pragma solidity ^0.4.18;


contract ERC20Basic {
  function totalSupply() public view returns (uint256);
  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);
}


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) {

    uint256 c = a / b;

    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;
  }
}


contract BasicToken is ERC20Basic {
  using SafeMath for uint256;

  mapping(address => uint256) balances;

  uint256 totalSupply_;

  function totalSupply() public view returns (uint256) {
    return totalSupply_;
  }


  function transfer(address _to, uint256 _value) 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 balanceOf(address _owner) public view returns (uint256 balance) {
    return balances[_owner];
  }

}

contract ERC20 is ERC20Basic {
  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 StandardToken is ERC20, BasicToken {

  mapping (address => mapping (address => uint256)) internal allowed;


  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] = 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 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] = allowed[msg.sender][_spender].add(_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] = oldValue.sub(_subtractedValue);
    }
    Approval(msg.sender, _spender, allowed[msg.sender][_spender]);
    return true;
  }

}


contract EnkronosToken is StandardToken {

	string public name = 'EnkronosToken';
	string public symbol = 'ENK';
	uint8 public decimals = 18;
	uint public INITIAL_SUPPLY = 500000000000000000000000000;


	function EnkronosToken() public {
	  totalSupply_ = INITIAL_SUPPLY;
	  balances[msg.sender] = INITIAL_SUPPLY;
	}

}

contract Crowdsale {
  using SafeMath for uint256;

  // The token being sold
  ERC20 public token;

  // Address where funds are collected
  address public wallet;

  // How many token units a buyer gets per wei
  uint256 public rate;

  // Amount of wei raised
  uint256 public weiRaised;

  /**
   * Event for token purchase logging
   * @param purchaser who paid for the tokens
   * @param beneficiary who got the tokens
   * @param value weis paid for purchase
   * @param amount amount of tokens purchased
   */
  event TokenPurchase(address indexed purchaser, address indexed beneficiary, uint256 value, uint256 amount);

  /**
   * @param _rate Number of token units a buyer gets per wei
   * @param _wallet Address where collected funds will be forwarded to
   * @param _token Address of the token being sold
   */
  function Crowdsale(uint256 _rate, address _wallet, ERC20 _token) public {
    require(_rate > 0);
    require(_wallet != address(0));
    require(_token != address(0));

    rate = _rate;
    wallet = _wallet;
    token = _token;
  }

  // -----------------------------------------
  // Crowdsale external interface
  // -----------------------------------------

  /**
   * @dev fallback function ***DO NOT OVERRIDE***
   */
  function () external payable {
    buyTokens(msg.sender);
  }

  /**
   * @dev low level token purchase ***DO NOT OVERRIDE***
   * @param _beneficiary Address performing the token purchase
   */
  function buyTokens(address _beneficiary) public payable {

    uint256 weiAmount = msg.value;
    _preValidatePurchase(_beneficiary, weiAmount);

    // calculate token amount to be created
    uint256 tokens = _getTokenAmount(weiAmount);

    // update state
    weiRaised = weiRaised.add(weiAmount);

    _processPurchase(_beneficiary, tokens);
    TokenPurchase(msg.sender, _beneficiary, weiAmount, tokens);

    _updatePurchasingState(_beneficiary, weiAmount);

    _forwardFunds();
    _postValidatePurchase(_beneficiary, weiAmount);
  }

  // -----------------------------------------
  // Internal interface (extensible)
  // -----------------------------------------

  /**
   * @dev Validation of an incoming purchase. Use require statements to revert state when conditions are not met. Use super to concatenate validations.
   * @param _beneficiary Address performing the token purchase
   * @param _weiAmount Value in wei involved in the purchase
   */
  function _preValidatePurchase(address _beneficiary, uint256 _weiAmount) internal {
    require(_beneficiary != address(0));
    require(_weiAmount != 0);
  }

  /**
   * @dev Validation of an executed purchase. Observe state and use revert statements to undo rollback when valid conditions are not met.
   * @param _beneficiary Address performing the token purchase
   * @param _weiAmount Value in wei involved in the purchase
   */
  function _postValidatePurchase(address _beneficiary, uint256 _weiAmount) internal {
    // optional override
  }

  /**
   * @dev Source of tokens. Override this method to modify the way in which the crowdsale ultimately gets and sends its tokens.
   * @param _beneficiary Address performing the token purchase
   * @param _tokenAmount Number of tokens to be emitted
   */
  function _deliverTokens(address _beneficiary, uint256 _tokenAmount) internal {
    token.transfer(_beneficiary, _tokenAmount);
  }

  /**
   * @dev Executed when a purchase has been validated and is ready to be executed. Not necessarily emits/sends tokens.
   * @param _beneficiary Address receiving the tokens
   * @param _tokenAmount Number of tokens to be purchased
   */
  function _processPurchase(address _beneficiary, uint256 _tokenAmount) internal {
    _deliverTokens(_beneficiary, _tokenAmount);
  }

  /**
   * @dev Override for extensions that require an internal state to check for validity (current user contributions, etc.)
   * @param _beneficiary Address receiving the tokens
   * @param _weiAmount Value in wei involved in the purchase
   */
  function _updatePurchasingState(address _beneficiary, uint256 _weiAmount) internal {
    // optional override
  }

  /**
   * @dev Override to extend the way in which ether is converted to tokens.
   * @param _weiAmount Value in wei to be converted into tokens
   * @return Number of tokens that can be purchased with the specified _weiAmount
   */
  function _getTokenAmount(uint256 _weiAmount) internal view returns (uint256) {
    return _weiAmount.mul(rate);
  }

  /**
   * @dev Determines how ETH is stored/forwarded on purchases.
   */
  function _forwardFunds() internal {
    wallet.transfer(msg.value);
  }
}



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;
  }

}


/**
 * @title WhitelistedCrowdsale
 * @dev Crowdsale in which only whitelisted users can contribute.
 */
contract WhitelistedCrowdsale is Crowdsale, Ownable {

  mapping(address => bool) public whitelist;

  /**
   * @dev Reverts if beneficiary is not whitelisted. Can be used when extending this contract.
   */
  modifier isWhitelisted(address _beneficiary) {
    require(whitelist[_beneficiary]);
    _;
  }

  /**
   * @dev Adds single address to whitelist.
   * @param _beneficiary Address to be added to the whitelist
   */
  function addToWhitelist(address _beneficiary) external onlyOwner {
    whitelist[_beneficiary] = true;
  }

  /**
   * @dev Adds list of addresses to whitelist. Not overloaded due to limitations with truffle testing.
   * @param _beneficiaries Addresses to be added to the whitelist
   */
  function addManyToWhitelist(address[] _beneficiaries) external onlyOwner {
    for (uint256 i = 0; i < _beneficiaries.length; i++) {
      whitelist[_beneficiaries[i]] = true;
    }
  }

  /**
   * @dev Removes single address from whitelist.
   * @param _beneficiary Address to be removed to the whitelist
   */
  function removeFromWhitelist(address _beneficiary) external onlyOwner {
    whitelist[_beneficiary] = false;
  }

  /**
   * @dev Extend parent behavior requiring beneficiary to be in whitelist.
   * @param _beneficiary Token beneficiary
   * @param _weiAmount Amount of wei contributed
   */
  function _preValidatePurchase(address _beneficiary, uint256 _weiAmount) internal isWhitelisted(_beneficiary) {
    super._preValidatePurchase(_beneficiary, _weiAmount);
  }

}

contract RefundVault is Ownable {
  using SafeMath for uint256;

  enum State { Active, Refunding, Closed }

  mapping (address => uint256) public deposited;
  address public wallet;
  State public state;

  event Closed();
  event RefundsEnabled();
  event Refunded(address indexed beneficiary, uint256 weiAmount);

  /**
   * @param _wallet Vault address
   */
  function RefundVault(address _wallet) public {
    require(_wallet != address(0));
    wallet = _wallet;
    state = State.Active;
  }

  /**
   * @param investor Investor address
   */
  function deposit(address investor) onlyOwner public payable {
    require(state == State.Active);
    deposited[investor] = deposited[investor].add(msg.value);
  }

  function close() onlyOwner public {
    require(state == State.Active);
    state = State.Closed;
    Closed();
    wallet.transfer(this.balance);
  }

  function enableRefunds() onlyOwner public {
    require(state == State.Active);
    state = State.Refunding;
    RefundsEnabled();
  }

  /**
   * @param investor Investor address
   */
  function refund(address investor) public {
    require(state == State.Refunding);
    uint256 depositedValue = deposited[investor];
    deposited[investor] = 0;
    investor.transfer(depositedValue);
    Refunded(investor, depositedValue);
  }
}

contract EnkronosCrowdsale is WhitelistedCrowdsale {
    //
    uint256 public goal;
    //
    uint256 public minBuy;
    //
    RefundVault public vault;
    //
    function EnkronosCrowdsale (
			       uint256 _rate,
             address _wallet,
             StandardToken _token,
             uint256 _goal
    )
    public
    Crowdsale(_rate, _wallet, _token)
    WhitelistedCrowdsale() {

      require(_goal > 0);
      vault = new RefundVault(wallet);
      goal = _goal;

      setMinBuyPrivate();
      setWhitelistOn();
    }

    /**
     * @dev Investors can claim refunds here if crowdsale is unsuccessful
     */
    function claimRefund() public {
        require(isFinalized);
        require(!goalReached());
        vault.refund(msg.sender);
    }

    /**
     * @dev Checks whether funding goal was reached.
     * @return Whether funding goal was reached
     */
    function goalReached() public view returns (bool) {
        return weiRaised >= goal;
    }


    bool public isFinalized = false;
    event Finalized();
    /**
     * @dev Must be called after crowdsale ends, to do some extra finalization
     * work. Calls the contract's finalization function.
     */
    function finalize() onlyOwner public {
        require(!isFinalized);
        //require(hasClosed()); From TimedCrowdsale

        finalization();
        Finalized();

        isFinalized = true;
    }

    /**
     * @dev Can be overridden to add finalization logic. The overriding function
     * should call super.finalization() to ensure the chain of finalization is
     * executed entirely.
     */
    function finalization() internal {
      //
      if (goalReached()) {
        vault.close();
      } else {
        vault.enableRefunds();
      }
      //
        uint remaining = token.balanceOf(this);
        token.transfer(owner, remaining);
    }
    /**
     * @dev Overrides Crowdsale fund forwarding, sending funds to vault.
     */
    function _forwardFunds() internal {
        vault.deposit.value(msg.value)(msg.sender);
    }
    //
    function _preValidatePurchase(address _beneficiary, uint256 _weiAmount) internal isWhitelisted(_beneficiary) {
        require(_weiAmount >= minBuy);
        super._preValidatePurchase(_beneficiary, _weiAmount);
    }
    //
    function setRate1666() onlyOwner public {
        rate = 1666;
    }
    function setRate555() onlyOwner public {
        rate = 555;
    }
    function setRate362() onlyOwner public {
        rate = 362;
    }
    function setRate347() onlyOwner public {
        rate = 347;
    }
    function setRate340() onlyOwner public {
        rate = 340;
    }
    function setRate333() onlyOwner public {
        rate = 333;
    }
    //
    function setMinBuyPrivate() onlyOwner public {
        minBuy = 10000000000000000000; // 10 ether
    }
    function setMinBuyPublic() onlyOwner public {
        minBuy = 100000000000000000; // 0.1 ether
    }
    //
    bool public isWhitelistOn;
    function setWhitelistOn() onlyOwner public {
        isWhitelistOn = true;
    }
    function setWhitelistOff() onlyOwner public {
        isWhitelistOn = false;
    }

    modifier isWhitelisted(address _beneficiary) {
      if(isWhitelistOn)
        require(whitelist[_beneficiary]);
      _;
    }
}