(define-module (taste-of-goblins)
  #:use-module (goblins)
  #:use-module (goblins actor-lib methods)
  #:export (^cell ^greeter ^cgreeter ^borked-cgreeter
		    ^car-factory ^borked-car-factory))

;; define with next argument wrapped in parentheses
;; defines a named function
(define (^greeter bcom our-name)    ; constructor (outer procedure)
  (lambda (your-name)               ; behavior    (inner procedure)
    (format #f "Hello ~a, my name is ~a!"     ; returned implicitly
            your-name our-name)))

(define (^cell bcom val)
  (methods            ; syntax for first-argument-symbol-based dispatch
    ((get)            ; takes no arguments
     val)             ; returns current value
    ((set new-val)    ; takes one argument, new-val
     (bcom (^cell bcom new-val)))))  ; become a cell with the new value

(define (^cgreeter bcom our-name)
  (define times-called   ; keeps track of how many times 'greet is called
    (spawn ^cell 0))     ; starts count at 0
  (methods
   ((get-times-called)
    ($ times-called 'get))
   ((greet your-name)
    (define current-times-called
      ($ times-called 'get))
    ;; increase the number of times called
    ($ times-called 'set
       (+ 1 current-times-called))
    (format #f "[~a] Hello ~a, my name is ~a!"
            ($ times-called 'get)
            your-name our-name))))

(define (^borked-cgreeter bcom our-name)
  (define times-called (spawn ^cell 0))
  (methods
   ((get-times-called)
    ($ times-called 'get))
   ((greet your-name)
    (pk 'before-incr ($ times-called 'get))
    ;; increase the number of times called
    ($ times-called 'set
       (+ 1 ($ times-called 'get)))
    (pk 'after-incr ($ times-called 'get))
    (error "Yikes")
    (format #f "[~a] Hello ~a, my name is ~a!"
            ($ times-called 'get)
            your-name our-name))))

;; Create a "car factory", which makes cars branded with
;; company-name.
(define (^car-factory bcom company-name)
  ;; The constructor for cars to create.
  (define (^car bcom model color)
    (methods                      ; methods for the ^car
     ((drive)                    ; drive the car
      (format #f "*Vroom vroom!*  You drive your ~a ~a ~a!"
              color company-name model))))
    ;; methods for the ^car-factory instance
  (methods                        ; methods for the ^car-factory
    ((make-car model color)       ; create a car
     (spawn ^car model color))))

(define (^borked-car-factory bcom company-name)
  (define (^car bcom model color)
    (methods                      ; methods for the ^car
     ((drive)                    ; drive the car
      (format #f "*Vroom vroom!*  You drive your ~a ~a ~a!"
              color company-name model))))
  ;; methods for the ^car-factory instance
  (methods                        ; methods for the ^car-factory
   ((make-car model color)       ; create a car
    (error "Your car exploded on the factory floor!  Ooops!")
    (spawn ^car model color))))