/**
 *  @class Audio
 *  @brief The UOP audio subsystem
 *  @author Samuel Kaufman
 *  @date 2002
 */
/*****
 *
 *  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 2 of the License, or
 *  (at your option) any later version.
 *
 *  This program is distributed in the hope that it will be useful,
 *  but WITHOUT ANY WARRANTY; without even the implied warranty of
 *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 *  GNU General Public License for more details.
 *
 *  You should have received a copy of the GNU General Public License
 *  along with this program; if not, write to the Free Software
 *  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
 *
 *****/

#include "uop.h"
#include <SDL/SDL.h>
#include <SDL/SDL_mixer.h>
#include <iostream>
#include <fstream>
#include <string>
#include <vector>
#ifdef HAVE_CONFIG_H
#include "config.h"
#endif
#include "audio.h"
#include "uopconfig.h"

extern UOPConfig *config;

AudioMessage::AudioMessage(AMessageHeader header)
{
  this->header = header;
  body = NULL;
  next = NULL;
}

Audio::Audio()
{
  messagesLock = SDL_CreateMutex();
  messages = NULL;
  audioPump = NULL;
  curMusic = NULL;
  musicOn = false;
  soundOn = false;
}

Audio::~Audio()
{
  if (audioPump)
    shutdown();
  SDL_DestroyMutex(messagesLock);
}

void Audio::start()
{
  if (!(config->getBoolean("SoundOn")||config->getBoolean("MusicOn")))
    return;

  if (Mix_OpenAudio(22050, AUDIO_S16, 2, 4096)) {
    cerr << "Unable to open audio: " << SDL_GetError() << endl;
    return;
  }

  audioPump = SDL_CreateThread(audioThread, this);

  // Music initialization
  // ------------------------
  if (!config->getBoolean("MusicOn"))
    return;
  ifstream lookupfile;

// TODO: Have a Registry entry added with data dir in Windows
#ifdef HAVE_CONFIG_H
  string fullpath = DATADIR;
#else
  string fullpath = "./";
#endif

  fullpath += "/musicmap.def";
  lookupfile.open(fullpath.c_str());
  if (!lookupfile.is_open())
    {
      lookupfile.open("musicmap.def");
      if (!lookupfile.is_open())
	{
	  cerr << "Couldn't open " << fullpath.c_str()
	       << " or ./musicmap.def" << endl
	       << "Music will be disabled for this session" << endl;
	  return;
	}
    }

  while (1)
    {
      if (!lookupfile.good())
	break;
      string buf;
      lookupfile >> buf;
      if (buf.size() != 0)
	lookupTable.push_back(buf);
    }

  musicOn = true;
  lookupfile.close();
}

void Audio::shutdown()
{
  Mix_CloseAudio();

  if (audioPump)
    {
      int exitCode;
      AudioMessage *message = new AudioMessage(Shutdown);
      addMessage(message);
      SDL_WaitThread(audioPump, &exitCode);

      if (exitCode)
	{
	  cerr << "Warning: Audio subsystem exited with abnormal exit code: "
	       << exitCode << endl;
	}
    }

  AudioMessage *cur = messages;
  while (cur != NULL)
    {
      AudioMessage *dest = cur->next;
      delete cur;
      cur = dest;
    }
}

void Audio::playMusic(Uint16 musicID)
{
  if ((audioPump == NULL) || (musicOn != true))
    return;
  AudioMessage *mesg = new AudioMessage(PlayMusic);
  Uint16 *mBuf = new Uint16;
  *mBuf = musicID;
  mesg->body = (char*)mBuf;
  addMessage(mesg);
}

void Audio::stopMusic()
{
  if (audioPump == NULL)
    return;
  AudioMessage *mesg = new AudioMessage(StopMusic);
  addMessage(mesg);
}

void Audio::addMessage(AudioMessage *newMessage)
{
  SDL_mutexP(messagesLock);

  if (!messages)
    messages = newMessage;
  else
    {
      AudioMessage *cur = messages;
      while (cur->next != NULL)
	cur = cur->next;
      cur->next = newMessage;
    }

  SDL_mutexV(messagesLock);
}

string Audio::getMusicPath(string name)
{
  string buf;
  buf=config->encapDatLoc("music/"+name+".mid");
  return buf;
}

int audioThread(void *audioSystem)
{
  Audio *audio = (Audio*)audioSystem;

  while (1)
    {
      SDL_mutexP(audio->messagesLock);
      if (audio->messages)
	{
	  AudioMessage *cur = audio->messages;
	  while (cur != NULL)
	    {
	      AudioMessage *dest = cur->next;
	      switch (cur->header)
		{
		case PlayMusic:
		  if (audio->curMusic != NULL)
		    {
		      Mix_FadeOutMusic(1000);
		      Mix_FreeMusic(audio->curMusic);
		    }
		  audio->curMusic = Mix_LoadMUS(audio->getMusicPath(*cur->body).c_str());
		  Mix_PlayMusic(audio->curMusic, 0);
		  break;
		case StopMusic:
		  if (audio->curMusic != NULL)
		    {
		      Mix_FadeOutMusic(1000);
		      Mix_FreeMusic(audio->curMusic);
		    }
		  break;
		case Shutdown:
		  return 0;
		}
	      delete cur;
	      cur = dest;
	    }
	}
      audio->messages = NULL;
      SDL_mutexV(audio->messagesLock);
      SDL_Delay(100); // Anti CPU hog
    }

  return 1; // This should never happen
}