(define-record-type root-wm :root-wm
  (make-root-wm dpy managers current-manager)
  root-wm?
  (dpy root-wm:dpy)
  (managers root-wm:managers set-root-wm:managers!)
  (current-manager root-wm:current-manager set-root-wm:current-manager!))

(define (create-root-wm dpy)
  (let* ((window (default-root-window dpy))
	 (children (window-children dpy window))
	 (in-channel (make-channel))
	 (root-wm (make-root-wm dpy '() #f))
	 (initial-manager (create-move-wm in-channel dpy window '())))
    (mdisplay "creating root-wm\n")
    (set-root-wm:managers! root-wm (list initial-manager))
    (set-root-wm:current-manager! root-wm initial-manager)

    (map-window dpy (wm:window initial-manager))

    (for-each (lambda (window)
		(wm-manage-window initial-manager window))
	      children)
    ;;(create-move-wm in-channel dpy window '())

    (call-with-event-channel
     dpy window (event-mask substructure-redirect)
     (lambda (event-channel)
       (call-with-current-continuation
	(lambda (exit)
	  (let loop ()
	    (select*
	     (wrap (receive-rv event-channel)
		   (lambda (xevent)
		     (handle-xevent root-wm exit xevent)))
	     (wrap (receive-rv in-channel)
		   (lambda (msg)
		     (handle-message root-wm exit msg))))
	    (loop))))))))

(define (handle-xevent root-wm exit xevent)
  (let ((type (any-event-type xevent))
	(dpy (root-wm:dpy root-wm)))
    (cond
     ((configure-request-event? xevent)
      ;; TODO: maybe let it configure by the future manager...
      (configure-window dpy (configure-request-event-window xevent)
                        (configure-request-event-window-change-alist xevent)))
     ((map-request-event? xevent)
      (wm-manage-window (root-wm:current-manager root-wm)
			(map-request-event-window xevent)
			#f))
     )))

(define (handle-message root-wm exit msg)
  'none)

;; *** observing managers ********************************************

(define (add-manager! manager)
  #t)