refactor: 提取 useGeolocation hook 和 joinRoom 工具函数

- useGeolocation: 将 PanicPage 中 ~50 行 GPS 定位逻辑（requestGps + reverseGeocode + 状态管理）提取为独立 hook
- joinRoom: 统一 3 处重复的 POST /api/room/:id/join 调用（room、invite、panic 页面）

src/app/invite/[id]/page.tsx

@@ -12,6 +12,7 @@ import {
   Coffee,
 } from "lucide-react";
 import { getUserId } from "@/lib/userId";
+import { joinRoom } from "@/lib/room";
 import { Skeleton, SkeletonCircle } from "@/components/Skeleton";
 import Button from "@/components/Button";
 import { getSceneConfig } from "@/lib/sceneConfig";
@@ -48,12 +49,7 @@ export default function InvitePage() {
   const handleJoin = async () => {
     setJoining(true);
     try {
-      const userId = getUserId();
+      await joinRoom(roomId, getUserId());
-      await fetch(`/api/room/${roomId}/join`, {
-        method: "POST",
-        headers: { "Content-Type": "application/json" },
-        body: JSON.stringify({ userId }),
-      });
       router.push(`/room/${roomId}`);
     } catch {
       setJoining(false);

src/app/panic/page.tsx

@@ -6,6 +6,8 @@ import { motion, AnimatePresence } from "framer-motion";
 import { Plus, LogIn, Loader2, MapPin, Navigation, X, Users, Heart, Sparkles, ChevronRight, Flame, ArrowLeft } from "lucide-react";
 import { getUserId, getCachedPreferences } from "@/lib/userId";
 import { SCENES, getSceneConfig } from "@/lib/sceneConfig";
+import { useGeolocation } from "@/hooks/useGeolocation";
+import { joinRoom } from "@/lib/room";
 import type { SceneType } from "@/types";
 
 interface LocationSuggestion {
@@ -17,52 +19,12 @@ interface LocationSuggestion {
   lng: number;
 }
 
-type GpsStatus = "idle" | "locating" | "success" | "failed" | "denied";
-
 const DISTANCE_OPTIONS = [
   { label: "1km", value: 1000 },
   { label: "3km", value: 3000 },
   { label: "5km", value: 5000 },
 ] as const;
 
-type GpsResult =
-  | { ok: true; lat: number; lng: number }
-  | { ok: false; reason: "unsupported" | "denied" | "timeout" | "unknown" };
-
-function requestGps(): Promise<GpsResult> {
-  return new Promise((resolve) => {
-    if (!navigator.geolocation) {
-      resolve({ ok: false, reason: "unsupported" });
-      return;
-    }
-
-    navigator.geolocation.getCurrentPosition(
-      (pos) =>
-        resolve({ ok: true, lat: pos.coords.latitude, lng: pos.coords.longitude }),
-      (err) => {
-        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 PanicPage() {
   const router = useRouter();
   const [roomCode, setRoomCode] = useState("");
@@ -81,9 +43,7 @@ export default function PanicPage() {
   const suggestRef = useRef<HTMLDivElement>(null);
   const debounceRef = useRef<ReturnType<typeof setTimeout>>(null);
 
-  const [gpsStatus, setGpsStatus] = useState<GpsStatus>("idle");
+  const geo = useGeolocation();
-  const [gpsCoords, setGpsCoords] = useState<{ lat: number; lng: number } | null>(null);
-  const [gpsLocationName, setGpsLocationName] = useState<string | null>(null);
 
   const [scene, setScene] = useState<SceneType>("eat");
   const sceneConfig = getSceneConfig(scene);
@@ -101,25 +61,6 @@ export default function PanicPage() {
     setPriceRange("any");
   }, []);
 
-  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([]);
@@ -170,16 +111,6 @@ export default function PanicPage() {
     return () => document.removeEventListener("mousedown", handleClickOutside);
   }, []);
 
-  const joinRoom = async (roomId: string) => {
-    const userId = getUserId();
-    const res = await fetch(`/api/room/${roomId}/join`, {
-      method: "POST",
-      headers: { "Content-Type": "application/json" },
-      body: JSON.stringify({ userId }),
-    });
-    if (!res.ok) throw new Error("房间不存在");
-    return roomId;
-  };
 
   const handleCreate = async () => {
     setError("");
@@ -188,9 +119,9 @@ export default function PanicPage() {
 
     if (selectedLocation) {
       coords = { lat: selectedLocation.lat, lng: selectedLocation.lng };
-    } else if (gpsCoords) {
+    } else if (geo.coords) {
-      coords = gpsCoords;
+      coords = geo.coords;
-    } else if (gpsStatus === "locating") {
+    } else if (geo.status === "locating") {
       setError("正在定位中，请稍候...");
       return;
     } else {
@@ -220,7 +151,7 @@ export default function PanicPage() {
       }
 
       setLoadingText("正在进入房间...");
-      await joinRoom(data.roomId);
+      await joinRoom(data.roomId, getUserId());
       router.push(`/room/${data.roomId}`);
     } catch (e) {
       setError(e instanceof Error ? e.message : "创建失败，请重试");
@@ -238,7 +169,7 @@ export default function PanicPage() {
     setLoading(true);
     setError("");
     try {
-      await joinRoom(roomCode);
+      await joinRoom(roomCode, getUserId());
       router.push(`/room/${roomCode}`);
     } catch {
       setError("房间不存在，请检查房间号");
@@ -384,32 +315,32 @@ export default function PanicPage() {
             </div>
           )}
 
-          {!selectedLocation && !locationQuery && gpsStatus === "locating" && (
+          {!selectedLocation && !locationQuery && geo.status === "locating" && (
             <div className="mt-1.5 flex items-center gap-1.5 px-1">
               <Loader2 size={12} className="shrink-0 animate-spin text-orange-400" />
               <span className="text-xs text-muted">正在获取当前位置...</span>
             </div>
           )}
 
-          {!selectedLocation && !locationQuery && gpsStatus === "success" && (
+          {!selectedLocation && !locationQuery && geo.status === "success" && (
             <div className="mt-1.5 flex items-center gap-1.5 px-1">
               <Navigation size={12} className="shrink-0 text-orange-400" />
               <span className="truncate text-xs text-orange-300/80">
-                当前位置：{gpsLocationName || "已定位"}
+                当前位置：{geo.locationName || "已定位"}
               </span>
             </div>
           )}
 
-          {!selectedLocation && !locationQuery && (gpsStatus === "failed" || gpsStatus === "denied") && (
+          {!selectedLocation && !locationQuery && (geo.status === "failed" || geo.status === "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-400/80">
-                  {gpsStatus === "denied" ? "定位权限被拒绝" : "定位失败"}，请搜索选择位置
+                  {geo.status === "denied" ? "定位权限被拒绝" : "定位失败"}，请搜索选择位置
                 </span>
               </div>
               <button
-                onClick={doGpsLocate}
+                onClick={geo.retry}
                 className="shrink-0 text-xs font-medium text-orange-400 active:text-orange-300"
               >
                 重试
@@ -417,7 +348,7 @@ export default function PanicPage() {
             </div>
           )}
 
-          {!selectedLocation && !locationQuery && gpsStatus === "idle" && (
+          {!selectedLocation && !locationQuery && geo.status === "idle" && (
             <div className="mt-1.5 flex items-center gap-1.5 px-1">
               <Navigation size={12} className="shrink-0 text-dim" />
               <span className="text-xs text-dim">将使用当前定位</span>

src/app/room/[id]/page.tsx

@@ -9,6 +9,7 @@ import LeaveConfirmModal from "@/components/LeaveConfirmModal";
 import Button from "@/components/Button";
 import { useRoomPolling } from "@/hooks/useRoomPolling";
 import { getUserId } from "@/lib/userId";
+import { joinRoom } from "@/lib/room";
 import { getSceneConfig } from "@/lib/sceneConfig";
 
 export default function RoomPage() {
@@ -31,14 +32,9 @@ export default function RoomPage() {
     const id = getUserId();
     setUserId(id);
 
-    fetch(`/api/room/${roomId}/join`, {
+    joinRoom(roomId, id)
-      method: "POST",
+      .then(() => setJoined(true))
-      headers: { "Content-Type": "application/json" },
+      .catch(() => setJoinFailed(true));
-      body: JSON.stringify({ userId: id }),
-    }).then((res) => {
-      if (res.ok) setJoined(true);
-      else setJoinFailed(true);
-    }).catch(() => setJoinFailed(true));
   }, [roomId]);
 
   useEffect(() => {

src/hooks/useGeolocation.ts

@@ -0,0 +1,70 @@
+"use client";
+
+import { useState, useEffect, useCallback } from "react";
+
+export type GpsStatus = "idle" | "locating" | "success" | "failed" | "denied";
+
+type GpsResult =
+  | { ok: true; lat: number; lng: number }
+  | { ok: false; reason: "unsupported" | "denied" | "timeout" | "unknown" };
+
+function requestGps(): Promise<GpsResult> {
+  return new Promise((resolve) => {
+    if (!navigator.geolocation) {
+      resolve({ ok: false, reason: "unsupported" });
+      return;
+    }
+
+    navigator.geolocation.getCurrentPosition(
+      (pos) =>
+        resolve({ ok: true, lat: pos.coords.latitude, lng: pos.coords.longitude }),
+      (err) => {
+        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 function useGeolocation() {
+  const [status, setStatus] = useState<GpsStatus>("idle");
+  const [coords, setCoords] = useState<{ lat: number; lng: number } | null>(null);
+  const [locationName, setLocationName] = useState<string | null>(null);
+
+  const locate = useCallback(async () => {
+    setStatus("locating");
+    const result = await requestGps();
+    if (result.ok) {
+      setCoords({ lat: result.lat, lng: result.lng });
+      setStatus("success");
+      const name = await reverseGeocode(result.lat, result.lng);
+      if (name) setLocationName(name);
+    } else {
+      setCoords(null);
+      setLocationName(null);
+      setStatus(result.reason === "denied" ? "denied" : "failed");
+    }
+  }, []);
+
+  useEffect(() => {
+    locate();
+  }, [locate]);
+
+  return { status, coords, locationName, retry: locate };
+}

src/lib/room.ts

@@ -0,0 +1,11 @@
+export async function joinRoom(roomId: string, userId: string): Promise<void> {
+  const res = await fetch(`/api/room/${roomId}/join`, {
+    method: "POST",
+    headers: { "Content-Type": "application/json" },
+    body: JSON.stringify({ userId }),
+  });
+  if (!res.ok) {
+    const data = await res.json().catch(() => ({}));
+    throw new Error(data.error || "加入房间失败");
+  }
+}