// set debug mode to TRUE or FALSE
#define DEBUG

// commands to send to play engine
#define SONG_PLAY   0x00000001  // flag to start the song playing
#define SONG_STOP   0x00000002  // flag to stop the current song playing
#define SONG_VOL    0x00000004  // flag to indicate a change / or the
                                // volume level
#define SONG_END    0x00000008  // End of playing song

// debugging command
DS (string sayd)
{
#ifdef DEBUG
   string scriptName = llGetScriptName();
   llOwnerSay(scriptName + ": " + sayd);
#endif
}

// golbal variable
list  currentSong_info; // list of current song info and uuid for wav files.
float volume;           // sound volume level

integer  listPlace;     // place in the currentSong_list that is playing.

default
{
   state_entry()
   {
      DS("Free Memory: " + (string) llGetFreeMemory());
   }

   link_message(integer sender_num, integer num, string str, key id)
   {
      DS("link_message : " + str);

      switch (num)
      {
         case (SONG_PLAY):
         {
            currentSong_info = llCSV2List(str);
            DS(llList2String(currentSong_info, 3));

            llPlaySound(llList2String(currentSong_info, 3), volume);
            llSetTimerEvent((llList2Float(currentSong_info, 2) - 1));

            llSoundPreload(llList2String(currentSong_info, (3 + 1)));
            listPlace = 3;
            break;
         }
         case (SONG_VOL):
         {
            volume = (float) str;
            break;
         }
         case (SONG_STOP):
         {
 #ifdef DEBUG
   llSay(888, "STOP");
#endif
            llSetTimerEvent(0);
            break;
         }
         default:
         {
            break;
         }
      }

   }

   timer()
   {
      DS("Timer");
      if(++listPlace < llGetListLength(currentSong_info))
      {
#ifdef DEBUG
   llSay(888, "RESET");
#endif
         DS("Playing UUID " + llList2String(currentSong_info, listPlace));

         llPlaySound(llList2String(currentSong_info, listPlace), volume);
         if(!(listPlace <= llGetListLength(currentSong_info)))
            llSoundPreload(llList2String(currentSong_info, (listPlace + 1)));
      }
      else
      {
#ifdef DEBUG
   llSay(888, "STOP");
#endif
         DS("end of song");
         llMessageLinked(LINK_SET, SONG_END, "","");
         llSetTimerEvent(0);
      }
   }
}