;;;; -*- Mode: Lisp; Syntax: ANSI-Common-Lisp; Base: 10; Package: modlisp -*-
;;;; *************************************************************************
;;;; FILE IDENTIFICATION
;;;;
;;;; Name:          utils.lisp
;;;; Purpose:       Utility functions for modlisp package
;;;; Programmer:    Kevin M. Rosenberg
;;;; Date Started:  Dec 2002
;;;;
;;;; $Id: utils.lisp,v 1.8 2003/07/19 20:32:47 kevin Exp $
;;;; *************************************************************************

(in-package #:modlisp)

(defun format-string (fmt)
  (case fmt
    (:html "text/html")
    (:xml "text/xml")
    (:text "text/plain")
    (otherwise fmt)))
			   
(defmacro with-ml-page ((&key (format :html) (precompute t) headers)
			&body body)
  (let ((fmt (gensym "FMT-"))
	(precomp (gensym "PRE-"))
	(result (gensym "RES-"))
	(outstr (gensym "STR-"))
	(stream (gensym "STRM-"))
	(hdr (gensym "HDR-")))
    `(let ((,fmt ,format)
	   (,precomp ,precompute)
	   ,result ,outstr ,stream)
       (declare (ignorable ,stream))
       (write-header-line "Status" "200 OK")
       (write-header-line "Content-Type" (format-string ,fmt))
       (dolist (,hdr ,headers)
	 (write-header-line (car ,hdr) (cdr ,hdr)))
       (unless ,precomp
	 (write-string "end" *modlisp-socket*)
	 (write-char #\NewLine *modlisp-socket*))
       (setq ,outstr
	 (with-output-to-string (,stream)
	   (let ((*modlisp-socket* (if ,precomp
				      ,stream
				    *modlisp-socket*)))
	     (setq ,result (progn ,@body)))))
       (cond
	(,precomp
	 (write-header-line "Content-Length" 
			    (write-to-string (length ,outstr)))
	 (write-header-line "Keep-Socket" "1")
	 (write-header-line "Connection" "Keep-Alive")
	 (write-string "end" *modlisp-socket*)
	 (write-char #\NewLine *modlisp-socket*)
	 (write-string ,outstr *modlisp-socket*)
	 (finish-output *modlisp-socket*)
	 (setq *close-modlisp-socket* nil))
	(t
	 (finish-output *modlisp-socket*)
	 (setq *close-modlisp-socket* t)))
       ,result)))

(defun redirect-to-location (url)
  (write-header-line "Status" "301 Moved Permanently")
  (write-header-line "Location" url)
  ;;(write-header-line "Keep-Socket" "1")
  ;;(write-header-line "Connection" "Keep-Alive")
  (write-string "end" *modlisp-socket*)
  (write-char #\NewLine *modlisp-socket*)
  (force-output *modlisp-socket*)
  (setq *close-modlisp-socket* t))

(defun output-ml-page (format html)
  (write-header-line "Status" "200 OK")
  (write-header-line "Content-Type" (format-string format))
  (write-header-line "Content-Length" (format nil "~d" (length html)))
  (write-header-line "Keep-Socket" "1")
  (write-header-line "Connection" "Keep-Alive")
  (write-string "end" *modlisp-socket*)
  (write-char #\NewLine *modlisp-socket*)
  (write-string html *modlisp-socket*)
  (force-output *modlisp-socket*)
  (setq *close-modlisp-socket* nil))

(defun output-html-page (str)
  (output-ml-page :html str))

(defun output-xml-page (str)
  (output-ml-page :xml str))

;; Utility functions for library users

(defun query-to-alist (posted-string)
  "Converts a posted string to an assoc list of keyword names and values,
\"a=1&bc=demo\" => ((:a . \"1\") (:bc . \"demo\"))"
  (when posted-string
    (let ((alist '()))
      (dolist (name=val (kmrcl:delimited-string-to-list posted-string #\&)
	       (nreverse alist))
	(let ((name-val-list (kmrcl:delimited-string-to-list name=val #\=)))
	  (if (= 2 (length name-val-list))
	    (destructuring-bind (name val) name-val-list
	      (push (cons (kmrcl:ensure-keyword name)
			  (kmrcl:decode-uri-query-string val))
		    alist))
	    (cmsg-c :debug "Invalid number of #\= in ~S" name-val-list)))))))