;;; debian-doc.el --- Debian doc-base integration with Emacs.

;;; Commentary:
;;

;;; Code:

(defvar debian-doc-dir "/usr/share/doc-base")
(defvar debian-doc-buffer-name "*debian-doc*")
(defvar debian-doc-buffer nil)

(defvar debian-doc-mode-map (make-sparse-keymap))

(defconst debian-doc-font-lock-keywords
  '(("^[^ ][^:\n]*: " . font-lock-function-name-face)
    ("^\\(Index\\|Files\\): \\(/.*\\)" 2 font-lock-doc-face)
    ("^Format: \\(.*\\)" 1 font-lock-type-face)
    ("^Document: \\(.*\\)" 1 font-lock-keyword-face)))

(defun debian-doc-mode ()
  "Debian-Doc mode for viewing doc-base information."
  (kill-all-local-variables)
  (setq major-mode 'debian-doc-mode
        mode-name "Debian-Doc")
  (use-local-map debian-doc-mode-map)
  (setq font-lock-defaults '((debian-doc-font-lock-keywords) t nil nil nil)))

(defvar debian-doc-completion-list nil)

;;;###autoload
(defun debian-doc (&optional prefix)
  "Build Debian-Doc buffer.

With PREFIX force to rebuild buffer from doc-base files."
  (interactive "P")
  (when prefix
    (kill-buffer debian-doc-buffer))
  (if (buffer-live-p debian-doc-buffer)
      (switch-to-buffer debian-doc-buffer)
    (setq debian-doc-completion-list nil)
    (setq debian-doc-buffer (get-buffer-create debian-doc-buffer-name))
    (switch-to-buffer debian-doc-buffer)
    (let ( (coding-system-for-read 'utf-8) )
      (mapc (lambda (file)
              (when (file-regular-p file)
                ;; (with-temp-buffer
                ;;   (insert-file-contents file))
                (insert "\n-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-\n\n")
                (insert-file-contents file)
                (goto-char (point-max))))
            (directory-files debian-doc-dir t)))
    (read-only-mode 1)
    (debian-doc-mode)
    (goto-char (point-min))))

;;;###autoload
(defun debian-doc-visit ()
  "Prompt for Debian package which represent docs and visit its entry in Debian-oc buffer."
  (interactive)
  (let (word start)
    (debian-doc)
    (unless debian-doc-completion-list
      (save-excursion
        (goto-char (point-min))
        (while (setq start (search-forward "Document: " nil t))
          (end-of-line)
          (push (buffer-substring-no-properties start (point)) debian-doc-completion-list))))
    (when (setq word (completing-read "Package: " debian-doc-completion-list nil t))
      (goto-char (point-min))
      (search-forward (concat "Document: " word) nil t)
      (recenter-top-bottom))))
(define-key debian-doc-mode-map (kbd "RET") 'debian-doc-visit-at-point)


(provide 'debian-doc)

;;; debian-doc.el ends here