Subversion Repositories SmartDukaan

package in.shop2020.serving.services;

import in.shop2020.model.v1.order.LineItem;

import in.shop2020.model.v1.order.Order;

import in.shop2020.model.v1.order.Transaction;

import in.shop2020.model.v1.order.TransactionServiceException;

import in.shop2020.model.v1.order.TransactionStatus;

import in.shop2020.model.v1.user.Cart;

import in.shop2020.model.v1.user.Line;

import in.shop2020.model.v1.user.PromotionException;

import in.shop2020.model.v1.user.ShoppingCartException;

import in.shop2020.payments.Payment;

import in.shop2020.payments.PaymentException;

import in.shop2020.serving.utils.Utils;

import in.shop2020.thrift.clients.PaymentServiceClient;

import in.shop2020.thrift.clients.PromotionServiceClient;

import in.shop2020.thrift.clients.TransactionServiceClient;

import in.shop2020.thrift.clients.UserContextServiceClient;

import java.util.HashMap;

import java.util.List;

import java.util.Map;

import org.apache.log4j.Logger;

import org.apache.thrift.TException;

/**

 * This class has methods to be used to process non-gateway-specific aspects of

 * payments and transactions.

 * 

 * @author Chandranshu

 * 

 */

public class CommonPaymentService {

	private static final boolean PAYMENT_NOT_CREATED = false;

	private static Logger log = Logger.getLogger(Class.class);

	private long paymentId;

	private double amount;

	public long getPaymentId() {

		return paymentId;

	}

	public double getAmount() {

		return amount;

	}

	/**

	 * Creates a payment for the given cart of the given user for the given

	 * transaction. Stores the id of the newly created payment and the amount

	 * for which this payment was created. They can be retrieved later on using

	 * {@link #getPaymentId()}getPaymentId() and {@link #getAmount()}getAmount()

	 * methods respectively later on.

	 * 

	 * @param currentCartId

	 *            The cart for which the payment object has to be created.

	 * @param userId

	 *            The user for whom the payment has to be created.

	 * @param txnId

	 *            The transaction against which the payment has to be created.

	 * @param gatewayId

	 * @return True if the payment object is successfully created, False

	 *         otherwise.

	 */

	public boolean createPayment(long currentCartId, long userId, long txnId, int gatewayId){

		PaymentServiceClient paymentServiceClient = null;

		try {

			paymentServiceClient = new PaymentServiceClient();

		} catch (Exception e) {

			log.error("Error while getting payment client", e);

			return PAYMENT_NOT_CREATED;

		}

		try {

			amount = calculatePaymentAmount(currentCartId);

		} catch (ShoppingCartException e1) {

			log.error("Unable to fetch payment amount from cart id.", e1);

			return PAYMENT_NOT_CREATED;

		} catch (TException e1) {

			log.error("Unable to fetch payment amount.", e1);

			return PAYMENT_NOT_CREATED;

		}

		try {

			paymentId = paymentServiceClient.getClient().createPayment(userId, amount, gatewayId, txnId);

			// This is being done to ensure that the amount which we pass on to

			// the PGs is same as what we have in the database.

			Payment payment = paymentServiceClient.getClient().getPayment(paymentId);

			amount = payment.getAmount();

		} catch (PaymentException e1) {

			log.error("Unable to create payment object.", e1);

			return PAYMENT_NOT_CREATED;

		} catch (TException e) {

			log.error("Not able to create payment object.", e);

			return PAYMENT_NOT_CREATED;

		}

		return true;

	}

	// TODO: The service client parameters in the processSuccessfulTxn et al are

	// unnecessary but initializing them again when the caller has the necessary

	// references has a performance overhead. Need to think more about this.

	/**

	 * Processes a successful transaction by:

	 * <ol>

	 * <li>Marking the given transaction as 'in process'.</li>

	 * <li>Removing the items in the cart for which the given transaction was

	 * processed.</li>

	 * <li>Marking the coupon associated with this transaction, if any, as used

	 * for this user.</li>

	 * <li>Queuing the transaction successful email, containing transaction

	 * info, to be sent later by a batch job.</li>

	 * </ol>

	 * <br>

	 * Please note that it's possible that a user has added items to the cart

	 * and so it's not possible to simply wipe out their cart. Therefore, it's

	 * important to ensure that we remove only as much quantity of items as for

	 * which the order was processed.

	 * 

	 * @param txnId

	 *            The transaction which should be marked as successful.

	 * @param userServiceClient

	 *            A user context service client to use.

	 * @param transactionServiceClient

	 *            A transaction service client to use.

	 */

	public static void processSuccessfulTxn(long txnId, UserContextServiceClient userServiceClient, TransactionServiceClient transactionServiceClient) {

		Transaction transaction = null;

		try {

			in.shop2020.model.v1.order.TransactionService.Client transactionClient = transactionServiceClient.getClient();

			transactionClient.changeTransactionStatus(txnId, TransactionStatus.IN_PROCESS, "Payment received for the order");

			transaction = transactionClient.getTransaction(txnId);

			transactionClient.enqueueTransactionInfoEmail(txnId);

		} catch (TException e1) {

			log.error("Unable to update status of transaction. Thrift Exception:", e1);

		} catch (TransactionServiceException e) {

			log.error("Unable to update status of transaction. Thrift Exception: ", e);

		}

		trackCouponUsage(transaction);

        resetCart(transaction, userServiceClient);

	}

	/**

	 * Marks a transaction as well as all its orders as failed.

	 * 

	 * @param txnId

	 *            The id of the transaction which has to be marked as failed.

	 * @param transactionServiceClient

	 */

	public static void processFailedTxn(long txnId, TransactionServiceClient transactionServiceClient) {

		try {

			in.shop2020.model.v1.order.TransactionService.Client transactionClient = transactionServiceClient.getClient();

			transactionClient.changeTransactionStatus(txnId, TransactionStatus.FAILED, "Payment failed for the transaction.");

		} catch(TException e){

			log.error("Thrift exception while getting information from transaction service.", e);

		} catch (TransactionServiceException e) {

			log.error("Error while updating status information in transaction database.", e);

		}

	}

	/**

	 * Calculates the amount for the payment required for the given cart.

	 * 

	 * @param cartId

	 *            Id of the cart for which this payment amount has to be

	 *            calculated.

	 * @return The total amount for which a payment should be created.

	 * @throws ShoppingCartException

	 *             If no cart can be found for the given id.

	 * @throws TException

	 */

	private double calculatePaymentAmount(long cartId) throws ShoppingCartException, TException{

		double totalAmount = 0;

		Cart cart;

		UserContextServiceClient userContextServiceClient = null;

		try {

			userContextServiceClient = new UserContextServiceClient();

		} catch (Exception e) {

			log.error("Unable to initialize user context service client", e);

			throw new ShoppingCartException(100, "Unable to initialize the user service client");

		}

		in.shop2020.model.v1.user.UserContextService.Client userClient = userContextServiceClient.getClient();

		cart = userClient.getCart(cartId);

		if(cart.getCouponCode() == null)  {

		    List<Line> lineItems = cart.getLines(); 

	        for (Line line : lineItems) {

	            long productId = line.getItemId();

	            // FIXME: It's expensive to get the price of each item from the

	            // catalog service. We maintain the pricing info in the line items

	            // themselves now.

	            totalAmount =  totalAmount + line.getQuantity() * Utils.getItemPrice(productId);

	        }

		} else {

		    totalAmount = cart.getDiscountedPrice();

		}

		return totalAmount;

	}

	/**

	 * Removes the items processed through the given transaction from the

	 * shopping cart.

	 * 

	 * @param transaction

	 *            The transaction whose items have to be removed from the

	 *            shopping cart.

	 * @param userServiceClient

	 */

	private static void resetCart(Transaction transaction, UserContextServiceClient userServiceClient) {

		Map<Long, Double> items = new HashMap<Long, Double>();

		for(Order order: transaction.getOrders()){

			for(LineItem lineitem: order.getLineitems()){

				Long itemId = lineitem.getItem_id();

				Double quantity = items.get(itemId);

				if(quantity==null){

					quantity = lineitem.getQuantity();

				} else {

					quantity= quantity + lineitem.getQuantity();

				}

				items.put(itemId, quantity);

			}

		}

		log.debug("Items to restr in cart are: " + items);

		try {

			//TODO Optimize the function to send less data over the wire

            userServiceClient.getClient().resetCart(transaction.getShoppingCartid(), items);

		}catch (TException e) {

			log.error("Error while updating information in payment database.", e);

		} catch (ShoppingCartException e) {

			log.error("Error while reseting the cart in cart database.", e);

		}catch (Exception e) {

			log.error("Unexpected exception", e);

        }

	}

	/**

	 * Mark the coupon associated with the given transaction as used.

	 * 

	 * @param transaction

	 *            The transaction to track coupon for.

	 * 

	 * @param userServiceClient

	 *            The user service client instance to use.

	 */

	private static void trackCouponUsage(Transaction transaction) {

        try {

            String couponCode = transaction.getCoupon_code();

            if (couponCode != null && !couponCode.isEmpty()) {

            	PromotionServiceClient promotionServiceClient = new PromotionServiceClient();

                promotionServiceClient.getClient().trackCouponUsage(couponCode, transaction.getId(), transaction.getCustomer_id());

            }

        } catch (PromotionException e) {

            log.error("Promotion Exception: " + e);

        } catch (TException e)  {

            log.error("Transport from Promotion Service failed:", e);

        } catch (Exception e) {

            log.error("Unexpected exception:", e);

        }

	}

}