;; Jaq Html
;; An extension with macros to html.
;; Created by Magnus Axelsson on 96-11-09.

;; New Syntax:
;; 
;; <macro newid> substitutehtmlcode </macro>
;; 
;; <macro newid arg1 ... argN> htmlcode argn html</macro>
;;
;; -----------------------------------------------------------
;; Example:
;;
;; <macro pic1> <img src="http://www..../abc.gif"> </macro>
;; <macro jstart> <b><i><font size=+2> </macro>
;; <macro /jstart> </font></i></b> </macro>
;; <macro jtd jcolor> <td bgcolor="#jcolorjcolorFF"></macro>
;; <macro /jtd> </td> </macro>
;;
;; Warning: <macro jtd color> <td bgcolor ...>
;; is not a good macro since color in bgcolor would be
;; replaced!
;;
;; -----------------------------------------------------------
;; Usage of above macros in example:
;;
;; <jstart>abc</jstart>
;; <pic1>
;; ...
;; <jtd 23> Tjohoo!</jtd>
;;
;; -----------------------------------------------------------
;; Filename extensions for Jaq Html: .jhtml
;; These functions save the resulting file as .html
;;
;; -----------------------------------------------------------
;; The name of the macro and the arguments of or to the macro
;; may contains the following characters: a-z A-Z 0-9 _ " # -
;; But no actual strings, no tabs and no spaces or linefeeds.

;; TODO:
;; match-beginning funkar dven p} search-forward. Anv{nd!!!!!.
;; match the regexp chars in the info above. Perhaps .+ is enogh?


(defun jaq-html-to-html (filename)

  (if (not (string-match ".jhtml\\'"   filename))
      (error "Not an .jhtml file!"))
  (find-file filename)
  ;; Search for <macro ...>
  (while (search-forward "<macro " (point-max) t)
      (let ((start-macro (- (point) 7))    ; Peka p} <
	    (start-args (point))
	    (end-macro (search-forward ">"))
	    (arglist)
	    (replacement)
	    (start-replace-from)
	    (rep-start)
	    (rep-arg)
	    (rep-end)
	    (actual-arglist)
	    (next-macro))
	(goto-char start-args)
	;; Find arguments include name of new macro.
	(while (search-forward-regexp "[a-zA-Z0-9~@\.:_/\"#\-]+" end-macro t)
	  (setq arglist (append arglist (list (buffer-substring 
					       (match-beginning 0) 
					       (match-end 0))))))
	(search-forward "</macro>")
	(setq replacement (buffer-substring end-macro (- (point) 8)))
	(delete-region start-macro (point))  ; Remove <macro ...> ... </macro>

	(setq next-macro (point))
	;;; Replacing.
	(setq start-replace-from (point))

	
	(while (search-forward (concat "<" (car arglist)) (point-max) t)
	  (setq rep-start (match-beginning 0))
	  (setq rep-arg (point))
	  (setq rep-end (search-forward ">"))
	  (goto-char rep-arg)
	  (setq actual-arglist nil)
	  ;;; Find actual arguments.
	  (while (search-forward-regexp "[a-zA-Z0-9~@\.:_/\"#\-]+" rep-end t)
	    (setq actual-arglist 
		  (append actual-arglist (list (buffer-substring
						(match-beginning 0) 
						(match-end 0))))))
	  ;; Replace macro.
	  (delete-region rep-start rep-end)
	  (insert replacement)
	  ;; Replace arguments of macro.
	  (setq rep-end (point-marker))
	  (goto-char start-replace-from)
	  (jaq-html-replace-args (cdr arglist) actual-arglist
				 start-replace-from rep-end)
	  (goto-char rep-end)
	  (setq start-replace-from (point)) ;; Where to continue from.
	  (move-marker rep-end nil)   )
	(goto-char next-macro)   ))

  ;; Save buffer with new name.
  (write-file (concat
	       (substring filename 0 (string-match ".jhtml\\'"   filename))
	       ".html"))
  )

(defun jaq-html-replace-args (arglist1 arglist2 start bookmark-stop)
  (cond ((null arglist1)
	 nil)
	((null arglist2)
	 nil)
	(t
	 (goto-char start)
	 (while (search-forward (car arglist1) bookmark-stop t)
	   (replace-match (car arglist2)))
	 (jaq-html-replace-args 
	  (cdr arglist1) (cdr arglist2) start bookmark-stop))))