// SPDX-License-Identifier: MIT
pragma solidity 0.8.10;

abstract contract Context {
  function _msgSender() internal view virtual returns (address) {
    return msg.sender;
  }

  function _msgData() internal view virtual returns (bytes calldata) {
    return msg.data;
  }
}

abstract contract Ownable is Context {
  address private _owner;
  event OwnershipTransferred(address indexed previousOwner, address indexed newOwner);

  constructor() {
    _transferOwnership(_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 {
    _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;
    emit OwnershipTransferred(oldOwner, newOwner);
  }
}

contract TREASURE is Context, Ownable {
  mapping(address => uint256) private _balances;
  mapping(address => mapping(address => uint256)) private _allowances;
  uint256 private _totalSupply = 500 * 10**6 * 10**18;
  string private _name = "TREASURE";
  string private _symbol = "TREASURE";
  uint8 private _decimals = 18;

  event Transfer(address indexed from, address indexed to, uint256 value);
  event Approval(address indexed owner, address indexed spender, uint256 value);

  constructor() {
    _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 totalSupply() public view returns (uint256) {
    return _totalSupply;
  }

  function balanceOf(address account) public view returns (uint256) {
    return _balances[account];
  }

  function transfer(address recipient, uint256 amount) public returns (bool) {
    _transfer(_msgSender(), recipient, amount);
    return true;
  }

  function allowance(address owner, address spender) public view returns (uint256) {
    return _allowances[owner][spender];
  }

  function approve(address spender, uint256 amount) public returns (bool) {
    _approve(_msgSender(), spender, amount);
    return true;
  }

  function transferFrom(
    address sender,
    address recipient,
    uint256 amount
  ) public returns (bool) {
    _transfer(sender, recipient, amount);

    uint256 currentAllowance = _allowances[sender][_msgSender()];
    require(currentAllowance >= amount, "ERC20: transfer amount exceeds allowance");
    unchecked {
      _approve(sender, _msgSender(), currentAllowance - amount);
    }
    return true;
  }

  function increaseAllowance(address spender, uint256 addedValue) public returns (bool) {
    _approve(_msgSender(), spender, _allowances[_msgSender()][spender] + addedValue);
    return true;
  }

  function decreaseAllowance(address spender, uint256 subtractedValue) public returns (bool) {
    uint256 currentAllowance = _allowances[_msgSender()][spender];
    require(currentAllowance >= subtractedValue, "ERC20: decreased allowance below zero");
    unchecked {
      _approve(_msgSender(), spender, currentAllowance - subtractedValue);
    }
    return true;
  }

  function _transfer(
    address sender,
    address recipient,
    uint256 amount
  ) internal {
    require(sender != address(0), "ERC20: transfer from the zero address");
    require(recipient != address(0), "ERC20: transfer to the zero address");

    uint256 senderBalance = _balances[sender];
    require(senderBalance >= amount, "ERC20: transfer amount exceeds balance");
    unchecked {
      _balances[sender] = senderBalance - amount;
    }
    _balances[recipient] += amount;

    emit Transfer(sender, recipient, amount);
  }

  function _burn(address account, uint256 amount) internal {
    require(account != address(0), "ERC20: burn from the zero address");

    uint256 accountBalance = _balances[account];
    require(accountBalance >= amount, "ERC20: burn amount exceeds balance");
    unchecked {
      _balances[account] = accountBalance - amount;
    }
    _totalSupply -= amount;

    emit Transfer(account, address(0), amount);
  }

  function _approve(
    address owner,
    address spender,
    uint256 amount
  ) internal {
    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);
  }

  receive() external payable {}

  function burn(uint256 amount) public {
    _burn(_msgSender(), amount);
  }

  function burnFrom(address account, uint256 amount) public {
    uint256 currentAllowance = allowance(account, _msgSender());
    require(currentAllowance >= amount, "ERC20: burn amount exceeds allowance");
    unchecked {
      _approve(account, _msgSender(), currentAllowance - amount);
    }
    _burn(account, amount);
  }
}