; A Circle is:
; (make-Circle posn number color)
(define-struct Circle (center radius clr))

(define C1 (make-Circle (make-posn 0 0) 5 "purple"))
(define C2 (make-Circle (make-posn 2 4) 12 "blue"))

; ;; Circle-fun: Circle ->
; ;; given ..., produces
; (define (Circle-fun a-Circle)
;   (Circle-center a-Circle)
;   (Circle-radius a-Circle)
;   (Circle-clr a-Circle))
;
; (check-expect (Circle-fun ...) ...)
; (check-expect (Circle-fun ...) ...)
;

;
; ;; 3.
;
; ;; Circle-circumference: Circle -> number
; ;; given a Circle, produces its circumference
; (define (Circle-circumference a-Circle)
;   (* 3.14 (expt (Circle-center a-Circle) 2)))
;
;
; (check-expect (Circle-circumference C1) )
; (check-expect (Circle-circumference C2) ...)


; ; 1.
;
; ; Circle-fun: Circle -> ?
;
; ; given ..., produces ...
;
; (define (Circle-fun a-Circle)
;
;   (Circle-center a-Circle)
;
;   (Circle-radius a-Circle)
;
;   (Circle-clr a-Circle))
;


; 3.

; Circle-circumference: Circle -> number
; given a Circle, produces its cirumference

(define (circumference a-Circle)
  (* 3.14 (* 2 Circle-radius a-Circle)))


(check-expect (Circle-circumference C1) 31.4)
(check-expect (Circle-circumference C2) 56.52)



; 4.

; Circle-area: Circle -> number
; given a Circle, produces its area

(define (Circle-area a-Circle)
  (* 3.14 (sqr Circle-radius a-Circle)))


(check-expect (Circle-area C1) 78.5)
(check-expect (Circle-area C2) 153.86)



; 5.

; Circle=?: Circle Circle -> boolean
; given two Circles, produces whether they're the same

(define (Circle=? a-Circle b-Circle)
  (and (posn=? (Circle-center a-Circle) (Circle-Center b-Circle))
       (= (Circle-radius a-Circle) (Circle-radius b-Circle))
       (string=? (Circle-clr a-Circle) (Circle-clr b-Circle))))


(check-expect (Circle=? S1 S2) false)
(check-expect (Circle=? S1 (make-Circle (make-posn 25 25) 5 "silver"))
              true)



; 6.

; draw-Circle: Circle -> image
; given a Circle, produces an image of a Circle of the correct size and
;   color

(define (draw-Circle a-Circle)
  (circle (Circle-center a-Circle)
           (Circle-radius a-Circle)
          "outline"
          (Circle-clr a-Circle)))


(check-expect (draw-Circle C1) (circle (make-posn 25 25) 5 "outline" "purple"))
(check-expect (draw-Circle C2) (circle (make-posn 7 7) 9 "outline" "green"))



; 7.

; place-Circle: Circle image -> image
; given a Circle and an image, produces a new image with the Circle
;   placed in the right location on it

; (define (place-Circle a-Circle bg)
;   (place-image/align (draw-Circle a-Circle)
;                      (posn-x (Circle-center a-Circle))
;                      (posn-y (Circle-Center a-Circle))
;                      "left" "top"
;                      bg))
;
;
;
; (check-expect (place-Circle C1 (empty-scene 100 100))
;               (place-image/align (circle (make-posn 25 25) 5 "blue")
;                                  "left" "top")
;                                  (empty-scene 100 100))
; (check-expect (place-Square C2 (rectangle 200 300 "solid" "black"))
;               (place-image/align (circle (make-posn 7 7) 9 "silver")
;                                  "left" "top")
;                                  (rectangle 200 300 "solid" "black"))




;8.
; Circle-translate: Circle number number -> Circle
; given a Circle and a number of pixels to move it down and over,
;   produces a new Circle at that location

(define (Circle-translate a-Circle delta-x delta-y)
  (make-Circle (posn-translate (Circle-center a-Circle)
                               delta-x
                               delta-y)
               (Circle-radius a-Circle)
               (Circle-clr a-Circle)))

(check-expect (Circle-translate C1 25 25)
              (make-Circle (make-posn 50 50) 10 "blue"))
(check-expect (Circle-translate C2 7 7)
              (make-Circle (make-posn 14 14) 16 "silver"))