(import
  (only (chicken string) ->string)
  test
  )

(include "../coin-change-impl.scm")

(define (sum-mult solution)
  (foldl (lambda (sum denom.count)
           (+ sum (* (car denom.count) (cdr denom.count))))
         0 solution))

(define ((check solve) has-solution? target denominations)
  (receive (solution memo) (solve target denominations)
    (and (eq? has-solution? (not (not solution)))
         (or (not solution)
             (= target (sum-mult solution))))))

(define coin-change% (check coin-change))
(define coin-change/unlimited% (check coin-change/unlimited))

(define-syntax test-each
  (syntax-rules ()
    ((test-each check (args ...) ...)
     (test-group (symbol->string 'check)
       (test-assert (->string '(check args ...)) (check args ...))
       ...))))

; has-solution? target denominations
(test-each
  coin-change%
  (#t 765 '((50 . 123) (10 . 456) (5 . 789)))
  (#f 767 '((50 . 123) (10 . 456) (5 . 789)))
  (#f 1000 '((50 . 1) (10 . 2) (5 . 3)))
  (#t 4320 '((5 . 999) (10 . 998) (20 . 997) (50 . 996)))

  (#f 10 '((20 . 10) (50 . 10)))
  (#t 20 '((20 . 10) (50 . 10)))
  (#t 50 '((20 . 10) (50 . 10)))
  (#t 70 '((20 . 10) (50 . 10)))

  (#t 100 '((20 . 10) (50 . 10)))
  (#t 110 '((20 . 10) (50 . 10)))
  (#t 120 '((20 . 10) (50 . 10)))
  (#t 150 '((20 . 10) (50 . 10)))
  (#t 170 '((20 . 10) (50 . 10)))

  (#f 10 '((50 . 10) (20 . 10)))
  (#t 20 '((50 . 10) (20 . 10)))
  (#t 50 '((50 . 10) (20 . 10)))
  (#t 70 '((50 . 10) (20 . 10)))

  (#t 100 '((50 . 10) (20 . 10)))
  (#t 110 '((50 . 10) (20 . 10)))
  (#t 120 '((50 . 10) (20 . 10)))
  (#t 150 '((50 . 10) (20 . 10)))
  (#t 170 '((50 . 10) (20 . 10)))
  )

(test-each
  coin-change/unlimited%
  (#t 765 '(50 10 5))
  (#f 767 '(50 10 5))
  (#t 1000 '(50 10 5))
  (#t 4320 '(5 10 20 50))
  )

(test-exit)