Fetch tomorow

src/clj/pmagnus/elprice/web/controllers/prices.clj

@@ -13,7 +13,10 @@
     (java.sql
       Timestamp)
     (java.time
+      Duration
+      Instant
       LocalDate
+      LocalTime
       ZoneId)
     (java.time.format
       DateTimeFormatter)))
@@ -125,11 +128,49 @@
   (get-prices-for-date query-fn (.plusDays (LocalDate/now dk-zone) 1) "DK1"))
 
 
+(def ^:private tomorrow-published-at
+  "Day-ahead prices for tomorrow are published around 13:00 CET."
+  (LocalTime/of 13 0))
+
+
+(defn- tomorrow-available?
+  "True once tomorrow's prices are expected to be published."
+  []
+  (not (.isBefore (LocalTime/now dk-zone) tomorrow-published-at)))
+
+
+(def ^:private retry-interval
+  "Minimum wait between fetches when the API has nothing new yet."
+  (Duration/ofMinutes 15))
+
+
+(defonce ^:private last-fetch-attempt (atom nil))
+
+
+(defn- retry-due?
+  "True when enough time has passed since the last fetch attempt."
+  []
+  (let [last @last-fetch-attempt]
+    (or (nil? last)
+        (>= (.compareTo (Duration/between last (Instant/now)) retry-interval) 0))))
+
+
 (defn ensure-current-prices!
-  "Fetch prices only when today's DK1 prices are missing from the database."
+  "Fetch prices when today's DK1 prices are missing, or - after 13:00 - when
+  tomorrow's are still missing."
   [query-fn]
-  (if (seq (get-today-prices query-fn))
+  (cond
+    (empty? (get-today-prices query-fn))
+    (do (reset! last-fetch-attempt (Instant/now))
+        (fetch-and-save! query-fn))
+
+    (and (tomorrow-available?)
+         (empty? (get-tomorrow-prices query-fn))
+         (retry-due?))
+    (do (reset! last-fetch-attempt (Instant/now))
+        (fetch-and-save! query-fn))
+
+    :else
     (do
       (log/info "Day-ahead prices already exist; skipping API fetch")
-      nil)
-    (fetch-and-save! query-fn)))
+      nil)))

src/clj/pmagnus/elprice/web/routes/api.clj

@@ -47,11 +47,12 @@
           rows (elprice/get-or-fetch! query-fn d)]
       (http-response/ok
         {:date   date
-         :prices (mapv (fn [r] {:time_dk    (str (:time_dk r))
-                                :price_area (:price_area r)
-                                :price_dkk  (:price_dkk r)
-                                :tariff_dkk (:tariff_dkk r)
-                                :total_dkk  (:total_dkk r)})
+         :prices (mapv (fn [r]
+                         {:time_dk    (str (:time_dk r))
+                          :price_area (:price_area r)
+                          :price_dkk  (:price_dkk r)
+                          :tariff_dkk (:tariff_dkk r)
+                          :total_dkk  (:total_dkk r)})
                        rows)}))
     (catch DateTimeParseException _
       (http-response/bad-request {:error "date must be YYYY-MM-DD"}))))