// ClassicalSharp copyright 2014-2016 UnknownShadow200 | Licensed under MIT
using System;
using System.IO;
using System.Threading;
using SharpWave;
using SharpWave.Codecs.Vorbis;

namespace ClassicalSharp.Audio {
	
	public sealed partial class AudioPlayer : IGameComponent {
		
		IAudioOutput musicOut;
		IAudioOutput[] monoOutputs, stereoOutputs;
		string[] files, musicFiles;
		Thread musicThread;
		Game game;
		
		public void Init( Game game ) {
			this.game = game;
			string path = Path.Combine( Program.AppDirectory, "audio" );
			if( Directory.Exists( path ) )
				files = Directory.GetFiles( path );
			else
				files = new string[0];
			
			game.UseMusic = Options.GetBool( OptionsKey.UseMusic, false );
			SetMusic( game.UseMusic );
			game.UseSound = Options.GetBool( OptionsKey.UseSound, false );
			SetSound( game.UseSound );
			game.UserEvents.BlockChanged += PlayBlockSound;
		}

		public void Ready( Game game ) { }		
		public void Reset( Game game ) { }
		public void OnNewMap( Game game ) { }
		public void OnNewMapLoaded( Game game ) { }		
		
		public void SetMusic( bool enabled ) {
			if( enabled )
				InitMusic();
			else
				DisposeMusic();
		}
		
		const StringComparison comp = StringComparison.OrdinalIgnoreCase;
		void InitMusic() {
			int musicCount = 0;
			for( int i = 0; i < files.Length; i++ ) {
				if( files[i].EndsWith( ".ogg", comp ) ) musicCount++;
			}
			
			musicFiles = new string[musicCount];
			for( int i = 0, j = 0; i < files.Length; i++ ) {
				if( !files[i].EndsWith( ".ogg", comp ) ) continue;
				musicFiles[j] = files[i]; j++;
			}
			
			disposingMusic = false;
			musicThread = MakeThread( DoMusicThread, ref musicOut,
			                         "ClassicalSharp.DoMusic" );
		}
		
		EventWaitHandle musicHandle = new EventWaitHandle( false, EventResetMode.AutoReset );
		void DoMusicThread() {
			if( musicFiles.Length == 0 ) return;
			Random rnd = new Random();
			while( !disposingMusic ) {
				string file = musicFiles[rnd.Next( 0, musicFiles.Length )];
				string path = Path.Combine( Program.AppDirectory, file );
				Utils.LogDebug( "playing music file: " + file );
				
				using( FileStream fs = File.OpenRead( path ) ) {
					OggContainer container = new OggContainer( fs );
					try {
						musicOut.PlayStreaming( container );
					} catch( InvalidOperationException ex) {
						HandleMusicError( ex );
						return;
					} catch( Exception ex ) {
						ErrorHandler.LogError( "AudioPlayer.DoMusicThread()", ex );
						game.Chat.Add( "&cError while trying to play music file " + Path.GetFileName( file ) );
					}
				}
				if( disposingMusic ) break;
				
				int delay = 2000 * 60 + rnd.Next( 0, 5000 * 60 );
				musicHandle.WaitOne( delay, false );
			}
		}
		
		void HandleMusicError( InvalidOperationException ex ) {
			ErrorHandler.LogError( "AudioPlayer.DoMusicThread()", ex );
			if( ex.Message == "No audio devices found" )
				game.Chat.Add( "&cNo audio devices found, disabling music." );
			else
				game.Chat.Add( "&cAn error occured when trying to play music, disabling music." );
			
			SetMusic( false );
			game.UseMusic = false;
		}
		
		bool disposingMusic;
		public void Dispose() {
			DisposeMusic();
			DisposeSound();
			musicHandle.Close();
			game.UserEvents.BlockChanged -= PlayBlockSound;
		}
		
		void DisposeMusic() {
			disposingMusic = true;
			musicHandle.Set();
			DisposeOf( ref musicOut, ref musicThread );
		}
		
		Thread MakeThread( ThreadStart func, ref IAudioOutput output, string name ) {
			output = GetPlatformOut();
			output.Create( 10 );
			
			Thread thread = new Thread( func );
			thread.Name = name;
			thread.IsBackground = true;
			thread.Start();
			return thread;
		}
		
		IAudioOutput GetPlatformOut() {
			if( OpenTK.Configuration.RunningOnWindows )
				return new WinMmOut();
			return new OpenALOut();
		}
		
		void DisposeOf( ref IAudioOutput output, ref Thread thread ) {
			if( output == null ) return;
			output.Stop();
			thread.Join();
			
			output.Dispose();
			output = null;
			thread = null;
		}
	}
}