feature request: fetch-ebook-metadata

[dalanicolai]

First of all thanks for this very beautiful package that almost saves me from opening Calibre-gui. However, usually after adding a book I fetch metadata (incl. cover) automatically with Calibre. Now calibre comes with a command-line utility for fetching the metadata. Would be great if we could use this from Calibre to set the metadata (and download the cover).
This command line utility returns only the first result from all possible sources (Google, Amazon.com etc.), while Calibre-gui let's you choose from multiple results (would be great to have that option here too).

Here is an example of how to use the command that also donwloads the cover in the current working directory:
fetch-ebook-metadata -p "Amazon.com" --authors "dominik" --title "org" -c cover.jpg

[dalanicolai]

As I thought this was a fun little project, I have coded a partial solution (it is working, but I would still like to choose between metadata from different sources). First here is the code:

(defun calibredb-fetch-metadata (author title)
  (let* ((authors (read-string "Authors: " author))
         (title (read-string "Title: " title))
         (sources '("Google" "Amazon.com")))
    (mapcar
     (lambda (source)
       (let* ((md (split-string (shell-command-to-string
                  (format
                   "fetch-ebook-metadata -p '%s' --authors '%s' --title '%s'"
                   source
                   authors
                   title)) "Comments" nil " *"))
              (no-comments 
               (mapcar (lambda (x)
                         (let ((string x))
                           (string-match "\\([A-z]*\\)(*\\(s\\)*)* *: *\\(.*\\)" string)
                           (cons (format "%s%s" (match-string 1 string) (cond ((match-string 2 string))
                                                                              ("")))
                                 (match-string 3 string))))
                       (split-string (car md) "\n" t " *"))))
         (append no-comments (list (cons "Comments" (substring (nth 1 md) 2))))))
     sources)))

(defun calibredb-fetch-and-set-metadata ()
  (interactive)
  (let* ((candidate (car (calibredb-find-candidate-at-point)))
         (authors (calibredb-getattr candidate :author-sort))
         (title (calibredb-getattr candidate :book-title))
         (metadata (calibredb-fetch-metadata authors title))
         (id (calibredb-getattr candidate :id)))
    (mapcar (lambda (x)
              (calibredb-command :command "set_metadata"
                                 :option "--field"
                                 :input (format "%s:\"%s\"" (downcase (car x)) (cdr x))
                                 :id id
                                 :library (format "--library-path \"%s\"" calibredb-root-dir)))
            (nth 0 metadata)))
  (cond ((equal major-mode 'calibredb-show-mode)
         (calibredb-show-refresh))
        ((eq major-mode 'calibredb-search-mode)
         (calibredb-search-refresh-or-resume))))

So the calibredb-fetch-metadata fetches metadata from Google and Amazon.com (more options can easily be added of course).
The function calibredb-fetch-and-set-metadata can be invoked interactively from the calibredb-search buffer. For now the last expression before refreshing the buffer, (nth 0/1 metadata), selects wether the Google or the Amazon metadata is used.

I was wondering if you have some suggestion how some functionality for previewing the metadata from different sources and subsequent selection could be nicely implemented

[chenyanming]

@dalanicolai Appreciate that your contribution to fetch-ebook-metadata which I would like to implement in the next version as well! I did an early merge. And I am testing on it.

[dalanicolai]

Thanks for testing! I developed on my Spacemacs configuration, where the new functionality is working perfectly fine (of course). However, now I test it on a plain (except that it has Ivy installed) Emacs installation and it returns a very strange error. Namely, while fetching metadata, at the first step where I should choose between the original and fetched cover, Emacs returns an error saying that the 'ivy-read' command receives an invalid keyword argument. However, the ivy-read command looks perfectly fine and it works perfectly fine on my Spacemacs configuration. I really don't know why it behaves like this. Do you have an idea?

Also of course I am happy to answer any question.

One more thing. Maybe I could mention my toc-mode package somewhere in the README as RELATED PACKAGE. Some people might be interested and it is otherwise not easy to find...

[dalanicolai]

As I would prefer to set the author and author_sort columns correctly, I asked Kovid (main Calibre developer), if it is possible to use the author_sort algorithm from the command line. So the algorithm can be use via:
calibre-debug -c "from calibre.ebooks.metadata import *; import sys; print(author_to_author_sort(' '.join(sys.argv[1:])))" Kovid Goyal. In case you might be interested...

[chenyanming]

I think this feature has been done. Shall we close the issue?

[dalanicolai]

Agreed!