youtube-dl-view.el

;;; youtube-dl-view.el --- shows video clip info in a separate buffer -*- lexical-binding: t; -*-

;; Copyright (C) 2022 Igor B. Poretsky <poretsky@mlbox.ru>

;; This file is not part of GNU Emacs.

;; 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 2, 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, you can either send email to this
;; program's maintainer or write to: The Free Software Foundation,
;; Inc.; 59 Temple Place, Suite 330; Boston, MA 02111-1307, USA.


;;; Commentary:

;; This module shows video clip info in a separate buffer. In this
;; buffer you can navigate and activate highlighted references.

;; The `youtube-dl-view' command retrieves video description
;; from specified URL or from an item under point in the download
;; list and shows it.

;;; Code:

(require 'cl-lib)
(require 'button)
(require 'custom)
(require 'youtube-dl)

(declare-function w3m-bookmark-add "w3m-bookmark" (url &optional title))

;;;###autoload
(defgroup youtube-dl-view ()
  "YouTube video descriptions view settings."
  :group 'youtube-dl)

(defcustom youtube-dl-view-fill-column 0
  "Column beyond which automatic line-wrapping should happen
in view buffer. Positive number means just that column. If it is 0,
full window width is used. Negative number means respective
subtraction from the window width. If it is nil, no filling
will be applied."
  :group 'youtube-dl-view
  :type '(choice (const :tag "No filling" nil) integer))

(defgroup youtube-dl-view-faces ()
  "Video description display faces."
  :group 'youtube-dl-view)

(defface youtube-dl-view-title
  '((t :inherit font-lock-comment-face))
  "Face for highlighting item title."
  :group 'youtube-dl-view-faces)

(defface youtube-dl-view-header
  '((t :inherit font-lock-comment-delimiter-face))
  "Face for highlighting header titles."
  :group 'youtube-dl-view-faces)

(defface youtube-dl-view-header-value
  '((t :inherit font-lock-comment-face))
  "Face for highlighting header values."
  :group 'youtube-dl-view-faces)

(define-button-type 'youtube-dl-view-play-start-time 'action
  (lambda (button)
    (youtube-dl-view-play-current-url (button-get button 'start-time)))
  :supertype 'button)

(define-button-type 'youtube-dl-view-play 'action
  (lambda (_button)
    (youtube-dl-view-play-current-url))
  :supertype 'button)

(define-button-type 'youtube-dl-view-download 'action
  (lambda (button)
    (cl-declare (special youtube-dl-view-item))
    (youtube-dl-submit (list youtube-dl-view-item)
                :immediate (youtube-dl-request-immediate)
                :extract-audio (button-get button 'audio-only)
                :display t))
  :supertype 'button)

(defvar youtube-dl-view-history nil
  "Viewing history.")

(defun youtube-dl-view--current-url ()
  "Return currently viewed item url."
  (cl-declare (special youtube-dl-view-item))
  (plist-get youtube-dl-view-item :url))

(defun youtube-dl-view-play-current-url (&optional start-time)
  "Play current url from specified start time."
  (interactive)
  (unless (eq major-mode 'youtube-dl-view-mode)
    (error "Not in youtube-dl-view buffer."))
  (youtube-dl-play (youtube-dl-view--current-url) start-time))

(defun youtube-dl-view-yank-current-url ()
  "Yank current clip URL into kill-ring."
  (interactive)
  (unless (eq major-mode 'youtube-dl-view-mode)
    (error "Not in youtube-dl-view buffer."))
  (let ((url (youtube-dl-view--current-url)))
    (kill-new url)
    (message "Yanked %s" url)))

(defun youtube-dl-view--stored-p ()
  "Returns non-nil if currently viewed item is stored at the top of history."
  (and youtube-dl-view-history
       (string-equal (plist-get (car youtube-dl-view-history) :url)
                     (youtube-dl-view--current-url))))

(define-button-type 'youtube-dl-view-link 'action
  (lambda (_button)
    (unless (youtube-dl-view--stored-p)
      (push youtube-dl-view-item youtube-dl-view-history))
    (let ((url (thing-at-point 'url t)))
      (if (zerop (call-process youtube-dl-program nil nil nil
                               "--ignore-config"
                               "--simulate"
                               "--flat-playlist"
                               "--"
                               url))
          (youtube-dl-view url)
        (browse-url url))))
  :supertype 'button)

(define-button-type 'youtube-dl-view-mail 'action
  (lambda (_button)
    (compose-mail (thing-at-point 'email t)))
  :supertype 'button)

(define-button-type 'youtube-dl-view-back 'action
  (lambda (_button)
    (when (youtube-dl-view--stored-p)
      (pop youtube-dl-view-history))
    (unless youtube-dl-view-history
      (error "No more history."))
    (youtube-dl-view (pop youtube-dl-view-history)))
  :supertype 'button)

(defun youtube-dl-view-quit ()
  "Clear history and close window. Also stops playback if any."
  (interactive)
  (unless (eq major-mode 'youtube-dl-view-mode)
    (error "Not in youtube-dl-view buffer."))
  (when (featurep 'youtube-dl-play)
    (youtube-dl-play-stop))
  (setq youtube-dl-view-history nil)
  (quit-window))

(defun youtube-dl-view-add-w3m-bookmark ()
  "Add currently viewed clip to the w3m bookmarks."
  (interactive)
  (unless (eq major-mode 'youtube-dl-view-mode)
    (error "Not in youtube-dl-view buffer."))
  (require 'w3m-bookmark)
  (w3m-bookmark-add (youtube-dl-view--current-url) header-line-format)
  (message "Bookmark added"))

(defvar youtube-dl-view-mode-map
  (let ((map (make-sparse-keymap)))
    (prog1 map
      (set-keymap-parent map button-buffer-map)
      (define-key map "y" #'youtube-dl-view-yank-current-url)
      (define-key map "a" #'youtube-dl-view-add-w3m-bookmark)
      (define-key map " " #'youtube-dl-view-play-current-url)
      (define-key map "k" #'youtube-dl-play-stop)
      (define-key map "q" #'youtube-dl-view-quit)))
  "Keymap for `youtube-dl-view-mode'")

(define-derived-mode youtube-dl-view-mode special-mode "youtube-dl-view"
  "Major mode for viewing youtube-dl items info."
  :group 'youtube-dl-view
  (use-local-map youtube-dl-view-mode-map))

(defconst youtube-dl-view-time-spec
  "\\(?:[0-9]+:\\)?[0-5]?[0-9]:[0-5][0-9]\\(?:\\.[0-9]+\\)?"
  "Timespec matching regexp.")

(cl-defun youtube-dl-view--show-description
    (text url submitted-p &key id title filesize duration timestamp views likes)
  "Show a description represented by given text.
The second argument specifies source URL for reference.
The third argument indicates whether this URL is already submitted
for download."
  (cl-declare (special youtube-dl-view-item))
  (with-current-buffer (get-buffer-create " *youtube-dl view*")
    (youtube-dl-view-mode)
    (let ((window (get-buffer-window))
          (inhibit-read-only t)
          (playable-p (youtube-dl-playable-p url)))
      (erase-buffer)
      (when title
        (setq header-line-format
              (propertize title 'face 'youtube-dl-view-title)))
      (when filesize
        (insert (propertize "FileSize" 'face 'youtube-dl-view-header)
                "  "
                (propertize (format "%d" filesize) 'face 'youtube-dl-view-header-value)
                "\n"))
      (when duration
        (insert (propertize "Duration" 'face 'youtube-dl-view-header)
                "  "
                (propertize (format-time-string "%T" (seconds-to-time duration) t)
                            'face 'youtube-dl-view-header-value)
                "\n"))
      (when timestamp
        (insert (propertize "Date" 'face 'youtube-dl-view-header)
                "      "
                (propertize (format-time-string "%c" (seconds-to-time timestamp))
                            'face 'youtube-dl-view-header-value)
                "\n"))
      (when views
        (insert (propertize "Views" 'face 'youtube-dl-view-header)
                "     "
                (propertize (format "%d" views) 'face 'youtube-dl-view-header-value)
                "\n"))
      (when likes
        (insert (propertize "Likes" 'face 'youtube-dl-view-header)
                "     "
                (propertize (format "%d" likes) 'face 'youtube-dl-view-header-value)
                "\n"))
      (unless (bobp)
        (insert "\n"))
      (when playable-p
        (insert-button "Play"
                       :type 'youtube-dl-view-play))
      (unless submitted-p
        (unless (bolp)
          (insert "  "))
        (insert-button "Download"
                       :type 'youtube-dl-view-download)
        (when playable-p
          (insert "  ")
          (insert-button "Download audio" 'audio-only t
                         :type 'youtube-dl-view-download)))
      (unless (bolp)
        (insert "\n\n"))
      (let ((start (point)))
        (insert (or text ""))
        (unless (or (bobp) (= (char-before) ?\n))
          (insert "\n"))
        (when youtube-dl-view-history
          (insert "\n")
          (insert-button "Back"
                         :type 'youtube-dl-view-back)
          (insert "\n"))
        (goto-char start)
        (while
            (re-search-forward
             (concat
              "\\( +\\)\\[?"
              youtube-dl-view-time-spec)
             nil t)
          (replace-match "\n" nil nil nil 1))
        (when (integerp youtube-dl-view-fill-column)
          (let ((fill-column
                 (if (> youtube-dl-view-fill-column 0)
                     youtube-dl-view-fill-column
                   (- (window-body-width) youtube-dl-view-fill-column))))
            (fill-individual-paragraphs start (point-max) nil
                                        (concat
                                         "\\[?"
                                         youtube-dl-view-time-spec
                                         "]? \\|-*[0-9]+\\.? \\|.+[ \t\n][^ \t\n]+\\(?:@\\|://\\)"))))
        (goto-char start))
      (while
          (re-search-forward
           (concat
            "\\([a-zA-Z0-9]@[a-zA-Z0-9]\\)\\|\\(https?://[a-zA-Z0-9]+\\.[a-zA-Z0-9]\\)\\|^\\(?:\\(-*\\([0-9]+\\.?\\)\\(?: \\| .* \\)(?\\("
            youtube-dl-view-time-spec
            "\\))?\\)\\|\\[?\\("
            youtube-dl-view-time-spec
            "\\)]?\\)")
           nil t)
        (cond
         ((match-string 1)
          (let ((link (bounds-of-thing-at-point 'email)))
            (when link
              (make-button (car link) (cdr link)
                           :type 'youtube-dl-view-mail))))
         ((match-string 2)
          (let ((link (bounds-of-thing-at-point 'url)))
            (when link
              (make-button (car link) (cdr link)
                           :type 'youtube-dl-view-link))))
         ((match-string 3)
          (make-button (match-beginning 4) (match-end 4)
                       'start-time (buffer-substring-no-properties (match-beginning 5) (match-end 5))
                       :type 'youtube-dl-view-play-start-time))
         (t (make-button (match-beginning 0) (match-end 0)
                         'start-time (buffer-substring-no-properties (match-beginning 6) (match-end 6))
                         :type 'youtube-dl-view-play-start-time))))
      (set (make-local-variable 'youtube-dl-view-item)
           (list
            :index 1
            :id id
            :url url
            :title title
            :description text
            :duration duration
            :filesize filesize))
      (goto-char (point-min))
      (when window
        (set-window-point window (point-min)))
      (let ((split-width-threshold nil))
        (pop-to-buffer (current-buffer))))))

;;;###autoload
(defun youtube-dl-view (thing)
  "Retrieves and shows info from specified URL or, being invoked
in the download listing, for an item under point. If specified URL
points to a playlist and it has more than one item, this playlist
is submitted for download as paused and shown in the listing.
The argument can be a plist of clip data as well."
  (interactive (youtube-dl-thing))
  (let* ((submitted-p (youtube-dl-item-p thing))
         (playlist
          (cond
           ((stringp thing)
            (youtube-dl-playlist-list thing))
           ((and submitted-p
                 (or (not (youtube-dl-item-description thing))
                     (not (youtube-dl-item-title thing))))
            (youtube-dl-playlist-list (youtube-dl-item-url thing)))
           (t nil)))
         (item
          (if playlist
              (car playlist)
            thing))
         (id
          (if (youtube-dl-item-p item)
              (youtube-dl-item-id item)
            (plist-get item :id)))
         (title
          (if (youtube-dl-item-p item)
              (youtube-dl-item-title item)
            (or (plist-get item :title) id)))
         (filesize
          (if (youtube-dl-item-p item)
              (youtube-dl-item-filesize item)
            (plist-get item :filesize)))
         (duration
          (if (youtube-dl-item-p item)
              (youtube-dl-item-duration item)
            (plist-get item :duration)))
         (timestamp
          (if (youtube-dl-item-p item)
              (youtube-dl-item-timestamp item)
            (plist-get item :timestamp)))
         (views
          (if (youtube-dl-item-p item)
              (youtube-dl-item-views item)
            (plist-get item :views)))
         (likes
          (if (youtube-dl-item-p item)
              (youtube-dl-item-likes item)
            (plist-get item :likes)))
         (text
          (or (if (youtube-dl-item-p item)
                  (youtube-dl-item-description item)
                (plist-get item :description))
              ""))
         (url
          (if (youtube-dl-item-p item)
              (youtube-dl-item-url item)
            (or (plist-get item :url) thing))))
    (if (> (length playlist) 1)
        (youtube-dl-submit playlist
                           :display t)
      (when (and submitted-p playlist)
        (youtube-dl-item-title-set thing title)
        (let ((name (youtube-dl-item-dest-name thing)))
          (when (string-match (format "^\\(?:[0-9]+-\\)?\\(%s\\)" id) name)
            (youtube-dl-item-dest-name-set
             thing (replace-match title nil nil name 1))
            (youtube-dl-redisplay)))
        (youtube-dl-item-description-set thing text)
        (youtube-dl-item-filesize-set thing filesize)
        (youtube-dl-item-duration-set thing duration)
        (youtube-dl-item-timestamp-set thing timestamp)
        (youtube-dl-item-views-set thing views)
        (youtube-dl-item-likes-set thing likes))
      (youtube-dl-view--show-description text url submitted-p
                                         :id id
                                         :title title
                                         :filesize filesize
                                         :duration duration
                                         :timestamp timestamp
                                         :views views
                                         :likes likes))))

(provide 'youtube-dl-view)

;;; youtube-dl-view.el ends here