;;; Based somewhat and inspired by the etags package
;;; Not nearly as complete, though

;;;###autoload
(defvar gnome-tag-repository "http://developer.gnome.org/doc/API"
  "The default location of the GNOME reference documentation.")

;;;###autoload
(defvar gnome-tag-browser-command "gnome-moz-remote"
  "The command used to view the reference doc.")

;;;###autoload
(defvar gnome-tags-file-name "/home/jrb/GNOME-TAGS"
  "*File name of gnome tags table.")

(defvar gnome-tags-buffer nil
  "The buffer used to store the gnome-tags in.")

(defun gnome-tag-find-default ()
  (save-excursion
    (while (looking-at "\\sw\\|\\s_")
      (forward-char 1))
    (if (or (re-search-backward "\\sw\\|\\s_"
				(save-excursion (beginning-of-line) (point))
				t)
	    (re-search-forward "\\(\\sw\\|\\s_\\)+"
			       (save-excursion (end-of-line) (point))
			       t))
	(progn (goto-char (match-end 0))
	       (buffer-substring (point)
				 (progn (forward-sexp -1)
					(while (looking-at "\\s'")
					  (forward-char 1))
					(point))))
      nil)))


(defun tags-verify-table (file)
  "Read FILE into a buffer and verify that it is a valid tags table.
Sets the current buffer to one visiting FILE (if it exists).
Returns non-nil iff it is a valid table."
  (if (get-file-buffer file)
      ;; The file is already in a buffer.  Check for the visited file
      ;; having changed since we last used it.
      (let (win)
	(set-buffer (get-file-buffer file))
	(setq win (or verify-tags-table-function (initialize-new-tags-table)))
	(if (or (verify-visited-file-modtime (current-buffer))
		;; Decide whether to revert the file.
		;; revert-without-query can say to revert
		;; or the user can say to revert.
		(not (or (let ((tail revert-without-query)
			       (found nil))
			   (while tail
			     (if (string-match (car tail) buffer-file-name)
				 (setq found t))
			     (setq tail (cdr tail)))
			   found)
			 tags-revert-without-query
			 (yes-or-no-p
			  (format "Tags file %s has changed, read new contents? "
				  file)))))
	    (and verify-tags-table-function
		 (funcall verify-tags-table-function))
	  (revert-buffer t t)
	  (initialize-new-tags-table)))
    (and (file-exists-p file)
	 (progn
	   (set-buffer (find-file-noselect file))
	   (or (string= file buffer-file-name)
	       ;; find-file-noselect has changed the file name.
	       ;; Propagate the change to tags-file-name and tags-table-list.
	       (let ((tail (member file tags-table-list)))
		 (if tail
		     (setcar tail buffer-file-name))
		 (if (eq file tags-file-name)
		     (setq tags-file-name buffer-file-name))))
	   (initialize-new-tags-table)))))


(defun find-tag-in-buffer (tag)
  (save-excursion
    (set-buffer "GNOME-TAGS")
    (let* ((tag-regexp (format "^%s:" tag)))
      (message tag-regexp)
      (goto-char (point-min))
      (let ((tag-point (search-forward-regexp tag-regexp)))
	(if tag-point
	    (buffer-substring tag-point (progn (end-of-line)(point))))))))

(defun load-tag-buffers ()
  (if (or (not gnome-tags-buffer)
	  (save-excursion (get-buffer gnome-tags-buffer)))
      (save-excursion
	(if (get-buffer "GNOME-TAGS")
	    (kill-buffer "GNOME-TAGS"))
	(set-buffer (find-file-noselect gnome-tags-file-name))
	(rename-buffer "GNOME-TAGS")
	(setq gnome-tags-buffer (get-buffer "GNOME-TAGS")))))

(defun confirm-tag (tag)
  (if (and tag
	   (load-tag-buffers))
      (find-tag-in-buffer tag)
      nil))

(defun create-name (tag)
  (format "\"%s/%s.html\"" gnome-tag-repository tag))

;;;###autoload
(defun send-gnome-function ()
  (interactive)
  "Lookup the GtkWidget at point and attempt to look it up"
  (let* ((tag (gnome-tag-find-default))
	 (location (confirm-tag tag)))
    (if location
	(message (format "%s %s/%s" gnome-tag-browser-command gnome-tag-repository location)))))