/**
 * @file sound.c
 *
 * @brief Handle all the sound details.
 */

#include <sys/stat.h>

#include <SDL.h>
#include <SDL_mixer.h>

#include "lephisto.h"
#include "log.h"
#include "pack.h"
#include "music.h"
#include "physics.h"
#include "sound.h"

#define SOUND_CHANNEL_MAX 256 /**< Number of sound channels to allocate. Overkill. */

#define SOUND_PREFIX      "../snd/sounds/" /**< Prefix of where to find sounds. */
#define SOUND_SUFFIX      ".wav"           /**< Suffix of sounds. */

/* Global sound properties. */
int sound_disabled        = 0;  /**< Whether sound is disabled. */
static int sound_reserved = 0;  /**< Amount of reserved channels. */
static double sound_pos[3];     /**< Position of listener. */

/* Give the buffers a name. */
typedef struct alSound_ {
  char* name;         /**< Buffers name. */
  Mix_Chunk* buffer;  /**< Buffer data. */
} alSound;

/* List of sounds available (All preloaded into a buffer). */
static alSound* sound_list  = NULL; /**< List of available sounds. */
static int sound_nlist      = 0;    /**< Number of available sounds. */

static int  sound_makeList(void);
static Mix_Chunk* sound_load(char* filename);
static void sound_free(alSound* snd);

/**
 * @fn int sound_init(void)
 *
 * @brief Initializes the sound subsystem.
 *    @return 0 on success.
 */
int sound_init(void) {
  int frequency;
  Uint16 format;
  int channels;
  SDL_version compile_version;
  const SDL_version* link_version;

  if(sound_disabled) return 0;

  SDL_InitSubSystem(SDL_INIT_AUDIO);
  if(Mix_OpenAudio(44100, MIX_DEFAULT_FORMAT, 2, 1024) < 0) {
    WARN("Opening Audio: %s", Mix_GetError());
    return -1;
  }
 
  Mix_AllocateChannels(SOUND_CHANNEL_MAX);

  /* Debug magic. */
  Mix_QuerySpec(&frequency, &format, &channels);
  MIX_VERSION(&compile_version);
  link_version = Mix_Linked_Version();
  DEBUG("SDL_Mixer: %d.%d.%d [compiled: %d.%d.%d]",
      compile_version.major, compile_version.minor, compile_version.patch,
      link_version->major, link_version->minor, link_version->patch);
  DEBUG("Format: %d HZ %s", frequency, (channels == 2) ? "Sterio" : "Mono");
  DEBUG();

  /* Load up all the sounds. */
  sound_makeList();
  sound_volume(0.4);

  /* Init the music. */
  music_init();

  return 0;
}

/**
 * @fn void sound_exit(void)
 *
 * @brief Clean up after the sound subsystem.
 */
void sound_exit(void) {
  int i;
  
  /* Free the sounds. */
  for(i = 0; i < sound_nlist; i++)
    sound_free(&sound_list[i]);
  free(sound_list);
  sound_list = NULL;
  sound_nlist = 0;

  music_exit();
}

/**
 * @fn void sound_get(char* name)
 *
 * @brief Get the buffer to sound of name.
 *    @param name Name of the sound to get id of.
 *    @return ID of the sound matching name.
 */
int sound_get(char* name) {
  int i;

  if(sound_disabled) return 0;

  for(i = 0; i < sound_nlist; i++)
    if(strcmp(name, sound_list[i].name)==0) {
      return i;
    }

  WARN("Sound '%s' not found in sound list", name);
  return -1;
}

/**
 * @fn int sound_play(int sound)
 *
 * @brief Play the sound in the first available channel.
 *    @param sound Sound to play.
 *    @return 0 on success.
 */
int sound_play(int sound) {
  int channel;

  if(sound_disabled) return 0;

  if((sound < 0) || (sound > sound_nlist))
    return -1;

  channel = Mix_PlayChannel(-1, sound_list[sound].buffer, 0);

  if(channel < 0)
    WARN("Unable to play sound: %s", Mix_GetError());

  return 0;
}

/**
 * @fn int sound_playPos(int sound, double x, double y)
 *
 * @brief Play a sound based on position.
 *    @param sound Sound to play.
 *    @param x X position of sound.
 *    @param y Y position of sound.
 *    @return 0 on success.
 */
int sound_playPos(int sound, double x, double y) {
  int channel;
  double angle, dist;
  double px, py;

  if(sound_disabled) return 0;

  if((sound < 0) || (sound > sound_nlist))
    return -1;

  px = x - sound_pos[0];
  py = y - sound_pos[1];

  angle = sound_pos[2] - ANGLE(px, py)/M_PI*180.;

  dist = MOD(px, py);

  channel = Mix_PlayChannel(-1, sound_list[sound].buffer, 0);

  if(channel < 0) {
    WARN("Unable to play sound: %s", Mix_GetError());
    return -1;
  }

  if(Mix_SetPosition(channel, (int)angle, (int)dist/10) < 0) {
    WARN("Unable to set sound position: %s", Mix_GetError());
    return -1;
  }

  return 0;
}

/**
 * @fn int sound_updateListener(double dir, double x, double y)
 *
 * @brief Update the sound listener.
 *    @param dir Direction listener if facing.
 *    @param x X position of the listener.
 *    @param y Y position of the listener.
 *
 * @sa sound_playPos
 */
int sound_updateListener(double dir, double x, double y) {
  sound_pos[0] = x;
  sound_pos[1] = y;
  sound_pos[2] = dir/M_PI*180.;
  return 0;
}

/**
 * @fn static int sound_makeList(void)
 *
 * @brief Make the list of available sounds.
 */
static int sound_makeList(void) {
  char** files;
  uint32_t nfiles, i;
  char tmp[64];
  int len;
  int mem;

  if(sound_disabled) return 0;

  /* Get the file list. */
  files = pack_listfiles(data, &nfiles);

  /* Load the profiles. */
  mem = 0;
  for(i = 0; i < nfiles; i++)
    if((strncmp(files[i], SOUND_PREFIX, strlen(SOUND_PREFIX))==0) &&
       (strncmp(files[i] + strlen(files[i]) - strlen(SOUND_SUFFIX),
                SOUND_SUFFIX, strlen(SOUND_SUFFIX))==0)) {

      /* Expand the selection size. */
      sound_nlist++;
      if(sound_nlist > mem) { /* We must grow. */
        mem += 32;  /* We'll overallocate most likely. */
        sound_list = realloc(sound_list, mem*sizeof(alSound));
      }

      /* Remove the prefix and suffix. */
      len = strlen(files[i]) - strlen(SOUND_SUFFIX SOUND_PREFIX);
      strncpy(tmp, files[i] + strlen(SOUND_PREFIX), len);
      tmp[len] = '\0';

      /* give it the new name. */
      sound_list[sound_nlist-1].name = strdup(tmp);
      sound_list[sound_nlist-1].buffer = sound_load(files[i]);
    }

  /* Shrink to minimum ram usage. */
  sound_list = realloc(sound_list, sound_nlist*sizeof(alSound));

  /* Free the char* allocated by pack. */
  for(i = 0; i < nfiles; i++)
    free(files[i]);
  free(files);

  DEBUG("Loaded %d sound%s", sound_nlist, (sound_nlist==1)?"":"s");

  return 0;
}

/**
 * @fn int sound_volume(const double vol)
 *
 * @brief Set the volume.
 *    @param vol Volume to set to.
 *    @return 0 on success.
 */
int sound_volume(const double vol) {
  if(sound_disabled) return 0;
  return Mix_Volume(-1, MIX_MAX_VOLUME*vol);
}

/**
 * @fn stastic Mix_Chunk* sound_load(char* filename)
 *
 * @brief Load a sound into the sound_list.
 *    @paramfilename Name for the file to load.
 *    @return The SDL_Mixer of the loaded chunk.
 *
 * @sa sound_makeList
 */
static Mix_Chunk* sound_load(char* filename) {
  void* wavdata;
  unsigned int size;
  SDL_RWops* rw;
  Mix_Chunk* buffer;

  if(sound_disabled) return NULL;

  /* Get the file data buffer from the packfile. */
  wavdata = pack_readfile(DATA, filename, &size);

  rw = SDL_RWFromMem(wavdata, size);

  /* Bind to OpenAL buffer. */
  buffer = Mix_LoadWAV_RW(rw, 1);

  if(buffer == NULL)
    DEBUG("Unable to load sound '%s' : %s", filename, Mix_GetError());

  /* Finish up. */
  free(wavdata);
  return buffer;
}

/**
 * @fn static void sound_free(alSound* snd)
 *
 * @brief Frees the sound.
 *    @param snd Sound to free.
 */
static void sound_free(alSound* snd) {
  /* Free the stuff. */
  if(snd->name) {
    free(snd->name);
    snd->name = NULL;
  }

  Mix_FreeChunk(snd->buffer);
  snd->buffer = NULL;
}

/**
 * @fn int sound_reverse(int num)
 * 
 * @brief Reserve num channels.
 *    @param num Number of channels to reserve.
 *    @return 0 on success.
 */
int sound_reserve(int num) {
  int ret;

  if(sound_disabled) return 0;

  sound_reserved += num;
  ret = Mix_ReserveChannels(num);

  if(ret != sound_reserved) {
    WARN("Unable to reserve %d channels: %s", sound_reserved, Mix_GetError());
    return -1;
  }

  return 0;
}

/**
 * @fn int sound_createGroup(int tag, int start, int size)
 *
 * @brief Create a sound group.
 *    @param tag Identifier of the group to create.
 *    @param start Where to start creating the group.
 *    @param size Size of the group.
 *    @return 0 on success.
 */
int sound_createGroup(int tag, int start, int size) {
  int ret;

  if(sound_disabled) return 0;

  ret = Mix_GroupChannels(start, start+size-1, tag);

  if(ret != size) {
    WARN("Unable to create sound group: %s", Mix_GetError());
    return -1;
  }

  return 0;
}

/**
 * @fn int sound_playGroup(int group, int sound, int once)
 *
 * @brief Play a sound in a group.
 *    @param group Group to play sound in.
 *    @param sound Sound to play.
 *    @param once Whether to play only once.
 *    @param 0 on success.
 */
int sound_playGroup(int group, int sound, int once) {
  int ret, channel;

  if(sound_disabled) return 0;

  channel = Mix_GroupAvailable(group);
  if(channel == -1) {
    WARN("Group '%d' has no free channels!", group);
    return -1;
  }

  ret = Mix_PlayChannel(channel, sound_list[sound].buffer,
      (once == 0) ? -1 : 0);

  if(ret < 0) {
    WARN("Unable to play sound %d for group %d: %s",
        sound, group, Mix_GetError());
    return -1;
  }

  return 0;
}

/**
 * @fn void sound_stopGroup(int group)
 *
 * @brief Stop all the sounds in a group.
 *    @param group Group to stop all it's sounds.
 */
void sound_stopGroup(int group) {
  if(sound_disabled) return;

  Mix_HaltGroup(group);
}