diff-by-key

(ns util.map
  (:require [schema.core :as s]
            [clojure.set :as set]
            [clojure.data :refer [diff]]
            [clojure.pprint :refer [pprint]]))

(s/def TAnyMap {s/Any s/Any})

(s/defn diff-by-key :- [(s/one TAnyMap "included")
                        (s/one TAnyMap "excluded")
                        (s/one {s/Any [(s/one s/Any "before")
                                       (s/one s/Any "after")]} "modified")]
  "Compares two maps by keys returning a vector of three items
  first- map with included keys with the values verbatim
  second - map with excluded keys with the values verbatim
  third - map of keys that had its values modified. the values of this map are vectors of two items [before-value after-value]
  "
  [m-a :- TAnyMap
   m-b :- TAnyMap]
  (let [keys-a (set (keys m-a))
        keys-b (set (keys m-b))
        included-keys (set/difference keys-b keys-a)
        excluded-keys (set/difference keys-a keys-b)
        ]
    [(select-keys m-b included-keys)
     (select-keys m-a excluded-keys)
     (->> m-b
          (filter (fn [[k v]]
                    (and (not (included-keys k))
                         (not (excluded-keys k))
                         (not= v (get m-a k)))))
          (map (fn [[k v]]
                 (let [v-a (get m-a k)
                       dif-v (diff v-a v)
                       dif-m (->> (second dif-v)
                                  (map (fn [[kk vv]]
                                         [kk [(get v-a kk) vv]]))
                                  (reduce (fn [m [kk vv]]
                                            (assoc m kk vv))
                                          {}))]
                   [k dif-m])))
          (reduce (fn [m [k v]]
                    (assoc! m k v))
                  (transient {}))
          (persistent!))]))

(comment 
  (pprint (diff-by-key {"01" {:codigo "01" :nome "Joao"}
                        "02" {:codigo "02" :nome "Maria"}
                        "03" {:codigo "03" :nome "pedro"}}

                       {"01" {:codigo "01" :nome "Joao da silva"}
                        "02" {:codigo "02" :nome "Maria"}
                        "04" {:codigo "04" :nome "mariana"}
                        }