// File: DQICoin.sol



pragma solidity 0.4.24;

import './Ownable.sol';
import './Pausable.sol';
import './SafeMath.sol';
import './ERC20.sol';


contract DetailedERC20 is ERC20 {
  string public name;
  string public symbol;
  uint8 public decimals;
  uint256 public unlocktime;

  function DetailedERC20(string _name, string _symbol, uint8 _decimals) public {
    name = _name;
    symbol = _symbol;
    decimals = _decimals;
  }
}

contract DQICoin is Pausable, DetailedERC20 {
  using SafeMath for uint256;

  mapping(address => uint256) balances;
  mapping (address => mapping (address => uint256)) internal allowed;
  mapping(address => uint256) public lockedBalances;

  address public crowdsaleContract = 0;

  function DQICoin() DetailedERC20("DotQii", "DQI", 18) public {
    unlocktime = 0;
    totalSupply = 300 * (10**6) * 10**uint256(decimals);  // 300 million
  }

  function setCrowdsaleContract(address crowdsale) onlyOwner public {
    crowdsaleContract = crowdsale;
  }

  modifier timeLock(address from, uint value) {
    if (now < unlocktime) {
      require(value <= balances[from] - lockedBalances[from]);
    } else {
      lockedBalances[from] = 0;
    }
    _;
  }

  function addToBalances(address _person,uint256 value) public {
    require(msg.sender == crowdsaleContract);
    balances[_person] = balances[_person].add(value);
    Transfer(address(this), _person, value);
  }

  function transfer(address _to, uint256 _value) timeLock(msg.sender, _value) whenNotPaused public returns (bool) {
    require(_to != address(0));
    require(_value <= balances[msg.sender]);

    balances[msg.sender] = balances[msg.sender].sub(_value);
    balances[_to] = balances[_to].add(_value);
    Transfer(msg.sender, _to, _value);
    return true;
  }

  function transferToLockedBalance(address _to, uint256 _value) whenNotPaused public returns (bool) {
    require(msg.sender == crowdsaleContract);
    if (transfer(_to, _value)) {
      lockedBalances[_to] = lockedBalances[_to].add(_value);
      return true;
    }
  }

  function balanceOf(address _owner) public view returns (uint256 balance) {
    return balances[_owner];
  }


  function transferFrom(address _from, address _to, uint256 _value) public timeLock(_from, _value) whenNotPaused returns (bool) {
    require(_to != address(0));
    require(_value <= balances[_from]);
    require(_value <= allowed[_from][msg.sender]);

    balances[_from] = balances[_from].sub(_value);
    balances[_to] = balances[_to].add(_value);
    allowed[_from][msg.sender] = allowed[_from][msg.sender].sub(_value);
    Transfer(_from, _to, _value);
    return true;
  }

  function approve(address _spender, uint256 _value) public whenNotPaused 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 whenNotPaused returns (bool) {
    allowed[msg.sender][_spender] = allowed[msg.sender][_spender].add(_addedValue);
    Approval(msg.sender, _spender, allowed[msg.sender][_spender]);
    return true;
  }

  function decreaseApproval(address _spender, uint _subtractedValue) public whenNotPaused returns (bool) {
    uint oldValue = allowed[msg.sender][_spender];
    if (_subtractedValue > oldValue) {
      allowed[msg.sender][_spender] = 0;
    } else {
      allowed[msg.sender][_spender] = oldValue.sub(_subtractedValue);
    }
    Approval(msg.sender, _spender, allowed[msg.sender][_spender]);
    return true;
  }

  function updateUnlocktime(uint newtime) onlyOwner public {
    unlocktime = newtime;
  }
}
// File: ERC20.sol



pragma solidity 0.4.24;

import "./ERC20Interface.sol";

contract ERC20 is ERC20Interface {

    string public name;
    string public symbol;
    uint8 public decimals;
    uint256 public totalSupply;

    // Function to access name of token .
    function name() public view returns (string _name) {
        return name;
    }
    // Function to access symbol of token .
    function symbol() public view returns (string _symbol) {
        return symbol;
    }
    // Function to access decimals of token .
    function decimals() public view returns (uint8 _decimals) {
        return decimals;
    }
    // Function to access total supply of tokens .
    function totalSupply() public view returns (uint256 _totalSupply) {
        return totalSupply;
    }

    mapping (address => uint256) balances;
    mapping (address => mapping (address => uint256)) allowed;

    function balanceOf(address participant) public constant returns (uint256 balance) {
        return balances[participant];
    }

    function transfer(address _to, uint256 _value) public onlyPayloadSize(2) returns (bool success) {
        require(_to != address(0));
        // documentation says transfer of 0 must be treated as a transfer and fire the transfer event
        require(balances[msg.sender] >= _value && _value > 0);
        balances[msg.sender] = safeSub(balances[msg.sender], _value);
        balances[_to] = safeAdd(balances[_to], _value);
        emit Transfer(msg.sender, _to, _value);

        return true;
    }

    function transferFrom(address _from, address _to, uint256 _value) onlyPayloadSize(3) public returns (bool success) {
        require(_to != address(0));
        require(balances[_from] >= _value && allowed[_from][msg.sender] >= _value && _value > 0);
        balances[_from] = safeSub(balances[_from], _value);
        balances[_to] = safeAdd(balances[_to], _value);
        allowed[_from][msg.sender] = safeSub(allowed[_from][msg.sender], _value);
        emit Transfer(_from, _to, _value);

        return true;
    }

 	// To change the approve amount you first have to reduce the addresses'
    //  allowance to zero by calling 'approve(_spender, 0)' if it is not
    //  already 0 to mitigate the race condition described here:
    //  https://github.com/ethereum/EIPs/issues/20#issuecomment-263524729
    function approve(address _spender, uint256 _value) onlyPayloadSize(2) public returns (bool success) {
        require((_value == 0) || (allowed[msg.sender][_spender] == 0));
        allowed[msg.sender][_spender] = _value;
        emit Approval(msg.sender, _spender, _value);

        return true;
    }

    function changeApproval(address _spender, uint256 _oldValue, uint256 _newValue) onlyPayloadSize(3) public returns (bool success) {
        require(allowed[msg.sender][_spender] == _oldValue);
        allowed[msg.sender][_spender] = _newValue;
        emit Approval(msg.sender, _spender, _newValue);

        return true;
    }

    function allowance(address _owner, address _spender) constant public returns (uint256 remaining) {
        return allowed[_owner][_spender];
    }

    // mitigate short address attack
    // thanks to https://github.com/numerai/contract/blob/c182465f82e50ced8dacb3977ec374a892f5fa8c/contracts/Safe.sol#L30-L34.
    // TODO: doublecheck implication of >= compared to ==
    modifier onlyPayloadSize(uint numWords) {
        assert(msg.data.length >= numWords * 32 + 4);
        _;
    }

    function safeMul(uint a, uint b) internal pure returns (uint) {
        uint c = a * b;
        assert(a == 0 || c / a == b);
        return c;
    }

    function safeSub(uint a, uint b) internal pure returns (uint) {
        assert(b <= a);
        return a - b;
    }

    function safeAdd(uint a, uint b) internal pure returns (uint) {
        uint c = a + b;
        assert(c>=a && c>=b);
        return c;
    }
}
// File: ERC20Interface.sol



pragma solidity 0.4.24;

contract ERC20Interface  {
    function balanceOf(address _owner) public constant returns (uint256 balance);
    function transfer(address _to, uint256 _value) public returns (bool success);
    function transferFrom(address _from, address _to, uint256 _value) public returns (bool success);
    function approve(address _spender, uint256 _value) public returns (bool success);
    function allowance(address _owner, address _spender) public constant returns (uint256 remaining);
    function totalSupply() public constant returns (uint256);

    event Transfer(address indexed _from, address indexed _to, uint256 _value);
    event Approval(address indexed _owner, address indexed _spender, uint256 _value);
}
// File: Ownable.sol



pragma solidity 0.4.24;


/**
 * @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() public {
    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) public onlyOwner {
    require(newOwner != address(0));
    OwnershipTransferred(owner, newOwner);
    owner = newOwner;
  }

}
// File: Pausable.sol



pragma solidity 0.4.24;


import "./Ownable.sol";


/**
 * @title Pausable
 * @dev Base contract which allows children to implement an emergency stop mechanism.
 */
contract Pausable is Ownable {
  event Pause();
  event Unpause();

  bool public paused = false;


  /**
   * @dev Modifier to make a function callable only when the contract is not paused.
   */
  modifier whenNotPaused() {
    require(!paused);
    _;
  }

  /**
   * @dev Modifier to make a function callable only when the contract is paused.
   */
  modifier whenPaused() {
    require(paused);
    _;
  }

  /**
   * @dev called by the owner to pause, triggers stopped state
   */
  function pause() onlyOwner whenNotPaused public {
    paused = true;
    Pause();
  }

  /**
   * @dev called by the owner to unpause, returns to normal state
   */
  function unpause() onlyOwner whenPaused public {
    paused = false;
    Unpause();
  }
}
// File: SafeMath.sol



pragma solidity 0.4.24;


/**
 * @title SafeMath
 * @dev Math operations with safety checks that throw on error
 */
library SafeMath {
  function mul(uint256 a, uint256 b) internal pure returns (uint256) {
    if (a == 0) {
      return 0;
    }
    uint256 c = a * b;
    assert(c / a == b);
    return c;
  }

  function div(uint256 a, uint256 b) internal pure 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 pure returns (uint256) {
    assert(b <= a);
    return a - b;
  }

  function add(uint256 a, uint256 b) internal pure returns (uint256) {
    uint256 c = a + b;
    assert(c >= a);
    return c;
  }
}