;;; Copyright (C) 2002 Thomas Mailund <thomas@mailund.dk>

;;; This file is not part of GNU Emacs, but it is distributed under the
;;; same conditions.

;;; ====================================================================

;;; This program is free software; you can redistribute it and/or
;;; modify it under the terms of the GNU General Public License as
;;; published by the Free Software Foundation; either version 2, or (at
;;; your option) any later version.

;;; This program is distributed in the hope that it will be useful, but
;;; WITHOUT ANY WARRANTY; without even the implied warranty of
;;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
;;; General Public License for more details.

;;; You should have received a copy of the GNU General Public License
;;; along with this software; see the file COPYING. If not, write to the
;;; Free Software Foundation, 675 Mass Ave, Cambridge, MA 02139, USA.

;;; ====================================================================

(require 'dprog-constants)
(provide 'dprog-indent)

(defun dprog-indent-to (column)
  "Indent this line to `column'."
  (let ((cur-column (current-column))
	(dummy (back-to-indentation))
	(cur-indent (current-column)))
    ;; handle indentation
    (delete-horizontal-space)
    (indent-to-column column)
    ;; position point afterwards
    (if (<= cur-column cur-indent)
	(move-to-column column)
      (move-to-column (+ cur-column (- column cur-indent))) )))

(defun dprog-open-close-search (nesting)
  (progn
    (if (re-search-backward (concat "\\(" dprog-open-block
				    "\\|" dprog-close-block "\\)") 0 t)
	(let ((new-nesting (if (looking-at dprog-open-block)
			       (- nesting 1)
			     (+ nesting 1))))
	  (if (= new-nesting 0)
	      (+ (current-column) 1)
	    (dprog-open-close-search new-nesting)))
	0)))

(defun dprog-find-block-indent-level nil
  "Find the level of indentation inside a block for the line containing point."
  (save-excursion
    (back-to-indentation)
    (dprog-open-close-search 1)))

(defun dprog-find-kw-indent-level nil
  "Find the level of indentation inside a keyword block."
  (save-excursion
    (back-to-indentation)
    (if (looking-at dprog-block-kw-regex) 0 tab-width)))

(defun dprog-find-indent-level nil
  "Find the level of indentation for the line containing point."
  (let ((indent-level (dprog-find-block-indent-level)))
    (if (= indent-level 0)
	;; if indent-level is 0 here, we're out of all {} blocks--try
	;; keyword blocks
	(dprog-find-kw-indent-level)
      indent-level)))

(defun dprog-indent-line nil
  "Indent current line."
  (let ((indent-level (dprog-find-indent-level)))
    (dprog-indent-to indent-level)))