+(defvar emus-records nil
+ "Emus audio library.")
+
+(defun emus-make-record (artist album title filename &optional pos)
+ (vector artist album title filename pos))
+
+(defun emus-record-artist (record)
+ (elt record 0))
+
+(defun emus-record-album (record)
+ (elt record 1))
+
+(defun emus-record-title (record)
+ (elt record 2))
+
+(defun emus-record-file (record)
+ (elt record 3))
+
+(defun emus-record-browser-pos (record)
+ (elt record 4))
+
+(defun emus-set-record-browser-pos (record pos)
+ (aset record 4 pos))
+
+(defun emus--load-library (then)
+ (emus--suspend-cp)
+ (setq emus-state 'stopped)
+ (let ((proc (emus-get-process))
+ (tagstr "")
+ (filenames (emus-get-audio-files)))
+ (setq emus-records nil)
+ (set-process-filter proc (lambda (proc string)
+ (setq tagstr (concat tagstr string))
+ (when (string-suffix-p "@P 1\n" string)
+ (add-to-list 'emus-records
+ (emus--make-record-from-tagstr (car filenames)
+ tagstr))
+ (setq tagstr "")
+ (setq filenames (cdr filenames))
+ (if filenames
+ (emus-send-cmd "lp" (car filenames))
+ (set-process-filter proc nil)
+ (setq emus-records (reverse emus-records))
+ (emus--sort-records)
+ (unless emus-current-record
+ (setq emus-current-record (car emus-records)))
+ (funcall then)
+ ;; (emus-render-records)
+ (emus--resume-cp)))))
+ (emus-send-cmd "lp" (car filenames))))
+
+(defun emus--make-record-from-tagstr (filename tagstr)
+ (let ((artist "")
+ (album "")
+ (title ""))
+ (dolist (line (split-string tagstr "\n"))
+ (let ((found-artist (elt (split-string line "@I ID3v2.artist:") 1))
+ (found-album (elt (split-string line "@I ID3v2.album:") 1))
+ (found-title (elt (split-string line "@I ID3v2.title:") 1)))
+ (cond
+ (found-artist (setq artist found-artist))
+ (found-album (setq album found-album))
+ (found-title (setq title found-title)))))
+ (emus-make-record artist album title filename nil)))
+
+(defun emus--sort-records ()
+ (sort emus-records
+ (lambda (r1 r2)
+ (let ((artist1 (emus-record-artist r1))
+ (artist2 (emus-record-artist r2)))
+ (if (string= artist1 artist2)
+ (let ((album1 (emus-record-album r1))
+ (album2 (emus-record-album r2)))
+ (string< album1 album2))
+ (string< artist1 artist2))))))
+
+(defmacro emus--with-library (&rest args)
+ `(if emus-records
+ (progn ,@args)
+ (emus--load-library
+ (lambda () ,@args))))
+
+;;; mpg123 process
+;;
+
+(defvar emus-proc-in-use nil)
+
+(defun emus-get-process ()
+ "Return current or new mpg123 process."
+ (let* ((emus-process-raw (get-process "emus-process"))
+ (emus-process (if emus-process-raw
+ (if (process-live-p emus-process-raw)
+ emus-process-raw
+ (kill-process emus-process-raw)
+ nil))))
+ (if emus-process
+ emus-process
+ (let ((proc
+ (make-process :name "emus-process"
+ ;; :buffer (get-buffer-create "*emus-process*")
+ :command `(,emus-mpg123-program "-R"))))
+ (set-process-query-on-exit-flag proc nil)
+ (process-send-string proc "silence\n")
+ proc))))
+
+
+(defun emus-send-cmd (cmd &rest args)
+ (process-send-string (emus-get-process)
+ (concat
+ (seq-reduce (lambda (s1 s2) (concat s1 " " s2)) args cmd)
+ "\n")))
+
+(defun emus-send-and-process (respfun predfun cmd &rest args)
+ (let ((respstr ""))
+ (set-process-filter (emus-get-process)
+ (lambda (proc string)
+ (setq respstr (concat respstr string))
+ (when (funcall predfun respstr)
+ (set-process-filter proc nil)
+ (funcall respfun respstr))))
+ (apply #'emus-send-cmd cmd args)))
+
+
+;;; Playback
+;;
+
+(defvar emus-current-record nil)
+(defvar emus-state 'stopped)
+(defvar emus-continuous-playback t)
+
+(defun emus--suspend-cp ()
+ (setq emus-continuous-playback nil))
+
+(defun emus--resume-cp ()
+ (setq emus-continuous-playback t)
+ (set-process-filter (emus-get-process)
+ (lambda (proc string)
+ (and emus-continuous-playback
+ (eq emus-state 'playing)
+ (string-suffix-p "@P 0\n" string)
+ (emus-play-next)))))
+
+(defun emus-play-record (record)
+ "Set RECORD as current and start playing."
+ (emus--with-library
+ (let ((old-record emus-current-record))
+ (emus-send-cmd "l" (emus-record-file record))
+ (setq emus-state 'playing)
+ (setq emus-current-record record)
+ (emus--update-record old-record)
+ (emus--update-record record)
+ (emus--resume-cp))))
+
+(defun emus-select-record (record)
+ "Set RECORD as current, but do not start playing."
+ (emus--with-library
+ (let ((old-record emus-current-record))
+ (setq emus-state 'stopped)
+ (setq emus-current-record record)
+ (emus--update-record old-record)
+ (emus--update-record record)
+ (emus-send-cmd "o")
+ (emus--resume-cp))))
+
+(defun emus-stop ()
+ "Stop playback of the current record."
+ (interactive)
+ (emus--with-library
+ (setq emus-state 'stopped)
+ (emus--update-record emus-current-record)
+ (emus-send-cmd "s")))
+
+(defun emus-playpause ()
+ (interactive)
+ (emus--with-library
+ (when emus-current-record
+ (if (eq emus-state 'stopped)
+ (emus-play-record emus-current-record)
+ (emus-send-cmd "p")
+ (pcase emus-state
+ ((or 'paused 'stopped) (setq emus-state 'playing))
+ ('playing (setq emus-state 'paused)))
+ (unless (eq emus-state 'paused)))
+ (emus--update-record emus-current-record))))
+
+(defvar emus-current-volume 100)
+
+(defun emus-set-volume (pct)
+ (emus--with-library
+ (setq emus-current-volume pct)
+ (emus-send-cmd "v" (number-to-string pct))))
+
+(defun emus-volume-increase-by (delta)
+ (emus-set-volume (max 0 (min 100 (+ emus-current-volume delta)))))
+
+(defun emus-volume-up ()
+ (interactive)
+ (emus-volume-increase-by 10))
+
+(defun emus-volume-down ()
+ (interactive)
+ (emus-volume-increase-by -10))
+
+(defun emus--play-adjacent-track (&optional prev)
+ (emus--with-library
+ (let ((idx (seq-position emus-records emus-current-record))
+ (offset (if prev -1 +1)))
+ (if idx
+ (let ((next-record (elt emus-records (+ idx offset))))
+ (if next-record
+ (if (eq emus-state 'playing)
+ (emus-play-record next-record)
+ (emus-select-record next-record))
+ (error "Track does not exist")))
+ (error "No track selected")))))
+
+(defun emus--play-adjacent-album (&optional prev)
+ (emus--with-library
+ (let ((idx (seq-position emus-records emus-current-record)))
+ (if idx
+ (let* ((search-list (if prev
+ (reverse (seq-subseq emus-records 0 idx))
+ (seq-subseq emus-records (+ idx 1))))
+ (current-album (emus-record-album emus-current-record))
+ (next-record (seq-some (lambda (r)
+ (if (string= (emus-record-album r)
+ current-album)
+ nil
+ r))
+ search-list)))
+ (if next-record
+ (if (eq emus-state 'playing)
+ (emus-play-record next-record)
+ (emus-select-record next-record))
+ (error "Track does not exist")))
+ (error "No track selected")))))
+
+(defun emus-play-next ()
+ (interactive)
+ (emus--play-adjacent-track))
+
+(defun emus-play-prev ()