Move HTML rendering to btcprice, send raw JSON over both WebSockets

Price and Strike WebSockets now emit JSON instead of HTML fragments.
Added Strike WebSocket endpoint and wired strike/ticker into API routes.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

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

@@ -12,9 +12,6 @@
    [reitit.swagger :as swagger])
   (:import
    [io.undertow.websockets.core WebSockets WebSocketChannel]
-   [java.time Instant ZoneId]
-   [java.time.format DateTimeFormatter]
-   [java.util Locale]
    [java.util.concurrent LinkedBlockingQueue TimeUnit]))
 
 (defn- price->json [{:keys [price prev-price recorded-at]} rates]
@@ -25,41 +22,6 @@
      rates (assoc :price_eur (str (.multiply (bigdec price) (:eur rates)))
                   :price_dkk (str (.multiply (bigdec price) (:dkk rates)))))))
 
-(def ^:private ts-fmt (DateTimeFormatter/ofPattern "dd-MM HH:mm:ss"))
-(def ^:private da-locale (Locale. "da" "DK"))
-
-(defn- da-fmt [fmt val]
-  (String/format da-locale fmt (into-array Object [val])))
-
-(defn- price->html [{:keys [price prev-price recorded-at]} rates]
-  (let [p  (double (bigdec price))
-        pp (when prev-price (double (bigdec prev-price)))
-        color (cond
-                (nil? pp) "text-gray-900"
-                (> p pp)  "text-green-600"
-                (< p pp)  "text-red-600"
-                :else     "text-gray-900")
-        ts (.format (.atZone (Instant/from recorded-at) (ZoneId/systemDefault)) ts-fmt)]
-    (str "<div id=\"price-display\">"
-         "<div class=\"bg-white rounded-2xl shadow-sm border border-gray-200 p-6\">"
-         "<div class=\"text-center\">"
-         "<p class=\"text-4xl font-bold " color "\">$" (da-fmt "%,.2f" p) "</p>"
-         (when rates
-           (let [eur (double (:eur rates))
-                 dkk (double (:dkk rates))
-                 p-eur (double (.multiply (bigdec price) (:eur rates)))
-                 p-dkk (double (.multiply (bigdec price) (:dkk rates)))]
-             (str "<div class=\"flex justify-center gap-4 mt-3\">"
-                  "<span class=\"text-2xl font-bold text-gray-600\">\u20AC" (da-fmt "%,.0f" p-eur) "</span>"
-                  "<span class=\"text-2xl font-bold text-gray-600\">" (da-fmt "%,.0f" p-dkk) " kr</span>"
-                  "</div>"
-                  "<div class=\"flex justify-center gap-4 mt-1\">"
-                  "<span class=\"text-xs text-gray-400\">EUR/USD " (da-fmt "%.4f" eur) "</span>"
-                  "<span class=\"text-xs text-gray-400\">DKK/USD " (da-fmt "%.4f" dkk) "</span>"
-                  "</div>")))
-         "<p class=\"text-xs text-gray-400 mt-2\">Updated " ts "</p>"
-         "</div></div></div>")))
-
 (defn- start-ws-send-loop! [^WebSocketChannel channel price-atom rates-atom]
   (let [queue (LinkedBlockingQueue.)
         wkey  (keyword (gensym "ws-"))
@@ -76,7 +38,7 @@
           (when (.isOpen channel)
             (if (.poll queue 15 TimeUnit/SECONDS)
               (when-let [v @price-atom]
-                (WebSockets/sendTextBlocking (price->html v @rates-atom) channel))
+                (WebSockets/sendTextBlocking (price->json v @rates-atom) channel))
               (WebSockets/sendTextBlocking "" channel))
             (recur)))
         (catch Exception _)
@@ -93,6 +55,34 @@
      {:on-open (fn [{:keys [^WebSocketChannel channel]}]
                  (start-ws-send-loop! channel price-atom rates-atom))}}))
 
+(defn- start-strike-ws-loop! [^WebSocketChannel channel strike-atom]
+  (let [queue (LinkedBlockingQueue.)
+        wkey  (keyword (gensym "ws-s-"))]
+    (add-watch strike-atom wkey
+      (fn [_ _ _ _] (.offer queue :update)))
+    (when @strike-atom
+      (.offer queue :update))
+    (future
+      (try
+        (loop []
+          (when (.isOpen channel)
+            (if (.poll queue 15 TimeUnit/SECONDS)
+              (when-let [rates @strike-atom]
+                (WebSockets/sendTextBlocking (json/write-str rates) channel))
+              (WebSockets/sendTextBlocking "" channel))
+            (recur)))
+        (catch Exception _)
+        (finally
+          (remove-watch strike-atom wkey)
+          (when (.isOpen channel)
+            (try (.close channel) (catch Exception _))))))))
+
+(defn- ws-strike-handler [{:keys [strike]} _req]
+  (let [strike-atom (:latest-rates strike)]
+    {:undertow/websocket
+     {:on-open (fn [{:keys [^WebSocketChannel channel]}]
+                 (start-strike-ws-loop! channel strike-atom))}}))
+
 (defn- latest-price-handler [{:keys [binance frankfurter]} _req]
   (let [price-atom (:latest-price binance)
         rates-atom (:rates frankfurter)
@@ -117,7 +107,11 @@
      :no-doc     true
      :middleware []}]
    ["/price/latest"
-    {:get (fn [req] (latest-price-handler opts req))}]])
+    {:get (fn [req] (latest-price-handler opts req))}]
+   ["/strike/ws"
+    {:get        (fn [req] (ws-strike-handler opts req))
+     :no-doc     true
+     :middleware []}]])
 
 (defn route-data [opts]
   (merge