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

static struct playlist_callbacks *callbacks = NULL;


static int __playlist_generic_find_sort(gconstpointer a, gconstpointer b)
{
	return abs(GPOINTER_TO_INT(a)) - abs(GPOINTER_TO_INT(b));
}

static int __playlist_generic_less_than(gconstpointer a, gconstpointer b,
					gpointer data)
{
	struct track *lhs = (struct track *)a;
	struct track *rhs = (struct track *)b;
	GSList *cur = ((struct playlist *)data)->pl_sort;
	int res, field;

	while (cur) {
		field = GPOINTER_TO_INT(cur->data);
		res   = track_compare(lhs, rhs, abs(field));
		if (res != 0)
			break;
		cur = g_slist_next(cur);
	};

	return (field > 0) ? res : -res;
}


void playlist_generic_set_callbacks(struct playlist_callbacks *cb)
{
	callbacks = cb;
}

void playlist_generic_init(struct playlist *playlist)
{
	if (playlist) {
		g_queue_init(&playlist->pl_tracks);
		playlist->pl_sort    = NULL;
		playlist->pl_current = NULL;
		playlist->pl_search  = NULL;
	}
}

void playlist_generic_init_sorted(struct playlist  *playlist)
{
	if (playlist) {
		playlist_generic_init(playlist);
		playlist_generic_sort(playlist, COMPARE_ARTIST);
		playlist_generic_sort(playlist, COMPARE_YEAR);
		playlist_generic_sort(playlist, COMPARE_TRACK);
	}
}

void playlist_generic_deinit(struct playlist *playlist)
{
	if (playlist) {
		playlist_generic_clear(playlist);
		playlist_clear_sort(playlist);
		g_strfreev(playlist->pl_search);
		playlist->pl_search = NULL;
		playlist->pl_length = 0;
	}
}

struct playlist *playlist_generic_alloc(gchar *name, enum playlist_type_t type,
					unsigned int id, struct playlist_ops *ops)
{
	struct playlist *playlist = g_malloc(sizeof(struct playlist));

	playlist->pl_name = name;
	playlist->pl_type = type;
	playlist->pl_id   = id;
	playlist->pl_ops  = ops;

	playlist_generic_init_sorted(playlist);
	if (callbacks)
		callbacks->pl_cb_alloc(playlist);
	return playlist;
}

void playlist_generic_free(struct playlist *playlist)
{
	if (playlist) {
		playlist_generic_deinit(playlist);
		g_free(playlist);
	}
}

void playlist_generic_save(struct playlist *playlist, struct file *file,
			   unsigned int flags)
{
	playlist_iter it;
	GSList *sort;
	int field;

	if (!playlist)
		return;

	if (flags & PL_SAVE_ITER)
		file_writef(file, "%u ", playlist_current_index(playlist));

	if (flags & PL_SAVE_FLAGS) {
		sort = playlist->pl_sort;
		file_writef(file, "%u ", playlist->pl_random ? PL_RANDOM : 0);
		file_writef(file, "%u",  g_slist_length(sort));
		while (sort) {
			field = GPOINTER_TO_INT(sort->data);
			file_writef(file, " %u %d", abs(field) - 1, field > 0);
			sort = g_slist_next(sort);
		}
		file_writef(file, "\n");
	}

	if (flags & PL_SAVE_TRACKS) {
		file_writef(file, "%u", playlist_size(playlist));
		playlist_for_each(playlist, it)
			file_writef(file, " %u",
					track_index(playlist_iter_track(it)));
		file_writef(file, "\n");
	}
}

void playlist_generic_load(struct playlist *playlist, struct file *file,
			   unsigned int flags)
{
	unsigned int f, n, i, t, it = 0;
	int field, ascending;
	gchar  *line;

	if (!playlist)
		return;

	if (flags & PL_SAVE_ITER)
		file_readf(file, "%u", &it);

	if (flags & PL_SAVE_FLAGS) {
		file_readf(file, "%u %u", &f, &n);
		playlist_clear_sort(playlist);
		for (i = 0; i < n; i++) {
			file_readf(file, "%u %d", &field, &ascending);
			field += 1;
			if (!ascending)
				field = -field;
			playlist->pl_sort = g_slist_append(playlist->pl_sort,
							GINT_TO_POINTER(field));
		}
		playlist_generic_resort(playlist);

		if (file_readf(file, "%m\n", &line))
			g_free(line);
	}

	if (flags & PL_SAVE_TRACKS) {
		file_readf(file, "%u ", &n);
		for (i = 0; i < n; i++) {
			file_readf(file, "%u", &t);
			playlist_generic_add(playlist, track_get(t));
		}
		if (file_readf(file, "%m\n", &line))
			g_free(line);
	}

	playlist_generic_set_random(playlist, f == PL_RANDOM);
	playlist_current_set(playlist, it);
}

bool playlist_generic_can_select(struct playlist *playlist)
{
	return playlist_size(playlist) > 0;
}

void playlist_generic_clear(struct playlist *playlist)
{
	unsigned int n;

	if (!playlist)
		return;

	n = playlist_size(playlist);
	g_queue_clear(&playlist->pl_tracks);
	playlist->pl_length  = 0;
	playlist->pl_current = NULL;
	if (callbacks)
		callbacks->pl_cb_removed(playlist, NULL, n);
}

bool playlist_generic_add(struct playlist *playlist, struct track *track)
{
	if (!playlist || !track || playlist_has(playlist, track))
		return false;

	playlist->pl_length += track->tr_length;
	if (playlist->pl_sort) {
		g_queue_insert_sorted(&playlist->pl_tracks, track,
				     __playlist_generic_less_than, playlist);
	} else
		g_queue_push_tail(&playlist->pl_tracks, track);

	if (callbacks)
		callbacks->pl_cb_added(playlist, track);
	return true;
}

bool playlist_generic_add_front(struct playlist *playlist, struct track *track)
{
	if (!playlist || !track)
		return false;

	playlist->pl_length += track->tr_length;
	g_queue_push_head(&playlist->pl_tracks, track);
	if (callbacks)
		callbacks->pl_cb_added(playlist, track);
	return true;
}

bool playlist_generic_remove(struct playlist *playlist, struct track *track)
{
	unsigned int count;

	if (!playlist || !track)
		return false;

	while (playlist_current_track(playlist) == track)
		playlist_current_previous(playlist);

	count = g_queue_remove_all(&playlist->pl_tracks, track);
	playlist->pl_length -= (count * track->tr_length);

	if (callbacks)
		callbacks->pl_cb_removed(playlist, track, count);
	return count > 0;
}

void playlist_generic_update(struct playlist *playlist, struct track *track)
{
	if (playlist && callbacks)
		callbacks->pl_cb_updated(playlist, track);
}

void playlist_generic_set_random(struct playlist *playlist, bool enabled)
{
	playlist->pl_random = enabled;
}

void playlist_generic_sort(struct playlist *playlist, enum compare_t field)
{
	gpointer sort  = GINT_TO_POINTER(field);
	GSList  *found = g_slist_find_custom(playlist->pl_sort, sort,
					   __playlist_generic_find_sort);

	if (found)
		found->data = GINT_TO_POINTER(-field);
	else
		playlist->pl_sort = g_slist_append(playlist->pl_sort, sort);

	playlist_generic_resort(playlist);
}

void playlist_generic_resort(struct playlist *playlist)
{
	if (!playlist || !playlist->pl_sort)
		return;

	g_queue_sort(&playlist->pl_tracks, __playlist_generic_less_than, playlist);
	playlist_generic_update(playlist, NULL);
}

struct track *playlist_generic_next(struct playlist *playlist)
{
	unsigned int pos, size = playlist_size(playlist);

	if (size == 0)
		return NULL;
	else if (playlist->pl_random) {
		pos  = playlist_current_index(playlist);
		pos += g_random_int_range(1, size);
		playlist_current_set(playlist, pos % size);
	} else if (!playlist_current_next(playlist))
		playlist_current_set(playlist, 0);

	return playlist_current_track(playlist);
}