Playlist.h

//
//  Playlist.h
//
//  Created by James Thompson on 5/31/12.
//  Copyright (c) 2012 Ligonier Ministries, Inc. All rights reserved.
//

#import <Foundation/Foundation.h>
#import <AVFoundation/AVFoundation.h>

#ifdef CORDOVA_FRAMEWORK
  #import <Cordova/CDVPlugin.h>
#else
  #import "CDVPlugin.h"
#endif

@interface Playlist : CDVPlugin {
  NSMutableArray* playlistSlots;
  NSMutableArray* playlist;
  AVQueuePlayer*  player;
}

- (void)play;
- (void)stop;

@end

Playlist.js

/**
 * Playlist.js
 *  
 * Created by James Thompson on 5/31/12.
 * Copyright (c) 2012 Ligonier Ministries, Inc. All rights reserved.
 *
 */
var Playlist = {
  play: function(success, fail) {
    return Cordova.exec(success, fail, "Playlist", "play");
  },
  
  stop: function(success, fail) {
    return Cordova.exec(success, fail, "Playlist", "stop");
  }
};

Playlist.m

//
//  Playlist.m
//
//  Created by James Thompson on 5/31/12.
//  Copyright (c) 2012 Ligonier Ministries, Inc. All rights reserved.
//

#import "Playlist.h"

#define PLAYLIST_API_ENDPOINT @"http://admin.refnet.fm/api/playlist.json"

@implementation Playlist

- (void)play {
  if (!playlistSlots || [playlistSlots count] == 0) {
    [self retrievePlaylistSlots];
  }
  
  [self cleanupPlaylistSlots];
  [self buildPlaylistFromSlots];
  [self seekInFirstPlaylistItem];
  
  if (!player) {
    AVQueuePlayer* player = [[AVQueuePlayer alloc] initWithItems:playlist];
  }
  
  [player play];
  
  [super writeJavascript:[[CDVPluginResult resultWithStatus:CDVCommandStatus_OK messageAsInt:1] toSuccessCallbackString:callbackId]];
}

- (void)stop {
  [player pause];
  
  [super writeJavascript:[[CDVPluginResult resultWithStatus:CDVCommandStatus_OK messageAsInt:1] toSuccessCallbackString:callbackId]];
}

- (void)retrievePlaylistSlots {
  NSURL*    playlistURL   = [NSURL URLWithString:PLAYLIST_API_ENDPOINT];
  NSString* playlistJSON  = [NSString stringWithContentsOfURL:playlistURL];
  NSData*   playlistData  = [playlistJSON dataUsingEncoding:NSUTF8StringEncoding];  
  NSError*  jsonError     = nil;
  
  NSDictionary *playlistDict = [NSJSONSerialization JSONObjectWithData:playlistData options:nil error:&jsonError];
  
  if (!playlistDict) {
    NSLog(@"Error parsing JSON: %@", jsonError);
  } else {
    NSLog(@"Playlist successfully retrieved.");    
    [playlistSlots addObjectsFromArray:[playlistDict valueForKey:@"collection"]];
  }
}

- (void)cleanupPlaylistSlots {
  for (NSDictionary* slot in playlistSlots) {
    NSDate* endTime = [self parseDateFromString:[slot valueForKey:@"ends"]];
    NSDate* now     = [NSDate date];
    
    NSComparisonResult dateComparison = [now compare:endTime];
    
    if (dateComparison == NSOrderedDescending || dateComparison == NSOrderedSame) {
      NSLog(@"Excluding slot with id: %@", [slot valueForKey:@"id"]);
      [playlistSlots removeObjectIdenticalTo:slot];
    }
  }
}

- (void)buildPlaylistFromSlots {
  if (!playlist) {
    NSMutableArray* playlist = [[NSMutableArray alloc] init];
  }
  
  for (NSDictionary* slot in playlistSlots) {
    [playlist addObject:[AVPlayerItem playerItemWithURL:[NSURL URLWithString:[slot valueForKey:@"url"]]]];
  }
}

- (void)seekInFirstPlaylistItem {
  NSDictionary* firstSlot     = [playlistSlots objectAtIndex:0];
  NSString*     startTimeStr  = [firstSlot valueForKey:@"starts"];  
  NSDate*       startTime     = [self parseDateFromString:startTimeStr];
  NSDate*       now           = [NSDate date];
  
  NSTimeInterval since = [now timeIntervalSinceDate:slotStartTime];
  
  CMTime seekTo = CMTimeMake(since, 1);

  [[playlist objectAtIndex:0] seekToTime:seekTo];
}

- (NSDate)parseDateFromString:(NSString*)date {
  NSDateFormatter* dateFormatter = [[NSDateFormatter alloc] init];
  
  [dateFormatter setTimeZone:[NSTimeZone timeZoneWithAbbreviation:@"GMT"]];
  [dateFormatter setDateFormat:@"yyyy-MM-dd'T'HH:mm:ss'Z'"];
  
  return [dateFormatter dateFromString:date];
}
@end