// created on 17/05/2002 at 19:18
using System;
using System.Runtime.InteropServices;
using System.Text;

namespace CD
{
	struct TOC
	{
		public uint min;
		public uint sec;
		public uint frames;
		
		public TOC(uint AFrames)
		{
			frames = AFrames % 75;
  		AFrames = AFrames / 75;
  		sec = AFrames % 60;
  		AFrames = AFrames / 60;
  		min = AFrames;
		}

		public TOC(string TOCString)
		{
			min = uint.Parse(TOCString.Substring(0, 2));
			sec = uint.Parse(TOCString.Substring(3, 2));
			frames = uint.Parse(TOCString.Substring(6, 2));
		}
		
		public override string ToString()
		{
			return min.ToString() + ":" + sec.ToString() + ":" + frames.ToString();
		}
	}

	class CDInfo
	{
		// imports from winmm.dll
		[ DllImport( "winmm.dll", EntryPoint="mciSendStringA", CharSet=CharSet.Ansi )]
		protected static extern int mciSendString(string lpstrCommand, StringBuilder lpstrReturnString, 
	                                          int uReturnLength, IntPtr hwndCallback);
	
		[ DllImport( "winmm.dll", EntryPoint="mciGetErrorStringA", CharSet=CharSet.Ansi )]
		protected static extern int mciGetErrorString(int dwError, StringBuilder lpstrBuffer, int uLength);
		
		private string Alias;

		// constructor
		public CDInfo(char Drive)
		{
			Alias = Guid.NewGuid().ToString();
			SendString("open " + Drive + ":\\ type cdaudio shareable wait alias " + Alias);	
		}

		public CDInfo()
		{
			Alias = Guid.NewGuid().ToString();
			SendString("open cdaudio shareable wait alias " + Alias);	
		}

		~CDInfo()
		{
			Close();
		}

		public void Close()
		{
			SendAliasedString("close");
		}

		protected string SendAliasedString(string Cmd, string Params)
		{
			return SendString(Cmd + " " + Alias + " " + Params);
		}

		protected string SendAliasedString(string Cmd)
		{
			return SendString(Cmd + " " + Alias);
		}

		protected string SendString(string Cmd)
		{
			int ret;
			StringBuilder buffer = new StringBuilder(255);
			ret = mciSendString(Cmd, buffer, buffer.Capacity, IntPtr.Zero);
			if (ret != 0)
				throw new Exception(GetMciError(ret));
			return buffer.ToString();
		}
		
		protected string GetMciError(int errorCode) 
		{
			StringBuilder buffer = new StringBuilder(255);
			if (mciGetErrorString(errorCode, buffer, buffer.Capacity) == 0)
				return "";
			return buffer.ToString();
		}

		public uint DiscID()
		{  
			TOC[] TOCList = new TOC[100];
			
			// for each track, get position (starting location)
			for (uint Loop = 1; Loop <= TotalTrackCount(); Loop++)
			{
				TOCList[Loop-1] = TrackPosition(Loop);
			}

			uint n = 0;
			uint i = 0;
			while (i < TotalTrackCount())
			{
				uint cddb_sum = 0;
				uint j = (TOCList[i].min * 60) + TOCList[i].sec;
				while (j>0)
				{
					cddb_sum = cddb_sum + (j % 10);
					j = j / 10;
				}
				n = n + cddb_sum;
    		i++;
			} 

			return ((n % 0xff) << 24 | TotalCDLength() << 8 | TotalTrackCount());
		}

		public string DiscIDHex()
		{
			return string.Format("{0:X8}", DiscID()); 
		} 

		public uint TOCToFrames(TOC ATOC)
		{
			return (ATOC.min*60*75) + (ATOC.sec*75) + ATOC.frames;
		}

		public uint TotalCDLength()
		{
			// get last track length
 	 		TOC LLastTrack = TrackLength(TotalTrackCount());

			// +1 to fix Windows MCI bug, according to cddb howto
  		LLastTrack.frames++;

			// compute lead-out track position (in frame format)
  		uint dwPos = TOCToFrames(TrackPosition(TotalTrackCount())) + TOCToFrames(LLastTrack);

			// save lead-out track position (in MSF format)
  		TOC LeadOutTrack = new TOC(dwPos);

			return ((LeadOutTrack.min * 60) + LeadOutTrack.sec) -	
				((TrackPosition(1).min * 60) + TrackPosition(1).sec);	
		}

		public TOC TrackLength(uint Track)
		{
			string LTrackLength = SendAliasedString("status", " length track " + Track); 
			TOC LToc = new TOC(LTrackLength);
			return LToc;
		}

		public uint TotalTrackCount()
		{
			return(uint.Parse(SendAliasedString("status", "number of tracks")));
		}

		public TOC TrackPosition(uint Track)
		{
			string trackpos = SendAliasedString("status", "position track " + Track.ToString());
			TOC LToc = new TOC(trackpos);
			return LToc;
		}

		public void Play()
		{
			SendAliasedString("play");
		}

		public void Pause()
		{
			SendAliasedString("pause");
		}

		public void Stop()
		{
			SendAliasedString("stop");
			SendAliasedString("seek", "to start");
		}

		public void GotoTrack(uint Track)
		{
			bool LPlaying = Playing();

			SendAliasedString("seek", "to " + TrackPosition(Track).ToString());

			if (LPlaying) 
			{
				Play();
			}
		}

		public void Next()
		{
			uint LTrackToGoTo;
			if (CurrentTrack() == TotalTrackCount())
    		LTrackToGoTo = 1;
  		else
    		LTrackToGoTo = CurrentTrack()+1;

			GotoTrack(LTrackToGoTo);
		}

		public void Previous()
		{
			uint LTrackToGoTo;
			if (CurrentTrack() == 1)
    		LTrackToGoTo = TotalTrackCount();
  		else
    		LTrackToGoTo = CurrentTrack()-1;

			GotoTrack(LTrackToGoTo);
		}

		public uint CurrentTrack()
		{
			return uint.Parse(SendAliasedString("status", "current track")); 
		}

		public bool Playing()
		{
			return (SendAliasedString("status", "mode") == "playing");
		}

		public void Eject()
		{
			SendAliasedString("set", "door open");
		}
	}
}