;;; ox-template.el --- A HTML exporter via templates for org-mode
;; Copyright (C) 2021 Sameer Rahmani
;; Author: Sameer Rahmani <lxsameer@gnu.org>
;; URL: https://devheroes.codes/lxsameer/lxhome
;;
;; 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 3 of the License, 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 program.  If not, see <http://www.gnu.org/licenses/>.
;;; Commentary:
;; Inspired by Juan Jose Garcia Ripoll work.
;;; Code:
;; We ensure the org infrastructure

(require 'org)
(require 'ox-publish)
(require 'mustache)
(require 'htmlize)
(require 'ht)

(advice-add 'org-html--tags :override 'org-html-tag-template)
(defun org-html-tag-template (tags info)
  (message "<<<<<<<<<<<< %s" tags)
  (let ((template (plist-get info :html-headline-template))
        (ctx (ht ("tags" (format "%s" tags))
                 ("base-url" (plist-get info :base-url)))))
    (mustache-render (use-html template) ctx)))


(defun use-html (path-to-template)
  "Use the given template at PATH-TO-TEMPLATE as a template."
  (with-temp-buffer
    (insert-file-contents path-to-template)
    (buffer-string)))


(org-export-define-derived-backend 'templated-html 'html
  :translate-alist '(;;(headline . templated-html-headline-fn)
                     (template . templated-html-template-fn)))


(defun render-template (template-name contents info)
  "Render the given template TEMPLATE-NAME using CONTENTS and INFO."
  (let ((ctx (ht ("content" contents)
                 ("head" (plist-get info :html-head-extra))
                 ("base-url" (plist-get info :base-url)))))
    (mustache-render (use-html template-name) ctx)))


(defun templated-html-template-fn (contents info)
  "Return the finalized html CONTENTS using the INFO and templates."
  (let ((template (plist-get info :html-template)))
    (if template
        (render-template template contents info)
      (org-html-template contents info))))

(defun org-html-publish-to-templated-html (plist filename pub-dir)
  "Publish an org file to HTML.

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 'templated-html filename
                      (concat "." (or (plist-get plist :html-extension)
                                      org-html-extension
                                      "html"))
                      plist pub-dir))


(provide 'lisp/ox-template)
;;; ox-template.el ends here