/*
 * Copyright 2016 (c) Anna Schumaker.
 */
#include <core/idle.h>
#include <core/playlists/system.h>
#include <core/string.h>

static struct playlist *pl_system_lookup(const gchar *);
static struct playlist *pl_system_get(unsigned int);
static void pl_system_update(const gchar *);
static void __sys_pl_save();
static bool __sys_pl_load();

static struct file sys_file         = FILE_INIT("playlist.db", 0);
static struct file sys_deck_f       = FILE_INIT("deck", 1);
static struct file sys_collection_f = FILE_INIT("library.q", 0);
static struct file sys_pl_file      = FILE_INIT("playlist.system", 0);


/*
 * Generic system playlist operations.
 */
static bool sys_pl_delete_clear(struct playlist *playlist)
{
	playlist_generic_clear(playlist);
	__sys_pl_save();
	return false;
}

static void sys_pl_generic_init(struct playlist *playlist, unsigned int flags,
				struct queue_ops *ops)
{
	playlist_generic_init(playlist, 0, ops);
}

static void sys_pl_update_init(struct playlist *playlist, unsigned int flags,
			       struct queue_ops *ops)
{
	sys_pl_generic_init(playlist, flags, ops);
	pl_system_update(playlist->pl_name);
}

static void sys_pl_save_partial(struct playlist *playlist, struct file *file)
{
	file_writef(file, "%s\n", playlist->pl_name);
	queue_save_flags(&playlist->pl_queue, file, true);
}

static void sys_pl_save_full(struct playlist *playlist, struct file *file)
{
	sys_pl_save_partial(playlist, file);
	queue_save_tracks(&playlist->pl_queue, file);
}

static void sys_pl_load_partial(struct playlist *playlist, struct file *file)
{
	queue_load_flags(&playlist->pl_queue, file, true);
}

static void sys_pl_load_full(struct playlist *playlist, struct file *file)
{
	sys_pl_load_partial(playlist, file);
	queue_load_tracks(&playlist->pl_queue, file);
}

static bool sys_pl_generic_add_front(struct playlist *playlist,
				     struct track *track)
{
	if (queue_has(&pl_system_get(SYS_PL_HIDDEN)->pl_queue, track))
		return false;
	return playlist_generic_add_track_front(playlist, track);
}



/*
 * Favorite tracks playlist operations.
 */
static struct playlist_ops favorites_ops = {
	.pl_add        = playlist_generic_add_track,
	.pl_can_select = playlist_generic_can_select,
	.pl_delete     = sys_pl_delete_clear,
	.pl_next       = playlist_generic_next,
	.pl_remove     = playlist_generic_remove_track,
	.pl_set_flag   = playlist_generic_set_flag,
	.pl_sort       = playlist_generic_sort,
};

static struct sys_playlist sys_favorites = {
	.spl_playlist = DEFINE_PLAYLIST(PL_SYSTEM, "Favorites",
					SYS_PL_FAVORITES, &favorites_ops),
	.spl_init     = playlist_generic_init,
	.spl_save     = sys_pl_save_full,
	.spl_load     = sys_pl_load_full,
};


/*
 * Hidden tracks playlist operations.
 */
static bool sys_pl_hidden_add(struct playlist *playlist, struct track *track)
{
	bool ret = playlist_generic_add_track(pl_system_get(SYS_PL_HIDDEN), track);
	playlist_generic_remove_track(pl_system_get(SYS_PL_COLLECTION),     track);
	playlist_generic_remove_track(pl_system_get(SYS_PL_UNPLAYED),       track);
	playlist_generic_remove_track(pl_system_get(SYS_PL_MOST_PLAYED),    track);
	playlist_generic_remove_track(pl_system_get(SYS_PL_LEAST_PLAYED),   track);
	return ret;
}

static bool sys_pl_hidden_remove(struct playlist *playlist, struct track *track)
{
	bool ret = playlist_generic_remove_track(playlist, track);
	unsigned int average = track_db_average_plays();
	unsigned int add_id  = SYS_PL_LEAST_PLAYED;

	add_id = (track->tr_count == 0)      ? SYS_PL_UNPLAYED    : add_id;
	add_id = (track->tr_count > average) ? SYS_PL_MOST_PLAYED : add_id;

	playlist_generic_add_track(pl_system_get(SYS_PL_COLLECTION), track);
	playlist_generic_add_track(pl_system_get(add_id),            track);
	return ret;
}

static bool sys_pl_hidden_clear(struct playlist *playlist)
{
	struct track *track;

	while (queue_size(&playlist->pl_queue) > 0) {
		track = queue_at(&playlist->pl_queue, 0);
		sys_pl_hidden_remove(playlist, track);
	}

	__sys_pl_save();
	return false;
}

static struct playlist_ops hidden_ops = {
	.pl_add        = sys_pl_hidden_add,
	.pl_can_select = playlist_generic_can_select,
	.pl_delete     = sys_pl_hidden_clear,
	.pl_next       = playlist_generic_next,
	.pl_remove     = sys_pl_hidden_remove,
	.pl_set_flag   = playlist_generic_set_flag,
	.pl_sort       = playlist_generic_sort,
};

static struct sys_playlist sys_hidden = {
	.spl_playlist = DEFINE_PLAYLIST(PL_SYSTEM, "Hidden",
					  SYS_PL_HIDDEN, &hidden_ops),
	.spl_init     = playlist_generic_init,
	.spl_save     = sys_pl_save_full,
	.spl_load     = sys_pl_load_full,
};


/*
 * Queued tracks playlist operations.
 */
static bool sys_pl_queued_load()
{
	struct queue *queue = &pl_system_get(SYS_PL_QUEUED)->pl_queue;
	unsigned int num, i, flags = 0;

	if (!file_open(&sys_deck_f, OPEN_READ))
		return true;

	file_readf(&sys_deck_f, "%u", &num);
	for (i = 0; i < num; i++) {
		file_readf(&sys_deck_f, "%u", &flags);
		flags &= Q_VALID_FLAGS;
		if (i == 0)
			queue->q_flags |= flags;
		queue_load_tracks(queue, &sys_deck_f);
	}

	file_close(&sys_deck_f);
	file_remove(&sys_deck_f);
	return true;
}

static void sys_pl_queued_init(struct playlist *playlist,
			       unsigned int flags, struct queue_ops *ops)
{
	queue_init(&playlist->pl_queue, 0, ops, playlist);
}

static struct track *sys_pl_queued_next(struct playlist *playlist)
{
	struct track *track = playlist_generic_next(playlist);
	unsigned int  pos   = playlist->pl_queue.q_cur.it_pos;

	queue_iter_prev(&playlist->pl_queue.q_cur);
	queue_remove(&playlist->pl_queue, pos);
	return track;
}

static struct playlist_ops queued_ops = {
	.pl_add        = playlist_generic_add_track,
	.pl_can_select = playlist_generic_can_select,
	.pl_delete     = sys_pl_delete_clear,
	.pl_next       = sys_pl_queued_next,
	.pl_remove     = playlist_generic_remove_track,
	.pl_set_flag   = playlist_generic_set_flag,
	.pl_sort       = playlist_generic_sort,
};

static struct sys_playlist sys_queued = {
	.spl_playlist = DEFINE_PLAYLIST(PL_SYSTEM, "Queued Tracks",
					SYS_PL_QUEUED, &queued_ops),
	.spl_init     = sys_pl_queued_init,
	.spl_save     = sys_pl_save_full,
	.spl_load     = sys_pl_load_full,
};


/*
 * Collection playlist operations.
 */
static bool sys_pl_collection_load()
{
	struct playlist *playlist = pl_system_get(SYS_PL_COLLECTION);

	if (file_open(&sys_collection_f, OPEN_READ)) {
		queue_load_flags(&playlist->pl_queue, &sys_collection_f, false);
		file_close(&sys_collection_f);
		file_remove(&sys_collection_f);
	}

	return true;
}

static bool sys_pl_collection_update(struct playlist *playlist,
				     struct track *track)
{
	return sys_pl_generic_add_front(playlist, track) || true;
}

static struct playlist_ops collection_ops = {
	.pl_can_select = playlist_generic_can_select,
	.pl_next       = playlist_generic_next,
	.pl_remove     = sys_pl_hidden_add,
	.pl_set_flag   = playlist_generic_set_flag,
	.pl_sort       = playlist_generic_sort,
};

static struct sys_playlist sys_collection = {
	.spl_playlist = DEFINE_PLAYLIST(PL_SYSTEM, "Collection",
					SYS_PL_COLLECTION, &collection_ops),
	.spl_init     = sys_pl_update_init,
	.spl_save     = sys_pl_save_partial,
	.spl_load     = sys_pl_load_partial,
	.spl_update   = sys_pl_collection_update,
};


/*
 * History playlist operations.
 */
static void sys_pl_history_init(struct playlist *playlist,
				 unsigned int flags, struct queue_ops *ops)
{
	queue_init(&playlist->pl_queue, 0, ops, playlist);
}

static bool sys_pl_history_add(struct playlist *playlist, struct track *track)
{
	queue_add_front(&playlist->pl_queue, track);
	queue_iter_set(&playlist->pl_queue, &playlist->pl_queue.q_cur, 0);
	return true;
}

static struct playlist_ops history_ops = {
	.pl_add  = sys_pl_history_add,
	.pl_next = playlist_generic_next,
};

static struct sys_playlist sys_history = {
	.spl_playlist = DEFINE_PLAYLIST(PL_SYSTEM, "History",
					SYS_PL_HISTORY, &history_ops),
	.spl_init     = sys_pl_history_init,
	.spl_save     = sys_pl_save_partial,
	.spl_load     = sys_pl_load_partial,
};


/*
 * Unplayed tracks playlist operations.
 */
static bool sys_pl_unplayed_update(struct playlist *playlist,
				   struct track *track)
{
	if (track->tr_count > 0)
		return false;
	return sys_pl_generic_add_front(playlist, track) || true;
}

static struct playlist_ops unplayed_ops = {
	.pl_can_select = playlist_generic_can_select,
	.pl_next       = playlist_generic_next,
	.pl_set_flag   = playlist_generic_set_flag,
	.pl_sort       = playlist_generic_sort,
};

static struct sys_playlist sys_unplayed = {
	.spl_playlist = DEFINE_PLAYLIST(PL_SYSTEM, "Unplayed",
					SYS_PL_UNPLAYED, &unplayed_ops),
	.spl_init     = sys_pl_update_init,
	.spl_save     = sys_pl_save_partial,
	.spl_load     = sys_pl_load_partial,
	.spl_update   = sys_pl_unplayed_update,
};


/*
 * Most played tracks playlist operations.
 */
static bool sys_pl_most_played_update(struct playlist *playlist,
				      struct track *track)
{
	unsigned int average = track_db_average_plays();
	if (track->tr_count <= average)
		return false;
	return sys_pl_generic_add_front(playlist, track) || true;
}

static struct playlist_ops most_played_ops = {
	.pl_can_select = playlist_generic_can_select,
	.pl_next       = playlist_generic_next,
	.pl_set_flag   = playlist_generic_set_flag,
	.pl_sort       = playlist_generic_sort,
};

static struct sys_playlist sys_most_played = {
	.spl_playlist = DEFINE_PLAYLIST(PL_SYSTEM, "Most Played",
					SYS_PL_MOST_PLAYED, &most_played_ops),
	.spl_init     = sys_pl_update_init,
	.spl_save     = sys_pl_save_partial,
	.spl_load     = sys_pl_load_partial,
	.spl_update   = sys_pl_most_played_update,
};


/*
 * Least played tracks playlist operations.
 */
static bool sys_pl_least_played_update(struct playlist *playlist,
				       struct track *track)
{
	unsigned int average = track_db_average_plays();
	if (!track->tr_count || track->tr_count > average)
		return false;
	return sys_pl_generic_add_front(playlist, track) || true;
}

static struct playlist_ops least_played_ops = {
	.pl_can_select = playlist_generic_can_select,
	.pl_next       = playlist_generic_next,
	.pl_set_flag   = playlist_generic_set_flag,
	.pl_sort       = playlist_generic_sort,
};

static struct sys_playlist sys_least_played = {
	.spl_playlist = DEFINE_PLAYLIST(PL_SYSTEM, "Least Played",
					SYS_PL_LEAST_PLAYED, &least_played_ops),
	.spl_init     = sys_pl_update_init,
	.spl_save     = sys_pl_save_partial,
	.spl_load     = sys_pl_load_partial,
	.spl_update   = sys_pl_least_played_update,
};


static struct sys_playlist *sys_playlists[SYS_PL_NUM_PLAYLISTS] = {
	[SYS_PL_FAVORITES]    = &sys_favorites,
	[SYS_PL_HIDDEN]       = &sys_hidden,
	[SYS_PL_QUEUED]       = &sys_queued,
	[SYS_PL_COLLECTION]   = &sys_collection,
	[SYS_PL_HISTORY]      = &sys_history,
	[SYS_PL_UNPLAYED]     = &sys_unplayed,
	[SYS_PL_MOST_PLAYED]  = &sys_most_played,
	[SYS_PL_LEAST_PLAYED] = &sys_least_played,
};


static struct sys_playlist * __sys_pl_lookup(const gchar *name)
{
	unsigned int i;

	for (i = 0; i < SYS_PL_NUM_PLAYLISTS; i++) {
		if (string_match(name, sys_playlists[i]->spl_playlist.pl_name))
			return sys_playlists[i];
	}
	return NULL;
}

static void __sys_pl_save()
{
	struct sys_playlist *sys_pl;
	unsigned int i;

	if (!file_open(&sys_pl_file, OPEN_WRITE))
		return;

	file_writef(&sys_pl_file, "%u\n", SYS_PL_NUM_PLAYLISTS);
	for (i = 0; i < SYS_PL_NUM_PLAYLISTS; i++) {
		sys_pl = sys_playlists[i];
		sys_pl->spl_save(&sys_pl->spl_playlist, &sys_pl_file);
	}

	file_close(&sys_pl_file);
}

static bool __sys_pl_update_save()
{
	__sys_pl_save();
	return true;
}

static bool __sys_pl_load_new()
{
	struct sys_playlist *sys_pl;
	unsigned int i, n;
	gchar *name;

	if (!file_open(&sys_pl_file, OPEN_READ)) {
		__sys_pl_load();
		sys_pl_collection_load();
		sys_pl_queued_load();
		__sys_pl_update_save();
		return true;
	}

	file_readf(&sys_pl_file, "%u\n", &n);
	for (i = 0; i < n; i++) {
		name   = file_readl(&sys_pl_file);
		sys_pl = __sys_pl_lookup(name);
		if (sys_pl)
			sys_pl->spl_load(&sys_pl->spl_playlist, &sys_pl_file);
		g_free(name);
	}

	file_close(&sys_pl_file);
	return true;
}

static bool __sys_pl_load()
{
	struct sys_playlist *plist;
	unsigned int i, n;
	gchar *name;

	if (!file_open(&sys_file, OPEN_READ))
		return true;

	file_readf(&sys_file, "%u\n", &n);
	for (i = 0; i < n; i++) {
		file_readf(&sys_file, "%*u %m[^\n]\n", &name);
		if (string_match(name, "Banned")) {
			g_free(name);
			name = g_strdup("Hidden");
		}

		plist = __sys_pl_lookup(name);
		if (plist)
			queue_load_tracks(&plist->spl_playlist.pl_queue, &sys_file);
		g_free(name);
	}

	file_close(&sys_file);
	file_remove(&sys_file);
	return true;
}


static void pl_system_save(void)
{
	__sys_pl_save();
}

static struct playlist *pl_system_lookup(const gchar *name)
{
	struct sys_playlist *sys_pl = __sys_pl_lookup(name);
	return sys_pl ? &sys_pl->spl_playlist : NULL;
}

static struct playlist *pl_system_get(unsigned int id)
{
	return (id < SYS_PL_NUM_PLAYLISTS) ? &sys_playlists[id]->spl_playlist : NULL;
}

static void pl_system_played(struct track *track)
{
	unsigned int i;
	for (i = 0; i < SYS_PL_NUM_PLAYLISTS; i++)
		queue_updated(&pl_system_get(i)->pl_queue, track);

	pl_system_update("Unplayed");
	pl_system_update("Most Played");
	pl_system_update("Least Played");
}

static void pl_system_update(const gchar *name)
{
	struct sys_playlist *sys_pl = __sys_pl_lookup(name);
	if (sys_pl)
		playlist_generic_update(&sys_pl->spl_playlist, sys_pl->spl_update);
}


struct playlist_type pl_system = {
	.pl_save   = pl_system_save,
	.pl_lookup = pl_system_lookup,
	.pl_get    = pl_system_get,
	.pl_played = pl_system_played,
};


void pl_system_init(struct queue_ops *ops)
{
	struct sys_playlist *sys_pl;
	unsigned int i;

	idle_schedule(IDLE_SYNC, __sys_pl_load_new, NULL);

	for (i = 0; i < SYS_PL_NUM_PLAYLISTS; i++) {
		sys_pl = sys_playlists[i];
		sys_pl->spl_init(&sys_pl->spl_playlist, 0, ops);
	}
}

void pl_system_deinit()
{
	for (unsigned int i = 0; i < SYS_PL_NUM_PLAYLISTS; i++)
		queue_deinit(&pl_system_get(i)->pl_queue);
}

void pl_system_new_track(struct track *track)
{
	playlist_generic_add_track(pl_system_lookup("Collection"), track);
	playlist_generic_add_track(pl_system_lookup("Unplayed"),   track);
}

void pl_system_delete_track(struct track *track)
{
	struct sys_playlist *sys_pl;
	unsigned int i;

	for (i = 0; i < SYS_PL_NUM_PLAYLISTS; i++) {
		sys_pl = sys_playlists[i];
		playlist_generic_remove_track(&sys_pl->spl_playlist, track);
	}
}