts/token/ERC20/IERC20.sol



// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v4.9.0) (token/ERC20/IERC20.sol)

pragma solidity ^0.8.0;

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

// 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;
    }
}

// File: contracts/DerpySale.sol



// SPDX-License-Identifier: UNLICENSED
pragma solidity ^0.8.0;

import "@openzeppelin/contracts/access/Ownable.sol";
import "@openzeppelin/contracts/token/ERC20/IERC20.sol";

contract DerpySale is Ownable {
    enum PresaleStatus {
        NotStarted,
        Started,
        Ended,
        Refund
    }

    // ERC20 token details
    IERC20 public DERPY_COIN;
    uint256 public presaleSupply = 30.1 gwei * 10 ** 18; // Total supply of the presale tokens

    // Presale status
    PresaleStatus public presaleStatus;
    uint256 public totalETHDeposited;
    uint256 public ethThreshold = 69 ether;

    uint256 public constant MAX_ETH_DEPOSIT = 0.69 ether;
    uint256 public constant MIN_ETH_DEPOSIT = 0.069 ether;

    // Mapping to keep track of user deposits
    mapping(address => uint256) public deposits;

    // Event emitted when a user claims their tokens
    event TokensClaimed(address user, uint amount);

    constructor() {
        presaleStatus = PresaleStatus.NotStarted;
    }

    modifier onlyDuringPresale() {
        require(
            presaleStatus == PresaleStatus.Started,
            "Presale not active"
        );
        _;
    }

    modifier onlyAfterPresale() {
        require(
            presaleStatus == PresaleStatus.Ended,
            "Presale has not ended yet"
        );
        _;
    }

    modifier onlyRefundOpen() {
        require(presaleStatus == PresaleStatus.Refund, "Refund not open");
        _;
    }

    function setPresaleStatus(PresaleStatus _status) external onlyOwner {
        presaleStatus = _status;
    }

    function setEthThreshold(uint _threshold) external onlyOwner {
        ethThreshold = _threshold;
    }

    function setCoinAddress(address _address) external onlyOwner {
        DERPY_COIN = IERC20(_address);
    }

    function deposit() public payable onlyDuringPresale {
        require(
            totalETHDeposited + msg.value <= ethThreshold,
            "Presale threshold reached"
        );
        require(
            deposits[msg.sender] + msg.value >= MIN_ETH_DEPOSIT,
            "Too little deposit"
        );
        require(
            deposits[msg.sender] + msg.value <= MAX_ETH_DEPOSIT,
            "Too large deposit"
        );

        deposits[msg.sender] += msg.value;
        totalETHDeposited += msg.value;
    }

    function claimTokens() external onlyAfterPresale {
        uint256 tokensToClaim = availableToClaim();
        require(tokensToClaim > 0, "No tokens to claim");

        DERPY_COIN.transfer(msg.sender, tokensToClaim);
        deposits[msg.sender] = 0;

        emit TokensClaimed(msg.sender, tokensToClaim);
    }

    function setPresaleSupply(uint256 _supply) external onlyOwner {
        presaleSupply = _supply;
    }

    function availableToClaim()
        public
        view
        onlyAfterPresale
        returns (uint256 tokens)
    {
        uint256 tokensToClaim = (deposits[msg.sender] * presaleSupply) /
            totalETHDeposited;

        return tokensToClaim;
    }

    function withdrawETH() external onlyOwner {
        (bool os, ) = payable(msg.sender).call{value: address(this).balance}(
            ""
        );
        require(os, "Withdraw not successful");
    }

    function refund() external onlyRefundOpen {
        require(deposits[msg.sender] > 0, "No amount to refund");
        (bool os, ) = payable(msg.sender).call{value: deposits[msg.sender]}("");
        require(os, "Withdraw not successful");
        deposits[msg.sender] = 0;
    }

    function withdrawTokens() external onlyOwner {
        DERPY_COIN.transfer(owner(), DERPY_COIN.balanceOf(address(this)));
    }

    // Fallback function to receive ETH
    receive() external payable onlyDuringPresale {
        deposit();
    }
}