(ns challenge.discrete-value-range-test
  (:require
   [clojure.test :refer [deftest testing is]]
   [challenge.discrete-value-range :as range]))

(deftype IntInclusiveDiscreteValueRange
         [^int start ^int end]
  range/DiscreteValueRange
  (abuts [_this other]
    (or (= 1 (abs (- start (.end other))))
        (= 1 (abs (- end (.start other))))))
  (value-before [__this]
    (dec start))
  (value-after [_this]
    (inc end))
  (start [_this]
    start)
  (end [_this]
    end)

  Object
  (toString [_this]
    (str start ".." end))
  (equals [_this other]
    (and (= start (.start other))
         (= end (.end other)))))

(defn int-range-inclusive [start end]
  (assert (<= start end))
  (->IntInclusiveDiscreteValueRange start end))

(deftest integer-ranges-sanity-test
  (testing "value equality"
    (is (= (int-range-inclusive 0 1)
           (int-range-inclusive 0 1))))

  (testing "abuts"
    (is (= true (range/abuts (int-range-inclusive 0 1)
                             (int-range-inclusive 2 3))))
    (is (= true (range/abuts (int-range-inclusive 1 1)
                             (int-range-inclusive 2 3))))
    (is (= true (range/abuts (int-range-inclusive 4 7)
                             (int-range-inclusive 2 3))))
    (is (= false (range/abuts (int-range-inclusive 4 7)
                              (int-range-inclusive 1 2)))))
  (testing "value-before"
    (is (= 0 (range/value-before (int-range-inclusive 1 8)))))
  (testing "value-after"
    (is (= 9 (range/value-after (int-range-inclusive 1 8)))))
  (testing "start"
    (is (= 1 (range/start (int-range-inclusive 1 8)))))
  (testing "end"
    (is (= 8 (range/end (int-range-inclusive 1 8))))))