;;; my-nov.el -- Extensions for nov.el -*- lexical-binding: t -*-

;; Copyright (C) 2023 Free Software Foundation.

;; Author: Yuchen Pei <id@ypei.org>
;; Package-Requires: ((emacs "28.2"))

;; This file is part of dotfiles.

;; dotfiles is free software: you can redistribute it and/or modify it under
;; the terms of the GNU Affero General Public License as published by
;; the Free Software Foundation, either version 3 of the License, or
;; (at your option) any later version.

;; dotfiles 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 Affero General
;; Public License for more details.

;; You should have received a copy of the GNU Affero General Public
;; License along with dotfiles.  If not, see <https://www.gnu.org/licenses/>.

;;; Commentary:

;; Extensions for nov.el.

;;; Code:

(require 'nov)

;; override nov-render-title
;; this is because header line does not work with follow mode
(defun my-nov-render-title (dom)
  "Custom <title> rendering function for DOM.
Sets `header-line-format' to a combination of the EPUB title and
chapter title."
  (let ((title (cdr (assq 'title nov-metadata)))
        (chapter-title (car (esxml-node-children dom))))
    (when (not chapter-title)
      (setq chapter-title "No title"))
    ;; this shouldn't happen for properly authored EPUBs
    (when (not title)
      (setq title "No title"))
    (setq mode-line-buffer-identification
	        (concat title ": " chapter-title))
    ))

(defun my-nov-scroll-up (arg)
  "Scroll with `scroll-up' or visit next chapter if at bottom."
  (interactive "P")
  (if (>= (follow-window-end) (point-max))
      (nov-next-document)
    (follow-scroll-up arg)))

(provide 'my-nov)
;;; my-nov.el ends here