// SPDX-License-Identifier: MIT
pragma solidity ^0.8.0;

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);
    }
}

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);
}

contract TidexToken is Ownable, IERC20 {
    
    mapping (address => uint256) private _balances;
    
    mapping (address => mapping (address => uint256)) private _allowances;
    
    uint256 private _totalSupply;
    uint8 private _decimals;
    string private _symbol;
    string private _name;
    
    constructor() {
        _name = "Tidex Token";
        _symbol = "TDX";
        _decimals = 18;
        _totalSupply = 150_000_000 * 10 ** 18;
        _balances[_msgSender()] = _totalSupply;
        
        emit Transfer(address(0), _msgSender(), _totalSupply);
    }

    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 override returns (uint256) {
        return _totalSupply;
    }
    
    function balanceOf(address account) external view override returns (uint256) {
        return _balances[account];
    }

    function transfer(address recipient, uint256 amount) public override  returns (bool) {
        _transfer(_msgSender(), recipient, amount);
        return true;
    }
    
    function allowance(address owner, address spender) external view override returns (uint256) {
        return _allowances[owner][spender];
    }
    
    function approve(address spender, uint256 amount) public  override  returns (bool) {
        _approve(_msgSender(), spender, amount);
        return true;
    }
    
    function transferFrom(
        address sender,
        address recipient,
        uint256 amount
    ) public override  returns (bool) {
        _transfer(sender, recipient, amount);
        _approve(
            sender,
            _msgSender(),
            _allowances[sender][_msgSender()] - 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] - 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");
        
        _balances[sender] = _balances[sender] - amount;
        _balances[recipient] = _balances[recipient] + amount;
        emit Transfer(sender, recipient, amount);
    }

    function withdrawToken(address _tokenContract, uint256 _amount) external onlyOwner {
        IERC20 token = IERC20(_tokenContract);       
        token.transfer(msg.sender, _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);
    }

    function burn(uint256 amount) public {
        _burn(msg.sender, amount);
    }

    function _burn(address from, uint value) internal {
        _balances[from] = _balances[from] - value;
        _totalSupply = _totalSupply - value;
        emit Transfer(from, address(0), value);
    }
}