1 files changed, 62 insertions, 0 deletions
diff --git a/src/frontend/app/hooks/useGeolocation.ts b/src/frontend/app/hooks/useGeolocation.ts
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+++ b/src/frontend/app/hooks/useGeolocation.ts
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+import { useCallback } from "react";
+import { useMap } from "../contexts/MapContext";
+import type { LngLatLike } from "maplibre-gl";
+
+export interface UseGeolocationResult {
+  userLocation: { latitude: number; longitude: number } | null;
+  hasLocationPermission: boolean;
+  requestLocation: () => void;
+}
+
+function lngLatToCoords(
+  loc: LngLatLike
+): { latitude: number; longitude: number } {
+  if (Array.isArray(loc)) {
+    // This codebase stores location as [latitude, longitude] (not the standard
+    // MapLibre [lng, lat] GeoJSON order). See MapContext.tsx where arrays are
+    // set as [position.coords.latitude, position.coords.longitude], and AppMap.tsx
+    // where getLatitude(center) returns center[0].
+    return { latitude: loc[0], longitude: loc[1] };
+  }
+  if ("lat" in loc) {
+    return {
+      latitude: loc.lat,
+      longitude: "lng" in loc ? (loc as any).lng : (loc as any).lon,
+    };
+  }
+  return { latitude: 0, longitude: 0 };
+}
+
+/**
+ * Provides the current user location from the global MapContext.
+ * Location updates are driven by the MapContext's watchPosition subscription
+ * (started automatically when geolocation permission is granted).
+ *
+ * Call `requestLocation()` to prompt the user for permission and start tracking.
+ */
+export function useGeolocation(): UseGeolocationResult {
+  const { mapState, setUserLocation, setLocationPermission } = useMap();
+
+  const requestLocation = useCallback(() => {
+    if (typeof window === "undefined" || !("geolocation" in navigator)) return;
+    navigator.geolocation.getCurrentPosition(
+      (pos) => {
+        setUserLocation([pos.coords.latitude, pos.coords.longitude]);
+        setLocationPermission(true);
+      },
+      () => {
+        setLocationPermission(false);
+      },
+      { enableHighAccuracy: false, maximumAge: 60000, timeout: 10000 }
+    );
+  }, [setUserLocation, setLocationPermission]);
+
+  const rawLoc = mapState.userLocation;
+  const userLocation = rawLoc ? lngLatToCoords(rawLoc) : null;
+
+  return {
+    userLocation,
+    hasLocationPermission: mapState.hasLocationPermission,
+    requestLocation,
+  };
+}