aboutsummaryrefslogtreecommitdiffstats
path: root/src/playlist.c
blob: 2eecc3beab9576c6cf682460183bdfb781dcbee6 (plain) (blame)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
813
814
815
816
817
818
819
820
821
822
823
824
825
826
827
828
829
830
831
832
833
834
835
836
837
838
839
840
841
842
843
844
845
846
847
848
849
850
851
852
853
854
855
856
857
858
859
860
861
862
863
864
865
866
867
868
869
870
871
872
873
874
875
876
877
878
879
880
881
882
883
884
885
886
887
888
889
890
891
892
893
894
895
896
897
898
899
900
901
902
903
904
905
906
907
908
909
910
911
912
913
914
915
916
917
918
919
920
921
922
923
924
925
926
927
928
929
930
931
932
933
934
935
936
937
938
939
940
941
942
943
944
945
946
947
948
949
950
951
952
953
954
955
956
957
958
959
960
961
962
963
964
965
966
967
968
969
970
971
972
973
974
975
976
977
978
979
980
981
982
983
984
985
986
987
988
989
990
991
992
993
994
995
996
997
998
999
1000
1001
1002
1003
1004
1005
1006
1007
1008
1009
1010
1011
1012
1013
1014
1015
1016
1017
1018
1019
1020
1021
1022
1023
1024
1025
1026
1027
1028
1029
1030
1031
1032
1033
1034
1035
1036
1037
1038
1039
1040
1041
1042
1043
1044
1045
1046
1047
1048
1049
1050
1051
1052
1053
1054
1055
1056
1057
1058
1059
1060
1061
1062
1063
1064
1065
1066
1067
1068
1069
1070
1071
1072
1073
1074
1075
1076
1077
1078
1079
1080
1081
1082
1083
1084
1085
1086
1087
1088
1089
1090
1091
1092
1093
1094
1095
1096
1097
1098
1099
1100
1101
1102
1103
1104
1105
1106
1107
1108
1109
1110
1111
1112
1113
1114
1115
1116
1117
1118
1119
1120
1121
1122
1123
1124
1125
1126
1127
1128
1129
1130
1131
1132
1133
1134
1135
1136
1137
1138
1139
1140
1141
1142
1143
1144
1145
1146
1147
1148
1149
1150
1151
1152
1153
1154
1155
1156
1157
1158
1159
1160
1161
1162
1163
1164
1165
1166
1167
1168
1169
1170
1171
1172
1173
1174
1175
1176
1177
1178
1179
1180
1181
1182
1183
/* the Music Player Daemon (MPD)
 * Copyright (C) 2003-2007 by Warren Dukes (warren.dukes@gmail.com)
 * This project's homepage is: http://www.musicpd.org
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
 */

#include "playlist.h"
#include "playlist_save.h"
#include "queue_print.h"
#include "queue_save.h"
#include "locate.h"
#include "player_control.h"
#include "command.h"
#include "ls.h"
#include "tag.h"
#include "song.h"
#include "conf.h"
#include "database.h"
#include "mapper.h"
#include "path.h"
#include "stored_playlist.h"
#include "ack.h"
#include "idle.h"
#include "event_pipe.h"

#include <glib.h>

#include <assert.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <unistd.h>
#include <stdlib.h>
#include <errno.h>

/**
 * When the "prev" command is received, rewind the current track if
 * this number of seconds has already elapsed.
 */
#define PLAYLIST_PREV_UNLESS_ELAPSED    10

#define PLAYLIST_STATE_FILE_STATE		"state: "
#define PLAYLIST_STATE_FILE_RANDOM		"random: "
#define PLAYLIST_STATE_FILE_REPEAT		"repeat: "
#define PLAYLIST_STATE_FILE_CURRENT		"current: "
#define PLAYLIST_STATE_FILE_TIME		"time: "
#define PLAYLIST_STATE_FILE_CROSSFADE		"crossfade: "
#define PLAYLIST_STATE_FILE_PLAYLIST_BEGIN	"playlist_begin"
#define PLAYLIST_STATE_FILE_PLAYLIST_END	"playlist_end"

#define PLAYLIST_STATE_FILE_STATE_PLAY		"play"
#define PLAYLIST_STATE_FILE_STATE_PAUSE		"pause"
#define PLAYLIST_STATE_FILE_STATE_STOP		"stop"

#define PLAYLIST_BUFFER_SIZE	2*MPD_PATH_MAX

#define PLAYLIST_HASH_MULT	4

/** random number generator fur shuffling */
static GRand *g_rand;

/** the global playlist object */
static struct playlist playlist;

static void playPlaylistOrderNumber(int orderNum);

static void incrPlaylistVersion(void)
{
	queue_increment_version(&playlist.queue);

	idle_add(IDLE_PLAYLIST);
}

void playlistVersionChange(void)
{
	queue_modify_all(&playlist.queue);
	idle_add(IDLE_PLAYLIST);
}

static void
playlist_tag_event(void)
{
	if (!playlist.playing)
		return;

	assert(playlist.current >= 0);

	queue_modify(&playlist.queue, playlist.current);
	idle_add(IDLE_PLAYLIST);
}

void initPlaylist(void)
{
	g_rand = g_rand_new();

	queue_init(&playlist.queue,
		   config_get_positive(CONF_MAX_PLAYLIST_LENGTH,
				       DEFAULT_PLAYLIST_MAX_LENGTH));

	playlist.queued = -1;
	playlist.current = -1;

	event_pipe_register(PIPE_EVENT_TAG, playlist_tag_event);
}

void finishPlaylist(void)
{
	queue_finish(&playlist.queue);

	g_rand_free(g_rand);
	g_rand = NULL;
}

const struct queue *
playlist_get_queue(void)
{
	return &playlist.queue;
}

void clearPlaylist(void)
{
	stopPlaylist();

	/* make sure there are no references to allocated songs
	   anymore */
	for (unsigned i = 0; i < queue_length(&playlist.queue); i++) {
		const struct song *song = queue_get(&playlist.queue, i);
		if (!song_in_database(song))
			pc_song_deleted(song);
	}

	queue_clear(&playlist.queue);

	playlist.current = -1;

	incrPlaylistVersion();
}

void savePlaylistState(FILE *fp)
{
	fprintf(fp, "%s", PLAYLIST_STATE_FILE_STATE);

	if (playlist.playing) {
		switch (getPlayerState()) {
		case PLAYER_STATE_PAUSE:
			fprintf(fp, "%s\n", PLAYLIST_STATE_FILE_STATE_PAUSE);
			break;
		default:
			fprintf(fp, "%s\n", PLAYLIST_STATE_FILE_STATE_PLAY);
		}
		fprintf(fp, "%s%i\n", PLAYLIST_STATE_FILE_CURRENT,
			queue_order_to_position(&playlist.queue,
						playlist.current));
		fprintf(fp, "%s%i\n", PLAYLIST_STATE_FILE_TIME,
		        getPlayerElapsedTime());
	} else
		fprintf(fp, "%s\n", PLAYLIST_STATE_FILE_STATE_STOP);

	fprintf(fp, "%s%i\n", PLAYLIST_STATE_FILE_RANDOM,
		playlist.queue.random);
	fprintf(fp, "%s%i\n", PLAYLIST_STATE_FILE_REPEAT,
		playlist.queue.repeat);
	fprintf(fp, "%s%i\n", PLAYLIST_STATE_FILE_CROSSFADE,
	        (int)(getPlayerCrossFade()));
	fprintf(fp, "%s\n", PLAYLIST_STATE_FILE_PLAYLIST_BEGIN);
	queue_save(fp, &playlist.queue);
	fprintf(fp, "%s\n", PLAYLIST_STATE_FILE_PLAYLIST_END);
}

static void loadPlaylistFromStateFile(FILE *fp, char *buffer,
				      int state, int current, int seek_time)
{
	int song;

	if (!fgets(buffer, PLAYLIST_BUFFER_SIZE, fp)) {
		g_warning("No playlist in state file");
		return;
	}

	while (!g_str_has_prefix(buffer, PLAYLIST_STATE_FILE_PLAYLIST_END)) {
		g_strchomp(buffer);

		song = queue_load_song(&playlist.queue, buffer);
		if (song >= 0 && song == current) {
			if (state != PLAYER_STATE_STOP) {
				playPlaylist(queue_length(&playlist.queue) - 1);
			}
			if (state == PLAYER_STATE_PAUSE) {
				playerPause();
			}
			if (state != PLAYER_STATE_STOP) {
				seekSongInPlaylist(queue_length(&playlist.queue) - 1,
						   seek_time);
			}
		}

		if (!fgets(buffer, PLAYLIST_BUFFER_SIZE, fp)) {
			g_warning("'%s' not found in state file",
				  PLAYLIST_STATE_FILE_PLAYLIST_END);
			break;
		}
	}
}

void readPlaylistState(FILE *fp)
{
	int current = -1;
	int seek_time = 0;
	int state = PLAYER_STATE_STOP;
	char buffer[PLAYLIST_BUFFER_SIZE];
	bool random_mode = false;

	while (fgets(buffer, sizeof(buffer), fp)) {
		g_strchomp(buffer);

		if (g_str_has_prefix(buffer, PLAYLIST_STATE_FILE_STATE)) {
			if (strcmp(&(buffer[strlen(PLAYLIST_STATE_FILE_STATE)]),
				   PLAYLIST_STATE_FILE_STATE_PLAY) == 0) {
				state = PLAYER_STATE_PLAY;
			} else
			    if (strcmp
				(&(buffer[strlen(PLAYLIST_STATE_FILE_STATE)]),
				 PLAYLIST_STATE_FILE_STATE_PAUSE)
				== 0) {
				state = PLAYER_STATE_PAUSE;
			}
		} else if (g_str_has_prefix(buffer, PLAYLIST_STATE_FILE_TIME)) {
			seek_time =
			    atoi(&(buffer[strlen(PLAYLIST_STATE_FILE_TIME)]));
		} else
		    if (g_str_has_prefix(buffer, PLAYLIST_STATE_FILE_REPEAT)) {
			if (strcmp
			    (&(buffer[strlen(PLAYLIST_STATE_FILE_REPEAT)]),
			     "1") == 0) {
				setPlaylistRepeatStatus(true);
			} else
				setPlaylistRepeatStatus(false);
		} else if (g_str_has_prefix(buffer, PLAYLIST_STATE_FILE_CROSSFADE)) {
			setPlayerCrossFade(atoi
					   (&
					    (buffer
					     [strlen
					      (PLAYLIST_STATE_FILE_CROSSFADE)])));
		} else if (g_str_has_prefix(buffer, PLAYLIST_STATE_FILE_RANDOM)) {
			random_mode =
				strcmp(buffer + strlen(PLAYLIST_STATE_FILE_RANDOM),
				       "1") == 0;
		} else if (g_str_has_prefix(buffer, PLAYLIST_STATE_FILE_CURRENT)) {
			current = atoi(&(buffer
					 [strlen
					  (PLAYLIST_STATE_FILE_CURRENT)]));
		} else if (g_str_has_prefix(buffer,
					    PLAYLIST_STATE_FILE_PLAYLIST_BEGIN)) {
			if (state == PLAYER_STATE_STOP)
				current = -1;
			loadPlaylistFromStateFile(fp, buffer, state,
						  current, seek_time);
		}
	}

	setPlaylistRandomStatus(random_mode);
}

/**
 * Queue a song, addressed by its order number.
 */
static void
playlist_queue_song_order(unsigned order)
{
	struct song *song;
	char *uri;

	assert(queue_valid_order(&playlist.queue, order));

	playlist.queued = order;

	song = queue_get_order(&playlist.queue, order);
	uri = song_get_uri(song);
	g_debug("playlist: queue song %i:\"%s\"",
		playlist.queued, uri);
	g_free(uri);

	queueSong(song);
}

/*
 * Queue the song following after the current one.  If no song is
 * played currently, start with the first song.
 */
static void queueNextSongInPlaylist(void)
{
	assert(playlist.queued < 0);

	if (playlist.current + 1 < (int)queue_length(&playlist.queue)) {
		playlist_queue_song_order(playlist.current + 1);
	} else if (!queue_is_empty(&playlist.queue) && playlist.queue.repeat) {
		/* end of queue: restart at the first song in repeat
		   mode */

		if (playlist.queue.random) {
			/* shuffle the song order again, so we get a
			   different order each time the playlist is
			   played completely */

			unsigned current_position =
				queue_order_to_position(&playlist.queue,
							playlist.current);
			queue_shuffle_order(&playlist.queue);

			/* make sure that the playlist.current still
			   points to the current song, after the song
			   order has been shuffled */
			playlist.current =
				queue_position_to_order(&playlist.queue,
							current_position);
		}

		playlist_queue_song_order(0);
	}
}

/**
 * Check if the player thread has already started playing the "queued"
 * song.
 */
static void syncPlaylistWithQueue(void)
{
	if (pc.next_song == NULL && playlist.queued != -1) {
		/* queued song has started: copy queued to current,
		   and notify the clients */

		playlist.current = playlist.queued;
		playlist.queued = -1;

		idle_add(IDLE_PLAYER);
	}
}

/**
 * Clears the currently queued song, and tells the player thread to
 * abort pre-decoding it.
 */
static void clearPlayerQueue(void)
{
	assert(playlist.queued >= 0);

	playlist.queued = -1;

	pc_cancel();
}

#ifndef WIN32
enum playlist_result
playlist_append_file(const char *path, int uid, unsigned *added_id)
{
	int ret;
	struct stat st;
	struct song *song;

	if (uid <= 0)
		/* unauthenticated client */
		return PLAYLIST_RESULT_DENIED;

	ret = stat(path, &st);
	if (ret < 0)
		return PLAYLIST_RESULT_ERRNO;

	if (st.st_uid != (uid_t)uid && (st.st_mode & 0444) != 0444)
		/* client is not owner */
		return PLAYLIST_RESULT_DENIED;

	song = song_file_load(path, NULL);
	if (song == NULL)
		return PLAYLIST_RESULT_NO_SUCH_SONG;

	return addSongToPlaylist(song, added_id);
}
#endif

static struct song *
song_by_url(const char *url)
{
	struct song *song;

	song = db_get_song(url);
	if (song != NULL)
		return song;

	if (uri_has_scheme(url))
		return song_remote_new(url);

	return NULL;
}

enum playlist_result addToPlaylist(const char *url, unsigned *added_id)
{
	struct song *song;

	g_debug("add to playlist: %s", url);

	song = song_by_url(url);
	if (song == NULL)
		return PLAYLIST_RESULT_NO_SUCH_SONG;

	return addSongToPlaylist(song, added_id);
}

enum playlist_result
addSongToPlaylist(struct song *song, unsigned *added_id)
{
	unsigned id;

	if (queue_is_full(&playlist.queue))
		return PLAYLIST_RESULT_TOO_LARGE;

	if (playlist.playing && playlist.queued >= 0 &&
	    playlist.current == (int)queue_length(&playlist.queue) - 1)
		/* currently, we are playing the last song in the
		   queue - the new song will be the new "queued song",
		   so we have to clear the old queued song first */
		clearPlayerQueue();

	id = queue_append(&playlist.queue, song);

	if (playlist.queue.random) {
		/* shuffle the new song into the list of remaining
		   songs to play */

		unsigned start;
		if (playlist.queued >= 0)
			start = playlist.queued + 1;
		else
			start = playlist.current + 1;
		if (start < queue_length(&playlist.queue)) {
			unsigned swap = g_rand_int_range(g_rand, start,
							 queue_length(&playlist.queue));
			queue_swap_order(&playlist.queue,
					 queue_length(&playlist.queue) - 1, swap);
		}
	}

	incrPlaylistVersion();

	if (added_id)
		*added_id = id;

	return PLAYLIST_RESULT_SUCCESS;
}

enum playlist_result swapSongsInPlaylist(unsigned song1, unsigned song2)
{
	if (!queue_valid_position(&playlist.queue, song1) ||
	    !queue_valid_position(&playlist.queue, song2))
		return PLAYLIST_RESULT_BAD_RANGE;

	if (playlist.playing && playlist.queued >= 0) {
		/* if song1 or song2 equals to the current or the
		   queued song, we must clear the player queue,
		   because the swap will result in a different
		   "queued" song */

		unsigned queuedSong = queue_order_to_position(&playlist.queue,
							      playlist.queued);
		unsigned currentSong = queue_order_to_position(&playlist.queue,
							       playlist.current);

		if (queuedSong == song1 || queuedSong == song2
		    || currentSong == song1 || currentSong == song2)
			clearPlayerQueue();
	}

	queue_swap(&playlist.queue, song1, song2);

	if (playlist.queue.random) {
		/* update the queue order, so that playlist.current
		   still points to the current song order */

		queue_swap_order(&playlist.queue,
				 queue_position_to_order(&playlist.queue,
							 song1),
				 queue_position_to_order(&playlist.queue,
							 song2));
	} else {
		/* correct the "current" song order */

		if (playlist.current == (int)song1)
			playlist.current = song2;
		else if (playlist.current == (int)song2)
			playlist.current = song1;
	}

	incrPlaylistVersion();

	return PLAYLIST_RESULT_SUCCESS;
}

enum playlist_result swapSongsInPlaylistById(unsigned id1, unsigned id2)
{
	int song1 = queue_id_to_position(&playlist.queue, id1);
	int song2 = queue_id_to_position(&playlist.queue, id2);

	if (song1 < 0 || song2 < 0)
		return PLAYLIST_RESULT_NO_SUCH_SONG;

	return swapSongsInPlaylist(song1, song2);
}

enum playlist_result deleteFromPlaylist(unsigned song)
{
	unsigned songOrder;

	if (song >= queue_length(&playlist.queue))
		return PLAYLIST_RESULT_BAD_RANGE;

	songOrder = queue_position_to_order(&playlist.queue, song);

	if (playlist.playing && playlist.queued >= 0
	    && (playlist.queued == (int)songOrder ||
		playlist.current == (int)songOrder))
		/* deleting the current or the queued song: clear the
		   queue, because this function will result in a
		   different "queued" song */
		clearPlayerQueue();

	if (playlist.playing && playlist.current == (int)songOrder) {
		bool paused = getPlayerState() == PLAYER_STATE_PAUSE;

		/* the current song is going to be deleted: stop the player */

		playerWait();

		/* see which song is going to be played instead */

		playlist.current = queue_next_order(&playlist.queue,
						    playlist.current);
		if (playlist.current == (int)songOrder)
			playlist.current = -1;

		if (playlist.current >= 0 && !paused)
			/* play the song after the deleted one */
			playPlaylistOrderNumber(playlist.current);
		else
			/* no songs left to play, stop playback
			   completely */
			stopPlaylist();
	}

	/* now do it: remove the song */

	if (!song_in_database(queue_get(&playlist.queue, song)))
		pc_song_deleted(queue_get(&playlist.queue, song));

	queue_delete(&playlist.queue, song);

	incrPlaylistVersion();

	/* update the "current" and "queued" variables */

	if (playlist.current > (int)songOrder) {
		playlist.current--;
	}

	if (playlist.queued > (int)songOrder) {
		playlist.queued--;
	}

	return PLAYLIST_RESULT_SUCCESS;
}

enum playlist_result deleteFromPlaylistById(unsigned id)
{
	int song = queue_id_to_position(&playlist.queue, id);
	if (song < 0)
		return PLAYLIST_RESULT_NO_SUCH_SONG;

	return deleteFromPlaylist(song);
}

void
deleteASongFromPlaylist(const struct song *song)
{
	for (int i = queue_length(&playlist.queue) - 1; i >= 0; --i)
		if (song == queue_get(&playlist.queue, i))
			deleteFromPlaylist(i);

	pc_song_deleted(song);
}

void stopPlaylist(void)
{
	if (!playlist.playing)
		return;

	assert(playlist.current >= 0);

	g_debug("playlist: stop");
	playerWait();
	playlist.queued = -1;
	playlist.playing = false;

	if (playlist.queue.random) {
		/* shuffle the playlist, so the next playback will
		   result in a new random order */

		unsigned current_position =
			queue_order_to_position(&playlist.queue,
						playlist.current);

		queue_shuffle_order(&playlist.queue);

		/* make sure that "current" stays valid, and the next
		   "play" command plays the same song again */
		playlist.current =
			queue_position_to_order(&playlist.queue,
						current_position);
	}
}

static void playPlaylistOrderNumber(int orderNum)
{
	struct song *song;
	char *uri;

	playlist.playing = true;
	playlist.queued = -1;

	song = queue_get_order(&playlist.queue, orderNum);

	uri = song_get_uri(song);
	g_debug("playlist: play %i:\"%s\"", orderNum, uri);
	g_free(uri);

	playerPlay(song);
	playlist.current = orderNum;
}

enum playlist_result playPlaylist(int song)
{
	unsigned i = song;

	clearPlayerError();

	if (song == -1) {
		/* play any song ("current" song, or the first song */

		if (queue_is_empty(&playlist.queue))
			return PLAYLIST_RESULT_SUCCESS;

		if (playlist.playing) {
			/* already playing: unpause playback, just in
			   case it was paused, and return */
			playerSetPause(0);
			return PLAYLIST_RESULT_SUCCESS;
		}

		/* select a song: "current" song, or the first one */
		i = playlist.current >= 0
			? playlist.current
			: 0;
	} else if (!queue_valid_position(&playlist.queue, song))
		return PLAYLIST_RESULT_BAD_RANGE;

	if (playlist.queue.random) {
		if (song >= 0)
			/* "i" is currently the song position (which
			   would be equal to the order number in
			   no-random mode); convert it to a order
			   number, because random mode is enabled */
			i = queue_position_to_order(&playlist.queue, song);

		if (!playlist.playing)
			playlist.current = 0;

		/* swap the new song with the previous "current" one,
		   so playback continues as planned */
		queue_swap_order(&playlist.queue,
				 i, playlist.current);
		i = playlist.current;
	}

	playlist.stop_on_error = false;
	playlist.error_count = 0;

	playPlaylistOrderNumber(i);
	return PLAYLIST_RESULT_SUCCESS;
}

enum playlist_result playPlaylistById(int id)
{
	int song;

	if (id == -1) {
		return playPlaylist(id);
	}

	song = queue_id_to_position(&playlist.queue, id);
	if (song < 0)
		return PLAYLIST_RESULT_NO_SUCH_SONG;

	return playPlaylist(song);
}

static void playPlaylistIfPlayerStopped(void);

/**
 * This is the "PLAYLIST" event handler.  It is invoked by the player
 * thread whenever it requests a new queued song, or when it exits.
 */
void syncPlayerAndPlaylist(void)
{
	if (!playlist.playing)
		/* this event has reached us out of sync: we aren't
		   playing anymore; ignore the event */
		return;

	if (getPlayerState() == PLAYER_STATE_STOP)
		/* the player thread has stopped: check if playback
		   should be restarted with the next song.  That can
		   happen if the playlist isn't filling the queue fast
		   enough */
		playPlaylistIfPlayerStopped();
	else {
		/* check if the player thread has already started
		   playing the queued song */
		syncPlaylistWithQueue();

		/* make sure the queued song is always set (if
		   possible) */
		if (pc.next_song == NULL)
			queueNextSongInPlaylist();
	}
}

void nextSongInPlaylist(void)
{
	int next_order;

	if (!playlist.playing)
		return;

	assert(!queue_is_empty(&playlist.queue));
	assert(queue_valid_order(&playlist.queue, playlist.current));

	syncPlaylistWithQueue();

	playlist.stop_on_error = false;

	/* determine the next song from the queue's order list */

	next_order = queue_next_order(&playlist.queue, playlist.current);
	if (next_order < 0) {
		/* no song after this one: stop playback */
		stopPlaylist();
		return;
	}

	if (next_order == 0 && playlist.queue.random) {
		/* The queue told us that the next song is the first
		   song.  This means we are in repeat mode.  Shuffle
		   the queue order, so this time, the user hears the
		   songs in a different than before */
		assert(playlist.queue.repeat);

		queue_shuffle_order(&playlist.queue);

		/* note that playlist.current and playlist.queued are
		   now invalid, but playPlaylistOrderNumber() will
		   discard them anyway */
	}

	playPlaylistOrderNumber(next_order);
}

/**
 * The player has stopped for some reason.  Check the error, and
 * decide whether to re-start playback
 */
static void playPlaylistIfPlayerStopped(void)
{
	enum player_error error;

	assert(playlist.playing);
	assert(getPlayerState() == PLAYER_STATE_STOP);

	error = getPlayerError();
	if (error == PLAYER_ERROR_NOERROR)
		playlist.error_count = 0;
	else
		++playlist.error_count;

	if ((playlist.stop_on_error && error != PLAYER_ERROR_NOERROR) ||
	    error == PLAYER_ERROR_AUDIO || error == PLAYER_ERROR_SYSTEM ||
	    playlist.error_count >= queue_length(&playlist.queue))
		/* too many errors, or critical error: stop
		   playback */
		stopPlaylist();
	else
		/* continue playback at the next song */
		nextSongInPlaylist();
}

bool getPlaylistRepeatStatus(void)
{
	return playlist.queue.repeat;
}

bool getPlaylistRandomStatus(void)
{
	return playlist.queue.random;
}

void setPlaylistRepeatStatus(bool status)
{
	if (status == playlist.queue.repeat)
		return;

	if (playlist.playing &&
	    playlist.queue.repeat && playlist.queued == 0)
		/* repeat mode will be switched off now - tell the
		   player thread not to play the first song again */
		clearPlayerQueue();

	playlist.queue.repeat = status;

	idle_add(IDLE_OPTIONS);
}

enum playlist_result moveSongInPlaylist(unsigned from, int to)
{
	int currentSong;

	if (!queue_valid_position(&playlist.queue, from))
		return PLAYLIST_RESULT_BAD_RANGE;

	if ((to >= 0 && to >= (int)queue_length(&playlist.queue)) ||
	    (to < 0 && abs(to) > (int)queue_length(&playlist.queue)))
		return PLAYLIST_RESULT_BAD_RANGE;

	if ((int)from == to) /* no-op */
		return PLAYLIST_RESULT_SUCCESS;

	/*
	 * (to < 0) => move to offset from current song
	 * (-playlist.length == to) => move to position BEFORE current song
	 */
	currentSong = playlist.current >= 0
		? (int)queue_order_to_position(&playlist.queue,
					      playlist.current)
		: -1;
	if (to < 0 && playlist.current >= 0) {
		if ((unsigned)currentSong == from)
			/* no-op, can't be moved to offset of itself */
			return PLAYLIST_RESULT_SUCCESS;
		to = (currentSong + abs(to)) % queue_length(&playlist.queue);
	}

	if (playlist.playing && playlist.queued >= 0) {
		int queuedSong = queue_order_to_position(&playlist.queue,
							 playlist.queued);
		if (queuedSong == (int)from || queuedSong == to
		    || currentSong == (int)from || currentSong == to)
			clearPlayerQueue();
	}

	queue_move(&playlist.queue, from, to);

	if (!playlist.queue.random) {
		/* update current/queued */
		if (playlist.current == (int)from)
			playlist.current = to;
		else if (playlist.current > (int)from &&
			 playlist.current <= to) {
			playlist.current--;
		} else if (playlist.current >= to &&
			   playlist.current < (int)from) {
			playlist.current++;
		}

		/* this first if statement isn't necessary since the queue
		 * would have been cleared out if queued == from */
		if (playlist.queued == (int)from)
			playlist.queued = to;
		else if (playlist.queued > (int)from && playlist.queued <= to) {
			playlist.queued--;
		} else if (playlist.queued>= to && playlist.queued < (int)from) {
			playlist.queued++;
		}
	}

	incrPlaylistVersion();

	return PLAYLIST_RESULT_SUCCESS;
}

enum playlist_result moveSongInPlaylistById(unsigned id1, int to)
{
	int song = queue_id_to_position(&playlist.queue, id1);
	if (song < 0)
		return PLAYLIST_RESULT_NO_SUCH_SONG;

	return moveSongInPlaylist(song, to);
}

static void orderPlaylist(void)
{
	if (playlist.current >= 0)
		/* update playlist.current, order==position now */
		playlist.current = queue_order_to_position(&playlist.queue,
							   playlist.current);

	if (playlist.playing && playlist.queued >= 0)
		/* clear the queue, because the next song will be
		   different now */
		clearPlayerQueue();

	queue_restore_order(&playlist.queue);
}

void setPlaylistRandomStatus(bool status)
{
	if (status == playlist.queue.random)
		return;

	if (playlist.queued >= 0)
		clearPlayerQueue();

	playlist.queue.random = status;

	if (playlist.queue.random) {
		/* shuffle the queue order, but preserve
		   playlist.current */

		int current_position = playlist.current >= 0
			? (int)queue_order_to_position(&playlist.queue,
						       playlist.current)
			: -1;

		queue_shuffle_order(&playlist.queue);

		if (current_position >= 0) {
			/* make sure the current song is the first in
			   the order list, so the whole rest of the
			   playlist is played after that */
			unsigned current_order =
				queue_position_to_order(&playlist.queue,
							current_position);
			queue_swap_order(&playlist.queue, 0, current_order);
			playlist.current = 0;
		}
	} else
		orderPlaylist();

	idle_add(IDLE_OPTIONS);
}

void previousSongInPlaylist(void)
{
	static time_t lastTime;
	time_t diff = time(NULL) - lastTime;

	lastTime += diff;

	if (!playlist.playing)
		return;

	syncPlaylistWithQueue();

	if (diff && getPlayerElapsedTime() > PLAYLIST_PREV_UNLESS_ELAPSED) {
		/* re-start playing the current song (just like the
		   "prev" button on CD players) */

		playPlaylistOrderNumber(playlist.current);
	} else {
		if (playlist.current > 0) {
			/* play the preceding song */
			playPlaylistOrderNumber(playlist.current - 1);
		} else if (playlist.queue.repeat) {
			/* play the last song in "repeat" mode */
			playPlaylistOrderNumber(queue_length(&playlist.queue) - 1);
		} else {
			/* re-start playing the current song if it's
			   the first one */
			playPlaylistOrderNumber(playlist.current);
		}
	}
}

void shufflePlaylist(void)
{
	unsigned i;

	if (queue_length(&playlist.queue) <= 1)
		return;

	if (playlist.playing) {
		if (playlist.queued >= 0)
			/* queue must be cleared, because the "next"
			   song will be different after shuffle */
			clearPlayerQueue();

		if (playlist.current >= 0)
			/* put current playing song first */
			queue_swap(&playlist.queue, 0,
				   queue_order_to_position(&playlist.queue,
							   playlist.current));

		if (playlist.queue.random) {
			playlist.current =
				queue_position_to_order(&playlist.queue, 0);
		} else
			playlist.current = 0;

		/* start shuffle after the current song */
		i = 1;
	} else {
		/* no playback currently: shuffle everything, and
		   reset playlist.current */

		i = 0;
		playlist.current = -1;
	}

	/* shuffle the rest of the list */
	queue_shuffle_range(&playlist.queue, i,
			    queue_length(&playlist.queue));

	incrPlaylistVersion();
}

enum playlist_result savePlaylist(const char *utf8file)
{
	FILE *fp;
	char *path;

	if (!is_valid_playlist_name(utf8file))
		return PLAYLIST_RESULT_BAD_NAME;

	path = map_spl_utf8_to_fs(utf8file);
	if (path == NULL)
		return PLAYLIST_RESULT_DISABLED;

	if (g_file_test(path, G_FILE_TEST_EXISTS)) {
		g_free(path);
		return PLAYLIST_RESULT_LIST_EXISTS;
	}

	while (!(fp = fopen(path, "w")) && errno == EINTR);
	g_free(path);

	if (fp == NULL)
		return PLAYLIST_RESULT_ERRNO;

	for (unsigned i = 0; i < queue_length(&playlist.queue); i++)
		playlist_print_song(fp, queue_get(&playlist.queue, i));

	while (fclose(fp) && errno == EINTR) ;

	idle_add(IDLE_STORED_PLAYLIST);
	return PLAYLIST_RESULT_SUCCESS;
}

int getPlaylistCurrentSong(void)
{
	if (playlist.current >= 0)
		return queue_order_to_position(&playlist.queue,
					       playlist.current);

	return -1;
}

unsigned long getPlaylistVersion(void)
{
	return playlist.queue.version;
}

int getPlaylistLength(void)
{
	return queue_length(&playlist.queue);
}

enum playlist_result seekSongInPlaylist(unsigned song, float seek_time)
{
	unsigned i;
	int ret;

	if (!queue_valid_position(&playlist.queue, song))
		return PLAYLIST_RESULT_BAD_RANGE;

	if (playlist.queue.random)
		i = queue_position_to_order(&playlist.queue, song);
	else
		i = song;

	clearPlayerError();
	playlist.stop_on_error = true;
	playlist.error_count = 0;

	if (playlist.playing) {
		if (playlist.queued >= 0)
			clearPlayerQueue();
	} else
		playPlaylistOrderNumber(i);

	if (playlist.current != (int)i) {
		playPlaylistOrderNumber(i);
	}

	ret = playerSeek(queue_get_order(&playlist.queue, i), seek_time);
	if (ret < 0)
		return PLAYLIST_RESULT_NOT_PLAYING;

	return PLAYLIST_RESULT_SUCCESS;
}

enum playlist_result seekSongInPlaylistById(unsigned id, float seek_time)
{
	int song = queue_id_to_position(&playlist.queue, id);
	if (song < 0)
		return PLAYLIST_RESULT_NO_SUCH_SONG;

	return seekSongInPlaylist(song, seek_time);
}

unsigned getPlaylistSongId(unsigned song)
{
	return queue_position_to_id(&playlist.queue, song);
}

enum playlist_result loadPlaylist(const char *utf8file)
{
	GPtrArray *list;

	if (!(list = spl_load(utf8file)))
		return PLAYLIST_RESULT_NO_SUCH_LIST;

	for (unsigned i = 0; i < list->len; ++i) {
		const char *temp = g_ptr_array_index(list, i);
		if ((addToPlaylist(temp, NULL)) != PLAYLIST_RESULT_SUCCESS) {
			/* for windows compatibility, convert slashes */
			char *temp2 = g_strdup(temp);
			char *p = temp2;
			while (*p) {
				if (*p == '\\')
					*p = '/';
				p++;
			}
			if ((addToPlaylist(temp, NULL)) != PLAYLIST_RESULT_SUCCESS) {
				g_warning("can't add file \"%s\"", temp2);
			}
			free(temp2);
		}
	}

	spl_free(list);
	return PLAYLIST_RESULT_SUCCESS;
}

/*
 * Not supporting '/' was done out of laziness, and we should really
 * strive to support it in the future.
 *
 * Not supporting '\r' and '\n' is done out of protocol limitations (and
 * arguably laziness), but bending over head over heels to modify the
 * protocol (and compatibility with all clients) to support idiots who
 * put '\r' and '\n' in filenames isn't going to happen, either.
 */
int is_valid_playlist_name(const char *utf8path)
{
	return strchr(utf8path, '/') == NULL &&
		strchr(utf8path, '\n') == NULL &&
		strchr(utf8path, '\r') == NULL;
}