Add question for start and end dates

src/packer/main.clj

@@ -51,7 +51,7 @@
       
     :else (let [script (last (eval-file template-file))
                 i18n (:i18n script)
-                nights (util/ask-int (:nights? i18n))
+                nights (util/ask-nights (:nights? i18n) (:start-date? i18n) (:end-date? i18n))
                 store (:store script)
                 profile ((:profile script) nights)]
         (spit output-file (str (core/produce store profile nights i18n) "\n"))))))

src/packer/util.clj

@@ -1,5 +1,9 @@
 (ns packer.util (:gen-class))
 
+(import '(java.time.temporal ChronoUnit)
+        '(java.time LocalDate)
+        '(java.time.format DateTimeFormatter))
+
 (defn ask 
   ([question prompt] (print (str question prompt))
               (flush)
@@ -21,3 +25,25 @@
     (if (.contains "yn" answer) 
       (= "y" answer)
       (recur question))))
+
+(defn parse-date [date]
+  (let [now (LocalDate/now)
+        parts (into [] (map #(format "%02d" (Integer/parseInt %)) (clojure.string/split date #"\W")))
+        formatter (DateTimeFormatter/ofPattern "dd-MM-yyyy")
+        month (String/format "%02d" (into-array Integer [(.getMonthValue now)]))
+        year (.toString (.getYear now))
+        full-date (case (count parts)
+                   1 (str (parts 0) "-" month "-" year)
+                   2 (str (parts 0) "-" (parts 1) "-" year)
+                   3 (str (parts 0) "-" (parts 1) "-" (parts 2))
+                   (throw (Exception. (str "Invalid date format: " date))))]
+        (LocalDate/parse full-date formatter)))
+
+(defn count-nights [start end]
+  (.between ChronoUnit/DAYS (parse-date start) (parse-date end)))
+
+(defn ask-nights [nightsQuestion startQuestion endQuestion]
+  (let [start (ask startQuestion)
+        end   (when (not (empty? start)) (ask endQuestion))
+        nights (when (empty? start) (ask-int nightsQuestion))]
+        (if (empty? start) nights (count-nights start end))))