contract Crowdsale is Context, ReentrancyGuard {
	using SafeMath for uint256;
	using SafeERC20 for IERC20;

	// The token being sold
	IERC20 private _token;

	// Address where funds are collected
	address payable private _wallet;

	// How many token units a buyer gets per wei.
	// The rate is the conversion between wei and the smallest and indivisible token unit.
	// So, if you are using a rate of 1 with a ERC20Detailed token with 3 decimals called TOK
	// 1 wei will give you 1 unit, or 0.001 TOK.
	uint256 private _rate;

	// Amount of wei raised
	uint256 private _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 TokensPurchased(address indexed purchaser, address indexed beneficiary, uint256 value, uint256 amount);

	/**
	 * @param rate Number of token units a buyer gets per wei
	 * @dev The rate is the conversion between wei and the smallest and indivisible
	 * token unit. So, if you are using a rate of 1 with a ERC20Detailed token
	 * with 3 decimals called TOK, 1 wei will give you 1 unit, or 0.001 TOK.
	 * @param wallet Address where collected funds will be forwarded to
	 * @param token Address of the token being sold
	 */
	constructor (uint256 rate, address payable wallet, IERC20 token) public {
		require(rate > 0, "Crowdsale: rate is 0");
		require(wallet != address(0), "Crowdsale: wallet is the zero address");
		require(address(token) != address(0), "Crowdsale: token is the zero address");

		_rate = rate;
		_wallet = wallet;
		_token = token;
	}

	/**
	 * @dev fallback function ***DO NOT OVERRIDE***
	 * Note that other contracts will transfer funds with a base gas stipend
	 * of 2300, which is not enough to call buyTokens. Consider calling
	 * buyTokens directly when purchasing tokens from a contract.
	 */
	function () external payable {
		buyTokens(_msgSender());
	}

	/**
	 * @return the token being sold.
	 */
	function token() public view returns (IERC20) {
		return _token;
	}

	/**
	 * @return the address where funds are collected.
	 */
	function wallet() public view returns (address payable) {
		return _wallet;
	}

	/**
	 * @return the number of token units a buyer gets per wei.
	 */
	function rate() public view returns (uint256) {
		return _rate;
	}

	/**
	 * @return the amount of wei raised.
	 */
	function weiRaised() public view returns (uint256) {
		return _weiRaised;
	}

	/**
	 * @dev low level token purchase ***DO NOT OVERRIDE***
	 * This function has a non-reentrancy guard, so it shouldn't be called by
	 * another `nonReentrant` function.
	 * @param beneficiary Recipient of the token purchase
	 */
	function buyTokens(address beneficiary) public nonReentrant 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);
		emit TokensPurchased(_msgSender(), beneficiary, weiAmount, tokens);

		_updatePurchasingState(beneficiary, weiAmount);

		_forwardFunds();
		_postValidatePurchase(beneficiary, weiAmount);
	}

	/**
	 * @dev Validation of an incoming purchase. Use require statements to revert state when conditions are not met.
	 * Use `super` in contracts that inherit from Crowdsale to extend their validations.
	 * Example from CappedCrowdsale.sol's _preValidatePurchase method:
	 *     super._preValidatePurchase(beneficiary, weiAmount);
	 *     require(weiRaised().add(weiAmount) <= cap);
	 * @param beneficiary Address performing the token purchase
	 * @param weiAmount Value in wei involved in the purchase
	 */
	function _preValidatePurchase(address beneficiary, uint256 weiAmount) internal view {
		require(beneficiary != address(0), "Crowdsale: beneficiary is the zero address");
		require(weiAmount != 0, "Crowdsale: weiAmount is 0");
		this; // silence state mutability warning without generating bytecode - see https://github.com/ethereum/solidity/issues/2691
	}

	/**
	 * @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 view {
		// solhint-disable-previous-line no-empty-blocks
	}

	/**
	 * @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.safeTransfer(beneficiary, tokenAmount);
	}

	/**
	 * @dev Executed when a purchase has been validated and is ready to be executed. Doesn't necessarily emit/send
	 * 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 {
		// solhint-disable-previous-line no-empty-blocks
	}

	/**
	 * @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);
	}
}
/**
 * @title Crowdsale
 * @dev Crowdsale is a base contract for managing a token crowdsale,
 * allowing investors to purchase tokens with ether. This contract implements
 * such functionality in its most fundamental form and can be extended to provide additional
 * functionality and/or custom behavior.
 * The external interface represents the basic interface for purchasing tokens, and conforms
 * the base architecture for crowdsales. It is *not* intended to be modified / overridden.
 * The internal interface conforms the extensible and modifiable surface of crowdsales. Override
 * the methods to add functionality. Consider using 'super' where appropriate to concatenate
 * behavior.
 */
function buyTokens(address beneficiary) public nonReentrant 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);
	emit TokensPurchased(_msgSender(), beneficiary, weiAmount, tokens);

	_updatePurchasingState(beneficiary, weiAmount);

	_forwardFunds();
	_postValidatePurchase(beneficiary, weiAmount);
}

/**
 	 * @dev low level token purchase ***DO NOT OVERRIDE***
 	 * This function has a non-reentrancy guard, so it shouldn't be called by
 	 * another `nonReentrant` function.
 	 * @param beneficiary Recipient of the token purchase
 	 */