pragma solidity >=0.4.21 <0.7.0;

contract MagicToken {
    string public name = "Magic Token";
    string public symbol = "MTK";
    string public standard = "Magic Token v1.0";
    address public adminAddress;
    uint256 public totalSupply;

    event Transfer(
        address indexed _from,
        address indexed _to,
        uint256 _value
    );

    event Approval(
        address indexed _owner,
        address indexed _spender,
        uint256 _value
    );

    mapping(address => uint256) public balanceOf;
    mapping(address => mapping(address => uint256)) public allowance;

    constructor (uint256 _totalSupply) public {
        balanceOf[msg.sender] = _totalSupply;
        totalSupply = _totalSupply;
        adminAddress = msg.sender;
    }

    function transfer(address _to, uint256 _value) public returns (bool success) {
        require(balanceOf[msg.sender] >= _value);

        balanceOf[msg.sender] -= _value;
        balanceOf[_to] += _value;

        emit Transfer(msg.sender, _to, _value);

        return true;
    }

    function approve(address _sender, uint256 _value) public returns (bool success) {

        allowance[msg.sender][_sender] = _value;
        emit Approval(msg.sender, _sender, _value);

        return true;
    }

    function transferFrom(address _from, address _to, uint256 _value) public returns (bool success) {
        require(_value <= balanceOf[_from]);
        require(_value <= allowance[_from][msg.sender]);

        balanceOf[_from] -= _value;
        balanceOf[_to] += _value;

        allowance[_from][msg.sender] -= _value;

        emit Transfer(_from, _to, _value);

        return true;
    }

}