GXSPFPlaylist.m

/*
    File: GXSPFPlaylist.m
    Description: XSPF playlist support (implementation).

    This file is part of Goonj.

    Goonj is free software: you can redistribute it and/or modify
    it under the terms of the GNU General Public License as published by
    the Free Software Foundation, either version 3 of the License, or
    (at your option) any later version.

    Goonj is distributed in the hope that it will be useful,
    but WITHOUT ANY WARRANTY; without even the implied warranty of
    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
    GNU General Public License for more details.

    You should have received a copy of the GNU General Public License
    along with Goonj. If not, see <http://www.gnu.org/licenses/>.

    Copyright 2009 Pratul Kalia.
    Copyright 2009 Ankur Sethi.
*/

#import "GXSPFPlaylist.h"


@implementation GXSPFPlaylist

- (id) initWithFile:(NSString *)aURL
{
	if (self = [super init]) {
        trackList = [[NSMutableArray alloc] initWithCapacity:0];
        aURL = [aURL stringByExpandingTildeInPath];

        if ([[NSFileManager defaultManager] fileExistsAtPath:aURL] == YES)
            [self loadCollection:[aURL stringByExpandingTildeInPath]];

        return self;
    }

    return nil;
}

- (void) addTrack:(GTrack *)track
{
    [trackList addObject:track];
}

- (void) addTrack:(GTrack *)track atIndex:(NSUInteger)index
{
    [trackList insertObject:track atIndex:index];
}

- (void) removeTrack:(GTrack *)track
{
    [trackList removeObject:track];
}

- (void) removeTrackAtIndex:(NSUInteger)index
{
    [trackList removeObjectAtIndex:index];
}

- (void) removeTracksAtIndexes:(NSIndexSet *)indexes
{
	[trackList removeObjectsAtIndexes:indexes];
}

- (void) moveTrackFromIndex:(NSUInteger)initIndex toIndex:(NSUInteger)endIndex
{
    id something = [trackList objectAtIndex:initIndex];
    [trackList removeObjectAtIndex:initIndex];
    [trackList insertObject:something atIndex:endIndex];
}

- (void) clearPlaylist
{
    [trackList removeAllObjects];
}

- (NSUInteger) count
{
    return [trackList count];
}

- (GTrack *) trackAtIndex:(NSUInteger)index
{
    return [trackList objectAtIndex:index];
}

- (BOOL) isLocalCollection
{
    return YES;
}

- (BOOL) saveCollectionAs:(NSString *)aURL
{
    // TODO: save more metadata.

	// Set up the namespace.
	NSXMLNode *XSPFNamespace = [[NSXMLNode alloc] initWithKind:NSXMLNamespaceKind];
	[XSPFNamespace setName:@""];
	[XSPFNamespace setStringValue:@"http://xspf.org/ns/0/"];

	// Why do I have to create a separate NSXMLNode for every single
	// attribute? Meh.
	NSXMLNode *XSPFVersion = [[NSXMLNode alloc] initWithKind:NSXMLAttributeKind];
	[XSPFVersion setName:@"version"];
	[XSPFVersion setStringValue:@"1.0"];

	// Create root element.
	NSXMLElement *XSPFRoot = [[NSXMLElement alloc] initWithName:@"playlist"];
	[XSPFRoot addNamespace:XSPFNamespace];
	[XSPFRoot addAttribute:XSPFVersion];

	// Create the actual document.
	NSXMLDocument *XSPFDoc = [[NSXMLDocument alloc] initWithRootElement:XSPFRoot];
	[XSPFDoc setVersion:@"1.0"];
	[XSPFDoc setCharacterEncoding:@"UTF-8"];

	NSXMLElement *XSPFTrackList = [[NSXMLElement alloc] initWithName:@"trackList"];
	[XSPFRoot addChild:XSPFTrackList];

	NSXMLElement *XSPFTrack;
	NSXMLElement *XSPFLocation;
    NSURL *fileURL;

	// It might be a good idea to check if the playlist is being saved in the
	// same directory as the music files. If yes, then we can use relative
	// paths instead of absolute paths.
	for (GTrack *track in trackList) {
		XSPFTrack = [[NSXMLElement alloc] initWithName:@"track"];
		[XSPFTrackList addChild:XSPFTrack];

		XSPFLocation = [[NSXMLElement alloc] initWithName:@"location"];
        fileURL = [[NSURL alloc] initWithScheme:NSURLFileScheme host:@"" path:[track path]];
		[XSPFLocation setStringValue:[[fileURL absoluteString]
            stringByAddingPercentEscapesUsingEncoding:NSUTF8StringEncoding]];
		[XSPFTrack addChild:XSPFLocation];
	}

	// Write data to file. TODO: replace existing file when saving.
	NSData *XMLData = [XSPFDoc XMLDataWithOptions:NSXMLNodePrettyPrint];
	return [XMLData writeToFile:[aURL stringByExpandingTildeInPath] atomically:NO];
}

- (BOOL) loadCollection:(NSString *)aURL
{
    NSError *err = nil;
    NSXMLDocument *XSPFDoc = [[NSXMLDocument alloc] initWithContentsOfURL:[NSURL fileURLWithPath:aURL]
        options:(NSXMLNodePreserveWhitespace|NSXMLNodePreserveCDATA)
        error:&err];

	if (XSPFDoc == nil)
		return NO;

    // Loading the playlist was a success, so clear the old playlist.
    [trackList removeAllObjects];

    NSXMLElement *XSPFRoot = [XSPFDoc rootElement];

	// There should be only ONE tracklist in a playlist, anyway.
    // If there are more than one tracklists, the remaining lists are ignored.
	NSXMLElement *XSPFTrackList = [[XSPFRoot elementsForName:@"trackList"] objectAtIndex:0];
	NSArray *XSPFTracks = [XSPFTrackList elementsForName:@"track"];

	GTrack *track;
	NSString *unescapedString;
	for (NSXMLElement *XSPFTrack in XSPFTracks) {
		NSXMLElement *XSPFLocation = [[XSPFTrack elementsForName:@"location"] objectAtIndex:0];

		// Need to call stringByReplacingPercentEscapesUsingEncoding twice. Insane, I tell you.
		unescapedString = [[XSPFLocation stringValue] stringByReplacingPercentEscapesUsingEncoding:NSUTF8StringEncoding];
		unescapedString = [unescapedString stringByReplacingPercentEscapesUsingEncoding:NSUTF8StringEncoding];
		track = [[GTrack alloc] initWithFile:unescapedString];
		[self addTrack:track];
	}

	return YES;
}

@end