past item operation

//
//  RW3PastPriceItemsOperation.m
//  Pecos
//
//  Created by Vitaly Dyachkov on 27.05.15.
//  Copyright (c) 2015 Vitaly Dyachkov. All rights reserved.
//

#import "RW3PastPriceItemsOperation.h"
#import "RW3PastPriceItem.h"

#define BUFFER_SIZE 500

@interface RW3PastPriceItemsOperation ()

@property (nonatomic, readonly) NSManagedObjectContext *context;
@property (nonatomic, readonly) NSMutableArray *items;

@property (nonatomic, readonly) NSMutableDictionary *buffer;

@property (nonatomic, strong) NSArray *alternatviePriceReasons;

@end

@implementation RW3PastPriceItemsOperation

- (instancetype)initWithRequest:(NSURLRequest *)request context:(NSManagedObjectContext *)context
{
   self = [super initWithRequest:request];
   if (self) {
      RW3LogNormal();
      _context = context;

      _items = [[NSMutableArray alloc] init];
      _buffer = [[NSMutableDictionary alloc] initWithCapacity:BUFFER_SIZE];

      __weak __typeof(self) weakSelf = self;
      [self setProcessingBlock:^(NSDictionary *JSONObject) {
         __strong __typeof(self) strongSelf = weakSelf;

         if (!strongSelf.alternatviePriceReasons) {
            [strongSelf.context performBlockAndWait:^{
               NSFetchRequest *request = [[NSFetchRequest alloc] initWithEntityName:@"AlternativePriceReason"];

               NSError *error = nil;
               strongSelf.alternatviePriceReasons = [context executeFetchRequest:request error:&error];
               if (!strongSelf.alternatviePriceReasons) {
                  RW3LogError(@"Error occurred while executing fetch request: %@", error);
               }
            }];
         }

         NSString *upc = JSONObject[@"Upc"];
         strongSelf.buffer[upc] = JSONObject;

         if ([strongSelf.buffer count] == BUFFER_SIZE) {
            [strongSelf processBufferedItems];
         }
      }];
   }
   return self;
}

- (void)processBufferedItems
{
   NSManagedObjectContext *context = self.context;

   [context performBlockAndWait:^{
      for (NSString *upc in [self.buffer allKeys]) {
         RW3PastPriceItem *item = [NSEntityDescription insertNewObjectForEntityForName:@"PastPriceItem" inManagedObjectContext:context];
         NSDictionary *JSONObject = self.buffer[upc];
         [item populateWithJSON:JSONObject alternativePriceReasons:self.alternatviePriceReasons];
         [self.items addObject:item];
      }
   }];

   [self.buffer removeAllObjects];
}

- (void)setCompletionBlockWithSuccess:(void (^)(NSArray *items))success failure:(void (^)(NSError *error))failure
{
   [super setCompletionBlockWithSuccess:^(RW3JSONRequestOperation *operation) {
      RW3PastPriceItemsOperation *pastPriceItemsOperation = (RW3PastPriceItemsOperation *)operation;

      [pastPriceItemsOperation processBufferedItems];
      RW3LogNormal(@"Processed %lu past price items.", (unsigned long)pastPriceItemsOperation.items.count);

      success(pastPriceItemsOperation.items);
   } failure:^(RW3JSONRequestOperation *operation, NSError *error) {
      failure(error);
   }];
}

@end