card.clj

(ns dojo.core)

(def prices {:A 2.5
             :B 3.0})

(def zones-map  {"Asterix" :A
                 "Aldgate" :A
                 "Barbican" :B
                 "Balham" :B})

(def daily-cap  {:A 7.0
                 :B 8.0})

(defn journey [& args]
  (let [zones  (map zones-map (concat  (map :from args) (map :to args)))
        legs   (partition 2 zones)
        prices (map #(max ((first %) prices) ((second %) prices)) legs)
        cap    (reduce max (map daily-cap (distinct zones)))]
    (min cap (reduce + prices))))



(ns dojo.core-spec
  (:require [speclj.core :refer :all]
            [dojo.core :refer :all]))

(def journeys  [{:from "Asterix" :to "Barbican"}
                 {:from "Barbican" :to "Asterix"}
                 {:from "Asterix" :to "Balham"}
                 {:from "Balham" :to "Asterix"}])

(describe "Clam card"
  (it "calculates the price for a single journey in zone A"
      (should= 2.5 (journey {:from "Asterix" :to "Aldgate"})))

  (it "calculates the price for journeys over several zones"
      (should= 6.0 (journey {:from "Asterix" :to "Barbican"} {:from "Barbican" :to "Balham"})))

  (it "has a daily cap"
      (should= 8.0 (apply journey (flatten journeys))))

  (it "has a weekly cap"
      (let [week-journeys  (mapcat (fn [r] (map #(assoc % :day r) journeys)) (range 1 8))]
        (should= 8.0 (apply  journey week-journeys)))))