/*

   Copyright (C) 1997-2017 Sam Lantinga <slouken@libsdl.org>

   This software is provided 'as-is', without any express or implied

   warranty.  In no event will the authors be held liable for any damages

   arising from the use of this software.

   Permission is granted to anyone to use this software for any purpose,

   including commercial applications, and to alter it and redistribute it

   freely.

 */

 /* Program to load a wave file and loop playing it using SDL audio */

 /* loopwaves.c is much more robust in handling WAVE files --

     This is only for simple WAVEs

 */

 #include "SDL_config.h"

 #include <stdio.h>

 #include <stdlib.h>

 #ifdef __EMSCRIPTEN__

 #include <emscripten/emscripten.h>

 #endif

 #include "SDL.h"

 static struct

 {

     SDL_AudioSpec spec;

     Uint8 *sound;               /* Pointer to wave data */

     Uint32 soundlen;            /* Length of wave data */

     int soundpos;               /* Current play position */

 } wave;

 static SDL_AudioDeviceID device;

 /* Call this instead of exit(), so we can clean up SDL: atexit() is evil. */

 static void

 quit(int rc)

 {

     SDL_Quit();

     exit(rc);

 }

 static void

 close_audio()

 {

     if (device != 0) {

         SDL_CloseAudioDevice(device);

         device = 0;

     }

 }

 static void

 open_audio()

 {

     /* Initialize fillerup() variables */

     device = SDL_OpenAudioDevice(NULL, SDL_FALSE, &wave.spec, NULL, 0);

     if (!device) {

         SDL_LogError(SDL_LOG_CATEGORY_APPLICATION, "Couldn't open audio: %s\n", SDL_GetError());

         SDL_FreeWAV(wave.sound);

         quit(2);

     }

     /* Let the audio run */

     SDL_PauseAudioDevice(device, SDL_FALSE);

 }

 static void reopen_audio()

 {

     close_audio();

     open_audio();

 }

 void SDLCALL

 fillerup(void *unused, Uint8 * stream, int len)

 {

     Uint8 *waveptr;

     int waveleft;

     /* Set up the pointers */

     waveptr = wave.sound + wave.soundpos;

     waveleft = wave.soundlen - wave.soundpos;

     /* Go! */

     while (waveleft <= len) {

         SDL_memcpy(stream, waveptr, waveleft);

         stream += waveleft;

         len -= waveleft;

         waveptr = wave.sound;

         waveleft = wave.soundlen;

         wave.soundpos = 0;

     }

     SDL_memcpy(stream, waveptr, len);

     wave.soundpos += len;

 }

 static int done = 0;

 #ifdef __EMSCRIPTEN__

 void

 loop()

 {

     if(done || (SDL_GetAudioDeviceStatus(device) != SDL_AUDIO_PLAYING))

         emscripten_cancel_main_loop();

 }

 #endif

 int

 main(int argc, char *argv[])

 {

     int i;

     char filename[4096];

     /* Enable standard application logging */

     SDL_LogSetPriority(SDL_LOG_CATEGORY_APPLICATION, SDL_LOG_PRIORITY_INFO);

     /* Load the SDL library */

     if (SDL_Init(SDL_INIT_AUDIO|SDL_INIT_EVENTS) < 0) {

         SDL_LogError(SDL_LOG_CATEGORY_APPLICATION, "Couldn't initialize SDL: %s\n", SDL_GetError());

         return (1);

     }

     if (argc > 1) {

         SDL_strlcpy(filename, argv[1], sizeof(filename));

     } else {

         SDL_strlcpy(filename, "sample.wav", sizeof(filename));

     }

     /* Load the wave file into memory */

     if (SDL_LoadWAV(filename, &wave.spec, &wave.sound, &wave.soundlen) == NULL) {

         SDL_LogError(SDL_LOG_CATEGORY_APPLICATION, "Couldn't load %s: %s\n", filename, SDL_GetError());

         quit(1);

     }

     wave.spec.callback = fillerup;

     /* Show the list of available drivers */

     SDL_Log("Available audio drivers:");

     for (i = 0; i < SDL_GetNumAudioDrivers(); ++i) {

         SDL_Log("%i: %s", i, SDL_GetAudioDriver(i));

     }

     SDL_Log("Using audio driver: %s\n", SDL_GetCurrentAudioDriver());

     open_audio();

     SDL_FlushEvents(SDL_AUDIODEVICEADDED, SDL_AUDIODEVICEREMOVED);

 #ifdef __EMSCRIPTEN__

     emscripten_set_main_loop(loop, 0, 1);

 #else

     while (!done) {

         SDL_Event event;

         while (SDL_PollEvent(&event) > 0) {

             if (event.type == SDL_QUIT) {

                 done = 1;

             }

             if ((event.type == SDL_AUDIODEVICEADDED && !event.adevice.iscapture) ||

                 (event.type == SDL_AUDIODEVICEREMOVED && !event.adevice.iscapture && event.adevice.which == device)) {

                 reopen_audio();

             }

         }

         SDL_Delay(100);

     }

 #endif

     /* Clean up on signal */

     close_audio();

     SDL_FreeWAV(wave.sound);

     SDL_Quit();

     return (0);

 }

 /* vi: set ts=4 sw=4 expandtab: */