contract StandardCrowdsale {
  using SafeMath for uint256;

  // The token being sold
  PATH public token;  // Path Modification

  // start and end timestamps where investments are allowed (both inclusive)
  uint256 public startTime;
  uint256 public endTime;

  // address where funds are collected
  address public wallet;

  // how many token units a buyer gets per wei
  uint256 public rate;

  // amount of raised money in wei
  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
  );

  function StandardCrowdsale(
    uint256 _startTime,
    uint256 _endTime,
    uint256 _rate,
    address _wallet,
    PATH _token
  )
    public
  {
    require(_startTime >= now);
    require(_endTime >= _startTime);
    require(_rate > 0);
    require(_wallet != address(0));
    require(_token != address(0));

    startTime = _startTime;
    endTime = _endTime;
    rate = _rate;
    wallet = _wallet;
    token = _token;
  }

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

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

    uint256 weiAmount = msg.value;

    // calculate token amount to be created
    uint256 tokens = getTokenAmount(weiAmount);

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

    require(token.transfer(beneficiary, tokens)); // PATH Modification

    TokenPurchase(
      msg.sender,
      beneficiary,
      weiAmount,
      tokens
    );

    forwardFunds();
  }

  // @return true if crowdsale event has ended
  function hasEnded() public view returns (bool) {
    return now > endTime;
  }

  // Override this method to have a way to add business logic to your crowdsale when buying
  function getTokenAmount(uint256 weiAmount) internal view returns(uint256) {
    return weiAmount.mul(rate);
  }

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

  // @return true if the transaction can buy tokens
  function validPurchase() internal view returns (bool) {
    bool withinPeriod = now >= startTime && now <= endTime;
    bool nonZeroPurchase = msg.value != 0;
    return withinPeriod && nonZeroPurchase;
  }
}
function getTokenAmount(uint256 weiAmount) internal view returns(uint256) {
  return weiAmount.mul(rate);
}

// Override this method to have a way to add business logic to your crowdsale when buying