(use ncurses posix extras posix-extras loops)
(define mazeData 
  (vector "OOOOOOOOOOOOOOO"
	  "O O O OOO O  OO"
	  "O             O"
	  "O O OOOOOOO O O"
	  "O O   O   O   O"
	  "O OOO  OO  OOOO"
	  "O    O O      O"
	  "OO O O O OOO OO"
	  "OO   O   O    O"
	  "OOOOOOOOOOOOOOO"))
; Get the character at the given maze location.
(define (mazeAt y x) 
  (string-ref (vector-ref mazeData y) x))

(define (setMazeAt y x v) 
    (string-set! (vector-ref mazeData y) x v))

(define (randomaze) 
  (do-for i (1 9)
	(do-for j (1 14)
	    (setMazeAt i j (if (zero? (random 3)) #\O  #\space))))
    (setMazeAt 8 13 #\space))

; Print a stack at a given location
(define (printStack x y stack) 
  (do-for i (0 (+ -1 (vector-length stack)) ) 
	    (mvaddstr (+ y i) x (vector-ref stack i)))
    (mvaddstr (+ y (vector-length stack)) x  "   "))

(define (save x y) (setMazeAt x y #\*))

(define (printMaze x y xStack yStack) 
    (do-for i (0 10) 
       (do-for j (0 15)
	  (mvaddch (+ i y) (+ j x) (mazeAt i j))))
    (mvaddch 0 40 #\y) 
    (mvaddch 0 50 #\x); Print the start of the x and y stack columns
    ; TODO: This may need to be cleaned up for perf at some point.
    ; (printStack 40 1 (list->vector (map number->string xStack)))
    ;(printStack 50 1 (list->vector (map number->string yStack)))
    (mvaddstr 0 0 "Randomaze")
    (mvaddstr 18 0 "Ctrl + C to Quit")
    (sleep .1) (refresh))
; Run the maze, starting with a pair of vectors
(define (runMaze)  
    (let loop (
	  (x 1) (y 1)
	  (xStack (list -1))
	  (yStack (list -1)))
      (randomaze)
      (cond [(not (or (and (= x 8) (= y 13)) (and (= x -1) (= y -1))))
	  (cond 
	    [(eq? (mazeAt x (+ y 1)) #\space) ; Right
	     (save x y) 
	     (set! y (+ y 1))
	     (printMaze 1 1 xStack yStack)
	     (loop x y (append '(x) xStack) (append '(y) yStack))]
	    [(eq? (mazeAt (+ x 1) y) #\space); Down
	     (save x y )
	     (set! x (+ x 1))
	     (printMaze 1 1 xStack yStack)
	     (loop x y (append '(x) xStack) (append '(y) yStack))]
	    [(eq? (mazeAt x (- y 1)) #\space); Left
	     (save x y )
	     (set! y (- y 1))
	     (printMaze 1 1 xStack yStack)
	     (loop x y (append '(x) xStack) (append '(y) yStack))]
	    [(eq? (mazeAt (- x 1) y) #\space); Up
	     (save x y )
	     (set! x (- x 1))
	     (printMaze 1 1 xStack yStack)
	     (loop x y (append '(x) xStack) (append '(y) yStack))] 
	    [else ; Backtrack
	      (setMazeAt x y #\D)
	      (printMaze 1 1 xStack yStack)
	      (loop (car xStack) (car yStack) 
		    (cdr xStack) (cdr yStack))
	       ])]
	[else
	    (printMaze 1 1 xStack yStack)
	    (sleep .1)
            (mvaddstr 12 2 (if (and (= x 8) (= y 13)) 
		       "Solved maze"
		       "No solution for maze"))
	    (printMaze 1 1 xStack yStack)
	    (void)])))
(define (mainLoop)   
    (runMaze)
    (erase) 
    (sleep 1)) 
(define (start) 
  (initscr)
  (nonl)
  (noecho)
  (randomize)
  (do-forever (mainLoop))
  (endwin))


;;; Run main, handling exceptions so that the terminal doesn't get
;;; wedged in a crazy state.
(define (main)
  (set-signal-handler! signal/int (lambda (nothing) (endwin) (exit)))
  (condition-case (start) 
	[err (exn) (begin (endwin) (signal err))]
	[() (endwin)]))
(main)