Refactor: save something and tidy things up.

* bongo.el: Try to implement a mechanism to play subtitles along with
  the music, but it is not yet finished.

* subed-conf.el: Make it work.

* text-conf.el (insert-section-heading): Delete unnecessary debugging
  mechanisms.

3 files changed, 318 insertions, 2 deletions

diff --git a/bongo.el b/bongo.el
index 7aa33ec..a0efde3 100644
--- a/bongo.el
+++ b/bongo.el
@@ -749,10 +749,273 @@ will do the right renaming."
            (write-region nil nil file)))))
      files)))
 
+;;; Play subtitles synchronously
+
+;; Sometimes I want to play the subtitles as the song plays.
+
+(defvar durand-bongo-sub-buffer-name "*Subtitles*"
+  "The name of the buffer for playing subtitles.")
+
+(defvar durand-bongo-sub-buffer nil
+  "The buffer for playing subtitles.")
+
+(defun durand-bongo-sub-stop-timer (player)
+  "Stop subtitle timer for the PLAYER."
+  (let ((timer (bongo-player-get player 'sub-timer)))
+    (cond
+     (timer
+      (cancel-timer timer)
+      (bongo-player-put player 'sub-timer nil)))))
+
+(defun durand-bongo-sub-tick (player)
+  "Tick when playing subtitles."
+  (if (or (null bongo-sub-buffer)
+          (not (bongo-player-running-p player))
+          (and (bongo-player-get player 'socket)
+               (not (equal (process-status (bongo-player-get player 'socket))
+                           'open))))
+      (durand-bongo-sub-stop-timer player)
+    (bongo--run-mpv-command player "sub-pos" "get_property" "time-pos")
+    (bongo-sub-redisplay)))
+
+(defun durand-bongo-sub-start-timer (player)
+  "Start ticking when playing subtitles."
+  (durand-bongo-sub-stop-timer player)
+  (let ((timer (run-with-timer bongo-mpv-initialization-period
+                               (bongo-player-get
+                                player 'time-update-delay-after-seek)
+                               'durand-bongo-sub-tick
+                               player)))
+    (bongo-player-put player 'sub-timer timer)))
+
+(defun durand-bongo-sub-start-timer-maybe (&rest _args)
+  "Start the subtitle timer for the mpv backend."
+  (with-bongo-playlist-buffer
+    (cond
+     ((and bongo-player (eq (car bongo-player) 'mpv))
+      (durand-bongo-sub-start-timer bongo-player)))))
+
+;;;; My custom filter
+
+;; To handle subtitle events
+
+(defun durand-bongo--mpv-socket-filter (process output)
+  "Filter for socket connection with mpv.
+
+PROCESS is the socket which returned the OUTPUT."
+  (let ((player (process-get process 'bongo-player)))
+    (dolist (parsed-response (mapcar #'json-read-from-string
+                                     (split-string output "\n" t)))
+      ;; Events are treated differently from normal responses
+      (if (assoc 'event parsed-response)
+          (pcase (bongo-alist-get parsed-response 'event)
+            (`"pause" (progn
+                        (bongo-player-put player 'paused t)
+                        (bongo-player-paused/resumed player)))
+            (`"unpause" (progn
+                          (bongo-player-put player 'paused nil)
+                          (bongo-player-paused/resumed player))))
+        ;; Use request-id to identify the type of response
+        (pcase (bongo-alist-get parsed-response 'request_id)
+          (`"sub-pos" (progn
+                        (message "data = %S" (bongo-alist-get parsed-response 'data))
+                        ;; (durand-bongo-update-sub-time
+                        ;;  player
+                        ;;  (bongo-alist-get parsed-response 'data))
+                        ))
+          (`"time-pos" (progn
+                         (bongo-player-update-elapsed-time player
+                                                           (bongo-alist-get parsed-response
+                                                                            'data))
+                         (bongo-player-times-changed player)))
+          (`"duration" (progn
+                         (bongo-player-update-total-time player
+                                                         (bongo-alist-get parsed-response
+                                                                          'data))
+                         (bongo-player-times-changed player)))
+          (`"metadata" (let* ((data (bongo-alist-get parsed-response 'data))
+                              (album (bongo-alist-get data 'album))
+                              (title (bongo-alist-get data 'title))
+                              (genre (bongo-alist-get data 'genre)))
+                         (bongo-player-put player 'metadata-fetched t)
+                         (when album
+                           (bongo-player-put player 'stream-name album))
+                         (when title
+                           (bongo-player-put player 'stream-part-title title))
+                         (when genre
+                           (bongo-player-put player 'stream-genre genre))
+                         (when (or album title genre)
+                           (bongo-player-metadata-changed player)))))))))
+
+(advice-add #'bongo--mpv-socket-filter :override
+            #'durand-bongo--mpv-socket-filter)
+
+;;;; Update subtime
+
+(defun durand-bongo-update-sub-time (player elapsed-time)
+  "Set PLAYER's `sub-time' property to ELAPSED-TIME,
+unless PLAYER's last seek happened less than N seconds ago, where N
+is the value of PLAYER's `time-update-delay-after-seek' property."
+  (let ((delay (bongo-player-get player 'time-update-delay-after-seek)))
+    (when (or (null delay) (zerop delay)
+              (let ((time (bongo-player-get player 'last-sub-time)))
+                (or (null time)
+                    (time-less-p (seconds-to-time delay)
+                                 (subtract-time (current-time) time)))))
+      (bongo-player-put player 'sub-time elapsed-time))))
+
+;;;; Redisplay
+
+(defvar bongo-sub-redisplaying nil
+  "Non-nil in the dynamic scope of `bongo-sub-redisplay'.")
+
+(defun bongo-sub-redisplay ()
+  "Update the Bongo Subtitle buffer to reflect the current time."
+  (interactive)
+  (unless bongo-sub-redisplaying
+    (let ((bongo-sub-redisplaying t))
+      (let ((inhibit-read-only t))
+        (set-buffer bongo-sub-buffer)
+        (delete-region (point-min) (point-max))
+        (insert (bongo-sub-status-string (window-width)))))))
+
+;;;; Display string
+
+(defun durand-convert-sub-second (time sub)
+  "Convert TIME to add sub-seconds time given by SUB.
+TIME must be a list of two to four elements."
+  (cond
+   ((and (listp time)
+         (<= (length time) 4)
+         (<= 2 (length time))))
+   ((error "Wrong time: %S" time)))
+  ;; high
+  (let ((th (car time))
+        (tl (cadr time))
+        (tu (cond
+             ((>= (length time) 3) (nth 3 time))
+             (0)))
+        (tp (cond
+             ((>= (length time) 4) (nth 4 time))
+             (0)))
+        (sub-digit-n
+         (let ((n sub)
+               (count 0))
+           (while (> n 0)
+             (setq count (1+ count))
+             (setq n (/ n 10)))
+           count)))
+    (cond
+     ((<= sub-digit-n 6)
+      (setq tu (+ tu sub)))
+     ((<= sub-digit-n 12)
+      (setq tu (+ tu (/ sub (expt 10 6))))
+      (setq tp (+ tp (% sub (expt 10 6)))))
+     ((error "Wrong sub: %S" sub)))
+    (append
+     (list th tl)
+     (delq
+      nil
+      (mapcar
+       (lambda (ele)
+         (cond ((/= ele 0) ele)))
+       (list tu tp))))))
+
+(defun bongo-sub-status-string (width)
+  "Return the subtitle filled to WIDTH."
+  (cond
+   ((and (bongo-playing-p)
+         (bongo-player-get bongo-player 'sub-time)
+         (bongo-player-get bongo-player 'sub-file-buffer))
+    (let ((fb (bongo-player-get bongo-player 'sub-file-buffer))
+          (time (bongo-player-get bongo-player 'sub-time))
+          found start start-sub end end-sub)
+      (setq time
+            (parse-time-string
+             (format-seconds "%.2h:%.2m:%.2s" time)))
+      (with-current-buffer fb
+        (goto-char (point-min))
+        (save-match-data
+          (while (and
+                  (not found)
+                  (re-search-forward
+                   (rx bol
+                       (group
+                        (1+ digit) ":"
+                        (1+ digit) ":" (1+ digit)
+                        (zero-or-one
+                         "," (1+ digit)))
+                       (zero-or-more " ")
+                       "-->"
+                       (zero-or-more " ")
+                       (group
+                        (1+ digit) ":"
+                        (1+ digit) ":" (1+ digit)
+                        (zero-or-one
+                         "," (1+ digit)))
+                       eol)
+                   nil t))
+            (setq start (match-string 1))
+            (setq end (match-string 2))
+            (cond
+             ((string-match ",\\([[:digit:]]+\\)$" start)
+              (setq start-sub (match-string 1 start))
+              (setq
+               start
+               (durand-convert-sub-second
+                (let ((fake-time (parse-time-string
+                                  (replace-regexp-in-string
+                                   ",.*$" "" start))))
+                  (encode-time
+                   (append
+                    (mapcar (lambda (ele) (or ele 0))
+                            (durand-take 6 fake-time))
+                    (nthcdr 6 fake-time))))
+                (string-to-number start-sub))))
+             ((setq start (parse-time-string start))))
+            (cond
+             ((string-match ",\\([[:digit:]]+\\)$" end)
+              (setq end-sub (match-string 1 end))
+              (setq
+               end
+               (durand-convert-sub-second
+                (let ((fake-time (parse-time-string
+                                  (replace-regexp-in-string
+                                   ",.*$" "" end))))
+                  (encode-time
+                   (append
+                    (mapcar (lambda (ele) (or ele 0))
+                            (durand-take 6 fake-time))
+                    (nthcdr 6 fake-time))))
+                (string-to-number end-sub))))
+             ((setq end (parse-time-string end))))
+            (cond
+             ((and (time-less-p start time)
+                   (time-less-p time end))
+              (setq found t))))
+          (cond
+           (found
+            (save-match-data
+              (save-excursion
+                (setq
+                 end
+                 (cond
+                  ((re-search-forward (rx bol (zero-or-more space) eol) nil t)
+                   (point))
+                  ((point-max)))))
+              (buffer-substring-no-properties
+               (1+ (point)) end))))))))))
+
 ;; Normally we should do this, but I override the function by my
 ;; custom function, so I can just call this function there.
 
 ;; (advice-add #'bongo-seek :after  #'durand-bongo-seek-start-timer-maybe)
 
+;;;; Subtitle command
+
+;; TODO
+
+;;; Volume package
+
 (use-package "volume" 'volume
   (define-key volume-mode-map [?s] #'volume-set))
diff --git a/subed-conf.el b/subed-conf.el
new file mode 100644
index 0000000..f9404ad
--- /dev/null
+++ b/subed-conf.el
@@ -0,0 +1,55 @@
+;;; subed-conf.el --- Configurations of Subed        -*- lexical-binding: t; -*-
+
+;; Copyright (C) 2021  Durand
+
+;; Author: 李俊緯 <mmemmew@gmail.com>
+;; Keywords: convenience, multimedia, data
+
+;; 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 3 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, see <https://www.gnu.org/licenses/>.
+
+;;; Commentary:
+
+;; My configurations of the superb package subed:
+;; https://github.com/sachac/subed
+
+;;; Code:
+
+(use-package "subed/subed" 'subed)
+
+;;; Use a shorter name for the socket
+
+(setq subed-mpv-socket-dir "/tmp/")
+
+;; Make some modifications so that mpv works
+
+(defun durand-subed-mpv--socket ()
+  "Path to mpv's RPC socket for a particular buffer.
+See also `subed-mpv-socket-dir'."
+  (unless (file-exists-p subed-mpv-socket-dir)
+    (condition-case err
+        (make-directory subed-mpv-socket-dir :create-parents)
+      (file-error
+       (error "%s" (mapconcat #'identity (cdr err) ": ")))))
+  (concat (file-name-as-directory subed-mpv-socket-dir)
+          (truncate-string-to-width
+           (format "%s%s"
+                   (let ((filename (file-name-sans-extension (subed--buffer-file-name))))
+                     (substring (substring filename 0 (min (length filename) 20))))
+                   (buffer-hash))
+           15)))
+
+(advice-add #'subed-mpv--socket :override #'durand-subed-mpv--socket)
+
+(provide 'subed-conf)
+;;; subed-conf.el ends here
diff --git a/text-conf.el b/text-conf.el
index ad0d78f..5bf2218 100644
--- a/text-conf.el
+++ b/text-conf.el
@@ -43,8 +43,6 @@ exactly the current ilne."
       (goto-char (line-end-position))
       (newline)
       (while (< index floor-length)
-        (message "index: %s" index)
-        (message "floor: %s" floor-length)
         (insert heading)
         (setq index (1+ index)))
       (insert remainder-string))))