src/mpdclient.c

   1 /* ncmpc (Ncurses MPD Client)
   2  * (c) 2004-2017 The Music Player Daemon Project
   3  * Project homepage: http://musicpd.org
   4  *
   5  * This program is free software; you can redistribute it and/or modify
   6  * it under the terms of the GNU General Public License as published by
   7  * the Free Software Foundation; either version 2 of the License, or
   8  * (at your option) any later version.
   9  *
  10  * This program is distributed in the hope that it will be useful,
  11  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  12  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  13  * GNU General Public License for more details.
  14  *
  15  * You should have received a copy of the GNU General Public License along
  16  * with this program; if not, write to the Free Software Foundation, Inc.,
  17  * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
  18  */
  19
  20 #include "mpdclient.h"
  21 #include "callbacks.h"
  22 #include "filelist.h"
  23 #include "config.h"
  24 #include "gidle.h"
  25 #include "charset.h"
  26
  27 #ifdef ENABLE_ASYNC_CONNECT
  28 #include "aconnect.h"
  29 #endif
  30
  31 #include <mpd/client.h>
  32
  33 #include <assert.h>
  34
  35 static gboolean
  36 mpdclient_enter_idle_callback(gpointer user_data)
  37 {
  38         struct mpdclient *c = user_data;
  39         assert(c->enter_idle_source_id != 0);
  40         assert(c->source != NULL);
  41         assert(!c->idle);
  42
  43         c->enter_idle_source_id = 0;
  44         c->idle = mpd_glib_enter(c->source);
  45         return false;
  46 }
  47
  48 static void
  49 mpdclient_schedule_enter_idle(struct mpdclient *c)
  50 {
  51         assert(c != NULL);
  52         assert(c->source != NULL);
  53
  54         if (c->enter_idle_source_id == 0)
  55                 /* automatically re-enter MPD "idle" mode */
  56                 c->enter_idle_source_id =
  57                         g_idle_add(mpdclient_enter_idle_callback, c);
  58 }
  59
  60 static void
  61 mpdclient_cancel_enter_idle(struct mpdclient *c)
  62 {
  63         if (c->enter_idle_source_id != 0) {
  64                 g_source_remove(c->enter_idle_source_id);
  65                 c->enter_idle_source_id = 0;
  66         }
  67 }
  68
  69 static void
  70 mpdclient_invoke_error_callback(enum mpd_error error,
  71                                 const char *message)
  72 {
  73         char *allocated;
  74         if (error == MPD_ERROR_SERVER)
  75                 /* server errors are UTF-8, the others are locale */
  76                 message = allocated = utf8_to_locale(message);
  77         else
  78                 allocated = NULL;
  79
  80         mpdclient_error_callback(message);
  81         g_free(allocated);
  82 }
  83
  84 static void
  85 mpdclient_invoke_error_callback1(struct mpdclient *c)
  86 {
  87         assert(c != NULL);
  88         assert(c->connection != NULL);
  89
  90         struct mpd_connection *connection = c->connection;
  91
  92         enum mpd_error error = mpd_connection_get_error(connection);
  93         assert(error != MPD_ERROR_SUCCESS);
  94
  95         mpdclient_invoke_error_callback(error,
  96                                         mpd_connection_get_error_message(connection));
  97 }
  98
  99 static void
 100 mpdclient_gidle_callback(enum mpd_error error,
 101                          gcc_unused enum mpd_server_error server_error,
 102                          const char *message, enum mpd_idle events,
 103                          void *ctx)
 104 {
 105         struct mpdclient *c = ctx;
 106
 107         c->idle = false;
 108
 109         assert(mpdclient_is_connected(c));
 110
 111         if (error != MPD_ERROR_SUCCESS) {
 112                 mpdclient_invoke_error_callback(error, message);
 113                 mpdclient_disconnect(c);
 114                 mpdclient_lost_callback();
 115                 return;
 116         }
 117
 118         c->events |= events;
 119         mpdclient_update(c);
 120
 121         mpdclient_idle_callback(c->events);
 122
 123         c->events = 0;
 124
 125         if (c->source != NULL)
 126                 mpdclient_schedule_enter_idle(c);
 127 }
 128
 129 /****************************************************************************/
 130 /*** mpdclient functions ****************************************************/
 131 /****************************************************************************/
 132
 133 bool
 134 mpdclient_handle_error(struct mpdclient *c)
 135 {
 136         enum mpd_error error = mpd_connection_get_error(c->connection);
 137
 138         assert(error != MPD_ERROR_SUCCESS);
 139
 140         if (error == MPD_ERROR_SERVER &&
 141             mpd_connection_get_server_error(c->connection) == MPD_SERVER_ERROR_PERMISSION &&
 142             mpdclient_auth_callback(c))
 143                 return true;
 144
 145         mpdclient_invoke_error_callback(error,
 146                                         mpd_connection_get_error_message(c->connection));
 147
 148         if (!mpd_connection_clear_error(c->connection)) {
 149                 mpdclient_disconnect(c);
 150                 mpdclient_lost_callback();
 151         }
 152
 153         return false;
 154 }
 155
 156 #ifdef ENABLE_ASYNC_CONNECT
 157 #ifndef WIN32
 158
 159 static bool
 160 is_local_socket(const char *host)
 161 {
 162         return *host == '/' || *host == '@';
 163 }
 164
 165 static bool
 166 settings_is_local_socket(const struct mpd_settings *settings)
 167 {
 168         const char *host = mpd_settings_get_host(settings);
 169         return host != NULL && is_local_socket(host);
 170 }
 171
 172 #endif
 173 #endif
 174
 175 struct mpdclient *
 176 mpdclient_new(const gchar *host, unsigned port,
 177               unsigned timeout_ms, const gchar *password)
 178 {
 179         struct mpdclient *c = g_new0(struct mpdclient, 1);
 180
 181 #ifdef ENABLE_ASYNC_CONNECT
 182         c->settings = mpd_settings_new(host, port, timeout_ms,
 183                                        NULL, NULL);
 184         if (c->settings == NULL)
 185                 g_error("Out of memory");
 186
 187 #ifndef WIN32
 188         c->settings2 = host == NULL && port == 0 &&
 189                 settings_is_local_socket(c->settings)
 190                 ? mpd_settings_new(host, 6600, timeout_ms, NULL, NULL)
 191                 : NULL;
 192 #endif
 193
 194 #else
 195         c->host = host;
 196         c->port = port;
 197 #endif
 198
 199         c->timeout_ms = timeout_ms;
 200         c->password = password;
 201
 202         playlist_init(&c->playlist);
 203         c->volume = -1;
 204         c->events = 0;
 205         c->playing = false;
 206
 207         return c;
 208 }
 209
 210 void
 211 mpdclient_free(struct mpdclient *c)
 212 {
 213         mpdclient_disconnect(c);
 214
 215         mpdclient_playlist_free(&c->playlist);
 216
 217 #ifdef ENABLE_ASYNC_CONNECT
 218         mpd_settings_free(c->settings);
 219
 220 #ifndef WIN32
 221         if (c->settings2 != NULL)
 222                 mpd_settings_free(c->settings2);
 223 #endif
 224 #endif
 225
 226         g_free(c);
 227 }
 228
 229 static char *
 230 settings_name(const struct mpd_settings *settings)
 231 {
 232         assert(settings != NULL);
 233
 234         const char *host = mpd_settings_get_host(settings);
 235         if (host == NULL)
 236                 host = "unknown";
 237
 238         if (host[0] == '/')
 239                 return g_strdup(host);
 240
 241         unsigned port = mpd_settings_get_port(settings);
 242         if (port == 0 || port == 6600)
 243                 return g_strdup(host);
 244
 245         return g_strdup_printf("%s:%u", host, port);
 246 }
 247
 248 char *
 249 mpdclient_settings_name(const struct mpdclient *c)
 250 {
 251         assert(c != NULL);
 252
 253 #ifdef ENABLE_ASYNC_CONNECT
 254         return settings_name(c->settings);
 255 #else
 256         struct mpd_settings *settings =
 257                 mpd_settings_new(c->host, c->port, 0, NULL, NULL);
 258         if (settings == NULL)
 259                 return g_strdup("unknown");
 260
 261         char *name = settings_name(settings);
 262         mpd_settings_free(settings);
 263         return name;
 264 #endif
 265 }
 266
 267 static void
 268 mpdclient_status_free(struct mpdclient *c)
 269 {
 270         if (c->status == NULL)
 271                 return;
 272
 273         mpd_status_free(c->status);
 274         c->status = NULL;
 275
 276         c->volume = -1;
 277         c->playing = false;
 278 }
 279
 280 void
 281 mpdclient_disconnect(struct mpdclient *c)
 282 {
 283 #ifdef ENABLE_ASYNC_CONNECT
 284         if (c->async_connect != NULL) {
 285                 aconnect_cancel(c->async_connect);
 286                 c->async_connect = NULL;
 287         }
 288 #endif
 289
 290         mpdclient_cancel_enter_idle(c);
 291
 292         if (c->source != NULL) {
 293                 mpd_glib_free(c->source);
 294                 c->source = NULL;
 295                 c->idle = false;
 296         }
 297
 298         if (c->connection) {
 299                 mpd_connection_free(c->connection);
 300                 ++c->connection_id;
 301         }
 302         c->connection = NULL;
 303
 304         mpdclient_status_free(c);
 305
 306         playlist_clear(&c->playlist);
 307
 308         if (c->song)
 309                 c->song = NULL;
 310
 311         /* everything has changed after a disconnect */
 312         c->events |= MPD_IDLE_ALL;
 313 }
 314
 315 static bool
 316 mpdclient_connected(struct mpdclient *c,
 317                     struct mpd_connection *connection)
 318 {
 319         c->connection = connection;
 320
 321         if (mpd_connection_get_error(connection) != MPD_ERROR_SUCCESS) {
 322                 mpdclient_invoke_error_callback1(c);
 323                 mpdclient_disconnect(c);
 324                 mpdclient_failed_callback();
 325                 return false;
 326         }
 327
 328 #ifdef ENABLE_ASYNC_CONNECT
 329         if (c->timeout_ms > 0)
 330                 mpd_connection_set_timeout(connection, c->timeout_ms);
 331 #endif
 332
 333         /* send password */
 334         if (c->password != NULL &&
 335             !mpd_run_password(connection, c->password)) {
 336                 mpdclient_invoke_error_callback1(c);
 337                 mpdclient_disconnect(c);
 338                 mpdclient_failed_callback();
 339                 return false;
 340         }
 341
 342         c->source = mpd_glib_new(connection,
 343                                  mpdclient_gidle_callback, c);
 344         mpdclient_schedule_enter_idle(c);
 345
 346         ++c->connection_id;
 347
 348         mpdclient_connected_callback();
 349         return true;
 350 }
 351
 352 #ifdef ENABLE_ASYNC_CONNECT
 353
 354 static void
 355 mpdclient_aconnect_start(struct mpdclient *c,
 356                          const struct mpd_settings *settings);
 357
 358 static void
 359 mpdclient_connect_success(struct mpd_connection *connection, void *ctx)
 360 {
 361         struct mpdclient *c = ctx;
 362         assert(c->async_connect != NULL);
 363         c->async_connect = NULL;
 364
 365         mpdclient_connected(c, connection);
 366 }
 367
 368 static void
 369 mpdclient_connect_error(const char *message, void *ctx)
 370 {
 371         struct mpdclient *c = ctx;
 372         assert(c->async_connect != NULL);
 373         c->async_connect = NULL;
 374
 375 #ifndef WIN32
 376         if (!c->connecting2 && c->settings2 != NULL) {
 377                 c->connecting2 = true;
 378                 mpdclient_aconnect_start(c, c->settings2);
 379                 return;
 380         }
 381 #endif
 382
 383         mpdclient_error_callback(message);
 384         mpdclient_failed_callback();
 385 }
 386
 387 static const struct aconnect_handler mpdclient_connect_handler = {
 388         .success = mpdclient_connect_success,
 389         .error = mpdclient_connect_error,
 390 };
 391
 392 static void
 393 mpdclient_aconnect_start(struct mpdclient *c,
 394                          const struct mpd_settings *settings)
 395 {
 396         aconnect_start(&c->async_connect,
 397                        mpd_settings_get_host(settings),
 398                        mpd_settings_get_port(settings),
 399                        &mpdclient_connect_handler, c);
 400 }
 401
 402 #endif
 403
 404 void
 405 mpdclient_connect(struct mpdclient *c)
 406 {
 407         /* close any open connection */
 408         mpdclient_disconnect(c);
 409
 410 #ifdef ENABLE_ASYNC_CONNECT
 411 #ifndef WIN32
 412         c->connecting2 = false;
 413 #endif
 414         mpdclient_aconnect_start(c, c->settings);
 415 #else
 416         /* connect to MPD */
 417         struct mpd_connection *connection =
 418                 mpd_connection_new(c->host, c->port, c->timeout_ms);
 419         if (connection == NULL)
 420                 g_error("Out of memory");
 421
 422         mpdclient_connected(c, connection);
 423 #endif
 424 }
 425
 426 bool
 427 mpdclient_update(struct mpdclient *c)
 428 {
 429         struct mpd_connection *connection = mpdclient_get_connection(c);
 430
 431         if (connection == NULL)
 432                 return false;
 433
 434         /* free the old status */
 435         mpdclient_status_free(c);
 436
 437         /* retrieve new status */
 438         c->status = mpd_run_status(connection);
 439         if (c->status == NULL)
 440                 return mpdclient_handle_error(c);
 441
 442         c->volume = mpd_status_get_volume(c->status);
 443         c->playing = mpd_status_get_state(c->status) == MPD_STATE_PLAY;
 444
 445         /* check if the playlist needs an update */
 446         if (c->playlist.version != mpd_status_get_queue_version(c->status)) {
 447                 bool retval;
 448
 449                 if (!playlist_is_empty(&c->playlist))
 450                         retval = mpdclient_playlist_update_changes(c);
 451                 else
 452                         retval = mpdclient_playlist_update(c);
 453                 if (!retval)
 454                         return false;
 455         }
 456
 457         /* update the current song */
 458         if (!c->song || mpd_status_get_song_id(c->status) >= 0) {
 459                 c->song = playlist_get_song(&c->playlist,
 460                                             mpd_status_get_song_pos(c->status));
 461         }
 462
 463         return true;
 464 }
 465
 466 struct mpd_connection *
 467 mpdclient_get_connection(struct mpdclient *c)
 468 {
 469         if (c->source != NULL && c->idle) {
 470                 c->idle = false;
 471                 mpd_glib_leave(c->source);
 472
 473                 mpdclient_schedule_enter_idle(c);
 474         }
 475
 476         return c->connection;
 477 }
 478
 479 static struct mpd_status *
 480 mpdclient_recv_status(struct mpdclient *c)
 481 {
 482         assert(c->connection != NULL);
 483
 484         struct mpd_status *status = mpd_recv_status(c->connection);
 485         if (status == NULL) {
 486                 mpdclient_handle_error(c);
 487                 return NULL;
 488         }
 489
 490         if (c->status != NULL)
 491                 mpd_status_free(c->status);
 492         return c->status = status;
 493 }
 494
 495 /****************************************************************************/
 496 /*** MPD Commands  **********************************************************/
 497 /****************************************************************************/
 498
 499 bool
 500 mpdclient_cmd_crop(struct mpdclient *c)
 501 {
 502         if (!mpdclient_is_playing(c))
 503                 return false;
 504
 505         int length = mpd_status_get_queue_length(c->status);
 506         int current = mpd_status_get_song_pos(c->status);
 507         if (current < 0 || mpd_status_get_queue_length(c->status) < 2)
 508                 return true;
 509
 510         struct mpd_connection *connection = mpdclient_get_connection(c);
 511         if (connection == NULL)
 512                 return false;
 513
 514         mpd_command_list_begin(connection, false);
 515
 516         if (current < length - 1)
 517                 mpd_send_delete_range(connection, current + 1, length);
 518         if (current > 0)
 519                 mpd_send_delete_range(connection, 0, current);
 520
 521         mpd_command_list_end(connection);
 522
 523         return mpdclient_finish_command(c);
 524 }
 525
 526 bool
 527 mpdclient_cmd_clear(struct mpdclient *c)
 528 {
 529         struct mpd_connection *connection = mpdclient_get_connection(c);
 530         if (connection == NULL)
 531                 return false;
 532
 533         /* send "clear" and "status" */
 534         if (!mpd_command_list_begin(connection, false) ||
 535             !mpd_send_clear(connection) ||
 536             !mpd_send_status(connection) ||
 537             !mpd_command_list_end(connection))
 538                 return mpdclient_handle_error(c);
 539
 540         /* receive the new status, store it in the mpdclient struct */
 541
 542         struct mpd_status *status = mpdclient_recv_status(c);
 543         if (status == NULL)
 544                 return false;
 545
 546         if (!mpd_response_finish(connection))
 547                 return mpdclient_handle_error(c);
 548
 549         /* update mpdclient.playlist */
 550
 551         if (mpd_status_get_queue_length(status) == 0) {
 552                 /* after the "clear" command, the queue is really
 553                    empty - this means we can clear it locally,
 554                    reducing the UI latency */
 555                 playlist_clear(&c->playlist);
 556                 c->playlist.version = mpd_status_get_queue_version(status);
 557                 c->song = NULL;
 558         }
 559
 560         c->events |= MPD_IDLE_QUEUE;
 561         return true;
 562 }
 563
 564 bool
 565 mpdclient_cmd_volume(struct mpdclient *c, gint value)
 566 {
 567         struct mpd_connection *connection = mpdclient_get_connection(c);
 568         if (connection == NULL)
 569                 return false;
 570
 571         mpd_send_set_volume(connection, value);
 572         return mpdclient_finish_command(c);
 573 }
 574
 575 bool
 576 mpdclient_cmd_volume_up(struct mpdclient *c)
 577 {
 578         if (c->volume < 0 || c->volume >= 100)
 579                 return true;
 580
 581         struct mpd_connection *connection = mpdclient_get_connection(c);
 582         if (connection == NULL)
 583                 return false;
 584
 585         return mpdclient_cmd_volume(c, ++c->volume);
 586 }
 587
 588 bool
 589 mpdclient_cmd_volume_down(struct mpdclient *c)
 590 {
 591         if (c->volume <= 0)
 592                 return true;
 593
 594         struct mpd_connection *connection = mpdclient_get_connection(c);
 595         if (connection == NULL)
 596                 return false;
 597
 598         return mpdclient_cmd_volume(c, --c->volume);
 599 }
 600
 601 bool
 602 mpdclient_cmd_add_path(struct mpdclient *c, const gchar *path_utf8)
 603 {
 604         struct mpd_connection *connection = mpdclient_get_connection(c);
 605         if (connection == NULL)
 606                 return false;
 607
 608         return mpd_send_add(connection, path_utf8)?
 609                 mpdclient_finish_command(c) : false;
 610 }
 611
 612 bool
 613 mpdclient_cmd_add(struct mpdclient *c, const struct mpd_song *song)
 614 {
 615         assert(c != NULL);
 616         assert(song != NULL);
 617
 618         struct mpd_connection *connection = mpdclient_get_connection(c);
 619         if (connection == NULL || c->status == NULL)
 620                 return false;
 621
 622         /* send the add command to mpd; at the same time, get the new
 623            status (to verify the new playlist id) and the last song
 624            (we hope that's the song we just added) */
 625
 626         if (!mpd_command_list_begin(connection, true) ||
 627             !mpd_send_add(connection, mpd_song_get_uri(song)) ||
 628             !mpd_send_status(connection) ||
 629             !mpd_send_get_queue_song_pos(connection,
 630                                          playlist_length(&c->playlist)) ||
 631             !mpd_command_list_end(connection) ||
 632             !mpd_response_next(connection))
 633                 return mpdclient_handle_error(c);
 634
 635         c->events |= MPD_IDLE_QUEUE;
 636
 637         struct mpd_status *status = mpdclient_recv_status(c);
 638         if (status == NULL)
 639                 return false;
 640
 641         if (!mpd_response_next(connection))
 642                 return mpdclient_handle_error(c);
 643
 644         struct mpd_song *new_song = mpd_recv_song(connection);
 645         if (!mpd_response_finish(connection) || new_song == NULL) {
 646                 if (new_song != NULL)
 647                         mpd_song_free(new_song);
 648
 649                 return mpd_connection_clear_error(connection) ||
 650                         mpdclient_handle_error(c);
 651         }
 652
 653         if (mpd_status_get_queue_length(status) == playlist_length(&c->playlist) + 1 &&
 654             mpd_status_get_queue_version(status) == c->playlist.version + 1) {
 655                 /* the cheap route: match on the new playlist length
 656                    and its version, we can keep our local playlist
 657                    copy in sync */
 658                 c->playlist.version = mpd_status_get_queue_version(status);
 659
 660                 /* the song we just received has the correct id;
 661                    append it to the local playlist */
 662                 playlist_append(&c->playlist, new_song);
 663         }
 664
 665         mpd_song_free(new_song);
 666
 667         return true;
 668 }
 669
 670 bool
 671 mpdclient_cmd_delete(struct mpdclient *c, gint idx)
 672 {
 673         struct mpd_connection *connection = mpdclient_get_connection(c);
 674
 675         if (connection == NULL || c->status == NULL)
 676                 return false;
 677
 678         if (idx < 0 || (guint)idx >= playlist_length(&c->playlist))
 679                 return false;
 680
 681         const struct mpd_song *song = playlist_get(&c->playlist, idx);
 682
 683         /* send the delete command to mpd; at the same time, get the
 684            new status (to verify the playlist id) */
 685
 686         if (!mpd_command_list_begin(connection, false) ||
 687             !mpd_send_delete_id(connection, mpd_song_get_id(song)) ||
 688             !mpd_send_status(connection) ||
 689             !mpd_command_list_end(connection))
 690                 return mpdclient_handle_error(c);
 691
 692         c->events |= MPD_IDLE_QUEUE;
 693
 694         struct mpd_status *status = mpdclient_recv_status(c);
 695         if (status == NULL)
 696                 return false;
 697
 698         if (!mpd_response_finish(connection))
 699                 return mpdclient_handle_error(c);
 700
 701         if (mpd_status_get_queue_length(status) == playlist_length(&c->playlist) - 1 &&
 702             mpd_status_get_queue_version(status) == c->playlist.version + 1) {
 703                 /* the cheap route: match on the new playlist length
 704                    and its version, we can keep our local playlist
 705                    copy in sync */
 706                 c->playlist.version = mpd_status_get_queue_version(status);
 707
 708                 /* remove the song from the local playlist */
 709                 playlist_remove(&c->playlist, idx);
 710
 711                 /* remove references to the song */
 712                 if (c->song == song)
 713                         c->song = NULL;
 714         }
 715
 716         return true;
 717 }
 718
 719 bool
 720 mpdclient_cmd_delete_range(struct mpdclient *c, unsigned start, unsigned end)
 721 {
 722         if (end == start + 1)
 723                 /* if that's not really a range, we choose to use the
 724                    safer "deleteid" version */
 725                 return mpdclient_cmd_delete(c, start);
 726
 727         struct mpd_connection *connection = mpdclient_get_connection(c);
 728         if (connection == NULL)
 729                 return false;
 730
 731         /* send the delete command to mpd; at the same time, get the
 732            new status (to verify the playlist id) */
 733
 734         if (!mpd_command_list_begin(connection, false) ||
 735             !mpd_send_delete_range(connection, start, end) ||
 736             !mpd_send_status(connection) ||
 737             !mpd_command_list_end(connection))
 738                 return mpdclient_handle_error(c);
 739
 740         c->events |= MPD_IDLE_QUEUE;
 741
 742         struct mpd_status *status = mpdclient_recv_status(c);
 743         if (status == NULL)
 744                 return false;
 745
 746         if (!mpd_response_finish(connection))
 747                 return mpdclient_handle_error(c);
 748
 749         if (mpd_status_get_queue_length(status) == playlist_length(&c->playlist) - (end - start) &&
 750             mpd_status_get_queue_version(status) == c->playlist.version + 1) {
 751                 /* the cheap route: match on the new playlist length
 752                    and its version, we can keep our local playlist
 753                    copy in sync */
 754                 c->playlist.version = mpd_status_get_queue_version(status);
 755
 756                 /* remove the song from the local playlist */
 757                 while (end > start) {
 758                         --end;
 759
 760                         /* remove references to the song */
 761                         if (c->song == playlist_get(&c->playlist, end))
 762                                 c->song = NULL;
 763
 764                         playlist_remove(&c->playlist, end);
 765                 }
 766         }
 767
 768         return true;
 769 }
 770
 771 bool
 772 mpdclient_cmd_move(struct mpdclient *c, unsigned dest_pos, unsigned src_pos)
 773 {
 774         if (dest_pos == src_pos)
 775                 return true;
 776
 777         struct mpd_connection *connection = mpdclient_get_connection(c);
 778         if (connection == NULL)
 779                 return false;
 780
 781         /* send the "move" command to MPD; at the same time, get the
 782            new status (to verify the playlist id) */
 783
 784         if (!mpd_command_list_begin(connection, false) ||
 785             !mpd_send_move(connection, src_pos, dest_pos) ||
 786             !mpd_send_status(connection) ||
 787             !mpd_command_list_end(connection))
 788                 return mpdclient_handle_error(c);
 789
 790         c->events |= MPD_IDLE_QUEUE;
 791
 792         struct mpd_status *status = mpdclient_recv_status(c);
 793         if (status == NULL)
 794                 return false;
 795
 796         if (!mpd_response_finish(connection))
 797                 return mpdclient_handle_error(c);
 798
 799         if (mpd_status_get_queue_length(status) == playlist_length(&c->playlist) &&
 800             mpd_status_get_queue_version(status) == c->playlist.version + 1) {
 801                 /* the cheap route: match on the new playlist length
 802                    and its version, we can keep our local playlist
 803                    copy in sync */
 804                 c->playlist.version = mpd_status_get_queue_version(status);
 805
 806                 /* swap songs in the local playlist */
 807                 playlist_move(&c->playlist, dest_pos, src_pos);
 808         }
 809
 810         return true;
 811 }
 812
 813 /* The client-to-client protocol (MPD 0.17.0) */
 814
 815 bool
 816 mpdclient_cmd_subscribe(struct mpdclient *c, const char *channel)
 817 {
 818         struct mpd_connection *connection = mpdclient_get_connection(c);
 819
 820         if (connection == NULL)
 821                 return false;
 822
 823         if (!mpd_send_subscribe(connection, channel))
 824                 return mpdclient_handle_error(c);
 825
 826         return mpdclient_finish_command(c);
 827 }
 828
 829 bool
 830 mpdclient_cmd_unsubscribe(struct mpdclient *c, const char *channel)
 831 {
 832         struct mpd_connection *connection = mpdclient_get_connection(c);
 833         if (connection == NULL)
 834                 return false;
 835
 836         if (!mpd_send_unsubscribe(connection, channel))
 837                 return mpdclient_handle_error(c);
 838
 839         return mpdclient_finish_command(c);
 840 }
 841
 842 bool
 843 mpdclient_cmd_send_message(struct mpdclient *c, const char *channel,
 844                            const char *text)
 845 {
 846         struct mpd_connection *connection = mpdclient_get_connection(c);
 847         if (connection == NULL)
 848                 return false;
 849
 850         if (!mpd_send_send_message(connection, channel, text))
 851                 return mpdclient_handle_error(c);
 852
 853         return mpdclient_finish_command(c);
 854 }
 855
 856 bool
 857 mpdclient_send_read_messages(struct mpdclient *c)
 858 {
 859         struct mpd_connection *connection = mpdclient_get_connection(c);
 860         if (connection == NULL)
 861                 return false;
 862
 863         return mpd_send_read_messages(connection)?
 864                 true : mpdclient_handle_error(c);
 865 }
 866
 867 struct mpd_message *
 868 mpdclient_recv_message(struct mpdclient *c)
 869 {
 870         struct mpd_connection *connection = mpdclient_get_connection(c);
 871         if (connection == NULL)
 872                 return false;
 873
 874         struct mpd_message *message = mpd_recv_message(connection);
 875         if (message == NULL &&
 876             mpd_connection_get_error(connection) != MPD_ERROR_SUCCESS)
 877                 mpdclient_handle_error(c);
 878
 879         return message;
 880 }
 881
 882 /****************************************************************************/
 883 /*** Playlist management functions ******************************************/
 884 /****************************************************************************/
 885
 886 /* update playlist */
 887 bool
 888 mpdclient_playlist_update(struct mpdclient *c)
 889 {
 890         struct mpd_connection *connection = mpdclient_get_connection(c);
 891         if (connection == NULL)
 892                 return false;
 893
 894         playlist_clear(&c->playlist);
 895
 896         mpd_send_list_queue_meta(connection);
 897
 898         struct mpd_entity *entity;
 899         while ((entity = mpd_recv_entity(connection))) {
 900                 if (mpd_entity_get_type(entity) == MPD_ENTITY_TYPE_SONG)
 901                         playlist_append(&c->playlist, mpd_entity_get_song(entity));
 902
 903                 mpd_entity_free(entity);
 904         }
 905
 906         c->playlist.version = mpd_status_get_queue_version(c->status);
 907         c->song = NULL;
 908
 909         return mpdclient_finish_command(c);
 910 }
 911
 912 /* update playlist (plchanges) */
 913 bool
 914 mpdclient_playlist_update_changes(struct mpdclient *c)
 915 {
 916         struct mpd_connection *connection = mpdclient_get_connection(c);
 917
 918         if (connection == NULL)
 919                 return false;
 920
 921         mpd_send_queue_changes_meta(connection, c->playlist.version);
 922
 923         struct mpd_song *song;
 924         while ((song = mpd_recv_song(connection)) != NULL) {
 925                 int pos = mpd_song_get_pos(song);
 926
 927                 if (pos >= 0 && (guint)pos < c->playlist.list->len) {
 928                         /* update song */
 929                         playlist_replace(&c->playlist, pos, song);
 930                 } else {
 931                         /* add a new song */
 932                         playlist_append(&c->playlist, song);
 933                 }
 934
 935                 mpd_song_free(song);
 936         }
 937
 938         /* remove trailing songs */
 939
 940         unsigned length = mpd_status_get_queue_length(c->status);
 941         while (length < c->playlist.list->len) {
 942                 guint pos = c->playlist.list->len - 1;
 943
 944                 /* Remove the last playlist entry */
 945                 playlist_remove(&c->playlist, pos);
 946         }
 947
 948         c->song = NULL;
 949         c->playlist.version = mpd_status_get_queue_version(c->status);
 950
 951         return mpdclient_finish_command(c);
 952 }
 953
 954
 955 /****************************************************************************/
 956 /*** Filelist functions *****************************************************/
 957 /****************************************************************************/
 958
 959 bool
 960 mpdclient_filelist_add_all(struct mpdclient *c, struct filelist *fl)
 961 {
 962         struct mpd_connection *connection = mpdclient_get_connection(c);
 963         if (connection == NULL)
 964                 return false;
 965
 966         if (filelist_is_empty(fl))
 967                 return true;
 968
 969         mpd_command_list_begin(connection, false);
 970
 971         for (unsigned i = 0; i < filelist_length(fl); ++i) {
 972                 struct filelist_entry *entry = filelist_get(fl, i);
 973                 struct mpd_entity *entity  = entry->entity;
 974
 975                 if (entity != NULL &&
 976                     mpd_entity_get_type(entity) == MPD_ENTITY_TYPE_SONG) {
 977                         const struct mpd_song *song =
 978                                 mpd_entity_get_song(entity);
 979
 980                         mpd_send_add(connection, mpd_song_get_uri(song));
 981                 }
 982         }
 983
 984         mpd_command_list_end(connection);
 985         return mpdclient_finish_command(c);
 986 }