(defvar geiriadur-mode-hook nil)

(defvar geiriadur-mode-map
  (let ((geiriadur-mode-map (make-sparse-keymap)))
    (define-key geiriadur-mode-map (kbd "C-j") 'newline-and-indent)
    (define-key geiriadur-mode-map (kbd "C-c C-c") 'geiriadur-make-translation)
    (define-key geiriadur-mode-map (kbd "C-c C-d") 'geiriadur-make-form)
    (define-key geiriadur-mode-map (kbd "C-c C-r") 'geiriadur-make-comment)
    geiriadur-mode-map)
  "Keymap for Geiriadur major mode")

(add-to-list 'auto-mode-alist '("\\.utf8\\'" . geiriadur-mode))

(defconst geiriadur-font-lock-keywords-1
  (list
   ;'("\\(\\[ [^]]* \\]\\)" . font-lock-variable-name-face)
   ;'("\\(( [^)]* )\\)" . font-lock-keyword-face)
   '("\\(<< [^>]* >>\\)" . font-lock-string-face)
   '("\\({{ [^|]* | [^}]* }}\\)" . font-lock-constant-face) ;font-lock-comment-face)
   '("\\(< [^>]* >\\)" . font-lock-type-face)
   '("\\({ [^}]* }\\)" . font-lock-builtin-face))
  "Minimal highlighting expressions for Geiriadur mode")

(defvar geiriadur-font-lock-keywords geiriadur-font-lock-keywords-1
  "Default highlighting expressions for Geiriadur mode")

(defun geiriadur-indent-line ()
  "Indent current line as Geiriadur code."
  (interactive)
  (beginning-of-line)
  (if (looking-at "^[ \t]*<<")
      (indent-line-to default-tab-width))
  (if (looking-at "^[ \t]*{{")
      (indent-line-to (* 2 default-tab-width))))

(defun geiriadur-make-translation (start end)
  "Makes selection a translation."
  (interactive "r")
  (goto-char end)
  (insert " >>")
  (if (looking-at "[,;]")
      (delete-char 1))
  (goto-char start)
  (insert "
<< ")
  (indent-line-to default-tab-width))

(defun geiriadur-make-form (start end)
  "Makes selection a translation."
  (interactive "r")
  (goto-char end)
  (insert " }")
  (if (looking-at "[,;)]")
      (delete-char 1))
  (goto-char start)
  (insert "{ "))

(defun geiriadur-make-comment (start end)
  "Makes selection a comment."
  (interactive "r")
  (goto-char end)
  (insert " }}")
  (if (looking-at ";")
      (delete-char 1))
  (goto-char start)
  (insert "
{{ "))

(define-derived-mode geiriadur-mode fundamental-mode "Geiriadur"
  "Major mode for editing Geiriadur input files."
  (set (make-local-variable 'font-lock-defaults) '(geiriadur-font-lock-keywords))
  (set (make-local-variable 'indent-line-function) 'geiriadur-indent-line))

(provide 'geiriadur-mode)