#include <bits/pthreadtypes.h>
#include <bits/types/sigset_t.h>
#include <errno.h>
#include <pthread.h>
#include <signal.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <sys/resource.h>
#include <unistd.h>
#include "common.h"
#include "playlist.h"
#include "streamer.h"
#include "transmuxer.h"

/* ===== Definitions ===== */
#define PRIORITY -10
struct Streamer {
	pthread_t       worker_thread;
	pthread_mutex_t worker_ready_mutex;
	pthread_cond_t  worker_ready_cond;
	int             worker_ready_flag;

	enum State      state;
	pthread_mutex_t state_mutex;

	HLSRemuxer     *remuxer;
	Playlist       *playlist;
	char           *current_song;
};

/* ===== Thread-local storage ===== */
static pthread_key_t  streamer_worker_key;
static pthread_once_t streamer_worker_once = PTHREAD_ONCE_INIT;

static void streamer_worker_key_create(void)
{
	pthread_key_create(&streamer_worker_key, NULL);
}


/* ====== Streamer initialisation ===== */
static void *streamer_worker       (void *t);

Streamer *streamer_init (const struct StreamerOpt *opts)
{
	Streamer   *s = NULL;
	Playlist   *p = NULL;
	HLSRemuxer *r = NULL;

	pthread_once(&streamer_worker_once, streamer_worker_key_create);

	if ((s = malloc(sizeof(*s))) == NULL)
		goto error;
	if ((p = playlist_init()) == NULL)
		goto error;
	if ((r = hls_remuxer_init(opts)) == NULL)
		goto error;

	if (pthread_create(&s->worker_thread, NULL, streamer_worker, s))
		goto error;

	s->playlist    = p;
	s->remuxer     = r;
	s->state       = STATE_STANDBY;
	s->state_mutex = (pthread_mutex_t) PTHREAD_MUTEX_INITIALIZER;
	return s;

error:
	hls_remuxer_free(r);
	playlist_free(p);
	free(s);
	return NULL;
}

int streamer_push(Streamer *s, const char *url, unsigned int index)
{
	return (index == PLAYLIST_END)
		? playlist_enqueue(s->playlist, url)
		: playlist_insert(s->playlist, index, url);
}

int streamer_pop(Streamer *s, unsigned int id)
{
	int err;
	struct Entry entry;

	if ((err = playlist_remove(s->playlist, id, &entry)))
		return err;
	free(entry.file);
	return 0;
}

void streamer_skip(Streamer *s)
{
	/* 'skip' only halt the current song, which is then replaced by the streamer
	 * worker, either immediately, or as soon as a song gets pushed.
	 */
	hls_remuxer_halt(s->remuxer);
}

void streamer_pause(Streamer *s)
{
	pthread_mutex_lock(&s->state_mutex);
	if (s->state == STATE_PLAYING) {
		hls_remuxer_pause(s->remuxer);
		s->state = STATE_PAUSED;
	}
	pthread_mutex_unlock(&s->state_mutex);
}

void streamer_resume(Streamer *s)
{
	pthread_mutex_lock(&s->state_mutex);
	if (s->state == STATE_PAUSED) {
		hls_remuxer_resume(s->remuxer);
		s->state = STATE_PLAYING;
	}
	pthread_mutex_unlock(&s->state_mutex);
}

int streamer_info(Streamer *streamer, struct StateInfo *info)
{
	pthread_mutex_lock(&streamer->state_mutex);
	info->state = streamer->state;

	if ((info->current_song = strdup(streamer->current_song)) == NULL) {
		pthread_mutex_unlock(&streamer->state_mutex);
		return -1;
	}

	if (playlist_list(streamer->playlist, info)) {
		pthread_mutex_unlock(&streamer->state_mutex);
		free(info->current_song);
		return -1;
	}

	pthread_mutex_unlock(&streamer->state_mutex);
	return 0;
}

void streamer_free (Streamer *s)
{
	pthread_kill(s->worker_thread, SIGTERM);
	hls_remuxer_halt(s->remuxer);
	pthread_join(s->worker_thread, NULL);
	playlist_free(s->playlist);
	free(s);
}


static void streamer_worker_sighandler(int sig)
{
	Streamer *streamer;
	streamer = pthread_getspecific(streamer_worker_key);

	pthread_mutex_lock(&streamer->state_mutex);
	streamer->state = STATE_TERM;
	pthread_mutex_unlock(&streamer->state_mutex);
}


static inline int streamer_worker_conf_priority(void)
{
	errno = 0;
	setpriority(PRIO_PROCESS, 0, PRIORITY);
	return errno ? -1 : 0;
}

static inline int streamer_worker_conf_sighandling(void)
{
	sigset_t set;
	struct sigaction sigact;

	/* Configure SIGTERM interuptor */
	sigact.sa_handler = streamer_worker_sighandler;
	sigact.sa_flags   = 0;
	sigemptyset(&sigact.sa_mask);
	sigaction(SIGTERM, &sigact, NULL); // term
	sigaction(SIGUSR1, &sigact, NULL); // play/pause
	sigaction(SIGUSR2, &sigact, NULL); // skip

	/* Unblock SIGTERM */
	sigemptyset(&set);
	sigaddset(&set, SIGTERM);
	sigaddset(&set, SIGUSR1);
	sigaddset(&set, SIGUSR2);
	pthread_sigmask(SIG_UNBLOCK, &set, NULL);
}

static void *streamer_worker(void *arg)
{
	Streamer *s;
	struct Entry next;

	pthread_setspecific(streamer_worker_key, (s = arg));

	/* Configure worker */
	pthread_mutex_lock(&s->worker_ready_mutex);
	streamer_worker_conf_priority();
	streamer_worker_conf_sighandling();
	s->worker_ready_flag = 1;
	pthread_cond_broadcast(&s->worker_ready_cond);
	pthread_mutex_unlock(&s->worker_ready_mutex);

	/* Main loop */
	while (s->state != ) {
		/* Attempt to fetch the next song, or go into standby mode */
		if (playlist_try_dequeue(s->playlist, &next)) {
			puts("The playlist is empty, going into standby mode.");
			pthread_mutex_lock(&s->state_mutex);
			s->state = STATE_STANDBY;
			pthread_mutex_unlock(&s->state_mutex);
			playlist_dequeue(s->playlist, &next);
		}

		/* Update the current state */
		pthread_mutex_lock(&s->state_mutex);
		printf("Next song: [%i] %s\n", next.id, next.file);
		s->current_song = next.file;
		s->state = STATE_PLAYING;
		pthread_mutex_unlock(&s->state_mutex);

		/* Play the song entirely */
		hls_remuxer_play(s->remuxer, next.file);

		/* Discard current_song, but keep the current 'playing' state. */
		pthread_mutex_lock(&s->state_mutex);
		free(s->current_song);
		s->current_song = NULL;
		pthread_mutex_unlock(&s->state_mutex);
	}

	return NULL;
}