feat: 优化定位体验——反向地理编码显示地名，定位失败明确提示

- 新增 /api/location/regeo 接口，通过高德逆地理编码将 GPS 坐标转为地名
- 页面加载时自动定位，成功后显示"当前位置：浦东新区 xxx"
- 定位失败/权限被拒时显示明确提示+重试按钮，不再静默默认上海
- 无可用位置时阻止创建房间，引导用户手动搜索选择地点

src/app/api/location/regeo/route.ts

@@ -0,0 +1,54 @@
+import { NextResponse } from "next/server";
+
+export async function GET(req: Request) {
+  const { searchParams } = new URL(req.url);
+  const lat = searchParams.get("lat");
+  const lng = searchParams.get("lng");
+
+  if (!lat || !lng) {
+    return NextResponse.json(
+      { error: "lat and lng are required" },
+      { status: 400 },
+    );
+  }
+
+  const apiKey = process.env.AMAP_API_KEY;
+  if (!apiKey) {
+    return NextResponse.json(
+      { error: "AMAP_API_KEY not configured" },
+      { status: 500 },
+    );
+  }
+
+  try {
+    const url = new URL("https://restapi.amap.com/v3/geocode/regeo");
+    url.searchParams.set("key", apiKey);
+    url.searchParams.set("location", `${lng},${lat}`);
+    url.searchParams.set("extensions", "base");
+
+    const res = await fetch(url.toString());
+    const data = await res.json();
+
+    if (data.status !== "1" || !data.regeocode) {
+      return NextResponse.json({ name: null });
+    }
+
+    const comp = data.regeocode.addressComponent;
+    const district = comp?.district || comp?.city || "";
+    const township = comp?.township || "";
+    const neighborhood = comp?.neighborhood?.name || "";
+
+    const name = [district, township, neighborhood]
+      .filter(Boolean)
+      .join(" ")
+      .trim();
+
+    return NextResponse.json({
+      name: name || data.regeocode.formatted_address || null,
+      formatted: data.regeocode.formatted_address || null,
+    });
+  } catch (e) {
+    console.error("Regeo error:", e);
+    return NextResponse.json({ name: null });
+  }
+}

src/app/page.tsx

@@ -18,7 +18,7 @@ interface LocationSuggestion {
   lng: number;
 }
 
-const SHANGHAI_COORDS = { lat: 31.2222, lng: 121.4764 };
+type GpsStatus = "idle" | "locating" | "success" | "failed" | "denied";
 
 const DISTANCE_OPTIONS = [
   { label: "1km", value: 1000 },
@@ -35,26 +35,44 @@ const PRICE_OPTIONS = [
 
 const HOT_CUISINES = ["火锅", "日料", "烧烤", "西餐", "川菜", "咖啡甜品", "小吃快餐"] as const;
 
-function getLocation(): Promise<{ lat: number; lng: number }> {
+type GpsResult =
-  if (process.env.NODE_ENV === "development") {
+  | { ok: true; lat: number; lng: number }
-    return Promise.resolve(SHANGHAI_COORDS);
+  | { ok: false; reason: "unsupported" | "denied" | "timeout" | "unknown" };
-  }
 
+function requestGps(): Promise<GpsResult> {
   return new Promise((resolve) => {
     if (!navigator.geolocation) {
-      resolve(SHANGHAI_COORDS);
+      resolve({ ok: false, reason: "unsupported" });
       return;
     }
 
     navigator.geolocation.getCurrentPosition(
       (pos) =>
-        resolve({ lat: pos.coords.latitude, lng: pos.coords.longitude }),
+        resolve({ ok: true, lat: pos.coords.latitude, lng: pos.coords.longitude }),
-      () => resolve(SHANGHAI_COORDS),
+      (err) => {
-      { timeout: 5000, enableHighAccuracy: false },
+        const reason =
+          err.code === err.PERMISSION_DENIED
+            ? "denied"
+            : err.code === err.TIMEOUT
+              ? "timeout"
+              : "unknown";
+        resolve({ ok: false, reason });
+      },
+      { timeout: 8000, enableHighAccuracy: false },
     );
   });
 }
 
+async function reverseGeocode(lat: number, lng: number): Promise<string | null> {
+  try {
+    const res = await fetch(`/api/location/regeo?lat=${lat}&lng=${lng}`);
+    const data = await res.json();
+    return data.name || data.formatted || null;
+  } catch {
+    return null;
+  }
+}
+
 export default function LandingPage() {
   const router = useRouter();
   const [roomCode, setRoomCode] = useState("");
@@ -73,6 +91,10 @@ export default function LandingPage() {
   const suggestRef = useRef<HTMLDivElement>(null);
   const debounceRef = useRef<ReturnType<typeof setTimeout>>(null);
 
+  const [gpsStatus, setGpsStatus] = useState<GpsStatus>("idle");
+  const [gpsCoords, setGpsCoords] = useState<{ lat: number; lng: number } | null>(null);
+  const [gpsLocationName, setGpsLocationName] = useState<string | null>(null);
+
   const [profile, setProfile] = useState<UserProfile | null>(null);
   const [authModalOpen, setAuthModalOpen] = useState(false);
 
@@ -86,6 +108,25 @@ export default function LandingPage() {
     if (prefs.radius) setRadius(prefs.radius);
   }, []);
 
+  const doGpsLocate = useCallback(async () => {
+    setGpsStatus("locating");
+    const result = await requestGps();
+    if (result.ok) {
+      setGpsCoords({ lat: result.lat, lng: result.lng });
+      setGpsStatus("success");
+      const name = await reverseGeocode(result.lat, result.lng);
+      if (name) setGpsLocationName(name);
+    } else {
+      setGpsCoords(null);
+      setGpsLocationName(null);
+      setGpsStatus(result.reason === "denied" ? "denied" : "failed");
+    }
+  }, []);
+
+  useEffect(() => {
+    doGpsLocate();
+  }, [doGpsLocate]);
+
   const fetchSuggestions = useCallback(async (query: string) => {
     if (query.length < 1) {
       setSuggestions([]);
@@ -148,20 +189,26 @@ export default function LandingPage() {
   };
 
   const handleCreate = async () => {
-    setLoading(true);
     setError("");
 
-    try {
+    let coords: { lat: number; lng: number };
-      let coords: { lat: number; lng: number };
 
-      if (selectedLocation) {
+    if (selectedLocation) {
-        coords = { lat: selectedLocation.lat, lng: selectedLocation.lng };
+      coords = { lat: selectedLocation.lat, lng: selectedLocation.lng };
-        setLoadingText("正在搜索周边美食...");
+    } else if (gpsCoords) {
-      } else {
+      coords = gpsCoords;
-        setLoadingText("正在获取位置...");
+    } else if (gpsStatus === "locating") {
-        coords = await getLocation();
+      setError("正在定位中，请稍候...");
-        setLoadingText("正在搜索周边美食...");
+      return;
-      }
+    } else {
+      setError("无法获取位置，请在上方搜索并选择一个地点");
+      return;
+    }
+
+    setLoading(true);
+
+    try {
+      setLoadingText("正在搜索周边美食...");
 
       const res = await fetch("/api/room/create", {
         method: "POST",
@@ -321,7 +368,40 @@ export default function LandingPage() {
             </div>
           )}
 
-          {!selectedLocation && !locationQuery && (
+          {!selectedLocation && !locationQuery && gpsStatus === "locating" && (
+            <div className="mt-1.5 flex items-center gap-1.5 px-1">
+              <Loader2 size={12} className="shrink-0 animate-spin text-emerald-400" />
+              <span className="text-xs text-zinc-400">正在获取当前位置...</span>
+            </div>
+          )}
+
+          {!selectedLocation && !locationQuery && gpsStatus === "success" && (
+            <div className="mt-1.5 flex items-center gap-1.5 px-1">
+              <Navigation size={12} className="shrink-0 text-emerald-500" />
+              <span className="truncate text-xs text-emerald-600">
+                当前位置：{gpsLocationName || "已定位"}
+              </span>
+            </div>
+          )}
+
+          {!selectedLocation && !locationQuery && (gpsStatus === "failed" || gpsStatus === "denied") && (
+            <div className="mt-1.5 flex items-center justify-between px-1">
+              <div className="flex items-center gap-1.5">
+                <MapPin size={12} className="shrink-0 text-amber-500" />
+                <span className="text-xs text-amber-600">
+                  {gpsStatus === "denied" ? "定位权限被拒绝" : "定位失败"}，请搜索选择位置
+                </span>
+              </div>
+              <button
+                onClick={doGpsLocate}
+                className="shrink-0 text-xs font-medium text-emerald-500 active:text-emerald-700"
+              >
+                重试
+              </button>
+            </div>
+          )}
+
+          {!selectedLocation && !locationQuery && gpsStatus === "idle" && (
             <div className="mt-1.5 flex items-center gap-1.5 px-1">
               <Navigation size={12} className="shrink-0 text-zinc-400" />
               <span className="text-xs text-zinc-400">将使用当前定位</span>