pragma solidity ^0.4.18;

contract SafeMath {
  function mulSafe(uint256 a, uint256 b) internal pure returns (uint256) {
    if (a == 0) {
       return 0;
     }
     uint256 c = a * b;
     assert(c / a == b);
     return c;
   }

  function divSafe(uint256 a, uint256 b) internal pure returns (uint256) {
     uint256 c = a / b;
     return c;
  }

  function subSafe(uint256 a, uint256 b) internal pure returns (uint256) {
    assert(b <= a);
     return a - b;
   }

  function addSafe(uint256 a, uint256 b) internal pure returns (uint256) {
     uint256 c = a + b;
    assert(c >= a);
     return c;
   }
}

contract Owned {
    address public owner;
    address public newOwner;
    event OwnershipTransferred(address indexed _from, address indexed _to);
    function Constructor() public { owner = msg.sender; }
    modifier onlyOwner {
        require(msg.sender == owner);
        _;
    }

    function transferOwnership(address _newOwner) public onlyOwner {
        newOwner = _newOwner;
    }
    function acceptOwnership() public {
        require(msg.sender == newOwner);
        OwnershipTransferred(owner, newOwner);
        owner = newOwner;
        newOwner = address(0);
    }
}

contract ERC20 {
   uint256 public totalSupply;
   function balanceOf(address who) public view returns (uint256);
   function transfer(address to, uint256 value) public returns (bool);
   event Transfer(address indexed from, address indexed to, uint256 value);
   function allowance(address owner, address spender) public view returns (uint256);
   function transferFrom(address from, address to, uint256 value) public returns (bool);
   function approve(address spender, uint256 value) public returns (bool);
   event Approval(address indexed owner, address indexed spender, uint256 value);
}

contract ERC223 {
    function transfer(address to, uint value, bytes data) public;
    event Transfer(address indexed from, address indexed to, uint value, bytes indexed data);
}

contract ERC223ReceivingContract { 
    function tokenFallback(address _from, uint _value, bytes _data) public;
}

contract StandardToken is ERC20, ERC223, SafeMath, Owned {
  event ReleaseSupply(address indexed receiver, uint256 value, uint256 releaseTime);
  mapping(address => uint256) balances;
  mapping (address => mapping (address => uint256)) internal allowed;

  function transfer(address _to, uint256 _value) public returns (bool) {
    require(_to != address(0));
    require(_value <= balances[msg.sender]);
    balances[msg.sender] = subSafe(balances[msg.sender], _value);
    balances[_to] = addSafe(balances[_to], _value);
    Transfer(msg.sender, _to, _value);
    return true;
  }

  function balanceOf(address _owner) public view returns (uint256 balance) {
    return balances[_owner];
   }

  function transferFrom(address _from, address _to, uint256 _value) public returns (bool) {
    require(_to != address(0));
    require(_value <= balances[_from]);
    require(_value <= allowed[_from][msg.sender]);

    balances[_from] = subSafe(balances[_from], _value);
     balances[_to] = addSafe(balances[_to], _value);
     allowed[_from][msg.sender] = subSafe(allowed[_from][msg.sender], _value);
    Transfer(_from, _to, _value);
     return true;
   }

   function approve(address _spender, uint256 _value) public returns (bool) {
     allowed[msg.sender][_spender] = _value;
     Approval(msg.sender, _spender, _value);
     return true;
   }

  function allowance(address _owner, address _spender) public view returns (uint256) {
     return allowed[_owner][_spender];
   }

   function increaseApproval(address _spender, uint _addedValue) public returns (bool) {
     allowed[msg.sender][_spender] = addSafe(allowed[msg.sender][_spender], _addedValue);
     Approval(msg.sender, _spender, allowed[msg.sender][_spender]);
     return true;
   }

  function decreaseApproval(address _spender, uint _subtractedValue) public returns (bool) {
     uint oldValue = allowed[msg.sender][_spender];
     if (_subtractedValue > oldValue) {
       allowed[msg.sender][_spender] = 0;
     } else {
       allowed[msg.sender][_spender] = subSafe(oldValue, _subtractedValue);
    }
     Approval(msg.sender, _spender, allowed[msg.sender][_spender]);
     return true;
   }

    function transfer(address _to, uint _value, bytes _data) public {
        require(_value > 0 );
        if(isContract(_to)) {
            ERC223ReceivingContract receiver = ERC223ReceivingContract(_to);
            receiver.tokenFallback(msg.sender, _value, _data);
        }
        balances[msg.sender] = subSafe(balances[msg.sender], _value);
        balances[_to] = addSafe(balances[_to], _value);
        Transfer(msg.sender, _to, _value, _data);
    }

    function isContract(address _addr) private view returns (bool is_contract) {
      uint length;
      assembly {
            //retrieve the size of the code on target address, this needs assembly
            length := extcodesize(_addr)
      }
      return (length>0);
    }

}

contract TQXToken is StandardToken {
  string public name = 'TQXToken';
  string public symbol = 'TQX';
  uint public decimals = 8;

  uint256 public createTime         = 1527782400;
  uint256 firstAnnual               = 1559318400;
  uint256 secondAnnual              = 1590940800;
  uint256 thirdAnnual               = 1622476800;

  uint256 public INITIAL_SUPPLY     = 1000000000;
  uint256 public frozenForever      =  400000000;

  uint256 firstAnnualReleasedAmount =  150000000;
  uint256 secondAnnualReleasedAmount=  150000000;
  uint256 thirdAnnualReleasedAmount =  100000000;

  function TQXToken() public {
    totalSupply = 200000000 ; 
    balances[msg.sender] = totalSupply * 10 ** uint256(decimals);
  }

  function releaseSupply() public onlyOwner returns(uint256 _actualRelease) {
    uint256 releaseAmount = getReleaseAmount();
    require(releaseAmount > 0);
    balances[owner] = addSafe(balances[owner], releaseAmount * 10 ** uint256(decimals));
    totalSupply = addSafe(totalSupply, releaseAmount);
    Transfer(address(0), msg.sender, releaseAmount);
    return releaseAmount;
  }

  function getReleaseAmount() internal returns(uint256 _actualRelease) {
        uint256 _amountToRelease;
        if (    now >= firstAnnual
             && now < secondAnnual
             && firstAnnualReleasedAmount > 0) {
            _amountToRelease = firstAnnualReleasedAmount;
            firstAnnualReleasedAmount = 0;
        } else if (    now >= secondAnnual 
                    && now < thirdAnnual
                    && secondAnnualReleasedAmount > 0) {
            _amountToRelease = secondAnnualReleasedAmount;
            secondAnnualReleasedAmount = 0;
        } else if (    now >= thirdAnnual 
                    && thirdAnnualReleasedAmount > 0) {
            _amountToRelease = thirdAnnualReleasedAmount;
            thirdAnnualReleasedAmount = 0;
        } else {
            _amountToRelease = 0;
        }
        return _amountToRelease;
    }
}