;; TODO
;;  Concept of order num incremented with each page access
;;     if a branch is taken then a new session would need to be created
;;

;; make-vector-record session session dbtype dbinit conn params path-params session-key session-id domain toppage page curr-page content-type page-type sroot twikidir pagedat alt-page-dat pagevars pagevars-before sessionvars sessionvars-before globalvars globalvars-before logpt formdat request-method session-cookie curr-err log-port logfile seen-pages page-dir-style debugmode
(define (make-sdat)(make-vector 35))
(define (sdat-get-dbtype               vec)    (vector-ref  vec 0))
(define (sdat-get-dbinit               vec)    (vector-ref  vec 1))
(define (sdat-get-conn                 vec)    (vector-ref  vec 2))
(define (sdat-get-pgconn               vec)    (vector-ref (vector-ref vec 2) 1))
(define (sdat-get-params               vec)    (vector-ref  vec 3))
(define (sdat-get-path-params          vec)    (vector-ref  vec 4))
(define (sdat-get-session-key          vec)    (vector-ref  vec 5))

(define (sdat-get-curr-err             vec)    (vector-ref  vec 27))
(define (sdat-get-log-port             vec)    (vector-ref  vec 28))
(define (sdat-get-logfile              vec)    (vector-ref  vec 29))
(define (sdat-get-seen-pages           vec)    (vector-ref  vec 30))
(define (sdat-get-page-dir-style       vec)    (vector-ref  vec 31))
(define (sdat-get-debugmode            vec)    (vector-ref  vec 32))
(define (sdat-get-shared-hash          vec)    (vector-ref  vec 33))
(define (sdat-get-script               vec)    (vector-ref  vec 34))

(define (session:get-shared vec varname)
  (hash-table-ref/default (vector-ref vec 33) varname #f))

(define (sdat-set-dbtype!              vec val)(vector-set! vec 0 val))
(define (sdat-set-dbinit!              vec val)(vector-set! vec 1 val))
(define (sdat-set-conn!                vec val)(vector-set! vec 2 val))

(define (sdat-set-curr-err!            vec val)(vector-set! vec 27 val))
(define (sdat-set-log-port!            vec val)(vector-set! vec 28 val))
(define (sdat-set-logfile!             vec val)(vector-set! vec 29 val))
(define (sdat-set-seen-pages!          vec val)(vector-set! vec 30 val))
(define (sdat-set-page-dir-style!      vec val)(vector-set! vec 31 val))
(define (sdat-set-debugmode!           vec val)(vector-set! vec 32 val))
(define (sdat-set-shared-hash!         vec val)(vector-set! vec 33 val))
(define (sdat-set-script!              vec val)(vector-set! vec 34 val))

(define (session:set-shared! vec varname val)
  (hash-table-set! (vector-ref vec 33) varname val))

;; The global session
(define s:session (make-sdat))

  (sdat-set-pagevars!           self (make-hash-table))
  (sdat-set-sessionvars!        self (make-hash-table))
  (sdat-set-globalvars!         self (make-hash-table))
  (sdat-set-pagevars-before!    self (make-hash-table))
  (sdat-set-sessionvars-before! self (make-hash-table))
  (sdat-set-globalvars-before!  self (make-hash-table))
  (sdat-set-domain!             self "locahost")   ;; end of defaults
  (sdat-set-script!             self #f)
  (let* ((rawconfigdat (session:read-config self))
	 (configdat (if rawconfigdat (eval rawconfigdat) '()))
	 (sroot     (s:find-param 'sroot    configdat))
	 (logfile   (s:find-param 'logfile  configdat))
	 (dbtype    (s:find-param 'dbtype   configdat))
	 (dbinit    (s:find-param 'dbinit   configdat))
	 (domain    (s:find-param 'domain   configdat))
	 (twikidir  (s:find-param 'twikidir configdat))
	 (page-dir  (s:find-param 'page-dir-style configdat))
	 (debugmode (s:find-param 'debugmode configdat))
         (script    (s:find-param 'script    configdat)))
    (if sroot    (sdat-set-sroot!    self sroot))
    (if logfile  (sdat-set-logfile!  self logfile))
    (if dbtype   (sdat-set-dbtype!   self dbtype))
    (if dbinit   (sdat-set-dbinit!   self dbinit))
    (if domain   (sdat-set-domain!   self domain))
    (if twikidir (sdat-set-twikidir! self twikidir))
    (if debugmode (sdat-set-debugmode! self debugmode))
    (if script    (sdat-set-script!    self script))
    (sdat-set-page-dir-style! self page-dir)
    ;; (print "configdat: ")(pp configdat)
    (if debugmode
	(session:log self "sroot: " sroot " logfile: " logfile " dbtype: " dbtype 
		     " dbinit: " dbinit " domain: " domain " page-dir-style: " page-dir))
    )
  (sdat-set-shared-hash! self (make-hash-table))

	      (string-intersperse newresult "&")
	      (loop (car tail)(cadr tail)(cddr tail) newresult))))))

(define (session:link-to self page params)
  (let* ((server    (if (get-environment-variable "HTTP_HOST")
			(get-environment-variable "HTTP_HOST")
			(get-environment-variable "SERVER_NAME")))
         (force-script  (sdat-get-script self))
	 (script (or force-script
                     (let ((script-name (string-split (get-environment-variable "SCRIPT_NAME") "/")))
                       (if (> (length script-name) 1)
                           (string-append (car script-name) "/" (cadr script-name))
                           (get-environment-variable "SCRIPT_NAME"))))) ;; build script name from first two elements. This is a hangover from before I used ? in the URL.)
         (session-key (sdat-get-session-key self))
	 (paramstr (session:param->string params)))
    ;; (session:log self "server=" server " script=" script " page=" page)
    (string-append "http://" server "/" script "/" page "?" paramstr))) ;; "/sn=" session-key)))

(define (session:cgi-out self)
  (let* ((content  (list (sdat-get-content-type self))) ;; '("Content-type: text/html; charset=iso-8859-1\n\n"))
	 (header   (let ((cookie (sdat-get-session-cookie self)))