contract DatCrowdPreSale is Ownable {
  using SafeMath for uint256;

  // The token being sold
  DatumGenesisToken public token;

  // start and end date where investments are allowed (both inclusive)
  uint256 public startDate = 1502460000; //Fri, 11 Aug 2017 14:00:00 +00:00
  uint256 public endDate = 1505138400; //Mon, 11 Sep 2017 14:00:00 +00:00

  // Minimum amount to participate
  uint256 public minimumParticipationAmount = 100000000000000000 wei; //0.1 ether

  // Maximum amount to participate
  uint256 public maximalParticipationAmount = 1000000000000000000000 wei; //1000 ether

  // address where funds are collected
  address wallet;

  // how many token units a buyer gets per ether
  uint256 rate = 15000;

  // amount of raised money in wei
  uint256 public weiRaised;

  //flag for final of crowdsale
  bool public isFinalized = false;

  //cap for the sale
  uint256 public cap = 5000000000000000000000 wei; //5000 ether
 



  event Finalized();

  /**
   * 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);



  /**
  * @notice Log an event for each funding contributed during the public phase
  * @notice Events are not logged when the constructor is being executed during
  *         deployment, so the preallocations will not be logged
  */
  event LogParticipation(address indexed sender, uint256 value, uint256 timestamp);


  
  function DatCrowdPreSale(address _wallet) {
    token = createTokenContract();
    wallet = _wallet;
  }


// creates the token to be sold. 
  // override this method to have crowdsale of a specific datum token.
  function createTokenContract() internal returns (DatumGenesisToken) {
    return new DatumGenesisToken();
}

  // fallback function can be used to buy tokens
  function () payable {
    buyTokens(msg.sender);
  }

  // low level token purchase function
  function buyTokens(address beneficiary) payable {
    require(beneficiary != 0x0);
    require(validPurchase());

    //get ammount in wei
    uint256 weiAmount = msg.value;

    // calculate token amount to be created
    uint256 tokens = weiAmount.mul(rate);

    //purchase tokens and transfer to beneficiary
    token.transferFromContract(beneficiary, tokens);

    // update state
    weiRaised = weiRaised.add(weiAmount);

    //Token purchase event
    TokenPurchase(msg.sender, beneficiary, weiAmount, tokens);

    //forward funds to wallet
    forwardFunds();
  }

  //send tokens to the given address used for investors with other conditions, only contract owner can call this
  function transferTokensManual(address beneficiary, uint256 amount) onlyOwner {
    require(beneficiary != 0x0);
    require(amount != 0);
    require(weiRaised.add(amount) <= cap);

    //transfer tokens
    token.transferFromContract(beneficiary, amount);

    // update state
    weiRaised = weiRaised.add(amount);

    //Token purchase event
    TokenPurchase(wallet, beneficiary, 0, amount);

  }

   /// @notice Enables token holders to transfer their tokens freely if true
   /// @param _transfersEnabled True if transfers are allowed in the clone
   function enableTransfers(bool _transfersEnabled) onlyOwner {
      token.enableTransfers(_transfersEnabled);
   }

  // send ether to the fund collection wallet
  // override to create custom fund forwarding mechanisms
  function forwardFunds() internal {
    wallet.transfer(msg.value);
  }

  // should be called after crowdsale ends or to emergency stop the sale
  function finalize() onlyOwner {
    require(!isFinalized);
    Finalized();
    isFinalized = true;
  }


  // @return true if the transaction can buy tokens
  // check for valid time period, min amount and within cap
  function validPurchase() internal constant returns (bool) {
    bool withinPeriod = startDate <= now && endDate >= now;
    bool nonZeroPurchase = msg.value != 0;
    bool minAmount = msg.value >= minimumParticipationAmount;
    bool withinCap = weiRaised.add(msg.value) <= cap;

    return withinPeriod && nonZeroPurchase && minAmount && !isFinalized && withinCap;
  }

    // @return true if the goal is reached
  function capReached() public constant returns (bool) {
    return weiRaised >= cap;
  }

  // @return true if crowdsale event has ended
  function hasEnded() public constant returns (bool) {
    return isFinalized;
  }

}
/**
 * @title  
 * @dev DatCrowdSale is a contract for managing a token crowdsale.
 * DatCrowdSale have a start and end date, where investors can make
 * token purchases and the crowdsale will assign them tokens based
 * on a token per ETH rate. Funds collected are forwarded to a refundable valut 
 * as they arrive.
 */
function capReached() public constant returns (bool) {
  return weiRaised >= cap;
}

// @return true if the goal is reached