//
//  MassURLDataDownloader.m
//  SixToEight
//
//  Created by Adam Wright on 14/07/2010.
//  Copyright 2010 Adam Wright. All rights reserved.
//

#import "MassURLDataDownloader.h"


@implementation MassURLDataDownloader

@synthesize delegate;

- (id)init
{
    return [self initWithURLSet:nil];
}

- (id)initWithURLSet:(NSArray*)urls
{
    self = [super init];
    
    if (self)
    {
        if (urls)
            pendingURLs = [[NSMutableArray arrayWithArray:urls] retain];
        else
            pendingURLs = [[NSMutableArray alloc] init];
        
        obtainedData = [[NSMutableDictionary alloc] init];
        complete = NO;
        cancel = NO;
        
        [self performSelectorInBackground:@selector(internalDoDownloading) withObject:nil];
    }
    
    return self;
}

- (void)dealloc
{
    cancel = YES;
    
    @synchronized (self)
    {
        [pendingURLs release];
        [obtainedData release];
    }
    
    [super dealloc];
}


- (NSData*)scheduleDownloadOrReturnData:(NSURL*)url
{
    @synchronized (self)
    {
        if ([obtainedData objectForKey:url] == nil)
            [pendingURLs addObject:url];
        else
            return [obtainedData objectForKey:url];
        
        if (complete)
        {
            complete = FALSE;
            [self performSelectorInBackground:@selector(internalDoDownloading) withObject:nil];
        }
    }
    
    return nil;
}

- (NSData*)dataForURL:(NSURL*)url
{
    @synchronized (self)
    {
        return [obtainedData objectForKey:url];
    }
}

- (void)cancel
{
    cancel = TRUE;
}

- (void)internalDoDownloading
{
    NSAutoreleasePool *pool = [[NSAutoreleasePool alloc] init];
    while (true)
    {
        NSURL *nextURL = nil;
        
        @synchronized (self)
        {
            if ([pendingURLs count] > 0)
            {
                nextURL = [pendingURLs objectAtIndex:0];
                [nextURL retain];                
                [pendingURLs removeObjectAtIndex:0];
            }
            else
            {
                break;
            }
        }
        
        NSData *result = [NSData dataWithContentsOfURL:nextURL];
        
        if (result)
        {
            @synchronized (self)
            {
                [obtainedData setObject:result forKey:nextURL];
            }

            [self performSelectorOnMainThread:@selector(deliverNotification:) withObject:nextURL waitUntilDone:NO];
        }
        
        [nextURL release];
    }
    
    complete = YES;
    [pool release];
}

- (void)deliverNotification:(NSURL*)url
{
    id del = self.delegate;
    
    if (del && !cancel)
    {
        [del dataReady:[self dataForURL:url] fromURL:url forDownloader:self];
    }
}

@end