Heavy RAC for REST API

- (RACSignal *)saveQuizBody:(Quiz *)quiz {
    NSString *path, *method;
    if (quiz.identifier) {
        path = NSStringWithFormat(@"/api/scrapbook/quizzes/%@", quiz.identifier);
        method = @"PUT";
    } else {
        path = @"/api/scrapbook/quizzes/";
        method = @"POST";
    }
    NSDictionary *quizJSON = @{@"quiz" : [MTLJSONAdapter JSONDictionaryFromModel:quiz]};

    NSMutableURLRequest *request = [self.service.http requestWithMethod:method path:path parameters:quizJSON];
    return [self.service startAuthorizedJSONRequest:request returningInstanceOfClass:[Quiz class]];
}

- (RACSignal *)saveQuizQuestionBody:(QuizQuestion *)questionToSave {
    NSString *path, *method;
    if (questionToSave.identifier) {
        path =  NSStringWithFormat(@"/api/scrapbook/quizzes/%@/questions/%@",
                                   questionToSave.quiz.identifier,
                                   questionToSave.identifier);
        method = @"PUT";
    } else {
        path =  NSStringWithFormat(@"/api/scrapbook/quizzes/%@/questions/",
                                   questionToSave.quiz.identifier);
        method = @"POST";
    }

    NSMutableDictionary *questionJson = [[MTLJSONAdapter JSONDictionaryFromModel:questionToSave] mutableCopy];
    NSMutableURLRequest *request = [self.service.http requestWithMethod:method
                                                                   path:path
                                                             parameters:@{@"quizQuestion":questionJson}];

    return [self.service startAuthorizedJSONRequest:request returningInstanceOfClass:[QuizQuestion class]];
}

- (RACSignal *)saveQuizQuestion:(QuizQuestion *)questionToSave {
    RACSignal *signal;
    if (questionToSave.coverImage) {
        signal = [[self.service startImageUploadRequestWithPath:@"api/files/upload" image:questionToSave.coverImage] flattenMap:^RACStream *(NSDictionary *val) {
            if (!questionToSave.cover) {
                questionToSave.cover = [CoverVO new];
            }
            questionToSave.cover.identifier = [val[@"file"][@"id"] integerValue];
            questionToSave.cover.originalImageURL = [NSURL URLWithString:val[@"file"][@"url"]];

            return [self saveQuizQuestionBody:questionToSave];
        }];
    } else {
        signal = [self saveQuizQuestionBody:questionToSave];
    }

    return [signal doNext:^(QuizQuestion *savedQuestion) {
        questionToSave.identifier = savedQuestion.identifier;

        Quiz *quiz = questionToSave.quiz;
        BOOL found = NO;
        for (NSString *questionId in quiz.questionIds) {
            if ([questionId isEqualToString:savedQuestion.identifier]) {
                found = YES;
                break;
            }
        }
        if (!found) {
            if (quiz.questionIds) {
                quiz.questionIds = [quiz.questionIds arrayByAddingObject:questionToSave.identifier];
            } else {
                quiz.questionIds = @[savedQuestion.identifier];
            }
        }

        NSUInteger answersToSaveCount = questionToSave.answers.count;
        NSUInteger savedAnswersCount = savedQuestion.answers.count;
        NSUInteger totalCount;

        if (answersToSaveCount == savedAnswersCount) {
            totalCount = answersToSaveCount;
            NSLog(@"ERROR: %d answers to save DON'T MATCH %d saved answers for questions: toSave = %@ saved = %@", answersToSaveCount, savedAnswersCount, questionToSave, savedQuestion);
        } else {
            totalCount = MIN(answersToSaveCount, savedAnswersCount);
        }

        for (NSInteger i = 0; i < totalCount; i ++) {
            ((QuizAnswer *)questionToSave.answers[i]).identifier = ((QuizAnswer *)savedQuestion.answers[i]).identifier;
        }
    }];
}