(in-package :cs325-user)

(defparameter *plan* nil)

(defparameter *map*  nil)

(defparameter *state* nil)

(define-test go-test
  (assert-equal '((robot-1 . room-1))
                (step-update '((robot-1 . room-2))
                             '(go room-1)
                             'robot-1))

  (assert-equal '((robot-1 . room-2) (robot-2 . room-1))
                (step-update '((robot-1 . room-2) (robot-2 . room-2))
                             '(go room-1)
                             'robot-2))
  
  (assert-equal nil
                (step-update '((robot-1 . room-2))
                             '(go room-1)
                             'robot-2))
  )


(defun step-update (state step robot)
  (cond ((null state) nil)
        ((eql (caar state) robot)
         (cons (cons robot (cadr step))
               (cdr state)))
        (t 
         (let ((result (step-update (cdr state) step robot)))
           (if (null result)
               nil
             (cons (car state) result))))))

(setq *plan* '(plan (go room-1) (pick-up box-3) (go room-4)  (drop)))