/**

 * PlaylistManager.cs

 * 

 * Takes care of managing the playlists.

 * 

 * * * * * * * * *

 * 

 * Copyright 2012 Simplare

 * 

 * This code is part of the Stoffi Music Player Project.

 * Visit our website at: stoffiplayer.com

 *

 * This program 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.

 * 

 * See stoffiplayer.com/license for more information.

 **/



using System;

using System.Collections;

using System.Collections.Generic;

using System.Collections.ObjectModel;

using System.Collections.Specialized;

using System.IO;

using System.Linq;

using System.Text;

using System.Threading;

using System.Xml;



namespace Stoffi

{

	/// <summary>

	/// Represents a manager that takes care of the playlist logic

	/// </summary>

	public static class PlaylistManager

	{

		#region Members



		private static String supportedFileFormats = "m3u;pls";



		#endregion



		#region Properties



		/// <summary>

		/// The currently active playlist that is being played.

		/// An empty string if no playlist is active.

		/// </summary>

		public static String CurrentPlaylist { get; set; }



		#endregion



		#region Methods



		#region Public



		/// <summary>

		/// Initializes the playlist manager

		/// </summary>

		public static void Initialize()

		{

			CurrentPlaylist = "";



			ThreadStart GUIThread = delegate()

			{

				foreach (PlaylistData playlist in SettingsManager.Playlists)

				{

					// fix null tracks

					bool allTracksNull = true;

					foreach (TrackData t in playlist.Tracks)

						if (t != null)

						{

							allTracksNull = false;

							break;

						}



					if (allTracksNull) playlist.Tracks.Clear();

					playlist.Tracks.CollectionChanged += TracksChanged;

					DispatchPlaylistModified(playlist, ModifyType.Created);

				}

			};



			if (SettingsManager.CurrentActiveNavigation.StartsWith("Playlist:"))

				CurrentPlaylist = SettingsManager.CurrentActiveNavigation.Split(new[]{':'},2)[1];



			Thread thread = new Thread(GUIThread);

			thread.Name = "Playlist Thread";

			thread.Priority = ThreadPriority.BelowNormal;

			thread.Start();

		}



		/// <summary>

		/// Add tracks to a playlist

		/// </summary>

		/// <param name="tracks">The list of tracks to be added</param>

		/// <param name="playlistName">The name of the playlist to add the tracks to</param>

		/// <param name="pos">The position to insert the track at (-1 means at the end)</param>

		public static void AddToPlaylist(List<object> tracks, String playlistName, int pos = -1)

		{

			PlaylistData playlist = FindPlaylist(playlistName);

			if (playlist == null) return;

			foreach (TrackData track in tracks)

			{

				if (!playlist.Tracks.Contains(track))

				{

					if (pos < 0 || pos >= playlist.Tracks.Count)

						playlist.Tracks.Add(track);

					else

						playlist.Tracks.Insert(pos, track);

					track.Source = "Playlist:" + playlist.Name;

				}

			}

		}



		/// <summary>

		/// Add tracks to a playlist

		/// </summary>

		/// <param name="tracks">The list of tracks to be added</param>

		/// <param name="playlistName">The name of the playlist to add the tracks to</param>

		/// <param name="pos">The position to insert the track at (-1 means at the end)</param>

		public static void AddToPlaylist(ObservableCollection<TrackData> tracks, String playlistName, int pos = -1)

		{

			PlaylistData playlist = FindPlaylist(playlistName);

			if (playlist == null) return;

			foreach (TrackData track in tracks)

			{

				if (!playlist.Tracks.Contains(track))

				{

					if (pos < 0 || pos >= playlist.Tracks.Count)

						playlist.Tracks.Add(track);

					else

						playlist.Tracks.Insert(pos, track);

					track.Source = "Playlist:" + playlist.Name;

				}

			}

		}



		/// <summary>

		/// Add tracks to a playlist

		/// </summary>

		/// <param name="tracks">The list of tracks to be added</param>

		/// <param name="playlistName">The name of the playlist to add the tracks to</param>

		/// <param name="pos">The position to insert the track at (-1 means at the end)</param>

		public static void AddToPlaylist(List<TrackData> tracks, String playlistName, int pos = -1)

		{

			PlaylistData playlist = FindPlaylist(playlistName);

			if (playlist == null) return;

			foreach (TrackData track in tracks)

			{

				// insert

				if (!playlist.Tracks.Contains(track))

				{

					if (pos < 0 || pos >= playlist.Tracks.Count)

						playlist.Tracks.Add(track);

					else

						playlist.Tracks.Insert(pos, track);

					track.Source = "Playlist:" + playlist.Name;

				}



				// move

				else if (pos != playlist.Tracks.IndexOf(track))

				{

					if (pos < 0 || pos >= playlist.Tracks.Count)

					{

						playlist.Tracks.Remove(track);

						playlist.Tracks.Add(track);

					}

					else if (pos < playlist.Tracks.IndexOf(track))

					{

						playlist.Tracks.Remove(track);

						playlist.Tracks.Insert(pos, track);

					}

					else

					{

						playlist.Tracks.Remove(track);

						playlist.Tracks.Insert(pos-1, track);

					}

				}

			}

		}



		/// <summary>

		/// Check to see if a file is a supported playlist file

		/// </summary>

		/// <param name="path">The filename to check</param>

		/// <returns>true of the file can be opened by Stoffi, otherwise false</returns>

		public static bool IsSupported(String path)

		{

			return path.StartsWith("playlist://") ||

				(supportedFileFormats.Split(';').Contains<string>(Path.GetExtension(path)));

		}



		/// <summary>

		/// Remove tracks from a playlist if they are found inside the playlist

		/// </summary>

		/// <param name="tracks">The list of t to be removed</param>

		/// <param name="playlistName">The name of the playlist to remove the t from</param>

		public static void RemoveFromPlaylist(List<TrackData> tracks, String playlistName)

		{

			PlaylistData playlist = FindPlaylist(playlistName);

			if (playlist != null)

			{

				foreach (TrackData track in tracks)

					foreach (TrackData trackInPlaylist in playlist.Tracks)

						if (trackInPlaylist.Path == track.Path)

						{

							playlist.Tracks.Remove(trackInPlaylist);

							break;

						}

			}

		}



		/// <summary>

		/// Creates a new playlist

		/// </summary>

		/// <param name="name">The name of the new playlist (this will be appended with a number if neccessary)</param>

		/// <returns>The newly created PlaylistData for the playlist</returns>

		public static PlaylistData CreatePlaylist(String name)

		{

			name = U.CleanXMLString(name);



			if (FindPlaylist(name) != null)

			{

				int pExt = 1;

				while (FindPlaylist(name + pExt) != null)

					pExt++;

				name = name + pExt;

			}



			PlaylistData playlist = new PlaylistData();

			playlist.Name = name;

			playlist.Time = 0;

			playlist.Tracks = new ObservableCollection<TrackData>();

			playlist.Tracks.CollectionChanged += TracksChanged;

			SettingsManager.Playlists.Add(playlist);



			DispatchPlaylistModified(playlist, ModifyType.Created);



			return playlist;

		}



		/// <summary>

		/// Renames a playlist. If a playlist with the new name already exist or the new name is either "Create new" or "" it will do nothing.

		/// </summary>

		/// <param name="oldName">The current name of the playlist to be renamed</param>

		/// <param name="newName">The new name of the playlist</param>

		public static void RenamePlaylist(String oldName, String newName)

		{

			newName = U.CleanXMLString(newName);



			PlaylistData pl = FindPlaylist(oldName);



			if (FindPlaylist(newName) != null)

			{

				int pExt = 1;

				while (FindPlaylist(newName + pExt) != null)

					pExt++;

				newName = newName + pExt;

			}



			if (pl != null && newName != "" && newName.ToLower() != U.T("NavigationCreateNew").ToLower())

				DispatchPlaylistRenamed(pl, oldName, newName);

		}



		/// <summary>

		/// Saves a playlist as a file

		/// </summary>

		/// <param name="path">The path of the saved playlist</param>

		/// <param name="name">The name of the playlist to save</param>

		public static void SavePlaylist(String path, String name)

		{

			PlaylistData pl = FindPlaylist(name);

			if (pl != null)

			{

				string ext = Path.GetExtension(path);

				System.IO.StreamWriter sw = System.IO.File.AppendText(path);



				if (ext == ".pls")

				{

					sw.WriteLine("[playlist]");

					sw.WriteLine("");

					int i = 0;

					foreach (TrackData track in pl.Tracks)

					{

						i++;

						sw.WriteLine(String.Format("File{0}={1}", i, track.Path));

						sw.WriteLine(String.Format("Title{0}={1}", i, track.Title));

						sw.WriteLine(String.Format("Length{0}={1}", i, (int)track.RawLength));

						sw.WriteLine("");

					}

					sw.WriteLine("NumberOfEntries=" + i);

					sw.WriteLine("Version=2");

				}

				else if (ext == ".m3u")

				{

					sw.WriteLine("#EXTM3U");

					sw.WriteLine("");

					foreach (TrackData track in pl.Tracks)

					{

						sw.WriteLine(String.Format("#EXTINF:{0},{1} - {2}", (int)track.RawLength, track.Artist, track.Title));

						sw.WriteLine(track.Path);

						sw.WriteLine("");

					}

				}

				sw.Close();

			}

		}



		/// <summary>

		/// Reads a file and creates a playlist using the name of the file.

		/// </summary>

		/// <param name="filename">The file to read</param>

		/// <returns>The PlaylistData of the newly created playlist</returns>

		public static PlaylistData LoadPlaylist(String filename)

		{

			//try

			//{

				string pName = Path.GetFileNameWithoutExtension(filename);

				if (FindPlaylist(pName) != null)

				{

					int pExt = 1;

					while (FindPlaylist(pName + pExt) != null)

						pExt++;

					pName = pName + pExt;

				}

				PlaylistData pl = CreatePlaylist(pName);

				StreamReader sr = new StreamReader(filename);

				string line;

				int nr = 0;

				if (Path.GetExtension(filename) == ".m3u")

				{

					bool ext = false;

					string inf = "";

					while ((line = sr.ReadLine()) != null)

					{

						nr++;

						if (line == "#EXTM3U")

							ext = true;

						else if (ext && line.StartsWith("#EXTINF:"))

							inf = line.Substring(8);

						else if (line.StartsWith("#") || line == "")

							continue;

						else

						{

							string path = line;



							if (!File.Exists(path) && File.Exists(Path.Combine(Path.GetDirectoryName(filename), path)))

								path = Path.Combine(Path.GetDirectoryName(filename), path);



							if (File.Exists(path))

							{

								string length = "";

								string artist = "";

								string title = "";

								if (inf != "")

								{

									if (!inf.Contains(','))

									{

										U.L(LogLevel.Warning, "PLAYLIST", "Bad format in " + filename + " on line "

											+ nr + ": expecting ','");

										continue;

									}

									string[] split = inf.Split(',');

									length = split[0];

									if (split[1].Contains('-'))

									{

										artist = split[1].Split('-')[0];

										title = split[1].Split('-')[1];

									}

									else

										title = split[1];

								}

								if (!FilesystemManager.PathIsAdded(path))

									FilesystemManager.AddSource(new SourceData() 

									{ 

										Data = path, 

										HumanType = U.T("SourcesTypeFile"),

										Type = SourceType.File,

										Include = true

									});

								foreach (TrackData t in SettingsManager.FileTracks)

									if (t.Path == path)

									{

										if (!pl.Tracks.Contains(t))

											pl.Tracks.Add(t);

										break;

									}

								inf = "";

							}

							else if (YouTubeManager.IsYouTube(path))

							{

								string yid = YouTubeManager.GetYouTubeID(path);

								TrackData t = YouTubeManager.CreateTrack(yid);

								if (!pl.Tracks.Contains(t))

									pl.Tracks.Add(t);

							}

						}

					}

				}

				else if (Path.GetExtension(filename) == ".pls")

				{

					bool hdr = false;

					string version = "";

					int noe = 0;

					while ((line = sr.ReadLine()) != null)

					{

						nr++;

						if (line == "[playlist]")

							hdr = true;

						else if (!hdr)

							U.L(LogLevel.Warning, "PLAYLIST", "Bad format in " + filename + " on line "

								+ nr + ": expecting '[playlist]'");

						else if (line.StartsWith("NumberOfEntries="))

							noe = Convert.ToInt32(line.Split('=')[1]);

						else if (line.StartsWith("Version="))

							version = line.Split('=')[1];

					}

					

					if (!hdr)

						U.L(LogLevel.Warning, "PLAYLIST", "Error in " + filename + ": No header found");

					else if (version != "2")

						U.L(LogLevel.Warning, "PLAYLIST", "Error in " + filename + ": Unsupported version '" + 

							version + "'");

					else

					{

						sr.Close();

						sr = new StreamReader(filename);

						string[,] tracks = new string[noe, 3];

						nr = 0;

						while ((line = sr.ReadLine()) != null)

						{

							if (line.StartsWith("File") || line.StartsWith("Title") || line.StartsWith("Length"))

							{

								int tmp = 4;

								int index = 0;

								if (line.StartsWith("Title")) { tmp = 5; index = 1; }

								else if (line.StartsWith("Length")) { tmp = 6; index = 2; }



								string[] split = line.Split('=');

								int number = Convert.ToInt32(split[0].Substring(tmp));



								if (number > noe)

									U.L(LogLevel.Warning, "PLAYLIST", "Bad format in " + filename + " on line "

										+ nr + ": entry number is '" + number + "' but NumberOfEntries is '" + noe + "'");

								else

									tracks[number-1, index] = split[1];

							}

							else if (!line.StartsWith("NumberOfEntries") && line != "[playlist]" && !line.StartsWith("Version="))

							{

								U.L(LogLevel.Warning, "PLAYLIST", "Bad format in " + filename + " on line "

									+ nr + ": unexpected '" + line + "'");

							}

						}

						for (int i = 0; i < noe; i++)

						{

							string path = tracks[i, 0];



							if (!File.Exists(path) && File.Exists(Path.Combine(Path.GetDirectoryName(filename), path)))

								path = Path.Combine(Path.GetDirectoryName(filename), path);



							if (File.Exists(path))

							{

								if (!FilesystemManager.PathIsAdded(path))

									FilesystemManager.AddSource(new SourceData() 

									{ 

										Data = path, 

										HumanType = U.T("SourcesTypeFile"),

										Type = SourceType.File,

										Include = true

									});

								foreach (TrackData t in SettingsManager.FileTracks)

									if (t.Path == path)

									{

										if (!pl.Tracks.Contains(t))

											pl.Tracks.Add(t);

										break;

									}

							}

							else if (YouTubeManager.IsYouTube(path))

							{

								string yid = YouTubeManager.GetYouTubeID(path);

								TrackData t = YouTubeManager.CreateTrack(yid);

								if (!pl.Tracks.Contains(t))

									pl.Tracks.Add(t);

							}

						}

					}

				}

				sr.Close();

				return pl;





			// TODO: Replace with dispatching a custom event



			//}

			//catch (Exception e)

			//{

			//    MessageBox.Show("Error trying to load playlist:\n" + e.Message, "Couldn't Load Playlist", MessageBoxButton.OK,

			//        MessageBoxImage.Error);

			//    return null;

			//}

		}



		/// <summary>

		/// Deletes a playlist

		/// </summary>

		/// <param name="name">The name of the playlist to delete</param>

		public static void RemovePlaylist(String name)

		{

			PlaylistData pl = FindPlaylist(name);

			if (pl != null)

			{

				DispatchPlaylistModified(pl, ModifyType.Removed);



				// and finally remove the playlist altogther (undo?)

				SettingsManager.Playlists.Remove(pl);

			}

		}



		/// <summary>

		/// Tries to find a playlist with a given name

		/// </summary>

		/// <param name="name">The name of the playlist to look for</param>

		/// <returns>The PlaylistData of the playlist with the name <paramref name="name"/> of such a playlist could be found, otherwise null.</returns>

		public static PlaylistData FindPlaylist(String name)

		{

			foreach (PlaylistData p in SettingsManager.Playlists)

				if (p.Name == name) return p;

			return null;

		}



		/// <summary>

		/// Update the "Last Played" and "Play Count" information of a given track

		/// </summary>

		/// <param name="RefTrack">The track that was just played</param>

		public static void TrackWasPlayed(TrackData RefTrack)

		{

			if (RefTrack == null) return;



			uint pc = RefTrack.PlayCount + 1;

			foreach (TrackData track in SettingsManager.FileTracks)

			{

				if (track.Path == RefTrack.Path)

				{

					track.PlayCount = pc;

					track.LastPlayed = DateTime.Now.ToString("g");

					track.RawLastPlayed = DateTime.Now.ToString("yyyyMMddHHmmss");

				}

			}



			foreach (TrackData track in SettingsManager.QueueTracks)

			{

				if (track.Path == RefTrack.Path)

				{

					track.PlayCount = pc;

					track.LastPlayed = DateTime.Now.ToString("g");

					track.RawLastPlayed = DateTime.Now.ToString("yyyyMMddHHmmss");

				}

			}



			foreach (TrackData track in SettingsManager.HistoryTracks)

				if (track.Path == RefTrack.Path)

					track.PlayCount = pc;



			foreach (PlaylistData playlist in SettingsManager.Playlists)

			{

				if (playlist.Name == CurrentPlaylist)

				{

					foreach (TrackData track in playlist.Tracks)

					{

						if (track.Path == RefTrack.Path)

						{

							track.PlayCount = pc;

							track.LastPlayed = DateTime.Now.ToString("g");

							track.RawLastPlayed = DateTime.Now.ToString("yyyyMMddHHmmss");

						}

					}

				}

			}

		}



        /// <summary>

        /// Finds all playlists that contains a given track.

        /// </summary>

        /// <param name="track">The track to look for</param>

        /// <returns>All playlists containing <paramref name="track"/></returns>

		public static List<PlaylistData> Has(TrackData track)

		{

			List<PlaylistData> has = new List<PlaylistData>();

			foreach (PlaylistData p in SettingsManager.Playlists)

                if (Contains(p, track))

                    has.Add(p);

			return has;

		}



        /// <summary>

        /// Checks whether a given playlist contains a given track.

        /// </summary>

        /// <param name="playlist">The playlist to search in</param>

        /// <param name="track">The track to search for</param>

        /// <returns>True of <paramref name="playlist"/> contains <paramref name="track"/>, otherwise false</returns>

        public static bool Contains(PlaylistData playlist, TrackData track)

        {

            foreach (TrackData t in playlist.Tracks)

                if (t.Path == track.Path)

                    return true;

            return false;

        }



        /// <summary>

        /// Checks whether a given playlist contains any of a given list of track.

        /// </summary>

        /// <param name="playlist">The playlist to search in</param>

        /// <param name="tracks">The tracks to search for</param>

        /// <returns>True of <paramref name="playlist"/> contains any of <paramref name="tracks"/>, otherwise false</returns>

        public static bool ContainsAny(PlaylistData playlist, List<TrackData> tracks)

        {

            foreach (TrackData t1 in playlist.Tracks)

                foreach (TrackData t2 in tracks)

                    if (t1.Path == t2.Path)

                        return true;

            return false;

        }



        /// <summary>

        /// Checks whether a given playlist contains all of a given list of track.

        /// </summary>

        /// <param name="playlist">The playlist to search in</param>

        /// <param name="tracks">The tracks to search for</param>

        /// <returns>True of <paramref name="playlist"/> contains all of <paramref name="tracks"/>, otherwise false</returns>

        public static bool ContainsAll(PlaylistData playlist, List<TrackData> tracks)

        {

            foreach (TrackData t1 in playlist.Tracks)

                foreach (TrackData t2 in tracks)

                    if (t1.Path != t2.Path)

                        return false;

            return playlist.Tracks.Count != 0;

        }



		#endregion



		#region Event handlers



		/// <summary>

		/// Updates the total time of all tracks of a playlist.

		/// </summary>

		/// <param name="sender">The sender of the event</param>

		/// <param name="e">The event data</param>

		private static void TracksChanged(object sender, NotifyCollectionChangedEventArgs e)

		{

			ObservableCollection<TrackData> tracks = sender as ObservableCollection<TrackData>;



			// find the playlist containing the track that sent the event

			PlaylistData pl = null;

			foreach (PlaylistData p in SettingsManager.Playlists)

			{

				if (p.Tracks == tracks)

				{

					pl = p;

					break;

				}

			}



			// no playlist found (weird!)

			if (pl == null) return;



			pl.Time = 0;

			foreach (TrackData t in pl.Tracks)

				pl.Time += t.RawLength;



			if (pl.Time < 0) pl.Time = 0;



			//// update gui if neccessary

			//if (ParentWindow.NavigationPane.CurrentSelectedNavigation == "Playlist:" + pl.Name)

			//{

			//    ParentWindow.InfoPaneTracks.Text = pl.Tracks.Count.ToString() + " songs";

			//    ParentWindow.InfoPaneDuration.Text = U.TimeSpanToLongString(new TimeSpan(0, 0, (int)pl.Time));

			//}

		}



		#endregion



		#region Dispatchers



		/// <summary>

		/// The dispatcher of the <see cref="PlaylistRenamed"/> event

		/// </summary>

		/// <param name="playlist">The playlist that was renamed</param>

		/// <param name="oldName">The name of the playlist before the change</param>

		/// <param name="newName">The name of the playlist after the change</param>

		private static void DispatchPlaylistRenamed(PlaylistData playlist, string oldName, string newName)

		{

			if (PlaylistRenamed != null)

				PlaylistRenamed(playlist, new RenamedEventArgs(WatcherChangeTypes.Renamed, "playlist", newName, oldName));

		}



		/// <summary>

		/// The dispatcher of the <see cref="PlaylistModified"/> event

		/// </summary>

		/// <param name="playlist">The playlist that was modified</param>

		/// <param name="type">The type of modification that occured</param>

		private static void DispatchPlaylistModified(PlaylistData playlist, ModifyType type)

		{

			if (PlaylistModified != null)

				PlaylistModified(playlist, new ModifiedEventArgs(type, null));

		}



		#endregion



		#endregion



		#region Events



		/// <summary>

		/// Occurs when a playlist has been renamed

		/// </summary>

		public static event RenamedEventHandler PlaylistRenamed;



		/// <summary>

		/// Occurs when a playlist has been created, removed or changed

		/// </summary>

		public static event ModifiedEventHandler PlaylistModified;



		#endregion

	}



	#region Delegates



	public delegate void ModifiedEventHandler(object sender, ModifiedEventArgs e);



	#endregion



	#region Event arguments



	/// <summary>

	/// Provides data for the events where something has been modified

	/// </summary>

	public class ModifiedEventArgs

	{

		/// <summary>

		/// Gets or sets the type of modification that occured

		/// </summary>

		public ModifyType Type { get; set; }



		/// <summary>

		/// Gets or sets the data of the modification

		/// </summary>

		public object Data { get; set; }



		/// <summary>

		/// Creates an instance of the ModifiedEventArgs class

		/// </summary>

		/// <param name="type">The type of modification that occured</param>

		/// <param name="data">The data of the modification</param>

		public ModifiedEventArgs(ModifyType type, object data)

		{

			Type = type;

			Data = data;

		}

	}



	#endregion



	#region Enums



	/// <summary>

	/// Represents the type of modification that can occur

	/// </summary>

	public enum ModifyType

	{

		/// <summary>

		/// The object was created

		/// </summary>

		Created,



		/// <summary>

		/// The object was removed

		/// </summary>

		Removed,



		/// <summary>

		/// The object was changed

		/// </summary>

		Changed

	}



	#endregion

}