;;; ox-org.el --- Org Back-End for Org Export Engine

;; Copyright (C) 2013  Free Software Foundation, Inc.

;; Author: Nicolas Goaziou <n.goaziou@gmail.com>
;; Keywords: org, wp

;; GNU Emacs 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 3 of the License, or
;; (at your option) any later version.

;; GNU Emacs 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 GNU Emacs.  If not, see <http://www.gnu.org/licenses/>.

;;; Commentary:

;; This library implements an Org back-end for Org exporter.  Since
;; its usage is mainly internal, it doesn't provide any interactive
;; function.

;;; Code:
(require 'ox)
(declare-function htmlize-buffer "htmlize" (&optional buffer))

(defgroup org-export-org nil
  "Options for exporting Org mode files to Org."
  :tag "Org Export Org"
  :group 'org-export
  :version "24.4"
  :package-version '(Org . "8.0"))

(define-obsolete-variable-alias
  'org-export-htmlized-org-css-url 'org-org-htmlized-css-url "24.4")
(defcustom org-org-htmlized-css-url nil
  "URL pointing to the CSS defining colors for htmlized Emacs buffers.
Normally when creating an htmlized version of an Org buffer,
htmlize will create the CSS to define the font colors.  However,
this does not work when converting in batch mode, and it also can
look bad if different people with different fontification setup
work on the same website.  When this variable is non-nil,
creating an htmlized version of an Org buffer using
`org-org-export-as-org' will include a link to this URL if the
setting of `org-html-htmlize-output-type' is 'css."
  :group 'org-export-org
  :type '(choice
	  (const :tag "Don't include external stylesheet link" nil)
	  (string :tag "URL or local href")))

(org-export-define-backend 'org
  '((babel-call . org-org-identity)
    (bold . org-org-identity)
    (center-block . org-org-identity)
    (clock . org-org-identity)
    (code . org-org-identity)
    (comment . (lambda (&rest args) ""))
    (comment-block . (lambda (&rest args) ""))
    (diary-sexp . org-org-identity)
    (drawer . org-org-identity)
    (dynamic-block . org-org-identity)
    (entity . org-org-identity)
    (example-block . org-org-identity)
    (fixed-width . org-org-identity)
    (footnote-definition . org-org-identity)
    (footnote-reference . org-org-identity)
    (headline . org-org-headline)
    (horizontal-rule . org-org-identity)
    (inline-babel-call . org-org-identity)
    (inline-src-block . org-org-identity)
    (inlinetask . org-org-identity)
    (italic . org-org-identity)
    (item . org-org-identity)
    (keyword . org-org-keyword)
    (latex-environment . org-org-identity)
    (latex-fragment . org-org-identity)
    (line-break . org-org-identity)
    (link . org-org-identity)
    (node-property . org-org-identity)
    (paragraph . org-org-identity)
    (plain-list . org-org-identity)
    (planning . org-org-identity)
    (property-drawer . org-org-identity)
    (quote-block . org-org-identity)
    (quote-section . org-org-identity)
    (radio-target . org-org-identity)
    (section . org-org-identity)
    (special-block . org-org-identity)
    (src-block . org-org-identity)
    (statistics-cookie . org-org-identity)
    (strike-through . org-org-identity)
    (subscript . org-org-identity)
    (superscript . org-org-identity)
    (table . org-org-identity)
    (table-cell . org-org-identity)
    (table-row . org-org-identity)
    (target . org-org-identity)
    (timestamp . org-org-identity)
    (underline . org-org-identity)
    (verbatim . org-org-identity)
    (verse-block . org-org-identity)))

(defun org-org-identity (blob contents info)
  "Transcode BLOB element or object back into Org syntax."
  (funcall
   (intern (format "org-element-%s-interpreter" (org-element-type blob)))
   blob contents))

(defun org-org-headline (headline contents info)
  "Transcode HEADLINE element back into Org syntax."
  (unless (plist-get info :with-todo-keywords)
    (org-element-put-property headline :todo-keyword nil))
  (unless (plist-get info :with-tags)
    (org-element-put-property headline :tags nil))
  (unless (plist-get info :with-priority)
    (org-element-put-property headline :priority nil))
  (org-element-headline-interpreter headline contents))

(defun org-org-keyword (keyword contents info)
  "Transcode KEYWORD element back into Org syntax.
Ignore keywords targeted at other export back-ends."
  (unless (member (org-element-property :key keyword)
		  (mapcar
		   (lambda (block-cons)
		     (and (eq (cdr block-cons) 'org-element-export-block-parser)
			  (car block-cons)))
		   org-element-block-name-alist))
    (org-element-keyword-interpreter keyword nil)))

;;;###autoload
(defun org-org-publish-to-org (plist filename pub-dir)
  "Publish an org file to org.

FILENAME is the filename of the Org file to be published.  PLIST
is the property list for the given project.  PUB-DIR is the
publishing directory.

Return output file name."
  (org-publish-org-to 'org filename ".org" plist pub-dir)
  (when (plist-get plist :htmlized-source)
    (require 'htmlize)
    (require 'ox-html)
    (let* ((org-inhibit-startup t)
	   (htmlize-output-type 'css)
	   (html-ext (concat "." (or (plist-get plist :html-extension)
				     org-html-extension "html")))
	   (visitingp (find-buffer-visiting filename))
	   (work-buffer (or visitingp (find-file filename)))
	   newbuf)
      (font-lock-fontify-buffer)
      (setq newbuf (htmlize-buffer))
      (with-current-buffer newbuf
	(when org-org-htmlized-css-url
	  (goto-char (point-min))
	  (and (re-search-forward
		"<style type=\"text/css\">[^\000]*?\n[ \t]*</style>.*" nil t)
	       (replace-match
		(format
		 "<link rel=\"stylesheet\" type=\"text/css\" href=\"%s\">"
		 org-org-htmlized-css-url) t t)))
	(write-file (concat pub-dir (file-name-nondirectory filename) html-ext)))
      (kill-buffer newbuf)
      (unless visitingp (kill-buffer work-buffer)))
    (set-buffer-modified-p nil)))

(provide 'ox-org)

;; Local variables:
;; generated-autoload-file: "org-loaddefs.el"
;; End:

;;; ox-org.el ends here