Function of merge directory A to directory B

mergeContentsOfPath

- (void)mergeContentsOfPath:(NSString *)srcDir intoPath:(NSString *)dstDir withError:(NSError **)error {
    NSLog(@"Merge from Dir: %@ to Dir: %@", srcDir, dstDir);
    
    NSString *sourceBasePath = srcDir;
    NSString *destBasePath = dstDir;
    NSURL *destBaseURL = [NSURL fileURLWithPath:destBasePath];
    int subPathIndex = (int)[sourceBasePath length] + 1;
    NSFileManager *fileManager = [NSFileManager defaultManager];
    NSDirectoryEnumerator *dirEnum = [fileManager enumeratorAtURL:[NSURL fileURLWithPath:sourceBasePath]
                                       includingPropertiesForKeys:[NSArray arrayWithObject:NSURLIsDirectoryKey]
                                                          options:NSDirectoryEnumerationSkipsHiddenFiles
                                                     errorHandler:nil];
    
    for (NSURL *url in dirEnum) {
        NSString *subPath = [[url path] substringFromIndex:subPathIndex];
        NSNumber *isDir;
        [url getResourceValue:&isDir forKey:NSURLIsDirectoryKey error:NULL];
        
        if ([isDir boolValue]) {
            [fileManager createDirectoryAtPath:[destBasePath stringByAppendingPathComponent:subPath] withIntermediateDirectories:YES attributes:nil error:nil];
        } else {
            if ([fileManager fileExistsAtPath:[destBaseURL URLByAppendingPathComponent:subPath].path]) {
                [fileManager removeItemAtURL:[destBaseURL URLByAppendingPathComponent:subPath] error:nil];
                [fileManager copyItemAtURL:url toURL:[destBaseURL URLByAppendingPathComponent:subPath] error:nil];
            } else {
                [fileManager copyItemAtURL:url toURL:[destBaseURL URLByAppendingPathComponent:subPath] error:nil];
            }
        }
    }
}