;;; gadialog.el --- major mode for editing gadialog dialog files -*- lexical-binding: t -*-

;; Copyright (C) 2019 by Oleksandr Gavenko <gavenkoa@gmail.com>

;; You can do anything with this file without any warranty.

;; Author: Oleksandr Gavenko <gavenkoa@gmail.com>

;; Maintainer: Oleksandr Gavenko <gavenkoa@gmail.com>

;; Created: 2019

;; Version: 0.17

;; Keywords: dict, dictionary

;;; Commentary:

;;

;; Mode can be installed by:

;;

;;   (autoload 'gadialog-mode "gadialog")

;;

;; File association can be registered by:

;;

;;   (add-to-list 'auto-mode-alist (cons "\\.gadialog$" 'gadialog-mode))

;;; Code:

(defvar gadialog-font-lock-keywords

  '(("^# [1-9][0-9]*" . font-lock-type-face)

    ("^## [1-9][0-9]*" . font-lock-warning-face)

    ("^- " . font-lock-keyword-face)))

(defvar gadialog-syntax-table

  (let ((table (make-syntax-table text-mode-syntax-table)))

    (modify-syntax-entry ?' "w" table)

    table))

(defun gadialog-next-num ()

  (save-excursion

    (goto-char (point-min))

    (let (beg end num)

      (catch 'return

        (when (looking-at "## \\([1-9][0-9]*\\)")

          (setq beg (match-beginning 1)

                end (match-end 1))

          (setq num (string-to-number (buffer-substring beg end)))

          (delete-region beg end)

          (goto-char beg)

          (setq num (1+ num))

          (insert (int-to-string num))

          (throw 'return num))

        (insert "## 1\n")

        1))))

(defun gadialog-cleaup-whitespaces-forward ()

  (while (memq (char-before) '(?\  ?\n ?\t))

    (delete-char -1)))

(defun gadialog-insert-template ()

  (interactive)

  (forward-line 0)

  (when (looking-at "# ")

    (forward-line 1))

  (unless (re-search-forward "^# " (+ (point) 10240) t)

    (goto-char (point-max)))

  (when (eobp) (insert-char ?\n))

  (forward-line 0)

  (gadialog-cleaup-whitespaces-forward)

  (insert "\n# ")

  (insert (int-to-string (gadialog-next-num)))

  (insert "\n- \n")

  (backward-char))

(defun gadialog-insert-sentence ()

  (interactive)

  (forward-line 1)

  (while (not (or (eobp)

                  (memq (char-after) (list ?- ?#))))

    (forward-line 1))

  (gadialog-cleaup-whitespaces-forward)

  (insert "\n- \n")

  (backward-char))

(define-derived-mode gadialog-mode fundamental-mode "gadialog"

  (setq font-lock-defaults '(gadialog-font-lock-keywords))

  (define-key (current-local-map) [C-return] 'gadialog-insert-template)

  (define-key (current-local-map) [S-return] 'gadialog-insert-sentence)

  (set-syntax-table gadialog-syntax-table)

  (setq paragraph-start "[#-]"))

(provide 'gadialog)

;;; gadialog.el ends here