/*
 * This is an alternate backend for the music system.
 * It uses SDL_mixer to provide a more reliable playback,
 * and allow processing of multiple audio formats.
 *
 *  -- MD2211 (2006-04-24)
 */

#include <SDL/SDL.h>
#include <SDL/SDL_mixer.h>
#include <string.h>
#ifdef __unix__
#include <sys/types.h>
#include <sys/stat.h>
#endif
#ifdef __WINDOWS__
#include <windows.h>
#include <dir.h>
#endif
#include "args.h"
#include "hmp2mid.h"
#include "digi_mixer_music.h"
#include "jukebox.h"

#include <stdio.h>
#include <stdlib.h>
#ifndef macintosh
#include <unistd.h>
#endif
#include <errno.h>
#include "cfile.h"

#define MIX_MUSIC_DEBUG 0
#define MUSIC_FADE_TIME 500 //milliseconds
#define MUSIC_EXTENSION_ARG "-music_ext"

Mix_Music *current_music = NULL;

void music_done() {
  Mix_HaltMusic();
  Mix_FreeMusic(current_music);
  current_music = NULL;
  jukebox_stop_hook();
}

void convert_hmp(char *filename, char *mid_filename) {

    if (MIX_MUSIC_DEBUG) printf("convert_hmp: converting %s to %s\n", filename, mid_filename);

    const char *err;
    CFILE *hmp_in;
    FILE *mid_out = fopen(mid_filename, "w");

    if (!mid_out) {
      fprintf(stderr, "Error could not open: %s for writing: %s\n", mid_filename, strerror(errno));
      return;
    }

    hmp_in = cfopen(filename, "rb");

    if (!hmp_in) {
      fprintf(stderr, "Error could not open: %s\n", filename);
      fclose(mid_out);
      return;
    }

    err = hmp2mid((hmp2mid_read_func_t) cfread, hmp_in, mid_out);

    fclose(mid_out);
    cfclose(hmp_in);

    if (err) {
      fprintf(stderr, "%s\n", err);
      unlink(mid_filename);
      return;
    }
}

/* This function handles playback of the internal songs (or their external counterparts) */
void mix_play_music(char *filename, int loop) {

  loop *= -1; 
  int i, got_end=0;
  char *basedir = "Music";
  char rel_filename[32];
  char music_title[16];

  // Quick hack to filter out the .hmp extension
  for (i=0; !got_end; i++) {
    switch (filename[i]) {
    case '.':
    case '\0':
      music_title[i] = '\0';
      got_end = 1;
      break;
    default:
      music_title[i] = filename[i];
    }
  }

  if (!cfexist(basedir))
    mkdir(basedir
#ifndef __WINDOWS__
    , 0775
#endif
    ); //try making directory

  // What is the extension of external files? If none, default to internal MIDI
  if (GameArg.SndExternalMusic) {
    sprintf(rel_filename, "%s/%s.%3s", basedir, music_title, GameArg.SndExternalMusic); // add extension
  }
  else {
    sprintf(rel_filename, "%s/%s.mid", basedir, music_title);
    convert_hmp(filename, rel_filename);
  }

  mix_play_file("", rel_filename, loop);
}

void mix_play_file(char *basedir, char *filename, int loop) {

  int fn_buf_len = strlen(basedir) + strlen(filename) + 1;
  char real_filename[fn_buf_len];
  sprintf(real_filename, "%s%s", basedir, filename); // build absolute path

  if ((current_music = Mix_LoadMUS(real_filename))) {
    if (Mix_PlayingMusic()) {
      // Fade-in effect sounds cleaner if we're already playing something
      Mix_FadeInMusic(current_music, loop, MUSIC_FADE_TIME);
    }
    else {
      Mix_PlayMusic(current_music, loop);
    }
    Mix_HookMusicFinished(music_done);
  }
  else {
    fprintf(stderr, "File %s%s could not be loaded\n", basedir, filename);
    Mix_HaltMusic();
  }
}

void mix_set_music_volume(int vol) {
  Mix_VolumeMusic(vol);
}

void mix_stop_music() {
  Mix_HaltMusic();
}