+(defvar emus-records nil
+ "Emus audio library.")
+
+(defun emus-make-record (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)))))
+ (vector artist album title filename nil)))
+
+(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-update-records ()
+ (interactive)
+ (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 (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)
+ (emus-render-records)
+ (emus-resume-cp)))))
+ (emus-send-cmd "lp" (car filenames))))
+
+(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))))))
+
+;;; 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"))))
+ (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."
+ (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."
+ (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)
+ (setq emus-state 'stopped)
+ (emus-update-record emus-current-record)
+ (emus-send-cmd "s"))
+
+(defun emus-playpause ()
+ (interactive)
+ (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)))
+
+(defun emus-set-volume (pct)
+ (emus-send-cmd "v" (number-to-string pct)))
+
+(defvar emus-current-volume 100)
+
+(defun emus-volume-delta (delta)
+ (setq emus-current-volume (max 0 (min 100 (+ emus-current-volume delta))))
+ (emus-set-volume emus-current-volume))
+
+(defun emus-volume-up ()
+ (interactive)
+ (emus-volume-delta 10))
+
+(defun emus-volume-down ()
+ (interactive)
+ (emus-volume-delta -10))
+
+(defun emus-play-nearby (offset)
+ (let ((idx (seq-position emus-records emus-current-record)))
+ (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 is currently selected."))))
+
+(defun emus-play-next ()
+ (interactive)
+ (emus-play-nearby 1))
+
+(defun emus-play-prev ()
+ (interactive)
+ (emus-play-nearby -1))
+
+(defun emus-display-status ()
+ (interactive)
+ (message
+ (concat "Emus: Volume %d%%"
+ (pcase emus-state
+ ('stopped " [Stopped]")
+ ('paused " [Paused]")
+ ('playing " [Playing]")
+ (_ ""))
+ (if emus-current-record
+ (format " - %.30s (%.20s)"
+ (emus-record-title emus-current-record)
+ (emus-record-artist emus-current-record))
+ ""))
+ emus-current-volume))
+
+
+;;; Browser
+;;
+
+(defun emus-insert-record (record &optional prev-record first)
+ (let* ((artist (emus-record-artist record))
+ (album (emus-record-album record))
+ (title (emus-record-title record))
+ (help-str (format "mouse-1, RET: Play '%.30s' (%.20s)" title artist)))
+ (when (or prev-record first)
+ (unless (equal (emus-record-artist prev-record) artist)
+ (insert-text-button
+ (propertize artist 'face 'emus-artist)
+ 'action #'emus-click-record
+ 'follow-link t
+ 'help-echo help-str
+ 'emus-record record)
+ (insert (propertize "\n" 'face 'emus-artist)))
+ (unless (equal (emus-record-album prev-record) album)
+ (insert-text-button
+ (propertize (concat " " album) 'face 'emus-album)
+ 'action #'emus-click-record
+ 'follow-link t
+ 'help-echo help-str
+ 'emus-record record)
+ (insert (propertize "\n" 'face 'emus-album))))
+ (emus-set-record-browser-pos record (point))
+ (let ((is-current (equal record emus-current-record)))
+ (insert-text-button
+ (concat
+ (if is-current
+ (propertize
+ (pcase emus-state
+ ('playing "->")
+ ('paused "-)")
+ ('stopped "-]"))
+ 'face 'emus-cursor)
+ (propertize " " 'face 'default))
+ (propertize (format " %s" title)
+ 'face (if is-current
+ 'emus-track-current
+ 'emus-track)))
+ 'action #'emus-click-record
+ 'follow-link t
+ 'help-echo help-str
+ 'emus-record record)
+ (insert (propertize "\n"
+ 'face (if is-current
+ 'emus-track-current
+ 'emus-track))))))
+
+(defun emus-update-record (record)
+ (let ((record-pos (emus-record-browser-pos record)))
+ (when (and (get-buffer "*emus*")
+ (emus-record-browser-pos record))
+ (with-current-buffer "*emus*"
+ (let ((inhibit-read-only t)
+ (old-point (point)))
+ (goto-char record-pos)
+ (search-forward "\n")
+ (delete-region record-pos (point))
+ (goto-char record-pos)
+ (emus-insert-record record)
+ (goto-char old-point))))))
+
+(defun emus-render-records ()
+ (with-current-buffer "*emus*"
+ (let ((inhibit-read-only t)
+ (old-pos (point)))
+ (erase-buffer)
+ (goto-char (point-min))
+ (let ((prev-record nil))
+ (dolist (record emus-records)
+ (emus-insert-record record prev-record (not prev-record))
+ (setq prev-record record)))
+ (goto-char old-pos))))
+
+(defun emus-click-record (button)
+ (emus-play-record (button-get button 'emus-record)))
+
+(defun emus-centre-current ()
+ (interactive)
+ (when (get-buffer "*emus*")
+ (switch-to-buffer "*emus*")
+ (when emus-current-record
+ (goto-char (emus-record-browser-pos emus-current-record))
+ (recenter))))
+
+(defun emus-browse ()
+ "Switch to *emus* audio library browser."