(ns test.core
  (:require [clojure.spec :as s]
            [clojure.spec.test :as stest]
            [clojure.test.check.generators :as gen]))

(s/def ::file-count nat-int?)
(s/def ::operations (s/map-of keyword? pos-int?))
(s/def ::time-total (s/and double? (complement neg?)))

(s/def ::summary-res
  (s/keys :req-un [::file-count
                   ::operations
                   ::time-total]))

(s/fdef combine-summaries
  :args (s/cat :xs (s/coll-of ::summary-res :min-count 1))
  :ret ::summary-res)

(defn combine-summaries
  [summaries]
  (letfn [(deep-merge [a b]
            (merge-with (fn [x y]
                          (if (map? y)
                            (deep-merge x y)
                            (+ x y)))
                        a b))]
    (reduce deep-merge summaries)))