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

static bool pl_system_add_track(const gchar *, struct track *);
static bool pl_system_remove_track(const gchar *, struct track *);
static void pl_system_update(const gchar *);
static inline struct queue *__sys_pl_queue(enum sys_playlist_t);
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);
static struct sys_playlist *sys_playlists[SYS_PL_NUM_PLAYLISTS];


/*
 * Generic system playlist operations.
 */
static void sys_pl_generic_init(struct playlist *playlist, unsigned int flags,
				struct queue_ops *ops)
{
	playlist_generic_init(playlist, Q_REPEAT | Q_ADD_FRONT, 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(struct playlist *playlist, struct track *track)
{
	if (queue_has(__sys_pl_queue(SYS_PL_HIDDEN), track))
		return false;
	return playlist_generic_add_track(playlist, track);
}



/*
 * Favorite tracks playlist operations.
 */
static struct sys_playlist sys_favorites = {
	.spl_playlist   = DEFINE_PLAYLIST(PL_SYSTEM, "Favorites"),
	.spl_init       = playlist_generic_init,
	.spl_save       = sys_pl_save_full,
	.spl_load       = sys_pl_load_full,
	.spl_can_select = playlist_generic_can_select,
	.spl_add        = playlist_generic_add_track,
	.spl_remove     = playlist_generic_remove_track,
	.spl_clear      = playlist_generic_clear,
	.spl_set_flag   = playlist_generic_set_flag,
	.spl_sort       = playlist_generic_sort,
	.spl_next       = playlist_generic_next,
};


/*
 * Hidden tracks playlist operations.
 */
static bool sys_pl_hidden_add(struct playlist *playlist, struct track *track)
{
	bool ret = playlist_generic_add_track(playlist, track);
	pl_system_remove_track("Collection",   track);
	pl_system_remove_track("Unplayed",     track);
	pl_system_remove_track("Most Played",  track);
	pl_system_remove_track("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);
	pl_system_add_track("Collection",   track);
	pl_system_add_track("Unplayed",     track);
	pl_system_add_track("Most Played",  track);
	pl_system_add_track("Least Played", track);
	return ret;
}

static void 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);
	}
}

static struct sys_playlist sys_hidden = {
	.spl_playlist   = DEFINE_PLAYLIST(PL_SYSTEM, "Hidden"),
	.spl_init       = playlist_generic_init,
	.spl_save       = sys_pl_save_full,
	.spl_load       = sys_pl_load_full,
	.spl_can_select = playlist_generic_can_select,
	.spl_add        = sys_pl_hidden_add,
	.spl_remove     = sys_pl_hidden_remove,
	.spl_clear      = sys_pl_hidden_clear,
	.spl_set_flag   = playlist_generic_set_flag,
	.spl_sort       = playlist_generic_sort,
	.spl_next       = playlist_generic_next,
};


/*
 * Queued tracks playlist operations.
 */
static bool sys_pl_queued_load()
{
	struct playlist *playlist  = &sys_playlists[SYS_PL_QUEUED]->spl_playlist;
	struct queue    *queue     = &playlist->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_SAVE_SORT | Q_SAVE_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, Q_ENABLED, ops, playlist);
}

static struct sys_playlist sys_queued = {
	.spl_playlist   = DEFINE_PLAYLIST(PL_SYSTEM, "Queued Tracks"),
	.spl_init       = sys_pl_queued_init,
	.spl_save       = sys_pl_save_full,
	.spl_load       = sys_pl_load_full,
	.spl_can_select = playlist_generic_can_select,
	.spl_add        = playlist_generic_add_track,
	.spl_remove     = playlist_generic_remove_track,
	.spl_clear      = playlist_generic_clear,
	.spl_set_flag   = playlist_generic_set_flag,
	.spl_sort       = playlist_generic_sort,
	.spl_next       = playlist_generic_next,
};


/*
 * Collection playlist operations.
 */
static bool sys_pl_collection_load()
{
	struct playlist *playlist = &sys_playlists[SYS_PL_COLLECTION]->spl_playlist;

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

	return true;
}

static bool sys_pl_collection_can_select(struct playlist *playlist)
{
	return true;
}

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

static struct sys_playlist sys_collection = {
	.spl_playlist   = DEFINE_PLAYLIST(PL_SYSTEM, "Collection"),
	.spl_init       = sys_pl_update_init,
	.spl_save       = sys_pl_save_partial,
	.spl_load       = sys_pl_load_partial,
	.spl_can_select = sys_pl_collection_can_select,
	.spl_add        = sys_pl_generic_add,
	.spl_remove     = playlist_generic_remove_track,
	.spl_clear      = playlist_noop_clear,
	.spl_update     = sys_pl_collection_update,
	.spl_set_flag   = playlist_generic_set_flag,
	.spl_sort       = playlist_generic_sort,
	.spl_next       = playlist_generic_next,
};


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

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

static struct sys_playlist sys_history = {
	.spl_playlist   = DEFINE_PLAYLIST(PL_SYSTEM, "History"),
	.spl_init       = sys_pl_history_init,
	.spl_save       = sys_pl_save_partial,
	.spl_load       = sys_pl_load_partial,
	.spl_can_select = playlist_noop_can_select,
	.spl_add        = sys_pl_history_add,
	.spl_remove     = playlist_generic_remove_track,
	.spl_clear      = playlist_noop_clear,
	.spl_set_flag   = playlist_noop_set_flag,
	.spl_sort       = playlist_noop_sort,
	.spl_next       = playlist_generic_next,
};


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

static bool sys_pl_unplayed_update(struct playlist *playlist,
				   struct track *track)
{
	if (track->tr_count > 0)
		return false;
	return sys_pl_generic_add(playlist, track) || true;
}

static struct sys_playlist sys_unplayed = {
	.spl_playlist   = DEFINE_PLAYLIST(PL_SYSTEM, "Unplayed"),
	.spl_init       = sys_pl_update_init,
	.spl_save       = sys_pl_save_partial,
	.spl_load       = sys_pl_load_partial,
	.spl_can_select = playlist_generic_can_select,
	.spl_add        = sys_pl_unplayed_add,
	.spl_remove     = playlist_generic_remove_track,
	.spl_clear      = playlist_noop_clear,
	.spl_update     = sys_pl_unplayed_update,
	.spl_set_flag   = playlist_generic_set_flag,
	.spl_sort       = playlist_generic_sort,
	.spl_next       = playlist_generic_next,
};


/*
 * Most played tracks playlist operations.
 */
static bool sys_pl_most_played_add(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(playlist, track);
}

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(playlist, track) || true;
}

static struct sys_playlist sys_most_played = {
	.spl_playlist   = DEFINE_PLAYLIST(PL_SYSTEM, "Most Played"),
	.spl_init       = sys_pl_update_init,
	.spl_save       = sys_pl_save_partial,
	.spl_load       = sys_pl_load_partial,
	.spl_can_select = playlist_generic_can_select,
	.spl_add        = sys_pl_most_played_add,
	.spl_remove     = playlist_generic_remove_track,
	.spl_update     = sys_pl_most_played_update,
	.spl_clear      = playlist_noop_clear,
	.spl_set_flag   = playlist_generic_set_flag,
	.spl_sort       = playlist_generic_sort,
	.spl_next       = playlist_generic_next,
};


/*
 * Least played tracks playlist operations.
 */
static bool sys_pl_least_played_add(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(playlist, track);
}

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(playlist, track) || true;
}

static struct sys_playlist sys_least_played = {
	.spl_playlist   = DEFINE_PLAYLIST(PL_SYSTEM, "Least Played"),
	.spl_init       = sys_pl_update_init,
	.spl_save       = sys_pl_save_partial,
	.spl_load       = sys_pl_load_partial,
	.spl_can_select = playlist_generic_can_select,
	.spl_clear      = playlist_noop_clear,
	.spl_add        = sys_pl_least_played_add,
	.spl_remove     = playlist_generic_remove_track,
	.spl_update     = sys_pl_least_played_update,
	.spl_set_flag   = playlist_generic_set_flag,
	.spl_sort       = playlist_generic_sort,
	.spl_next       = playlist_generic_next,
};


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 inline struct queue *__sys_pl_queue(enum sys_playlist_t plist)
{
	return &sys_playlists[plist]->spl_playlist.pl_queue;
}

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 queue *pl_system_get_queue(const gchar *name)
{
	struct sys_playlist *sys_pl = __sys_pl_lookup(name);
	return sys_pl ? &sys_pl->spl_playlist.pl_queue : NULL;
}

static unsigned int pl_system_get_id(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 i;
	}
	return SYS_PL_NUM_PLAYLISTS;
}

static gchar *pl_system_get_name(unsigned int id)
{
	if (id < SYS_PL_NUM_PLAYLISTS)
		return g_strdup(sys_playlists[id]->spl_playlist.pl_name);
	return NULL;
}

static bool pl_system_can_select(const gchar *name)
{
	struct sys_playlist *sys_pl = __sys_pl_lookup(name);
	return sys_pl ? sys_pl->spl_can_select(&sys_pl->spl_playlist) : false;
}

static bool pl_system_new(const gchar *name)
{
	return false;
}

static bool pl_system_delete(const gchar *name)
{
	struct sys_playlist *sys_pl = __sys_pl_lookup(name);
	if (sys_pl) {
		sys_pl->spl_clear(&sys_pl->spl_playlist);
		__sys_pl_save();
	}
	return false; /* Don't remove the playlist from the sidebar. */
}

static bool pl_system_add_track(const gchar *name, struct track *track)
{
	struct sys_playlist *sys_pl = __sys_pl_lookup(name);
	bool ret = false;

	if (sys_pl) {
		ret = sys_pl->spl_add(&sys_pl->spl_playlist, track);
		if (ret)
			__sys_pl_save();
	}
	return ret;
}

static bool pl_system_remove_track(const gchar *name, struct track *track)
{
	struct sys_playlist *sys_pl = __sys_pl_lookup(name);
	bool ret = false;

	if (sys_pl) {
		ret = sys_pl->spl_remove(&sys_pl->spl_playlist, track);
		if (ret)
			__sys_pl_save();
	}
	return ret;
}

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);
}

static void pl_system_set_flag(const gchar *name, enum queue_flags flag,
			       bool enabled)
{
	struct sys_playlist *sys_pl = __sys_pl_lookup(name);
	if (sys_pl) {
		sys_pl->spl_set_flag(&sys_pl->spl_playlist, flag, enabled);
		__sys_pl_save();
	}
}

static void pl_system_sort(const gchar *name, enum compare_t sort, bool reset)
{
	struct sys_playlist *sys_pl = __sys_pl_lookup(name);
	if (sys_pl) {
		sys_pl->spl_sort(&sys_pl->spl_playlist, sort, reset);
		__sys_pl_save();
	}
}

static struct track *pl_system_next(const gchar *name)
{
	struct sys_playlist *sys_pl = __sys_pl_lookup(name);
	struct track *track = NULL;;
	if (sys_pl) {
		track = sys_pl->spl_next(&sys_pl->spl_playlist);
		__sys_pl_save();
	}
	return track;
}


struct playlist_type pl_system = {
	.pl_save         = pl_system_save,
	.pl_get_queue    = pl_system_get_queue,
	.pl_get_id       = pl_system_get_id,
	.pl_get_name     = pl_system_get_name,
	.pl_can_select   = pl_system_can_select,
	.pl_new          = pl_system_new,
	.pl_delete       = pl_system_delete,
	.pl_add_track    = pl_system_add_track,
	.pl_remove_track = pl_system_remove_track,
	.pl_update       = pl_system_update,
	.pl_set_flag     = pl_system_set_flag,
	.pl_sort         = pl_system_sort,
	.pl_next         = pl_system_next,
};


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, Q_REPEAT, ops);
	}
}

void pl_system_deinit()
{
	unsigned int i;

	for (i = 0; i < SYS_PL_NUM_PLAYLISTS; i++)
		queue_deinit(__sys_pl_queue(i));
}

void pl_system_new_track(struct track *track)
{
	pl_system_add_track("Collection", track);
	pl_system_add_track("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];
		sys_pl->spl_remove(&sys_pl->spl_playlist, track);
	}
}