/*
 * Copyright 2016 (c) Anna Schumaker.
 */
#include <core/idle.h>
#include <core/playlists/artist.h>
#include <core/playlists/library.h>
#include <core/playlists/system.h>
#include <core/playlists/user.h>
#include <unistd.h>

struct scan_data {
	struct library *sd_library;
	gchar          *sd_path;
};

static bool __lib_pl_scan_dir(void *);
static struct file lib_file = FILE_INIT_DATA("", "playlist.library", 0);

static struct playlist_ops pl_library_ops;


static struct playlist *__lib_pl_alloc(struct library *library)
{
	return playlist_generic_alloc(library->li_path, PL_LIBRARY,
				      library_index(library), &pl_library_ops,
				      4, COMPARE_ARTIST, COMPARE_YEAR,
					 COMPARE_ALBUM,  COMPARE_TRACK);
}

static bool __lib_pl_add(void *data)
{
	struct playlist *playlist = (struct playlist *)data;
	struct library  *library  = library_lookup(playlist->pl_name);
	struct db_entry *dbe, *next;

	db_for_each(dbe, next, track_db_get()) {
		if (TRACK(dbe)->tr_library == library)
			playlist_generic_add_front(playlist, TRACK(dbe));
	}

	playlist_generic_resort(playlist);
	return true;
}

static struct playlist *__lib_pl_lookup(const gchar *name)
{
	struct library *library  = library_lookup(name);
	return library ? library->li_playlist : NULL;
}

static bool __lib_pl_load(void *data)
{
	struct playlist *playlist;
	unsigned int i, n;
	gchar *name;

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

	n = file_readu(&lib_file);
	for (i = 0; i < n; i++) {
		name     = file_readl(&lib_file);
		playlist = __lib_pl_lookup(name);
		if (playlist)
			playlist_generic_load(playlist, &lib_file,
							 PL_SAVE_METADATA);
		g_free(name);
	}

	file_close(&lib_file);
	return true;
}

static void __lib_pl_scan_dir_idle(struct library *library, const gchar *path)
{
	struct scan_data *scan = g_malloc(sizeof(struct scan_data));

	scan->sd_library = library;
	scan->sd_path    = g_strdup(path);

	/* scan data is freed by __lib_pl_scan_dir() */
	idle_schedule(IDLE_SYNC, __lib_pl_scan_dir, scan);
}

static void __lib_pl_read_path(struct scan_data *scan, const gchar *name)
{
	gchar *path = g_build_filename(scan->sd_path, name, NULL);
	struct playlist *playlist = scan->sd_library->li_playlist;
	struct track *track;

	if (g_file_test(path, G_FILE_TEST_IS_DIR))
		__lib_pl_scan_dir_idle(scan->sd_library, path);
	else {
		track = track_add(scan->sd_library, path);
		if (track) {
			playlist_generic_add(playlist, track);
			pl_system_new_track(track);
			pl_artist_new_track(track);
		}
	}

	g_free(path);
}

static bool __lib_pl_scan_dir(void *data)
{
	struct scan_data *scan = (struct scan_data *)data;
	const gchar *name;
	GDir *dir;

	dir = g_dir_open(scan->sd_path, 0, NULL);
	if (!dir)
		goto out;

	name = g_dir_read_name(dir);
	while (name != NULL) {
		__lib_pl_read_path(scan, name);
		name = g_dir_read_name(dir);
	}

	g_dir_close(dir);
	track_db_commit();

out:
	/* Allocated by __lib_pl_scan_dir_idle() */
	g_free(scan->sd_path);
	g_free(scan);
	return true;
}

static bool __lib_pl_update(void *data)
{
	struct playlist *playlist = (struct playlist *)data;
	struct library  *library  = library_lookup(playlist->pl_name);
	struct db_entry *dbe, *next;
	gchar *path;

	db_for_each(dbe, next, track_db_get()) {
		if (TRACK(dbe)->tr_library != library)
			continue;

		path = track_path(TRACK(dbe));
		if (g_access(path, F_OK) < 0) {
			pl_system_delete_track(TRACK(dbe));
			pl_artist_delete_track(TRACK(dbe));
			playlist_generic_remove(playlist, TRACK(dbe));
			track_remove(TRACK(dbe));
		}
		g_free(path);
	}

	track_db_commit();
	__lib_pl_scan_dir_idle(library, library->li_path);
	return true;
}


static bool pl_library_delete(struct playlist *playlist)
{
	struct library *library = library_lookup(playlist->pl_name);
	playlist_iter it;

	if (!library)
		return false;

	playlist_for_each(playlist, it) {
		pl_system_delete_track(playlist_iter_track(it));
		pl_artist_delete_track(playlist_iter_track(it));
		pl_user_delete_track(playlist_iter_track(it));
	}
	playlist_generic_free(playlist);

	track_remove_all(library);
	library_remove(library);
	return true;
}


static struct playlist_ops pl_library_ops = {
	.pl_can_select = playlist_generic_can_select,
	.pl_delete     = pl_library_delete,
	.pl_set_random = playlist_generic_set_random,
	.pl_sort       = playlist_generic_sort,
	.pl_rearrange  = playlist_generic_rearrange,
};


static void pl_library_save(void)
{
	struct db_entry *dbe, *next;
	struct playlist *playlist;

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

	file_writef(&lib_file, "%u\n", library_db_get()->db_size);
	db_for_each(dbe, next, library_db_get()) {
		playlist = LIBRARY(dbe)->li_playlist;
		file_writef(&lib_file, "%s\n", playlist->pl_name);
		playlist_generic_save(playlist, &lib_file, PL_SAVE_METADATA);
	}

	file_close(&lib_file);
}

static struct playlist *pl_library_lookup(const gchar *name)
{
	return __lib_pl_lookup(name);
}

static struct playlist *pl_library_get(unsigned int id)
{
	struct library *library = LIBRARY(db_at(library_db_get(), id));
	return library ? library->li_playlist : NULL;
}

static struct playlist *pl_library_new(const gchar *name)
{
	struct library *library;

	if (__lib_pl_lookup(name) || !g_file_test(name, G_FILE_TEST_IS_DIR))
		return NULL;

	library = library_find(name);
	library->li_playlist = __lib_pl_alloc(library);

	__lib_pl_scan_dir_idle(library, name);
	return library->li_playlist;
}

static void pl_library_played(struct track *track)
{
	struct library *library = track->tr_library;
	playlist_generic_update(library->li_playlist, track);
}


struct playlist_type pl_library = {
	.pl_save     = pl_library_save,
	.pl_lookup   = pl_library_lookup,
	.pl_get      = pl_library_get,
	.pl_new      = pl_library_new,
	.pl_played   = pl_library_played,
	.pl_selected = pl_library_played,
};


void pl_library_init(void)
{
	struct db_entry *dbe, *next;
	struct playlist *playlist;

	db_for_each(dbe, next, library_db_get()) {
		playlist = __lib_pl_alloc(LIBRARY(dbe));
		LIBRARY(dbe)->li_playlist = playlist;

		idle_schedule(IDLE_SYNC, __lib_pl_add,    playlist);
		idle_schedule(IDLE_SYNC, __lib_pl_update, playlist);
	}

	idle_schedule(IDLE_SYNC, __lib_pl_load, NULL);
}

void pl_library_deinit()
{
	struct db_entry *dbe, *next;

	db_for_each(dbe, next, library_db_get()) {
		playlist_generic_free(LIBRARY(dbe)->li_playlist);
		LIBRARY(dbe)->li_playlist = NULL;
	}
}

void pl_library_update(struct playlist *playlist)
{
	idle_schedule(IDLE_SYNC, __lib_pl_update, playlist);
}