// File: contracts/MBS.sol




// SPDX-License-Identifier: MIT

pragma solidity 0.8.19;

    error NotOwner();    
    error InvalidAddress();
    error NoFunds();
    error OverFlow();    

/**
 * @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;
    }

}


// OpenZeppelin Contracts (last updated v4.7.0) (access/Ownable.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() internal 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");
        if (owner() != _msgSender()) revert NotOwner();
    }

    /**
     * @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");
        if (newOwner == address(0)) revert InvalidAddress();
        _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);
    }    
}



interface IERC20 {

  function totalSupply() external view returns (uint256);

  function decimals() external view returns (uint8);

  function symbol() external view returns (string memory);

  function name() external view returns (string memory);  

  function balanceOf(address account) external view returns (uint256);

  function allowance(address _owner, address spender) external view returns (uint256);

  function getOwner() external view returns (address);

  function transfer(address recipient, uint256 amount) external returns (bool); 

  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);
}


library SafeMath {    
   

    /**
     * @dev Returns the subtraction of two unsigned integers, reverting on
     * overflow (when the result is negative).
     *
     * Counterpart to Solidity's `-` operator.
     *
     * Requirements:
     *
     * - Subtraction cannot overflow.
     */
    function sub(uint256 a, uint256 b) internal pure returns (uint256) {
        if (b > a) revert OverFlow(); 
        return a - b;
    } 
       
}

//DAO Safe Token Version 1.1.0

contract MonteBiancoSafe is IERC20, Ownable {
  using SafeMath for uint256;

  mapping (address => uint256) private _balances;

  mapping (address => mapping (address => uint256)) private _allowances;
  
  uint8 private _decimals;
  uint256 private _totalSupply;  
  string private _symbol;
  string private _name;

  //address private safeAddress;  


  constructor() {
    _name = "Monte Bianco Safe";
    _symbol = "MBS";
    _decimals = 18;
    _totalSupply = 100_000 * 10 ** _decimals;
    _balances[msg.sender] = _totalSupply;

   emit Transfer(address(0), msg.sender, _totalSupply);
  }

  receive() external payable {
        // Allow the contract to receive native coins.
  }  


  function decimals() external view returns (uint8) {
    return _decimals;
  }

  function symbol() external view returns (string memory) {
    return _symbol;
  }

  function name() external view returns (string memory) {
    return _name;
  }
  
  function totalSupply() external view returns (uint256) {
    return _totalSupply;
  }

  function balanceOf(address account) external view returns (uint256) {
    return _balances[account];
  }  
/*
  function setSafeAddress(address _safeAddress) external onlyOwner {
        //require(_safeAddress != address(0), "Error: zero address");
        //require(_safeAddress != owner(), "Error: owner address");
        if ((_safeAddress == address(0)) || (_safeAddress == owner())) revert InvalidAddress();        
        
        safeAddress = _safeAddress;
    }
*/

  function getOwner() external view returns (address) {
        return owner();
  }

  function withdrawTokens() external onlyOwner {        
        //require(_balances[address(this)] > 0, "Invalid token amount");
        if (_balances[address(this)] <= 0) revert NoFunds();     
        _transfer(address(this), owner(), _balances[address(this)]); 
    }
    
    function withdrawFunds() external onlyOwner returns (bool _success) {        
        //require(address(this).balance > 0, "cannot withdraw zero funds");
        if (address(this).balance == 0) revert NoFunds();                
        (_success,) = owner().call{value: address(this).balance}("");        
        return _success;        
    }

  function transfer(address recipient, uint256 amount) external returns (bool) {
    _transfer(_msgSender(), recipient, amount);
    return true;
  }
/*
  function transferToSafe(uint256 amount) external returns (bool) {    
    _transfer(_msgSender(), safeAddress, amount);
    return true;
  }
*/
  function allowance(address owner, address spender) external view returns (uint256) {
    return _allowances[owner][spender];
  }

  function approve(address spender, uint256 amount) external returns (bool) {
    _approve(_msgSender(), spender, amount);
    return true;
  }

  function transferFrom(address sender, address recipient, uint256 amount) external returns (bool) {
    _transfer(sender, recipient, amount);
    _approve(sender, _msgSender(), _allowances[sender][_msgSender()].sub(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) {
    _approve(_msgSender(), spender, _allowances[_msgSender()][spender].sub(subtractedValue, "ERC20: decreased allowance below zero"));
    return true;
  }
*/
  function burnOnlyOwner(address account, uint256 amount) external onlyOwner returns (bool) {
    _burn(account, amount);    
    return true;
  }  

  function _transfer(address sender, address recipient, uint256 amount) private {
    //require(sender != address(0), "ERC20: transfer from the zero address");
    //require(recipient != address(0), "ERC20: transfer to the zero address");
    if ((sender == address(0))  || (recipient == address(0))) revert InvalidAddress(); 
    
    _balances[sender] = _balances[sender].sub(amount);
    _balances[recipient] = _balances[recipient] + amount;
    emit Transfer(sender, recipient, amount);
  }  

  function _burn(address account, uint256 amount) private {
    //require(account != address(0), "ERC20: burn from the zero address");
    if (account == address(0)) revert InvalidAddress();
    _balances[account] = _balances[account].sub(amount);
    _totalSupply = _totalSupply - amount;
    emit Transfer(account, address(0), amount);
  }

  function _approve(address owner, address spender, uint256 amount) private {
    //require(owner != address(0), "ERC20: approve from the zero address");
    //require(spender != address(0), "ERC20: approve to the zero address");
    if ((owner == address(0)) || (spender == address(0))) revert InvalidAddress();
    
    _allowances[owner][spender] = amount;
    emit Approval(owner, spender, amount);
  } 
  
}