From c33b0ab8a4c9a8b80712b79b6e5dd246b901f9f3 Mon Sep 17 00:00:00 2001
From: Pierre Neidhardt <ambrevar@gmail.com>
Date: Sat, 25 Aug 2018 13:22:02 +0200
Subject: [PATCH] eww: Allow eww-add-bookmark to modify tags and title

---
 .emacs.d/lisp/init-eww.el | 52 +++++++++++++++++++++++++++++----------
 1 file changed, 39 insertions(+), 13 deletions(-)

diff --git a/.emacs.d/lisp/init-eww.el b/.emacs.d/lisp/init-eww.el
index 1d5dd30f..827ba102 100644
--- a/.emacs.d/lisp/init-eww.el
+++ b/.emacs.d/lisp/init-eww.el
@@ -171,32 +171,58 @@ word(s) will be searched for via `eww-search-prefix'."
 ;; TODO: Add bookmark editing functions such as edit title, tags, quickmark,
 ;; search-engine.  Use eww-buffers and Helm.
 (defun ambrevar/eww-add-bookmark (&optional url title)
-  "Bookmark the current page."
+  "Bookmark the current page.
+With prefix argument, prompt for bookmark title."
   (setq url (or url (plist-get eww-data :url)))
   (setq title (or title (plist-get eww-data :title)))
   (interactive)
   (eww-read-bookmarks)
-  (let (tag-list)
+  (let (tag-list existing-bookmark)
     (dolist (bookmark eww-bookmarks)
       (when (equal
              ;; PATCH: Ignore protocol when sorting.
              ;; TODO: Include "sort-bookmarks": Warn for unique tags, warn for same URL up to paragraph.  Make this customizable.
              (replace-regexp-in-string "^https?" "" url)
              (replace-regexp-in-string "^https?" "" (plist-get bookmark :url)))
-        (user-error "Already bookmarked"))
+        (if existing-bookmark
+            (user-error "Duplicate bookmarks: %s, %s" existing-bookmark bookmark)
+          (setq existing-bookmark bookmark)))
       (setq tag-list (append tag-list (plist-get bookmark :tags))))
     (cl-delete-duplicates tag-list)
-    (let ((tags (completing-read-multiple "Tags for bookmark (comma separated): " tag-list))
-          (title (replace-regexp-in-string "[\n\t\r]" " " title)))
-      (setq title (replace-regexp-in-string "\\` +\\| +\\'" "" title))
-      (push `(:url ,url
-                   :title ,title
-                   :time ,(current-time-string)
-                   ,@(if tags (list :tags tags)))
-            eww-bookmarks)
+    (let ((tags (completing-read-multiple (format "%s for bookmark (comma separated): "
+                                                  (if existing-bookmark "Update tags" "Tags"))
+                                          tag-list
+                                          nil nil nil nil
+                                          (and existing-bookmark
+                                               (mapconcat 'identity
+                                                          (plist-get existing-bookmark :tags) ","))))
+          (existing-title (or (and existing-bookmark (plist-get existing-bookmark :title))
+                              ""))
+          (sanitize-title (lambda (title)
+                            (setq title (string-trim title))
+                            (setq title (replace-regexp-in-string "[\n\t\r]" " " title)))))
+      (setq title (funcall sanitize-title title))
+      (setq existing-title (funcall sanitize-title existing-title))
+      (setq title (or (and (not current-prefix-arg)
+                           (not (string-empty-p (if existing-bookmark existing-title title)))
+                           (if existing-bookmark existing-title title))
+                      (completing-read "Title: "
+                                       (if existing-bookmark
+                                           (list title existing-title)
+                                         (list title))
+                                       nil nil nil nil
+                                       (if existing-bookmark existing-title title))))
+      (setq title (funcall sanitize-title title))
+      (let ((new-bookmark `(:url ,url
+                                 :title ,title
+                                 :time ,(or (and existing-bookmark (plist-get existing-bookmark :time))
+                                            (current-time-string))
+                                 ,@(if tags (list :tags tags)))))
+        (if existing-bookmark
+            (cl-nsubstitute new-bookmark existing-bookmark eww-bookmarks :count 1)
+          (push new-bookmark eww-bookmarks)))
       (eww-write-bookmarks)
-      (message "Bookmarked %s (%s)" url
-               (plist-get eww-data :title)))))
+      (message "Bookmarked %s (%s)" url title))))
 (advice-add 'eww-add-bookmark :override 'ambrevar/eww-add-bookmark)
 
 (defun ambrevar/eww-read-bookmarks ()