MailCore tip1

DataSingleton.m

- (void)updateAttachmentsPresenceForMessages:(NSArray*)newMessages forAccount:(Account*)account{
    
    NSManagedObjectContext *moc = [self getContextForBGTask];
    
    [moc performBlock:^{
        
        Account *__account = (Account*)[moc objectWithID:[account objectID]];
        
        // get old messages
        NSSortDescriptor *sortDescriptor = [[NSSortDescriptor alloc] initWithKey:@"mcUid"
                                                                       ascending:YES];
        
        NSPredicate *predicate = [NSPredicate predicateWithFormat:
                                  @"isDownloadBody == %@ AND \
                                  visible == %@ AND\
                                  account == %@",@(YES),@(YES),__account];
        
        NSArray *allMessages = [self getObjectsOfType:entity_name_Message
                                  withSortDescriptors:@[sortDescriptor]
                                         andPredicate:predicate
                                            inContext:moc];
        NSArray *oldMessages = nil;
        NSPredicate *uidPredicate;
        Message *theMessage = nil;
        NSArray *attachments = nil;
        NSArray *inlineAttachments = nil;
        NSString *mimeType = nil;
        Attachment *attach = nil;
        NMAttachmentType attType = 0;
        
        NSPredicate *partIDPredicate;
        NSSet *twinSet;
        
        for (MCOIMAPMessage *message in newMessages) {
            
            attachments = [message attachments];
            inlineAttachments = [message htmlInlineAttachments];
            
            if ([attachments count] ||
                [inlineAttachments count]) {
                
                int uid = [message uid];
                uidPredicate = [NSPredicate predicateWithFormat:@"mcUid == %@",@(uid)];
                oldMessages = [allMessages filteredArrayUsingPredicate:uidPredicate];
                
                if ([oldMessages count]) {
                    
                    theMessage = [oldMessages objectAtIndex:0];
                    
                    NSMutableArray *allAttachments = [[NSMutableArray alloc] init];
                    [allAttachments addObjectsFromArray:attachments];
                    [allAttachments addObjectsFromArray:inlineAttachments];
                    
                    for (MCOIMAPPart *part in allAttachments) {
                        
                        partIDPredicate = [NSPredicate predicateWithFormat:@"mcPartID == %@",[part partID]];
                        twinSet = [(NSSet*)[theMessage attachments] filteredSetUsingPredicate:partIDPredicate];
                        
                        if ([twinSet count])
                            continue;
                        
                        mimeType = [part mimeType];
                        
                        if ([mimeType isEqualToString:@"text/CALENDAR"])
                            attType = NMAttachmentTypeCalendarInvite;
                        else if ([mimeType isEqualToString:@"image/GIF"] ||
                                 [mimeType isEqualToString:@"image/PNG"] ||
                                 [mimeType isEqualToString:@"image/JPEG"]||
                                 [mimeType isEqualToString:@"image/jpeg"]||
                                 [mimeType isEqualToString:@"image/png"])
                            attType = NMAttachmentTypePicture;
                        else
                            attType = NMAttachmentTypeFile;
                        
                        //create new
                        attach = [NSEntityDescription insertNewObjectForEntityForName:entity_name_Attachment
                                                               inManagedObjectContext:moc];
                        [attach setMessage:theMessage];
                        [attach setFileName:[part filename]];
                        [attach setMcMimeType:mimeType];
                        [attach setMcPartID:[part partID]];
                        [attach setType:@(attType)];
                        [attach setMcEncoding:@([part encoding])];
                        
                        /*
                         we can't wait tham attach store in moc and merge in mainMOC
                         that we carefly perform catch attach with account in mainMOC
                         and theMessage and attach in backgroundMOC and wait 5 sec to perform
                         */
                        [moc processPendingChanges];
                        [self saveContextForBGTask:moc];
                        
                        NSManagedObjectContext *mainMOC = [self managedObjectContext];
                        [mainMOC performBlock:^{
                            
                            Account *mmAccount      = (Account*)[mainMOC objectWithID:      [account objectID]];
                            Attachment *mmAttach    = (Attachment*)[mainMOC objectWithID:   [attach objectID]];
                            Message *mmMessage      = (Message*)[mainMOC objectWithID:      [theMessage objectID]];
                            
                            [[PostCollector defaultCollector] downloadMessageAttachmentForMessage:mmMessage
                                                                                    andAttachment:mmAttach
                                                                                     andMTAccount:mmAccount];
                        }];
                    }
                }
            }
        }

        [self saveContextForBGTask:moc];
    }];
}