dates.cljs

(ns cljs-play.dates.core
  (:require [goog.date.Date]
            [goog.date.Interval]
            [clojure.browser.repl :as repl]))

(repl/connect "http://localhost:9000/repl")

(defn date [dstr]
  (let [[m d y] (map js/parseInt (.split dstr "/"))]
    (goog.date.Date. y m d)))

(defn pad [xs n]
  (reduce
    (fn [v _]
      (let [last (peek v)]
        (conj v
          {:group (:group last)
           :date  (doto (.clone (:date last))
                    (.add (goog.date.Interval. 0 0 1)))
           :value 0})))
    xs
    (range n)))

(defn add-defaults [data]
  (let [grouped (group-by :key data)
        maxn    (->> grouped vals (map count) (apply max))]
    (->> (reduce
           (fn [m [k v]]
             (let [v (into [] (sort v))]
               (if (= (count v) maxn)
                 (assoc m k v)
                 (assoc m k (pad v (- maxn (count v)))))))
           {} grouped)
      vals
      (apply concat)
      (sort-by :key))))

(def data [{:key "Group1" :date (date "01/01/12") :value 200}
           {:key "Group2" :date (date "01/01/12") :value 100}
           {:key "Group1" :date (date "01/01/13") :value 400}])
(comment
  (add-defaults data)
  )