Tag completion for Nikola in emacs

nikola-tag-completion.el

;; Get tags used in the nikola site, using the tags plugin.
(defun nikola-tags-get ()
  "Get the current tags in the site, given the site path."
  (let* ((nikola-command
          "/home/punchagan/.virtualenvs/ultimatesport/bin/nikola")
         (nikola-site (file-name-directory
                       (directory-file-name
                        (file-name-directory
                         (or (buffer-file-name (current-buffer)) "/")))))
         (tags (shell-command-to-string
                (format "cd %s && %s tags -l" nikola-site nikola-command))))
    (unless (search "ERROR" tags)
      (cdr (split-string tags "\n" t "\s+")))))

(defun nikola-tags-insert ()
  "Insert a nikola tag at point."
  (interactive)
  (let* ((word-match (or (current-word t) ""))
         (tags (completing-read-multiple "Tag: " (nikola-tags-get) nil nil word-match)))
    (when (and word-match tags)
      (delete-backward-char (length word-match)))
    (mapc (lambda (tag) (insert (format "%s, " tag))) tags)))