;;; nob.el --- custom bookmarks for dealing with novels in eww.  -*- lexical-binding: t; -*-

;; Copyright (C) 2019 Robert Rose

;; Author: Robert Rose <overclucker@gmail.com>
;; Keywords: lisp eww novel bookmark
;; Version: 0.0.1
;; Package-Requires ((dash "2.15.0) (emacs "24") (ivy "20190214.1032")

;; 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 <http://www.gnu.org/licenses/>.

;;; Commentary:

;; This package provides functions for saving and selecting novels for
;; for reading in eww. I wrote nob because bookmarking a chapter in eww
;; and then always having to remove old bookmarks is ridiculous. nov-save
;; works by queryinh the bookmark list a pattern that matches the current
;; url. If it finds a match, it updates the title and url and moves it to
;; the front of the list. This makes shoosing what to to read next, and
;; picking up where you left off much easier. The nob-select function
;; provides an easy to navigate pop up list.

;;; Code:

(require 'eww)
(require 'eww-http-code-advice)
(require 'dash)
(require 'ivy)

(defgroup nob nil
  "Settings for nob."
  :group 'novels)

(defcustom nob-bookmarks-file (concat user-emacs-directory "nob-bookmarks.el")
  "Location of the file nob uses for bookmark storage."
  :group 'nob)

(defcustom nob-autosave-on-render t
  "Adds `nob-eww-after-render-hook' to `eww-after-render-hook' (locally) when `nob-mode' is enabled."
  :type 'boolean
  :group 'nob)

(defmacro with-nob (&rest body)
  "Execute body with variable: `novels' set."
  `(let ((novels
	  (with-temp-buffer
	    (insert-file-contents nob-bookmarks-file)
	    (read (buffer-string)))))
     (unwind-protect ,@body)))

(defmacro with-eww-buffer (&rest body)
  "Execute body with variables: `title' and `url' set."
  `(let ((title (plist-get eww-data :title))
	 (url (plist-get eww-data :url)))
     (unwind-protect ,@body)))

;;; I will need to explore options for replacing `--map-first'
;;; Maybe it's as simple as popping and pushing. That would be nice.
(defun nob-update-bookmark (novels title url)
  "Update an existing bookmark. Returns updated novels list.'
This function has no side affects."
  (--map-first (string-match (car it) url) `(,(car it) ,title ,url)
	       (--sort (string-match (car it) url) novels)))

(defun nob-write-file (novels)
  (let ((inhibit-message 1))
    (with-temp-buffer
      (insert (pp novels))
      (write-file nob-bookmarks-file))))

(defun nob-convert-bookmarks ()
  "Used to convert bookmarks file to the new format.
(cons pattern (cons title url))
As I've started hacking away at nob mode, I've come
to realize that I can't simply rewrite the functions.
I'll need some scafolding in place so that nob remains
functional while I continue working on it."
  (interactive))
(with-temp-file (concat user-emacs-directory "nob-bookmarks")
  (with-nob
      (let*
	  ((n (mapcar
	       (lambda (x)
		 (cons (car x) (cons (cadr x) (caddr x))))
	       novels)))
	(insert (pp n))	)))

(defun nob-save ()
  "Saves current novel."
  (interactive)
  (with-nob
      (with-eww-buffer
	  (let ((n (--first (string-match (car it) url) novels)))
	    (if n
		(if (not (string-equal (nth 2 n) url))
		    (progn
		      (nob-write-file (nob-update-bookmark novels title url))
		      (message "Bookmarked: %s" title))
		  (message "Already Bookmarked"))
	      (if (y-or-n-p "Add this novel?")
		  (progn
		    (nob-write-file
		     (push `(,(read-string "Match: " url) ,title ,url) novels))
		    (message "Bookmarked: %s" title))) )) )) )

(defun nob-select ()
  "Select novel for reading in `eww'."
  (interactive)
  ;; 
  ;; version two
  ;; `assoc' is a wonderful thing.
  ;; originally required `--map' and `--first' from `dash.el'
  ;; okay, still using `--map'
  (with-nob ; novels: ((pattern title url))
      (let*
	  ((n (--map (cons (cadr it) (caddr it)) novels))
	   ;; the mapcar version is bigger.
	   ;; (n (mapcar
	   ;;     (lambda (x)
	   ;; 	 (cons (cadr x) (caddr x)))
	   ;;     novels))
	   (s (cdr (assoc (ivy-read "Select Novel: " n) n))) )
	(switch-to-buffer "*nob*")
	(unless (eq major-mode 'eww-mode)
	  (eww-mode))
	(stride-mode 1)
	(nob-mode 1)
	(article-mode 1)
	(eww-browse-url s))))

(defun nob-remove ()
  "Remove an novel."
  (interactive)
  (with-nob
      (let ((s (ivy-read "Remove Novel: " (--map (cdr it) novels))))
	(when (y-or-n-p (format "Remove \"%s\"?" s))
	  (nob-write-file
	   (--remove (string-equal s (car (cdr it))) novels))
	  (message "Removed: %s" s)) )) )

(defun nob-eww-after-render-hook ()
  "Eww render hook for nob autosave"
  (let ((status (third (plist-get eww-data :error))))
    (if (not (member status '(400 404)))
	(with-nob
	    (with-eww-buffer
		(let ((n (--first (string-match (car it) url) novels)))
		  (if n
		      (if (not (string-equal (nth 2 n) url))
			  (nob-write-file (nob-update-bookmark novels title url))))) )))) )

(setq nob-mode-map (make-sparse-keymap))
(define-key nob-mode-map [?b] 'nob-save)
(define-key nob-mode-map [?B] 'nob-select)

(define-minor-mode nob-mode
  "Novel bookmarks minor mode."
  :lighter " Nob"
  :keymap nob-mode-map
  (when nob-autosave-on-render
    (if nob-mode
	(add-hook 'eww-after-render-hook 'nob-eww-after-render-hook nil t)
      (remove-hook 'eww-after-render-hook 'nob-eww-after-render-hook t) )))

(provide 'nob)

;;; nob.el ends here