source: trunk/Sparkle/SUAppcast.m @ 1046

//
//  SUAppcast.m
//  Sparkle
//
//  Created by Andy Matuschak on 3/12/06.
//  Copyright 2006 Andy Matuschak. All rights reserved.
//

#import "Sparkle.h"
#import "SUAppcast.h"

@interface SUAppcast (Private)
- (void)reportError:(NSError *)error;
- (NSXMLNode *)bestNodeInNodes:(NSArray *)nodes;
@end

@implementation SUAppcast

- (void)dealloc
{
    [items release];
    [userAgentString release];
    [super dealloc];
}

- (NSArray *)items
{
    return items;
}

- (void)fetchAppcastFromURL:(NSURL *)url
{
    NSMutableURLRequest *request = [NSMutableURLRequest requestWithURL:url cachePolicy:NSURLRequestReloadIgnoringCacheData timeoutInterval:30.0];
    if (userAgentString)
        [request setValue:userAgentString forHTTPHeaderField:@"User-Agent"];
            
    NSURLDownload *download = [[[NSURLDownload alloc] initWithRequest:request delegate:self] autorelease];
    CFRetain(download);
}

- (void)download:(NSURLDownload *)download decideDestinationWithSuggestedFilename:(NSString *)filename
{
    NSString *destinationFilename = [NSTemporaryDirectory() stringByAppendingPathComponent:filename];
    [download setDestination:destinationFilename allowOverwrite:NO];
}

- (void)download:(NSURLDownload *)download didCreateDestination:(NSString *)path
{
    [downloadFilename release];
    downloadFilename = [path copy];
}

- (void)downloadDidFinish:(NSURLDownload *)download
{
    CFRelease(download);
    
    NSError *error = nil;
    NSXMLDocument *document = [[NSXMLDocument alloc] initWithContentsOfURL:[NSURL fileURLWithPath:downloadFilename] options:0 error:&error];
    BOOL failed = NO;
    NSArray *xmlItems = nil;
    NSMutableArray *appcastItems = [NSMutableArray array];
    
    [[NSFileManager defaultManager] removeFileAtPath:downloadFilename handler:nil];
    [downloadFilename release];
    downloadFilename = nil;
    
    if (nil == document)
    {
        failed = YES;
    }
    else
    {
        xmlItems = [document nodesForXPath:@"/rss/channel/item" error:&error];
        if (nil == xmlItems)
        {
            failed = YES;
        }
    }
    
    if (failed == NO)
    {
        
        NSEnumerator *nodeEnum = [xmlItems objectEnumerator];
        NSXMLNode *node;
        NSMutableDictionary *nodesDict = [NSMutableDictionary dictionary];
        NSMutableDictionary *dict = [NSMutableDictionary dictionary];
        
        while (failed == NO && (node = [nodeEnum nextObject]))
        {
            // First, we'll "index" all the first-level children of this appcast item so we can pick them out by language later.
            if ([[node children] count])
            {
                node = [node childAtIndex:0];
                while (nil != node)
                {
                    NSString *name = [node name];
                    if (name)
                    {
                        NSMutableArray *nodes = [nodesDict objectForKey:name];
                        if (nodes == nil)
                        {
                            nodes = [NSMutableArray array];
                            [nodesDict setObject:nodes forKey:name];
                        }
                        [nodes addObject:node];
                    }
                    node = [node nextSibling];
                }
            }
            
            NSEnumerator *nameEnum = [nodesDict keyEnumerator];
            NSString *name;
            while ((name = [nameEnum nextObject]))
            {
                node = [self bestNodeInNodes:[nodesDict objectForKey:name]];
                if ([name isEqualToString:@"enclosure"])
                {
                    // enclosure is flattened as a separate dictionary for some reason
                    NSEnumerator *attributeEnum = [[(NSXMLElement *)node attributes] objectEnumerator];
                    NSXMLNode *attribute;
                    NSMutableDictionary *encDict = [NSMutableDictionary dictionary];
                    
                    while ((attribute = [attributeEnum nextObject]))
                        [encDict setObject:[attribute stringValue] forKey:[attribute name]];
                    [dict setObject:encDict forKey:@"enclosure"];
                    
                }
                else if ([name isEqualToString:@"pubDate"])
                {
                    // pubDate is expected to be an NSDate by SUAppcastItem, but the RSS class was returning an NSString
                    NSDate *date = [NSDate dateWithNaturalLanguageString:[node stringValue]];
                    if (date)
                        [dict setObject:date forKey:name];
                }
                else if (name != nil)
                {
                    // add all other values as strings
                    [dict setObject:[[node stringValue] stringByTrimmingCharactersInSet:[NSCharacterSet whitespaceAndNewlineCharacterSet]] forKey:name];
                }
            }
            
            SUAppcastItem *anItem = [[SUAppcastItem alloc] initWithDictionary:dict];
            if (anItem)
            {
                [appcastItems addObject:anItem];
                [anItem release];
            }
            else
            {
                NSLog(@"Sparkle Updater: Failed to parse appcast item with appcast dictionary %@!", dict);
            }
            [nodesDict removeAllObjects];
            [dict removeAllObjects];
        }
    }
    
    [document release];
    
    if ([appcastItems count])
    {
        NSSortDescriptor *sort = [[[NSSortDescriptor alloc] initWithKey:@"date" ascending:NO] autorelease];
        [appcastItems sortUsingDescriptors:[NSArray arrayWithObject:sort]];
        items = [appcastItems copy];
    }
    
    if (failed)
    {
        [self reportError:[NSError errorWithDomain:SUSparkleErrorDomain code:SUAppcastParseError userInfo:[NSDictionary dictionaryWithObjectsAndKeys:SULocalizedString(@"An error occurred while parsing the update feed.", nil), NSLocalizedDescriptionKey, nil]]];
    }
    else if ([delegate respondsToSelector:@selector(appcastDidFinishLoading:)])
    {
        [delegate appcastDidFinishLoading:self];
    }
}

- (void)download:(NSURLDownload *)download didFailWithError:(NSError *)error
{
    CFRelease(download);
    
    [[NSFileManager defaultManager] removeFileAtPath:downloadFilename handler:nil];
    [downloadFilename release];
    downloadFilename = nil;
    
    [self reportError:error];
}

- (NSURLRequest *)download:(NSURLDownload *)download willSendRequest:(NSURLRequest *)request redirectResponse:(NSURLResponse *)redirectResponse
{
    return request;
}

- (void)reportError:(NSError *)error
{
    if ([delegate respondsToSelector:@selector(appcast:failedToLoadWithError:)])
    {
        [delegate appcast:self failedToLoadWithError:[NSError errorWithDomain:SUSparkleErrorDomain code:SUAppcastError userInfo:[NSDictionary dictionaryWithObjectsAndKeys:SULocalizedString(@"An error occurred in retrieving update information. Please try again later.", nil), NSLocalizedDescriptionKey, [error localizedDescription], NSLocalizedFailureReasonErrorKey, nil]]];
    }
}

- (NSXMLNode *)bestNodeInNodes:(NSArray *)nodes
{
    // We use this method to pick out the localized version of a node when one's available.
    if ([nodes count] == 1)
        return [nodes objectAtIndex:0];
    else if ([nodes count] == 0)
        return nil;
    
    NSEnumerator *nodeEnum = [nodes objectEnumerator];
    NSXMLElement *node;
    NSMutableArray *languages = [NSMutableArray array];
    NSString *lang;
    NSInteger i;
    while ((node = [nodeEnum nextObject]))
    {
        lang = [[node attributeForName:@"xml:lang"] stringValue];
        [languages addObject:(lang ?: @"")];
    }
    lang = [[NSBundle preferredLocalizationsFromArray:languages] objectAtIndex:0];
    i = [languages indexOfObject:([languages containsObject:lang] ? lang : @"")];
    if (i == NSNotFound)
        i = 0;
    return [nodes objectAtIndex:i];
}

- (void)setUserAgentString:(NSString *)uas
{
    if (uas != userAgentString)
    {
        [userAgentString release];
        userAgentString = [uas copy];
    }
}

- (void)setDelegate:del
{
    delegate = del;
}

@end