#include <SDL.h>

#include <SDL_mixer.h>

#include "private.h"

#include "sound.h"

#define HELI_SOUND_CHANNELS 64

typedef struct _HeliSoundInstance {

	char *path;

	Mix_Chunk *chunk;

	int refcount;

} HeliSoundInstance;

typedef struct _HeliSoundTrashItem {

	Mix_Chunk *chunk;

	unsigned int time;

} HeliSoundTrashItem;

struct _Sound {

	HeliSoundInstance *instance;

};

static int initialized;

static int ready;

static HeliArray cache;

static Sound channels[HELI_SOUND_CHANNELS];

static HeliSoundTrashItem *trash;

static size_t trashSize;

static int memSoundIndex = 0;

static int less(unsigned int a, unsigned int b)

	{ return (b - a) < (1u << 31); }

static void trashAdd(Mix_Chunk *chunk) {

	if (!chunk) return;

	unsigned int time = SDL_GetTicks() + 1000u;

	for(int i = 0; i < trashSize; ++i)

		if (!trash[i].chunk) 

			{ trash[i].chunk = chunk; trash[i].time = time; return; }

	size_t prevSize = trashSize;

	trashSize += trashSize/4 + 32;

	trash = realloc(trash, trashSize*sizeof(*trash));

	memset(&trash[prevSize], 0, (trashSize - prevSize)*sizeof(*trash));

	trash[prevSize].chunk = chunk;

	trash[prevSize].time = time;

}

static void trashProcess() {

	unsigned int time = SDL_GetTicks();

	for(int i = 0; i < trashSize; ++i)

		if (trash[i].chunk && !less(time, trash[i].time))

			{ Mix_FreeChunk(trash[i].chunk); trash[i].chunk = NULL; }

}

static void trashDestroy() {

	for(int i = 0; i < trashSize; ++i)

		if (trash[i].chunk) Mix_FreeChunk(trash[i].chunk);

	trashSize = 0;

	free(trash);

	trash = NULL;

}

static void init() {

	if (initialized) return;

	if (SDL_Init(SDL_INIT_AUDIO) == 0) {

		int loaded = Mix_Init(MIX_INIT_OGG | MIX_INIT_FLAC | MIX_INIT_MP3);

		if (!(loaded & MIX_INIT_OGG )) fprintf(stderr, "helianthus: cannot initialize OGG  support\n");

		if (!(loaded & MIX_INIT_FLAC)) fprintf(stderr, "helianthus: cannot initialize FLAC support\n");

		if (!(loaded & MIX_INIT_MP3 )) fprintf(stderr, "helianthus: cannot initialize MP3  support\n");

		ready = Mix_OpenAudio(44100, MIX_DEFAULT_FORMAT, 2, 1024) == 0;

		if (!ready) fprintf(stderr, "helianthus: cannot open audio device\n");

	}

	initialized = TRUE;

}

static void deinit() {

	if (!initialized) return;

	heliArrayDestroy(&cache);

	if (ready) Mix_CloseAudio();

	trashDestroy();

	Mix_Quit();

	SDL_Quit();

	for(int i = 0; i < HELI_SOUND_CHANNELS; ++i) channels[i] = NULL;

	ready = FALSE;

	initialized = FALSE;

}

static HeliSoundInstance* load(const char *path) {

	HeliSoundInstance *s = calloc(1, sizeof(*s));

	s->path = heliStringCopy(path);

	if (ready) {

		if (strncmp(path, "helimem:", 8) == 0) {

			void *data = NULL;

			int size = 0;

			s->chunk = NULL;

			if (sscanf(path, "helimem:%p:%d:", &data, &size) != EOF && data && size > 0) {

				SDL_RWops *rw = SDL_RWFromMem((void*)data, size);

				if (rw) s->chunk = Mix_LoadWAV_RW(rw, SDL_TRUE);

			}

			if (!s->chunk)

				fprintf(stderr, "helianthus: cannot load sound from memory\n");

		} else {

			s->chunk = Mix_LoadWAV(path);

			if (!s->chunk)

				fprintf(stderr, "helianthus: cannot load sound file: %s\n", path);

		}

	}

	return s;

}

static void unload(HeliSoundInstance *s) {

	assert(!s->refcount);

	free(s->path);

	trashAdd(s->chunk);

	free(s);

}

Sound createSound(const char *path) {

	if (!heliInitialized) return NULL;

	init();

	HeliPair *item = heliStringmapGet(&cache, path);

	if (!item) item = heliStringmapAdd(&cache, path, load(path), (HeliFreeCallback)&unload);

	HeliSoundInstance *s = (HeliSoundInstance*)item->value;

	++s->refcount;

	Sound sound = calloc(1, sizeof(*sound));

	sound->instance = s;

	heliObjectRegister(sound, (HeliFreeCallback)&soundDestroy);

	return sound;

}

Sound createSoundFromMemory(const void *data, int size) {

	char buffer[1024] = {};

	sprintf(buffer, "helimem:%p:%d:%d", data, size, ++memSoundIndex);

	return createSound(buffer);

}

Sound soundClone(Sound sound) {

	if (!sound) return NULL;

	return createSound(sound->instance ? sound->instance->path : NULL);

}

void soundDestroy(Sound sound) {

	heliObjectUnregister(sound);

	soundStop(sound);

	if (--sound->instance->refcount <= 0)

		heliStringmapRemove(&cache, sound->instance->path);

	free(sound);

}

void soundPlay(Sound sound, int loop) {

	if (!ready) return;

	if (sound->instance->chunk) {

		int channel = Mix_PlayChannel(-1, sound->instance->chunk, loop ? -1 : 0);

		assert(channel < HELI_SOUND_CHANNELS);

		if (channel >= 0 && channel < HELI_SOUND_CHANNELS)

			channels[channel] = sound;

	}

}

void soundStop(Sound sound) {

	for(int i = 0; i < HELI_SOUND_CHANNELS; ++i) {

		if (channels[i] == sound) {

			Mix_Pause(i);

			Mix_HaltChannel(i);

			channels[i] = NULL;

		}

	}

}

double soundDuration(Sound sound)

    { return ready && sound->instance->chunk ? sound->instance->chunk->alen/44100.0/2/2 : 0; }

void heliSoundUpdate()

	{ trashProcess(); }

void heliSoundFinish()

	{ deinit(); }