MKStoreManager.m

//
//  MKStoreManager.m
//  MKStoreKit (Version 5.0)
//
//	File created using Singleton XCode Template by Mugunth Kumar (http://mugunthkumar.com
//  Permission granted to do anything, commercial/non-commercial with this file apart from removing the line/URL above
//  Read my blog post at http://mk.sg/1m on how to use this code

//  Created by Mugunth Kumar (@mugunthkumar) on 04/07/11.
//  Copyright (C) 2011-2020 by Steinlogic Consulting And Training Pte Ltd.

//  Permission is hereby granted, free of charge, to any person obtaining a copy
//  of this software and associated documentation files (the "Software"), to deal
//  in the Software without restriction, including without limitation the rights
//  to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
//  copies of the Software, and to permit persons to whom the Software is
//  furnished to do so, subject to the following conditions:
//
//  The above copyright notice and this permission notice shall be included in
//  all copies or substantial portions of the Software.
//
//  THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
//  IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
//  FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
//  AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
//  LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
//  OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
//  THE SOFTWARE.

//  As a side note on using this code, you might consider giving some credit to me by
//	1) linking my website from your app's website
//	2) or crediting me inside the app's credits page
//	3) or a tweet mentioning @mugunthkumar
//	4) A paypal donation to mugunth.kumar@gmail.com


#import "MKStoreManager.h"
#import "SFHFKeychainUtils.h"
#import "MKSKSubscriptionProduct.h"
#import "MKSKProduct.h"
#import "NSData+Base64.h"
#if ! __has_feature(objc_arc)
#error MKStoreKit is ARC only. Either turn on ARC for the project or use -fobjc-arc flag
#endif

#ifndef __IPHONE_5_0
#error "MKStoreKit uses features (NSJSONSerialization) only available in iOS SDK  and later."
#endif


@interface MKStoreManager () //private methods and properties

@property (nonatomic, copy) void (^onTransactionCancelled)();
@property (nonatomic, copy) void (^onTransactionCompleted)(NSString *productId, NSData* receiptData, NSArray* downloads);

@property (nonatomic, copy) void (^onRestoreFailed)(NSError* error);
@property (nonatomic, copy) void (^onRestoreCompleted)();

@property (nonatomic, assign, getter=isProductsAvailable) BOOL isProductsAvailable;

@property (nonatomic, strong) SKProductsRequest *productsRequest;

- (void) requestProductData;
- (void) startVerifyingSubscriptionReceipts;
-(void) rememberPurchaseOfProduct:(NSString*) productIdentifier withReceipt:(NSData*) receiptData;
-(void) addToQueue:(NSString*) productId;
@end

@implementation MKStoreManager

static MKStoreManager* _sharedStoreManager;

+(void) updateFromiCloud:(NSNotification*) notificationObject {
  
  NSLog(@"Updating from iCloud");
  
  NSUbiquitousKeyValueStore *iCloudStore = [NSUbiquitousKeyValueStore defaultStore];
  NSDictionary *dict = [iCloudStore dictionaryRepresentation];
  NSMutableArray *products = [self allProducts];
  
  [products enumerateObjectsUsingBlock:^(id obj, NSUInteger idx, BOOL *stop) {
    
    id valueFromiCloud = [dict objectForKey:obj];
    
    if(valueFromiCloud) {
      NSError *error = nil;
      [SFHFKeychainUtils storeUsername:obj
                           andPassword:valueFromiCloud
                        forServiceName:@"MKStoreKit"
                        updateExisting:YES
                                 error:&error];
      if(error) NSLog(@"%@", error);
    }
  }];
}

+(BOOL) iCloudAvailable {
  
  if(NSClassFromString(@"NSUbiquitousKeyValueStore")) { // is iOS 5?
    
    if([NSUbiquitousKeyValueStore defaultStore]) {  // is iCloud enabled
      
      return YES;
    }
  }
  
  return NO;
}

+(void) setObject:(id) object forKey:(NSString*) key
{
  if(object) {
    NSString *objectString = nil;
    if([object isKindOfClass:[NSData class]])
    {
      objectString = [[NSString alloc] initWithData:object encoding:NSUTF8StringEncoding];
    }
    if([object isKindOfClass:[NSNumber class]])
    {
      objectString = [(NSNumber*)object stringValue];
    }
    
    NSError *error = nil;
    [SFHFKeychainUtils storeUsername:key andPassword:objectString forServiceName:@"MKStoreKit" updateExisting:YES error:&error];
    if(error) NSLog(@"%@", error);
    
    if([self iCloudAvailable]) {
      [[NSUbiquitousKeyValueStore defaultStore] setObject:objectString forKey:key];
      [[NSUbiquitousKeyValueStore defaultStore] synchronize];
    }
  } else {
    
    NSError *error = nil;
    [SFHFKeychainUtils deleteItemForUsername:key andServiceName:@"MKStoreKit" error:&error];
    if(error) NSLog(@"%@", error);
    
    if([self iCloudAvailable]) {
      [[NSUbiquitousKeyValueStore defaultStore] removeObjectForKey:key];
      [[NSUbiquitousKeyValueStore defaultStore] synchronize];
    }
  }
}

+(id) receiptForKey:(NSString*) key {
  
  NSData *receipt = [MKStoreManager objectForKey:key];
  if(!receipt)
    receipt = [MKStoreManager objectForKey:[NSString stringWithFormat:@"%@-receipt", key]];
  
  return receipt;
}

+(id) objectForKey:(NSString*) key
{
  NSError *error = nil;
  id password = [SFHFKeychainUtils getPasswordForUsername:key andServiceName:@"MKStoreKit" error:&error];
  if(error) NSLog(@"%@", error);
  
  return password;
}

+(NSNumber*) numberForKey:(NSString*) key
{
  return [NSNumber numberWithInt:[[MKStoreManager objectForKey:key] intValue]];
}

+(NSData*) dataForKey:(NSString*) key
{
  NSString *str = [MKStoreManager objectForKey:key];
  return [str dataUsingEncoding:NSUTF8StringEncoding];
}

#pragma mark Singleton Methods

+ (MKStoreManager*)sharedManager
{
	if(!_sharedStoreManager) {
		static dispatch_once_t oncePredicate;
		dispatch_once(&oncePredicate, ^{
			_sharedStoreManager = [[self alloc] init];
      _sharedStoreManager.purchasableObjects = [NSMutableArray array];
#ifdef __IPHONE_6_0
      _sharedStoreManager.hostedContents = [NSMutableArray array];
#endif
      [_sharedStoreManager requestProductData];
      [[SKPaymentQueue defaultQueue] addTransactionObserver:_sharedStoreManager];
      [_sharedStoreManager startVerifyingSubscriptionReceipts];
    });
    
    if([self iCloudAvailable])
      [[NSNotificationCenter defaultCenter] addObserver:self
                                               selector:@selector(updateFromiCloud:)
                                                   name:NSUbiquitousKeyValueStoreDidChangeExternallyNotification
                                                 object:nil];
    
    
  }
  return _sharedStoreManager;
}

#pragma mark Internal MKStoreKit functions

+(NSDictionary*) storeKitItems
{
  return [NSDictionary dictionaryWithContentsOfFile:
          [[[NSBundle mainBundle] resourcePath] stringByAppendingPathComponent:
           @"MKStoreKitConfigs.plist"]];
}

- (void) restorePreviousTransactionsOnComplete:(void (^)(void)) completionBlock
                                       onError:(void (^)(NSError*)) errorBlock
{
  self.onRestoreCompleted = completionBlock;
  self.onRestoreFailed = errorBlock;
  
	[[SKPaymentQueue defaultQueue] restoreCompletedTransactions];
}

-(void) restoreCompleted
{
  if(self.onRestoreCompleted)
    self.onRestoreCompleted();
  self.onRestoreCompleted = nil;
}

-(void) restoreFailedWithError:(NSError*) error
{
  if(self.onRestoreFailed)
    self.onRestoreFailed(error);
  self.onRestoreFailed = nil;
}

-(void) requestProductData
{
  NSMutableArray *productsArray = [NSMutableArray array];
  NSArray *consumables = [[[MKStoreManager storeKitItems] objectForKey:@"Consumables"] allKeys];
  NSArray *nonConsumables = [[MKStoreManager storeKitItems] objectForKey:@"Non-Consumables"];
  NSArray *subscriptions = [[[MKStoreManager storeKitItems] objectForKey:@"Subscriptions"] allKeys];
  
  [productsArray addObjectsFromArray:consumables];
  [productsArray addObjectsFromArray:nonConsumables];
  [productsArray addObjectsFromArray:subscriptions];
  
	self.productsRequest = [[SKProductsRequest alloc] initWithProductIdentifiers:[NSSet setWithArray:productsArray]];
	self.productsRequest.delegate = self;
	[self.productsRequest start];
}

+(NSMutableArray*) allProducts {
  
  NSMutableArray *productsArray = [NSMutableArray array];
  NSArray *consumables = [[[self storeKitItems] objectForKey:@"Consumables"] allKeys];
  NSArray *nonConsumables = [[self storeKitItems] objectForKey:@"Non-Consumables"];
  NSArray *subscriptions = [[[self storeKitItems] objectForKey:@"Subscriptions"] allKeys];
  
  [productsArray addObjectsFromArray:consumables];
  [productsArray addObjectsFromArray:nonConsumables];
  [productsArray addObjectsFromArray:subscriptions];
  
  return productsArray;
}

- (BOOL) removeAllKeychainData {
  
  NSMutableArray *productsArray = [MKStoreManager allProducts];
  int itemCount = productsArray.count;
  NSError *error;
  
  //loop through all the saved keychain data and remove it
  for (int i = 0; i < itemCount; i++ ) {
    [SFHFKeychainUtils deleteItemForUsername:[productsArray objectAtIndex:i] andServiceName:@"MKStoreKit" error:&error];
  }
  if (!error) {
    return YES;
  }
  else {
    return NO;
  }
}

- (void)productsRequest:(SKProductsRequest *)request didReceiveResponse:(SKProductsResponse *)response
{
	[self.purchasableObjects addObjectsFromArray:response.products];
	
#ifndef NDEBUG
	for(int i=0;i<[self.purchasableObjects count];i++)
	{
		SKProduct *product = [self.purchasableObjects objectAtIndex:i];
		NSLog(@"Feature: %@, Cost: %f, ID: %@",[product localizedTitle],
          [[product price] doubleValue], [product productIdentifier]);
	}
	
	for(NSString *invalidProduct in response.invalidProductIdentifiers)
		NSLog(@"Problem in iTunes connect configuration for product: %@", invalidProduct);
#endif
  
	self.isProductsAvailable = YES;
  [[NSNotificationCenter defaultCenter] postNotificationName:kProductFetchedNotification
                                                      object:[NSNumber numberWithBool:self.isProductsAvailable]];
	self.productsRequest = nil;
}

- (void)request:(SKRequest *)request didFailWithError:(NSError *)error
{
	self.isProductsAvailable = NO;
  [[NSNotificationCenter defaultCenter] postNotificationName:kProductFetchedNotification
                                                      object:[NSNumber numberWithBool:self.isProductsAvailable]];
	self.productsRequest = nil;
}

// call this function to check if the user has already purchased your feature
+ (BOOL) isFeaturePurchased:(NSString*) featureId
{
  return [[MKStoreManager numberForKey:featureId] boolValue];
}

- (BOOL) isSubscriptionActive:(NSString*) featureId
{
  MKSKSubscriptionProduct *subscriptionProduct = [self.subscriptionProducts objectForKey:featureId];
  if(!subscriptionProduct.receipt) return NO;
  
  id jsonObject = [NSJSONSerialization JSONObjectWithData:subscriptionProduct.receipt options:NSJSONReadingAllowFragments error:nil];
  NSData *receiptData = [NSData dataFromBase64String:[jsonObject objectForKey:@"latest_receipt"]];
  
  NSPropertyListFormat plistFormat;
  NSDictionary *payloadDict = [NSPropertyListSerialization propertyListWithData:receiptData
                                                                        options:NSPropertyListImmutable
                                                                         format:&plistFormat
                                                                          error:nil];
  
  receiptData = [NSData dataFromBase64String:[payloadDict objectForKey:@"purchase-info"]];
  
  NSDictionary *receiptDict = [NSPropertyListSerialization propertyListWithData:receiptData
                                                                        options:NSPropertyListImmutable
                                                                         format:&plistFormat
                                                                          error:nil];
  
  NSTimeInterval expiresDate = [[receiptDict objectForKey:@"expires-date"] doubleValue]/1000.0f;
  return expiresDate > [[NSDate date] timeIntervalSince1970];
}

// Call this function to populate your UI
// this function automatically formats the currency based on the user's locale

- (NSMutableArray*) purchasableObjectsDescription
{
	NSMutableArray *productDescriptions = [[NSMutableArray alloc] initWithCapacity:[self.purchasableObjects count]];
	for(int i=0;i<[self.purchasableObjects count];i++)
	{
		SKProduct *product = [self.purchasableObjects objectAtIndex:i];
		
		NSNumberFormatter *numberFormatter = [[NSNumberFormatter alloc] init];
		[numberFormatter setFormatterBehavior:NSNumberFormatterBehavior10_4];
		[numberFormatter setNumberStyle:NSNumberFormatterCurrencyStyle];
		[numberFormatter setLocale:product.priceLocale];
		NSString *formattedString = [numberFormatter stringFromNumber:product.price];
		
		// you might probably need to change this line to suit your UI needs
		NSString *description = [NSString stringWithFormat:@"%@ (%@)",[product localizedTitle], formattedString];
		
#ifndef NDEBUG
		NSLog(@"Product %d - %@", i, description);
#endif
		[productDescriptions addObject: description];
	}
	
	return productDescriptions;
}

/*Call this function to get a dictionary with all prices of all your product identifers
 
 For example,
 
 NSDictionary *prices = [[MKStoreManager sharedManager] pricesDictionary];
 
 NSString *upgradePrice = [prices objectForKey:@"com.mycompany.upgrade"]
 
 */
- (NSMutableDictionary *)pricesDictionary {
  NSMutableDictionary *priceDict = [NSMutableDictionary dictionary];
	for(int i=0;i<[self.purchasableObjects count];i++)
	{
		SKProduct *product = [self.purchasableObjects objectAtIndex:i];
		
		NSNumberFormatter *numberFormatter = [[NSNumberFormatter alloc] init];
		[numberFormatter setFormatterBehavior:NSNumberFormatterBehavior10_4];
		[numberFormatter setNumberStyle:NSNumberFormatterCurrencyStyle];
		[numberFormatter setLocale:product.priceLocale];
		NSString *formattedString = [numberFormatter stringFromNumber:product.price];
    
    NSString *priceString = [NSString stringWithFormat:@"%@", formattedString];
    [priceDict setObject:priceString forKey:product.productIdentifier];
    
  }
  return priceDict;
}

-(void) showAlertWithTitle:(NSString*) title message:(NSString*) message {
  
#if TARGET_OS_IPHONE
  UIAlertView *alert = [[UIAlertView alloc] initWithTitle:title
                                                  message:message
                                                 delegate:nil
                                        cancelButtonTitle:NSLocalizedString(@"Dismiss", @"")
                                        otherButtonTitles:nil];
  [alert show];
#elif TARGET_OS_MAC
  NSAlert *alert = [[NSAlert alloc] init];
  [alert addButtonWithTitle:NSLocalizedString(@"Dismiss", @"")];
  
  [alert setMessageText:title];
  [alert setInformativeText:message];
  [alert setAlertStyle:NSInformationalAlertStyle];
  
  [alert runModal];
  
#endif
}

- (void) buyFeature:(NSString*) featureId
         onComplete:(void (^)(NSString*, NSData*, NSArray*)) completionBlock
        onCancelled:(void (^)(void)) cancelBlock
{
  self.onTransactionCompleted = completionBlock;
  self.onTransactionCancelled = cancelBlock;
  
  [MKSKProduct verifyProductForReviewAccess:featureId
                                 onComplete:^(NSNumber * isAllowed)
   {
     if([isAllowed boolValue])
     {
       [self showAlertWithTitle:NSLocalizedString(@"Review request approved", @"")
                        message:NSLocalizedString(@"You can use this feature for reviewing the app.", @"")];
       
       if(self.onTransactionCompleted)
         self.onTransactionCompleted(featureId, nil, nil);
     }
     else
     {
       [self addToQueue:featureId];
     }
     
   }
                                    onError:^(NSError* error)
   {
     NSLog(@"Review request cannot be checked now: %@", [error description]);
     [self addToQueue:featureId];
   }];
}

-(void) addToQueue:(NSString*) productId
{
  if ([SKPaymentQueue canMakePayments])
	{
    NSArray *allIds = [self.purchasableObjects valueForKey:@"productIdentifier"];
    int index = [allIds indexOfObject:productId];
    
    if(index == NSNotFound) return;
    
    SKProduct *thisProduct = [self.purchasableObjects objectAtIndex:index];
		SKPayment *payment = [SKPayment paymentWithProduct:thisProduct];
		[[SKPaymentQueue defaultQueue] addPayment:payment];
	}
	else
	{
    [self showAlertWithTitle:NSLocalizedString(@"In-App Purchasing disabled", @"")
                     message:NSLocalizedString(@"Check your parental control settings and try again later", @"")];
	}
}

- (BOOL) canConsumeProduct:(NSString*) productIdentifier
{
	int count = [[MKStoreManager numberForKey:productIdentifier] intValue];
	
	return (count > 0);
	
}

- (BOOL) canConsumeProduct:(NSString*) productIdentifier quantity:(int) quantity
{
	int count = [[MKStoreManager numberForKey:productIdentifier] intValue];
	return (count >= quantity);
}

- (BOOL) consumeProduct:(NSString*) productIdentifier quantity:(int) quantity
{
	int count = [[MKStoreManager numberForKey:productIdentifier] intValue];
	if(count < quantity)
	{
		return NO;
	}
	else
	{
		count -= quantity;
    [MKStoreManager setObject:[NSNumber numberWithInt:count] forKey:productIdentifier];
		return YES;
	}
}

- (void) startVerifyingSubscriptionReceipts
{
  NSDictionary *subscriptions = [[MKStoreManager storeKitItems] objectForKey:@"Subscriptions"];
  
  self.subscriptionProducts = [NSMutableDictionary dictionary];
  for(NSString *productId in [subscriptions allKeys])
  {
    MKSKSubscriptionProduct *product = [[MKSKSubscriptionProduct alloc] initWithProductId:productId subscriptionDays:[[subscriptions objectForKey:productId] intValue]];
    product.receipt = [MKStoreManager dataForKey:productId]; // cached receipt
    
    if(product.receipt)
    {
      [product verifyReceiptOnComplete:^(NSNumber* isActive)
       {
         if([isActive boolValue] == NO)
         {
           [[NSNotificationCenter defaultCenter] postNotificationName:kSubscriptionsInvalidNotification
                                                               object:product.productId];
           
           NSLog(@"Subscription: %@ is inactive", product.productId);
           product.receipt = nil;
           [self.subscriptionProducts setObject:product forKey:productId];
           [MKStoreManager setObject:nil forKey:product.productId];
         }
         else
         {
           NSLog(@"Subscription: %@ is active", product.productId);
         }
       }
                               onError:^(NSError* error)
       {
         NSLog(@"Unable to check for subscription validity right now");
       }];
    }
    
    [self.subscriptionProducts setObject:product forKey:productId];
  }
}

-(NSData*) receiptFromBundle {
  // mac support, method not implemented yet
  return nil;
}

#ifdef __IPHONE_6_0
-(void) hostedContentDownloadStatusChanged:(NSArray*) hostedContents {
  
  __block SKDownload *thisHostedContent = nil;
  
  NSMutableArray *itemsToBeRemoved = [NSMutableArray array];
  [hostedContents enumerateObjectsUsingBlock:^(id obj, NSUInteger idx, BOOL *stop) {
    
    thisHostedContent = obj;
    
    [self.hostedContents enumerateObjectsUsingBlock:^(id obj1, NSUInteger idx1, BOOL *stop1) {
      
      SKDownload *download = obj1;
      if([download.contentIdentifier isEqualToString:thisHostedContent.contentIdentifier]) {
        [itemsToBeRemoved addObject:obj1];
      }
    }];
  }];
  
  [self.hostedContents removeObjectsInArray:itemsToBeRemoved];
  [self.hostedContents addObjectsFromArray:hostedContents];
  
  if(self.hostedContentDownloadStatusChangedHandler)
    self.hostedContentDownloadStatusChangedHandler(self.hostedContents);
}
#endif

#pragma mark In-App purchases callbacks
// In most cases you don't have to touch these methods
-(void) provideContent: (NSString*) productIdentifier
            forReceipt:(NSData*) receiptData
         hostedContent:(NSArray*) hostedContent
{
  MKSKSubscriptionProduct *subscriptionProduct = [self.subscriptionProducts objectForKey:productIdentifier];
  if(subscriptionProduct)
  {
    // MAC In App Purchases can never be a subscription product (at least as on Dec 2011)
    // so this can be safely ignored.
    
    subscriptionProduct.receipt = receiptData;
    [subscriptionProduct verifyReceiptOnComplete:^(NSNumber* isActive)
     {
       [[NSNotificationCenter defaultCenter] postNotificationName:kSubscriptionsPurchasedNotification
                                                           object:productIdentifier];
       
       [MKStoreManager setObject:receiptData forKey:productIdentifier];
       if(self.onTransactionCompleted)
         self.onTransactionCompleted(productIdentifier, receiptData, hostedContent);
     }
                                         onError:^(NSError* error)
     {
       NSLog(@"%@", [error description]);
     }];
  }
  else
  {
    if(!receiptData) {
      
      // could be a mac in app receipt.
      // read from receipts and verify here
      receiptData = [self receiptFromBundle];
      if(!receiptData) {
        if(self.onTransactionCancelled)
        {
          self.onTransactionCancelled(productIdentifier);
        }
        else
        {
          NSLog(@"Receipt invalid");
        }
      }
    }
    
    if(OWN_SERVER && SERVER_PRODUCT_MODEL)
    {
      // ping server and get response before serializing the product
      // this is a blocking call to post receipt data to your server
      // it should normally take a couple of seconds on a good 3G connection
      MKSKProduct *thisProduct = [[MKSKProduct alloc] initWithProductId:productIdentifier receiptData:receiptData];
      
      [thisProduct verifyReceiptOnComplete:^
       {
         [self rememberPurchaseOfProduct:productIdentifier withReceipt:receiptData];
         if(self.onTransactionCompleted)
           self.onTransactionCompleted(productIdentifier, receiptData, hostedContent);
       }
                                   onError:^(NSError* error)
       {
         if(self.onTransactionCancelled)
         {
           self.onTransactionCancelled(productIdentifier);
         }
         else
         {
           NSLog(@"The receipt could not be verified");
         }
       }];
    }
    else
    {
      [self rememberPurchaseOfProduct:productIdentifier withReceipt:receiptData];
      if(self.onTransactionCompleted)
        self.onTransactionCompleted(productIdentifier, receiptData, hostedContent);
    }
  }
}


-(void) rememberPurchaseOfProduct:(NSString*) productIdentifier withReceipt:(NSData*) receiptData
{
  NSDictionary *allConsumables = [[MKStoreManager storeKitItems] objectForKey:@"Consumables"];
  if([[allConsumables allKeys] containsObject:productIdentifier])
  {
    NSDictionary *thisConsumableDict = [allConsumables objectForKey:productIdentifier];
    int quantityPurchased = [[thisConsumableDict objectForKey:@"Count"] intValue];
    NSString* productPurchased = [thisConsumableDict objectForKey:@"Name"];
    
    int oldCount = [[MKStoreManager numberForKey:productPurchased] intValue];
    int newCount = oldCount + quantityPurchased;
    
    [MKStoreManager setObject:[NSNumber numberWithInt:newCount] forKey:productPurchased];
  }
  else
  {
    [MKStoreManager setObject:[NSNumber numberWithBool:YES] forKey:productIdentifier];
  }
  
  [MKStoreManager setObject:receiptData forKey:[NSString stringWithFormat:@"%@-receipt", productIdentifier]];
}

#pragma -
#pragma mark Store Observer

- (void)paymentQueue:(SKPaymentQueue *)queue updatedTransactions:(NSArray *)transactions
{
	for (SKPaymentTransaction *transaction in transactions)
	{
		switch (transaction.transactionState)
		{
			case SKPaymentTransactionStatePurchased:
				
        [self completeTransaction:transaction];
				
        break;
				
      case SKPaymentTransactionStateFailed:
				
        [self failedTransaction:transaction];
				
        break;
				
      case SKPaymentTransactionStateRestored:
				
        [self restoreTransaction:transaction];
				
      default:
				
        break;
		}
	}
}

- (void)paymentQueue:(SKPaymentQueue *)queue restoreCompletedTransactionsFailedWithError:(NSError *)error
{
  [self restoreFailedWithError:error];
}

- (void)paymentQueueRestoreCompletedTransactionsFinished:(SKPaymentQueue *)queue
{
  [self restoreCompleted];
}

- (void) failedTransaction: (SKPaymentTransaction *)transaction
{
  
#ifndef NDEBUG
  NSLog(@"Failed transaction: %@", [transaction description]);
  NSLog(@"error: %@", transaction.error);
#endif
	
  [[SKPaymentQueue defaultQueue] finishTransaction: transaction];
  
  if(self.onTransactionCancelled)
    self.onTransactionCancelled();
}

- (void) completeTransaction: (SKPaymentTransaction *)transaction
{
#if TARGET_OS_IPHONE
  
  NSArray *downloads = nil;
  
#ifdef __IPHONE_6_0
  downloads = transaction.downloads;
  if([downloads count] > 0) {
    
    [[SKPaymentQueue defaultQueue] startDownloads:transaction.downloads];
  }
#endif
  
  [self provideContent:transaction.payment.productIdentifier
            forReceipt:transaction.transactionReceipt
         hostedContent:downloads];
#elif TARGET_OS_MAC
  [self provideContent:transaction.payment.productIdentifier
            forReceipt:nil
         hostedContent:nil];
#endif
  
  [[SKPaymentQueue defaultQueue] finishTransaction: transaction];
}

- (void) restoreTransaction: (SKPaymentTransaction *)transaction
{
#if TARGET_OS_IPHONE
  NSArray *downloads = nil;
  
#ifdef __IPHONE_6_0
  downloads = transaction.downloads;
#endif
  
  [self provideContent: transaction.originalTransaction.payment.productIdentifier
            forReceipt:transaction.transactionReceipt
         hostedContent:downloads];
#elif TARGET_OS_MAC
  [self provideContent: transaction.originalTransaction.payment.productIdentifier
            forReceipt:nil
         hostedContent:nil];
#endif
	
  [[SKPaymentQueue defaultQueue] finishTransaction: transaction];
}

#ifdef __IPHONE_6_0
- (void)paymentQueue:(SKPaymentQueue *)queue updatedDownloads:(NSArray *)downloads {
  
  [self hostedContentDownloadStatusChanged:downloads];
}
#endif

@end