fix(phase26): geocode pre-caching (BUG-09) + gate trips on OBD presence (BUG-10)

static/js/history.js

@@ -33,17 +33,65 @@
 
     let _geoTimer = null;
     let _lastGeoKey = null;
+    let _geoCache = {};  // key → label, pre-populated on trip load
+
+    function _geoKey(lat, lon) {
+        return `${lat.toFixed(3)},${lon.toFixed(3)}`;
+    }
+
+    function preloadGeocodes(points) {
+        // Collect unique rounded coordinates and batch-fetch all labels upfront.
+        _geoCache = {};
+        const seen = new Set();
+        const queue = [];
+        for (const p of points) {
+            const key = _geoKey(p.latitude, p.longitude);
+            if (seen.has(key)) continue;
+            seen.add(key);
+            queue.push({ key, lat: p.latitude, lon: p.longitude });
+        }
+
+        // Fetch in parallel with a small concurrency cap
+        const CONCURRENCY = 4;
+        let idx = 0;
+        function next() {
+            if (idx >= queue.length) return;
+            const item = queue[idx++];
+            const ctrl = new AbortController();
+            const t = setTimeout(() => ctrl.abort(), 4000);
+            return fetch(`/api/geocode?lat=${item.lat}&lon=${item.lon}`, { signal: ctrl.signal })
+                .then(r => { clearTimeout(t); return r.ok ? r.json() : null; })
+                .then(data => {
+                    _geoCache[item.key] = (data && data.label) || null;
+                })
+                .catch(() => { clearTimeout(t); _geoCache[item.key] = null; })
+                .finally(() => next());
+        }
+        // Start initial batch
+        for (let i = 0; i < CONCURRENCY && i < queue.length; i++) next();
+    }
 
     function geocodePoint(lat, lon) {
-        const key = `${lat.toFixed(3)},${lon.toFixed(3)}`;
+        const key = _geoKey(lat, lon);
         if (key === _lastGeoKey) return;
         _lastGeoKey = key;
         const fallback = `${lat.toFixed(5)}, ${lon.toFixed(5)}`;
+
+        // Use cache if available
+        if (_geoCache.hasOwnProperty(key)) {
+            replayLocation.textContent = _geoCache[key] || fallback;
+            return;
+        }
+
         const ctrl = new AbortController();
-        const t = setTimeout(() => ctrl.abort(), 6000);
+        const t = setTimeout(() => ctrl.abort(), 4000);
         fetch(`/api/geocode?lat=${lat}&lon=${lon}`, { signal: ctrl.signal })
             .then(r => { clearTimeout(t); return r.ok ? r.json() : null; })
-            .then(data => { replayLocation.textContent = (data && data.label) ? data.label : fallback; })
+            .then(data => {
+                const label = (data && data.label) || fallback;
+                _geoCache[key] = (data && data.label) || null;
+                replayLocation.textContent = label;
+            })
             .catch(() => { clearTimeout(t); replayLocation.textContent = fallback; });
     }
 
@@ -177,6 +225,7 @@
             + `avg ${formatSpeed(result.trip.average_speed_kmh)} · `
             + `max ${formatSpeed(result.trip.max_speed_kmh)} · `
             + `${result.points.length} route points`;
+        preloadGeocodes(result.points);
         initializeTimeline(result.points);
     }