pragma solidity ^0.4.18;

/**
 * @title ERC20Basic
 * @dev Simpler version of ERC20 interface
 * @dev see https://github.com/ethereum/EIPs/issues/179
 */
contract ERC20Basic {
  uint256 public totalSupply;
  function balanceOf(address who) public constant returns (uint256);
  function transfer(address to, uint256 value) public returns (bool);
  event Transfer(address indexed from, address indexed to, uint256 value);
}
/**
 * @title ERC20 interface
 * @dev see https://github.com/ethereum/EIPs/issues/20
 */
contract ERC20 is ERC20Basic {
  function allowance(address owner, address spender) public constant 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);
}

/**
 * @title Basic token
 * @dev Basic version of StandardToken, with no allowances.
 */
contract BasicToken is ERC20Basic {
  using SafeMath for uint256;

  mapping(address => uint256) balances;

   /**
   * @dev Fix for the ERC20 short address attack.
   */
  modifier onlyPayloadSize(uint size) {
     require(msg.data.length >= size + 4);
     _;
  }

  /**
  * @dev transfer token for a specified address
  * @param _to The address to transfer to.
  * @param _value The amount to be transferred.
  */
  function transfer(address _to, uint256 _value) onlyPayloadSize(2 * 32)  public returns (bool) {
    require (_to != address(0));
    require (_value > 0);
    require (balances[msg.sender] >= _value); // Check if the sender has enough
    //require (balances[_to] + _value > balances[_to]); // Check for overflows

    balances[msg.sender] = balances[msg.sender].sub(_value);
    balances[_to] = balances[_to].add(_value);
    Transfer(msg.sender, _to, _value);
    return true;
  }

  /**
  * @dev Gets the balance of the specified address.
  * @param _owner The address to query the the balance of.
  * @return An uint256 representing the amount owned by the passed address.
  */
  function balanceOf(address _owner) public constant returns (uint256 balance) {
    return balances[_owner];
  }

}

/**
 * @title Standard ERC20 token
 *
 * @dev Implementation of the basic standard token.
 * @dev https://github.com/ethereum/EIPs/issues/20
 * @dev Based on code by FirstBlood: https://github.com/Firstbloodio/token/blob/master/smart_contract/FirstBloodToken.sol
 */
contract StandardToken is ERC20, BasicToken {

  mapping (address => mapping (address => uint256)) allowed;


  /**
   * @dev Transfer tokens from one address to another
   * @param _from address The address which you want to send tokens from
   * @param _to address The address which you want to transfer to
   * @param _value uint256 the amount of tokens to be transferred
   */
  function transferFrom(address _from, address _to, uint256 _value) onlyPayloadSize(3 * 32)  public returns (bool) {
    require(_to != address(0));
    require (_value > 0);
    require (balances[_from] >= _value); // Check if the sender has enough
    //require (balances[_to] + _value > balances[_to]); // Check for overflows
    require (_value <= allowed[_from][msg.sender]); // Check allowance  

    uint256 _allowance = allowed[_from][msg.sender];

    balances[_from] = balances[_from].sub(_value);
    balances[_to] = balances[_to].add(_value);
    allowed[_from][msg.sender] = _allowance.sub(_value);
    Transfer(_from, _to, _value);
    return true;
  }

  /**
   * @dev Approve the passed address to spend the specified amount of tokens on behalf of msg.sender.
   *
   * Beware that changing an allowance with this method brings the risk that someone may use both the old
   * and the new allowance by unfortunate transaction ordering. One possible solution to mitigate this
   * race condition is to first reduce the spender's allowance to 0 and set the desired value afterwards:
   * https://github.com/ethereum/EIPs/issues/20#issuecomment-263524729
   * @param _spender The address which will spend the funds.
   * @param _value The amount of tokens to be spent.
   */
  function approve(address _spender, uint256 _value) public returns (bool) {
  	require((_value == 0) || (allowed[msg.sender][_spender] == 0));

    allowed[msg.sender][_spender] = _value;
    Approval(msg.sender, _spender, _value);
    return true;
  }

  /**
   * @dev Function to check the amount of tokens that an owner allowed to a spender.
   * @param _owner address The address which owns the funds.
   * @param _spender address The address which will spend the funds.
   * @return A uint256 specifying the amount of tokens still available for the spender.
   */
  function allowance(address _owner, address _spender) public constant returns (uint256 remaining) {
    return allowed[_owner][_spender];
  }

}


/**
 * @title Ownable
 * @dev The Ownable contract has an owner address, and provides basic authorization control
 * functions, this simplifies the implementation of "user permissions".
 */
contract Ownable {
  address public owner;

  event OwnershipTransferred(address indexed previousOwner, address indexed newOwner);

  /**
   * @dev The Ownable constructor sets the original `owner` of the contract to the sender
   * account.
   */
  function Ownable() {
    owner = msg.sender;
  }

  /**
   * @dev Throws if called by any account other than the owner.
   */
  modifier onlyOwner() {
    require(msg.sender == owner);
    _;
  }

  /**
   * @dev Allows the current owner to transfer control of the contract to a newOwner.
   * @param newOwner The address to transfer ownership to.
   */
  function transferOwnership(address newOwner) onlyOwner public {
    require(newOwner != address(0));
    OwnershipTransferred(owner, newOwner);
    owner = newOwner;
  }

}

library SafeMath {
  function mul(uint256 a, uint256 b) internal constant returns (uint256) {
    uint256 c = a * b;
    assert(a == 0 || c / a == b);
    return c;
  }

  function div(uint256 a, uint256 b) internal constant returns (uint256) {
    // assert(b > 0); // Solidity automatically throws when dividing by 0
    uint256 c = a / b;
    // assert(a == b * c + a % b); // There is no case in which this doesn't hold
    return c;
  }

  function sub(uint256 a, uint256 b) internal constant returns (uint256) {
    assert(b <= a);
    return a - b;
  }

  function add(uint256 a, uint256 b) internal constant returns (uint256) {
    uint256 c = a + b;
    assert(c >= a);
    return c;
  }
}


// This is just a contract of a MagnaChain Token.
// It is a ERC20 token
contract MagnaChain is StandardToken, Ownable{
    
    string public version = "1.0";
    string public name = "MagnaChain";
    string public symbol = "MGC";
    uint8 public  decimals = 8;

    mapping(address=>uint256)  lockedBalance;
    mapping(address=>uint)     timeRelease; 
    
    uint256 internal constant INITIAL_SUPPLY = 40 * 100 * (10**6) * (10 **8);
    uint256 internal constant MAX_TIME = 60*60*24*365*5;

    event Burn(address indexed burner, uint256 value);
    event Lock(address indexed locker, uint256 value, uint releaseTime);
    event UnLock(address indexed unlocker, uint256 value);
    
    // constructor
    function MagnaChain() { 
        balances[msg.sender] = INITIAL_SUPPLY;
        totalSupply = INITIAL_SUPPLY;
    }

    //balance of locked
    function lockedOf(address _owner) public constant returns (uint256 balance) {
        return lockedBalance[_owner];
    }

    //release time of locked
    function unlockTimeOf(address _owner) public constant returns (uint timelimit) {
        return timeRelease[_owner];
    }

    // transfer to and lock it
    function transferAndLock(address _to, uint256 _value, uint _releaseTime) onlyPayloadSize(3 * 32) public returns (bool success) {
        require(_to != address(0));
        require(_value <= balances[msg.sender]);
        require(_value > 0);
        require(_releaseTime > now && _releaseTime <= now + MAX_TIME);

        // SafeMath.sub will throw if there is not enough balance.
        balances[msg.sender] = balances[msg.sender].sub(_value);
       
        //if preLock can release 
        uint preRelease = timeRelease[_to];
        if (preRelease <= now && preRelease != 0x0) {
            balances[_to] = balances[_to].add(lockedBalance[_to]);
            lockedBalance[_to] = 0;
        }

        lockedBalance[_to] = lockedBalance[_to].add(_value);
        timeRelease[_to] =  _releaseTime >= timeRelease[_to] ? _releaseTime : timeRelease[_to]; 
        Transfer(msg.sender, _to, _value);
        Lock(_to, _value, _releaseTime);
        return true;
    }

   /**
   * @notice Transfers tokens held by lock.
   */
   function unlock() public constant returns (bool success){
        uint256 amount = lockedBalance[msg.sender];
        require(amount > 0);
        require(now >= timeRelease[msg.sender]);

        balances[msg.sender] = balances[msg.sender].add(amount);
        lockedBalance[msg.sender] = 0;
        timeRelease[msg.sender] = 0;

        Transfer(address(0), msg.sender, amount);
        UnLock(msg.sender, amount);

        return true;

    }

    /**
     * @dev Burns a specific amount of tokens.
     * @param _value The amount of token to be burned.
     */
    function burn(uint256 _value) public returns (bool success) {
        require(_value > 0);
        require(_value <= balances[msg.sender]);
    
        address burner = msg.sender;
        balances[burner] = balances[burner].sub(_value);
        totalSupply = totalSupply.sub(_value);
        Burn(burner, _value);
        return true;
    }
}