Added Lirc and MPCL modules.
[lisp-utils.git] / mpcl.lisp
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1;;;; MPCL -- Common Lisp MPD Client library
2
3#-sbcl (error "No known socket interface for ~a" (lisp-implementation-type))
4
5(eval-when (:compile-toplevel :load-toplevel :execute)
6 (require 'sb-bsd-sockets)
7 (require 'cl-ppcre))
8(defpackage :mpcl (:use :cl :sb-bsd-sockets))
9(in-package :mpcl)
10
11;;; Global variables
12(defvar *socket* nil)
13(defvar *last-command* 0)
14(defvar *last-server* nil)
15(defvar *retries* 0)
16#+sbcl (defvar *conn-lock* (sb-thread:make-mutex))
17
18;;; Utility functions
19(defmacro concat (&rest strings)
20 `(concatenate 'string ,@strings))
21
22(defun assert-type (type val)
23 (assert (typep val type))
24 val)
25
26(defun clipnum (num min max)
27 (cond ((< num min) min)
28 ((> num max) max)
29 (t num)))
30
31(defmacro regex-cond (key &body clauses)
32 (let ((match (gensym))
33 (sub (gensym))
34 (val (gensym))
35 (block-nm (gensym)))
36 (flet ((ctrans (clause)
37 (if (eq (first clause) 'otherwise)
38 `(return-from ,block-nm
39 (progn ,@(rest clause)))
40 (destructuring-bind (regex arglist &body body)
41 clause
42 `(multiple-value-bind (,match ,sub)
43 (ppcre:scan-to-strings ,regex ,val)
44 ,@(if (null arglist)
45 `((declare (ignore ,sub))))
46 (if ,match
47 (return-from ,block-nm
48 (let ,(let ((argno 0))
49 (mapcar #'(lambda (arg)
50 (prog1 `(,arg (aref ,sub ,argno))
51 (incf argno)))
52 arglist))
53 ,@body))))))))
54 `(block ,block-nm
55 (let ((,val (the string ,key)))
56 ,@(mapcar #'ctrans clauses))))))
57
58;;; Error conditions
59(define-condition protocol-error (error)
60 ((message :reader protocol-error-message
61 :initarg :message
62 :type string)
63 (real-error :reader protocol-error-cause
64 :initarg :cause
65 :type condition
66 :initform nil)
67 (retries :reader protocol-error-retries
68 :initarg :retries
69 :type integer
70 :initform 0))
71 (:report (lambda (c s)
72 (if (protocol-error-cause c)
73 (format s "~A: ~A" (protocol-error-message c) (protocol-error-cause c))
74 (format s "Protocol error occurred on mpd socket: ~A" (protocol-error-message c))))))
75
76(define-condition protocol-input-error (protocol-error)
77 ((inputs :reader protocol-error-inputs
78 :initarg :inputs))
79 (:report (lambda (c s)
80 (apply #'format s (protocol-error-message c) (protocol-error-inputs c)))))
81
82(define-condition command-error (error)
83 ((err-code :reader command-error-code
84 :initarg :err-code
85 :type integer)
86 (message :reader command-error-message
87 :initarg :message
88 :type string))
89 (:report (lambda (c s)
90 (format s "mpd error response: ~A" (command-error-message c)))))
91
92(defvar *command-error-types* (make-hash-table))
93
94(defmacro def-command-error-type (code name desc)
95 (let ((cond-sym (intern (concat "COMMAND-ERROR-" (symbol-name name)))))
96 `(progn (define-condition ,cond-sym (command-error)
97 ()
98 (:report (lambda (c s)
99 (format s "mpd error response: ~A (message was: `~A')" ,desc (command-error-message c)))))
100 (setf (gethash ,code *command-error-types*) ',cond-sym)
101 (export '(,cond-sym)))))
102;; The following are fetched from libmpdclient.h. In all honesty, I
103;; can't really figure out what they mean just from their names, so
104;; the descriptions aren't optimal in every conceivable way.
105(def-command-error-type 1 not-list "not list")
106(def-command-error-type 2 arg "argument")
107(def-command-error-type 3 password "bad password")
108(def-command-error-type 4 permission "permission denied")
109(def-command-error-type 5 unknown-cmd "unknown command")
110(def-command-error-type 50 no-exist "item does not exist")
111(def-command-error-type 51 playlist-max "playlist overload") ; ?!
112(def-command-error-type 52 system "system error")
113(def-command-error-type 53 playlist-load "could not load playlist")
114(def-command-error-type 54 update-already "already updated") ; ?!
115(def-command-error-type 55 player-sync "player sync") ; ?!
116(def-command-error-type 56 exist "item already exists")
117
118(export '(protocol-error reconnect command-error
119 protocol-error-retries command-error-code
120 command-error-message))
121
122;;; Struct definitions
123(defstruct song
124 (file "" :type string)
125 (id -1 :type integer)
126 (pos -1 :type integer)
127 (length -1 :type integer)
128 (track -1 :type integer)
129 artist title album genre composer date)
130
131(export '(song
132 song-file song-id song-pos song-length song-track
133 song-artist song-title song-album song-genre
134 song-composer song-date))
135
136(defstruct status
137 (volume 0 :type integer)
138 (playlist-version -1 :type integer)
139 (num-songs 0 :type integer)
140 (song -1 :type integer)
141 (songid -1 :type integer)
142 (pos -1 :type integer)
143 (song-len -1 :type integer)
144 repeat repeat-song random state)
145
146;;; Basic protocol management
147#+sbcl (defmacro with-conn-lock (&body body)
148 `(sb-thread:with-recursive-lock (*conn-lock*) ,@body))
149#-sbcl (defmacro with-conn-lock (&body body)
150 body)
151
152(defun disconnect ()
153 "Disconnect from MPD."
154 (with-conn-lock
155 (let ((sk (prog1 *socket* (setf *socket* nil))))
156 (if sk (ignore-errors (close sk))))))
157
158(defun connection-error (condition-type &rest condition-args)
159 (disconnect)
160 (error (apply #'make-condition condition-type :retries *retries* condition-args)))
161
162(defun command-error (code message)
163 (error (funcall #'make-condition (gethash code *command-error-types* 'command-error)
164 :err-code code
165 :message message)))
166
167(defun get-response ()
168 (let ((ret '()) (last nil))
169 (loop (let ((line (handler-case
170 (read-line *socket*)
171 (error (err)
172 (connection-error 'protocol-error
173 :message "Socket read error"
174 :cause err)))))
175 (regex-cond line
176 ("^OK( .*)?$"
177 ()
178 (return ret))
179 ("^ACK \\[(\\d+)@(\\d+)\\] \\{([^\\}]*)\\} (.*)$"
180 (code list-pos command rest)
181 (declare (ignore list-pos command))
182 (command-error (parse-integer code) rest))
183 ("^([^:]+): (.*)$"
184 (key val)
185 (let ((new (list (cons (intern (string-upcase key) (find-package 'keyword))
186 val))))
187 (if last
188 (setf (cdr last) new last new)
189 (setf ret new last new))))
190 (otherwise
191 (connection-error 'protocol-input-error
192 :message "Invalid response from mpd: ~A"
193 :inputs (list line))))))))
194
195(defun connect (&key (host "localhost") (port 6600))
196 "Connect to a running MPD."
197 (disconnect)
198 (with-conn-lock
199 (setf *socket* (block outer
200 (let ((last-err nil))
201 (dolist (address (host-ent-addresses (get-host-by-name host)))
202 (handler-case
203 (let ((sk (make-instance 'inet-socket :type :stream)))
204 (socket-connect sk address port)
205 (return-from outer (socket-make-stream sk :input t :output t :buffering :none)))
206 (error (err)
207 (setf last-err err)
208 (warn "mpd connection failure on address ~A: ~A" address err))))
209 (if last-err
210 (error "Could not connect to mpd: ~A" last-err)
211 (error "Could not connect to mpd: host name `~A' did not resolve to any addreses" host)))))
212 (setf *last-server* (cons host port))
213 (setf *last-command* (get-universal-time))
214 (get-response)))
215
216(defmacro dovector ((var vec) &body body)
217 (let ((i (gensym)))
218 `(dotimes (,i (length ,vec))
219 (let ((,var (aref ,vec ,i)))
220 ,@body))))
221
222(defmacro with-push-vector ((push-fun type &key (init-length 16)) &body body)
223 (let ((vec (gensym)))
224 `(let ((,vec (make-array (list ,init-length) :element-type ',type :adjustable t :fill-pointer 0)))
225 (flet ((,push-fun (el)
226 (declare (type ,type el))
227 (vector-push-extend el ,vec)))
228 ,@body)
229 ,vec)))
230
231(defun quote-argument (arg)
232 (declare (type string arg))
233 (if (= (length arg) 0)
234 "\"\""
235 (let* ((quote nil)
236 (res (with-push-vector (add character)
237 (dovector (elt arg)
238 (case elt
239 ((#\space #\tab)
240 (setf quote t) (add elt))
241 ((#\")
242 (setf quote t) (add #\\) (add #\"))
243 ((#\newline)
244 (error "Cannot send strings containing newlines to mpd: ~S" arg))
245 (t (add elt)))))))
246 (if quote
247 (concat "\"" res "\"")
248 res))))
249
250(defun arg-to-string (arg)
251 (quote-argument
252 (typecase arg
253 (string arg)
254 (t (write-to-string arg :escape nil)))))
255
256(defun mpd-command (&rest words)
257 (with-conn-lock
258 (let ((*retries* 0))
259 (loop
260 (restart-case
261 (progn (if (null *socket*)
262 (connection-error 'protocol-error
263 :message "Not connected to mpd"))
264 (handler-case
265 (progn (write-string (reduce #'(lambda (a b) (concat a " " b))
266 (mapcar #'arg-to-string words))
267 *socket*)
268 (terpri *socket*)
269 (force-output *socket*))
270 (error (err)
271 (connection-error 'protocol-error
272 :message "Socket write error"
273 :cause err)))
274 (setf *last-command* (get-universal-time))
275 (return (get-response)))
276 (reconnect ()
277 :test (lambda (c) (and (typep c 'protocol-error) (not (null *last-server*))))
278 :report (lambda (s)
279 (format s "Reconnect to ~A:~D and try again (~D retries so far)" (car *last-server*) (cdr *last-server*) *retries*))
280 (incf *retries*)
281 (connect :host (car *last-server*)
282 :port (cdr *last-server*))))))))
283
284(export '(connect disconnect))
285
286;;; Slot parsers
287;; These, and the structures themselves, should probably be rewritten
288;; using macros instead. There's a lot of redundancy.
289(defun cons-status (info)
290 (let ((ret (make-status)))
291 (dolist (line info ret)
292 (handler-case
293 (case (car line)
294 ((:time)
295 (let ((pos (assert-type '(integer 0 *) (position #\: (cdr line)))))
296 (setf (status-pos ret) (parse-integer (subseq (cdr line) 0 pos))
297 (status-song-len ret) (parse-integer (subseq (cdr line) (1+ pos))))))
298 ((:state) (setf (status-state ret) (intern (string-upcase (cdr line)) (find-package 'keyword))))
299 ((:repeat) (setf (status-repeat ret) (not (equal (cdr line) "0"))))
300 ((:repeatsong) (setf (status-repeat-song ret) (not (equal (cdr line) "0"))))
301 ((:random) (setf (status-random ret) (not (equal (cdr line) "0"))))
302 ((:volume) (setf (status-volume ret) (parse-integer (cdr line))))
303 ((:playlistlength) (setf (status-num-songs ret) (parse-integer (cdr line))))
304 ((:song) (setf (status-song ret) (parse-integer (cdr line))))
305 ((:songid) (setf (status-songid ret) (parse-integer (cdr line))))
306 ((:playlist) (setf (status-playlist-version ret) (parse-integer (cdr line))))
307 ;; Ignored:
308 ((:xfade :bitrate :audio))
309 (t (warn "Unknown status slot ~A" (car line))))
310 (parse-error ()
311 (warn "Status slot parse error in ~S, slot was ~S" ret line))))))
312
313(defun song-list (info)
314 (let ((ret '()) (cur nil))
315 (dolist (line info ret)
316 (handler-case
317 (case (car line)
318 ((:file)
319 (setf cur (make-song :file (cdr line)))
320 (setf ret (nconc ret (list cur))))
321 ((:time) (setf (song-length cur) (parse-integer (cdr line))))
322 ((:id) (setf (song-id cur) (parse-integer (cdr line))))
323 ((:pos) (setf (song-pos cur) (parse-integer (cdr line))))
324 ((:track) (setf (song-track cur) (parse-integer (cdr line))))
325 ((:title) (setf (song-title cur) (cdr line)))
326 ((:album) (setf (song-album cur) (cdr line)))
327 ((:artist) (setf (song-artist cur) (cdr line)))
328 ((:genre) (setf (song-genre cur) (cdr line)))
329 ((:composer) (setf (song-composer cur) (cdr line)))
330 ((:date) (setf (song-date cur) (cdr line)))
331 (t (warn "Unknown song slot ~A" (car line))))
332 (parse-error ()
333 (warn "Song slot parse error in ~A, slot was ~A" cur line))))))
334
335;;; Functions for individual commands
336(defun status ()
337 "Fetch and return the current status of the MPD as a STATUS structure."
338 (cons-status (mpd-command "status")))
339
340(defmacro with-status (slots &body body)
341 "Fetch the current status of the MPD, and then run BODY with the
342variables in the SLOTS bound to their curresponding status items.
343Available slots are:
344
345 STATE (SYMBOL)
346 The current state of the MPD
347 Known values are :STOP, :PAUSE and :PLAY
348 VOLUME (INTEGER 0 100)
349 Current output volume
350 PLAYLIST-VERSION (INTEGER 0 *)
351 Increases by one each time the playlist changes
352 NUM-SONGS (INTEGER 0 *)
353 Number of songs in the playlist
354 SONG (INTEGER 0 NUM-SONGS)
355 Index, in the playlist, of the currently playing song
356 SONGID (INTEGER)
357 ID of the currently playing song
358 SONG-LEN (INTEGER 0 *)
359 Length, in seconds, of currently playing song
360 POS (INTEGER 0 SONG-LEN)
361 Current time position of the currently playing song, in seconds
362 REPEAT (NIL or T)
363 Non-NIL if the MPD is in repeat mode
364 REPEAT-SONG (NIL or T)
365 Non-NIL if the MPD is repeating the current song
366 (not available without patching)
367 RANDOM (NIL or T)
368 Non-NIL if the MPD is in random mode"
369 (let ((status (gensym "STATUS")))
370 `(let* ((,status (status))
371 ;; This is kinda ugly, but I don't really know any better
372 ;; way to do it with structs.
373 ,@(mapcar #'(lambda (slot-sym)
374 (let ((slot-fun (intern (concat "STATUS-" (symbol-name slot-sym))
375 (find-package 'mpcl))))
376 `(,slot-sym (,slot-fun ,status))))
377 slots))
378 ,@body)))
379
380(defun play-song (song)
381 "Switch to a new song. SONG can be either an integer, indicating the
382position in the playlist of the song to be played, or a SONG structure
383instance (as received from the PLAYLIST function, for example),
384reflecting the song to be played."
385 (etypecase song
386 (song (mpd-command "playid" (song-id song)))
387 (integer (mpd-command "play" song))))
388
389(defun next ()
390 "Go to the next song in the playlist."
391 (mpd-command "next"))
392
393(defun prev ()
394 "Go to the previous song in the playlist."
395 (mpd-command "previous"))
396
397(defun toggle-pause ()
398 "Toggle between the :PAUSE and :PLAY states. Has no effect if the
399MPD is in the :STOP state."
400 (mpd-command "pause"))
401
402(defun pause ()
403 "Pause the playback, but only in the :PLAY state."
404 (if (eq (status-state (status)) :play)
405 (toggle-pause)))
406
407(defun ping ()
408 "Ping the MPD, so as to keep connection open."
409 (mpd-command "ping"))
410
411(defun maybe-ping ()
412 "Ping the MPD, but only if more than 10 seconds have elapsed since a
413command was last sent to it."
414 (if (and *socket*
415 (> (- (get-universal-time) *last-command*) 10))
416 (progn (ping) t)
417 nil))
418
419(defun stop ()
420 "Stop playback."
421 (mpd-command "stop"))
422
423(defun play ()
424 "Start playback of the current song."
425 (mpd-command "play"))
426
427(defun current-song ()
428 "Returns a SONG structure instance reflecting the currently playing song."
429 (first (song-list (mpd-command "currentsong"))))
430
431(defun song-info (song-num)
432 "Returns a SONG structure instance describing the song with the
433number SONG-NUM in the playlist"
434 (declare (type (integer 0 *) song-num))
435 (first (song-list (mpd-command "playlistinfo" song-num))))
436
437(defun playlist ()
438 "Return a list of SONG structure instances, reflecting the songs in
439the current playlist."
440 (song-list (mpd-command "playlistinfo")))
441
442(defun search-song (type datum)
443 "Search the entire song database for songs matching DATUM. TYPE
444specifies what data to search among, and can be one of the following
445symbols:
446
447 :ARTIST
448 :ALBUM
449 :TITLE
450 :TRACK
451 :GENRE
452 :COMPOSER
453 :PERFORMER
454 :COMMENT
455
456This function returns a list of SONG instances describing the search
457results, but meaningful information in the ID and POS slots, whether
458or not the songs are actually part of the current playlist."
459 (song-list (mpd-command "search" (string-downcase (symbol-name type)) datum)))
460
461(defun search-playlist (type datum)
462 "Works like the SEARCH-SONG function, but limits the search to the
463currently loaded playlist, and will return meaningful ID and POS
464information. See the documentation for the SEARCH-SONG function for
465further information."
466 (song-list (mpd-command "playlistsearch" (string-downcase (symbol-name type)) datum)))
467
468(defun seek (sec &optional relative)
469 "Seek in the currently playing song. If RELATIVE is NIL (the
470default), seeks to SEC seconds from the start; otherwise, seeks to SEC
471seconds from the current position (may be negative)."
472 (with-status (songid pos)
473 (if relative
474 (setf sec (+ pos sec)))
475 (mpd-command "seekid" songid sec)))
476
477(defun set-volume (value &optional relative)
478 "Tells the MPD to change the audio system volume to VALUE, ranging
479from 0 to 100. If RELATIVE is non-NIL, change the current volume by
480VALUE (which may be negative) instead."
481 (mpd-command "setvol"
482 (clipnum (if relative
483 (with-status (volume)
484 (+ volume value))
485 value)
486 0 100)))
487
488(export '(current-song song-info playlist status with-status ping maybe-ping
489 play-song next prev toggle-pause pause play stop seek set-volume
490 search-song search-playlist))
491(provide :mpcl)