update app and index.html

app/data-service.js

@@ -11,6 +11,14 @@
   const textLexiconCache = new Map();
   const textLexiconOccurrencesCache = new Map();
   const textSearchCache = new Map();
+  const NOW_SNAPSHOT_MIN_INTERVAL_MS = 5 * 60 * 1000;
+  let nowSnapshotCache = {
+    geoKey: "",
+    fetchedAtMs: 0,
+    value: null,
+    pendingGeoKey: "",
+    pendingPromise: null
+  };
 
   const DATA_ROOT = "data";
   const MAGICK_ROOT = DATA_ROOT;
@@ -215,6 +223,26 @@
     return url.toString();
   }
 
+  function normalizeGeoKey(geo) {
+    const latitude = Number(geo?.latitude);
+    const longitude = Number(geo?.longitude);
+
+    if (!Number.isFinite(latitude) || !Number.isFinite(longitude)) {
+      return "";
+    }
+
+    return `${latitude.toFixed(6)},${longitude.toFixed(6)}`;
+  }
+
+  function isNowSnapshotPollingEnabled() {
+    if (typeof document !== "undefined" && document.hidden === true) {
+      return false;
+    }
+
+    const activeSection = String(window.TarotSectionStateUi?.getActiveSection?.() || "home").trim();
+    return activeSection === "home";
+  }
+
   function toApiAssetUrl(assetPath) {
     const { apiBaseUrl, apiKey } = resolveConnectionSettings();
     const normalizedAssetPath = String(assetPath || "")
@@ -247,6 +275,13 @@
     textLexiconCache.clear();
     textLexiconOccurrencesCache.clear();
     textSearchCache.clear();
+    nowSnapshotCache = {
+      geoKey: "",
+      fetchedAtMs: 0,
+      value: null,
+      pendingGeoKey: "",
+      pendingPromise: null
+    };
   }
 
   function normalizeTarotName(value) {
@@ -370,11 +405,58 @@
   }
 
   async function fetchNowSnapshot(geo, timestamp = new Date()) {
-    return fetchJson(buildApiUrl("/api/v1/now", {
+    const geoKey = normalizeGeoKey(geo);
+    const nowMs = Date.now();
+
+    if (!isNowSnapshotPollingEnabled()) {
+      if (geoKey && nowSnapshotCache.pendingPromise && nowSnapshotCache.pendingGeoKey === geoKey) {
+        return nowSnapshotCache.pendingPromise;
+      }
+
+      if (geoKey && geoKey === nowSnapshotCache.geoKey && nowSnapshotCache.value) {
+        return nowSnapshotCache.value;
+      }
+
+      return null;
+    }
+
+    if (
+      geoKey
+      && geoKey === nowSnapshotCache.geoKey
+      && nowSnapshotCache.value
+      && Number.isFinite(nowSnapshotCache.fetchedAtMs)
+      && (nowMs - nowSnapshotCache.fetchedAtMs) < NOW_SNAPSHOT_MIN_INTERVAL_MS
+    ) {
+      return nowSnapshotCache.value;
+    }
+
+    if (geoKey && nowSnapshotCache.pendingPromise && nowSnapshotCache.pendingGeoKey === geoKey) {
+      return nowSnapshotCache.pendingPromise;
+    }
+
+    const requestPromise = fetchJson(buildApiUrl("/api/v1/now", {
       latitude: geo?.latitude,
       longitude: geo?.longitude,
       date: timestamp instanceof Date ? timestamp.toISOString() : timestamp
-    }));
+    }))
+      .then((snapshot) => {
+        if (geoKey) {
+          nowSnapshotCache.geoKey = geoKey;
+          nowSnapshotCache.fetchedAtMs = Date.now();
+          nowSnapshotCache.value = snapshot;
+        }
+        return snapshot;
+      })
+      .finally(() => {
+        if (nowSnapshotCache.pendingPromise === requestPromise) {
+          nowSnapshotCache.pendingPromise = null;
+          nowSnapshotCache.pendingGeoKey = "";
+        }
+      });
+
+    nowSnapshotCache.pendingPromise = requestPromise;
+    nowSnapshotCache.pendingGeoKey = geoKey;
+    return requestPromise;
   }
 
   async function loadTarotCards(filters = {}) {