[FEATURE] 전화번호 중복가입 차단 및 로그인 플로우 개선

android/.gitignore

@@ -66,7 +66,7 @@ keystore.properties
 .cxx/
 
 # Google Services (e.g. APIs or Firebase)
-# google-services.json
+google-services.json
 
 # Freeline
 freeline.py

src/apis/member/requestPhoneVerification.api.ts

@@ -17,7 +17,7 @@ export async function requestPhoneVerification(
   const body = res.data;
 
   if (!body.success) {
-    throw new Error(body.message);
+    throw Object.assign(new Error(body.message), { code: body.code });
   }
 
   return body;

src/assets/icon/index.ts

@@ -54,6 +54,7 @@ export { default as RestoraionSparkleIcon } from "./restoration-sparkle.svg?reac
 export { default as TooltipXIcon } from "./tooltip-x.svg?react";
 export { default as AiRestoreIcon } from "./ai-restore.svg?react";
 export { default as FindersLogoFooterIcon } from "./finders-logo-footer.svg?react";
+export { default as PolygonIcon } from "./polygon.svg?react";
 
 // 소셜 / 브랜드
 export { default as AppleIcon } from "./apple.svg?react";

src/components/auth/RecentLoginDialog.tsx

@@ -0,0 +1,16 @@
+import { PolygonIcon } from "@/assets/icon";
+
+interface RecentLoginDialogProps {
+  className?: string;
+}
+
+export function RecentLoginDialog({ className = "" }: RecentLoginDialogProps) {
+  return (
+    <div className={`flex flex-col items-center self-center ${className}`}>
+      <div className="bg-neutral-0 rounded-lg px-2 py-1.25 text-xs font-semibold text-orange-500">
+        최근에 로그인 했어요
+      </div>
+      <PolygonIcon className="-mt-0.5 h-2.5 w-2.5" />
+    </div>
+  );
+}

src/components/auth/index.ts

@@ -5,3 +5,4 @@ export { ActionButton } from "./ActionButton";
 export { TermsAgreementItem } from "./TermsAgreementItem";
 export { TermsContent } from "./TermsContent";
 export { TermsAccordionRow } from "./TermsAccordionRow";
+export { RecentLoginDialog } from "./RecentLoginDialog";

src/constants/member/phone.constant.ts

@@ -0,0 +1,2 @@
+// 서버 ErrorCode: 인증번호 발송 시 이미 가입된 전화번호
+export const PHONE_ALREADY_REGISTERED_CODE = "MEMBER_412";

src/hooks/auth/login/useAppleLogin.ts

@@ -1,5 +1,6 @@
 import { useState } from "react";
 import { loginWithApple } from "@/utils/auth/appleSdk";
+import { setRecentLoginProvider } from "@/utils/auth/recentLoginProvider";
 import { tokenStorage } from "@/utils/tokenStorage";
 import { useOauth } from "./useOauth";
 import { useAuthStore } from "@/store/useAuth.store";
@@ -26,6 +27,8 @@ export function useAppleLogin({
       const data = res.data;
 
       if ("accessToken" in data) {
+        // 가입이 끝난 계정만 "최근 로그인"으로 기록 (신규 회원은 아직 계정이 없음)
+        setRecentLoginProvider("APPLE");
         tokenStorage.setTokens({
           accessToken: data.accessToken,
           signupToken: null,

src/hooks/auth/login/useKakaoOAuth.ts

@@ -1,6 +1,7 @@
 import { useEffect, useRef } from "react";
 import { useSearchParams } from "react-router";
 import { consumeAndValidateKakaoState } from "@/utils/auth/kakaoOauth";
+import { setRecentLoginProvider } from "@/utils/auth/recentLoginProvider";
 import { tokenStorage } from "@/utils/tokenStorage";
 import { useOauth } from "./useOauth";
 import { useAuthStore } from "@/store/useAuth.store";
@@ -30,6 +31,8 @@ export function useKakaoOauth({
 
       if ("accessToken" in data) {
         // 기존 회원: accessToken 저장 후 메인으로 (refreshToken은 httpOnly 쿠키)
+        // 가입이 끝난 계정만 "최근 로그인"으로 기록 (신규 회원은 아직 계정이 없음)
+        setRecentLoginProvider("KAKAO");
         tokenStorage.setTokens({
           accessToken: data.accessToken,
           signupToken: null,

src/hooks/auth/onBoarding/useOnBoardingForm.ts

@@ -4,10 +4,12 @@ import type { TermsType } from "@/types/auth";
 import { useDebouncedValue, useDebouncedTrue } from "@/hooks/common";
 import { useShakeTrigger } from "@/hooks/common/useShakeTrigger";
 import {
+  extractPhoneVerifyErrorCode,
   useConfirmPhoneVerification,
   useNicknameCheck,
   useRequestPhoneVerification,
 } from "@/hooks/member";
+import { PHONE_ALREADY_REGISTERED_CODE } from "@/constants/member/phone.constant";
 import { tokenStorage } from "@/utils/tokenStorage";
 import { useSocialSignup } from "./useSignUp";
 import { useAuthStore } from "@/store/useAuth.store";
@@ -43,6 +45,7 @@ export function useOnBoardingForm(options?: Options) {
 
   const [phoneVerifyMessage, setPhoneVerifyMessage] = useState<string>(""); // 성공 문구
   const [phoneVerifyError, setPhoneVerifyError] = useState<string>(""); // 실패 문구
+  const [isDuplicatePhone, setIsDuplicatePhone] = useState(false); // 이미 가입된 번호 안내
 
   // 닉네임 인증
   const debouncedNickname = useDebouncedValue(nickname, 400);
@@ -134,7 +137,13 @@ export function useOnBoardingForm(options?: Options) {
       }
         // prettier-ignore
       },
-      onError: (e) => console.error(e.message),
+      onError: (e) => {
+        if (extractPhoneVerifyErrorCode(e) === PHONE_ALREADY_REGISTERED_CODE) {
+          setIsDuplicatePhone(true);
+          return;
+        }
+        console.error(e.message);
+      },
     });
 
   const { mutate: confirmCode, isPending: isConfirmingCode } =
@@ -340,6 +349,10 @@ export function useOnBoardingForm(options?: Options) {
     phoneTextClass,
     lockPhoneForm,
 
+    // 이미 가입된 번호 안내
+    isDuplicatePhone,
+    closeDuplicatePhoneDialog: () => setIsDuplicatePhone(false),
+
     // shake keys
     nicknameShakeKey,
     phoneShakeKey,

src/hooks/member/index.ts

@@ -1,5 +1,8 @@
 export { useNicknameCheck } from "./useCheckNickName";
-export { useRequestPhoneVerification } from "./useRequestPhoneVerification";
+export {
+  useRequestPhoneVerification,
+  extractPhoneVerifyErrorCode,
+} from "./useRequestPhoneVerification";
 export { useConfirmPhoneVerification } from "./useConfirmPhoneVerification";
 export { useMe, type MeResponse, ME_QUERY_KEY } from "./useMe";
 export { useEditMe } from "./useEditMe";

src/hooks/member/useRequestPhoneVerification.ts

@@ -1,4 +1,5 @@
 import { useMutation, type UseMutationOptions } from "@tanstack/react-query";
+import { isAxiosError } from "axios";
 import type { ApiResponse } from "@/types/common/apiResponse";
 import { requestPhoneVerification } from "@/apis/member";
 import type {
@@ -18,3 +19,16 @@ export function useRequestPhoneVerification(
     ...options,
   });
 }
+
+// axios 에러(HTTP 에러 상태) 또는 200 + success:false로 던져진 에러 모두에서 서버 ApiResponse.code(MEMBER_xxx) 추출
+export function extractPhoneVerifyErrorCode(
+  error: unknown,
+): string | undefined {
+  if (isAxiosError<{ code?: string }>(error)) {
+    return error.response?.data?.code ?? error.code;
+  }
+  if (error instanceof Error && "code" in error) {
+    return (error as Error & { code?: string }).code;
+  }
+  return error instanceof Error ? error.message : undefined;
+}

src/layouts/RootLayout.tsx

@@ -1,18 +1,27 @@
-import { useEffect } from "react";
+import { useEffect, useState } from "react";
 import { useNavigate, Outlet } from "react-router";
 import { App } from "@capacitor/app";
 import { Capacitor } from "@capacitor/core";
+import { DialogBox } from "@/components/common/DialogBox";
 import GlobalLoginDialog from "@/components/common/GlobalLoginDialog";
 import { useNewPostState } from "@/store/useNewPostState.store";
 
 export default function RootLayout() {
   const navigate = useNavigate();
+  const [isExitDialogOpen, setIsExitDialogOpen] = useState(false);
 
   useEffect(() => {
     if (!Capacitor.isNativePlatform()) return;
 
     // Promise 자체를 붙잡아, resolve 타이밍과 무관하게 클린업에서 리스너를 제거한다.
     const handlePromise = App.addListener("backButton", ({ canGoBack }) => {
+      // 종료 다이얼로그가 떠 있으면 뒤로가기는 다이얼로그만 닫는다
+      // (DialogBox의 useDismiss는 pointerdown/Escape만 처리 — 안드로이드 back은 안 잡힘)
+      if (isExitDialogOpen) {
+        setIsExitDialogOpen(false);
+        return;
+      }
+
       // 게시글 등록 직후엔 하드웨어 뒤로가기도 이전 작성 단계가 아니라 피드로 이동
       if (useNewPostState.getState().isNewPost) {
         useNewPostState.getState().setIsNewPost(false);
@@ -22,19 +31,39 @@ export default function RootLayout() {
 
       if (canGoBack) {
         navigate(-1);
-      } else {
-        App.exitApp();
+        return;
       }
+
+      // 가입 플로우(약관/온보딩)는 전 구간 replace라 히스토리가 비어 있다.
+      // 여기서 앱을 닫으면 입력 중이던 가입 정보가 날아가므로 로그인으로 되돌린다.
+      // (이벤트 발생 시점에 읽어야 리스너 재등록 없이 최신 경로가 잡힌다)
+      const { pathname } = window.location;
+      if (pathname.startsWith("/auth/") && pathname !== "/auth/login") {
+        navigate("/auth/login", { replace: true });
+        return;
+      }
+
+      // 뒤로 갈 히스토리가 없음(=뒤로가기 시 앱 종료): 즉시 종료 대신 확인 다이얼로그
+      setIsExitDialogOpen(true);
     });
 
     return () => {
       handlePromise.then((handle) => handle.remove());
     };
-  }, [navigate]);
+  }, [navigate, isExitDialogOpen]);
 
   return (
     <div className="min-h-dvh w-full bg-neutral-900 text-neutral-100">
       <GlobalLoginDialog />
+      <DialogBox
+        isOpen={isExitDialogOpen}
+        title="파인더스 앱 닫기"
+        description="파인더스를 종료하시겠어요?"
+        cancelText="아니오"
+        onCancel={() => setIsExitDialogOpen(false)}
+        confirmText="네"
+        onConfirm={() => App.exitApp()}
+      />
       {/* safe-area + 중앙 레이아웃(PC) + 패딩(모바일) */}
       <div className="mx-auto flex min-h-dvh w-full max-w-120 flex-col px-4 pt-[env(safe-area-inset-top)] pb-[env(safe-area-inset-bottom)] sm:px-6 lg:px-8">
         {/* Rootlayout으로 감싸진 모든 컴포넌트 렌더링*/}

src/pages/auth/LoginPage.tsx

@@ -1,4 +1,4 @@
-import { AppleButton, KakaoButton } from "@/components/auth";
+import { AppleButton, KakaoButton, RecentLoginDialog } from "@/components/auth";
 import { CTA_Button, Press } from "@/components/common";
 import { Link, useNavigate, useSearchParams } from "react-router";
 import { useEffect, useMemo, useState } from "react";
@@ -9,6 +9,10 @@ import { Capacitor3KakaoLogin } from "capacitor3-kakao-login";
 import { isNativeApp } from "@/utils/auth/envUtils";
 import { isAndroidApp } from "@/utils/platform";
 import { oauth } from "@/apis/auth";
+import {
+  getRecentLoginProvider,
+  setRecentLoginProvider,
+} from "@/utils/auth/recentLoginProvider";
 import { tokenStorage } from "@/utils/tokenStorage";
 import { consumeRedirectAfterLogin } from "../demoDay/redirectAfterLogin";
 import { SplashScreen } from "@capacitor/splash-screen"; // 앱 초기 스플래시 제어용
@@ -34,6 +38,9 @@ export function LoginPage() {
   const [authCheckStatus, setAuthCheckStatus] =
     useState<AuthCheckStatus>("pending");
 
+  // 최근에 로그인했던 SNS (버튼 위 안내용)
+  const [recentLoginProvider] = useState(() => getRecentLoginProvider());
+
   // 앱 실행 시 네이티브 스플래시 숨김 & 백그라운드 토큰 검사
   useEffect(() => {
     // 앱인 경우 기본 제공되는 스플래시를 즉시 가리고 리액트 애니메이션 띄우기
@@ -162,6 +169,8 @@ export function LoginPage() {
           });
           navigate("/auth/onboarding", { replace: true });
         } else if ("member" in data) {
+          // 가입이 끝난 계정만 "최근 로그인"으로 기록 (신규 회원은 아직 계정이 없음)
+          setRecentLoginProvider("KAKAO");
           await tokenStorage.setTokens({
             accessToken: data.accessToken,
             signupToken: null,
@@ -240,7 +249,7 @@ export function LoginPage() {
           >
             <CTA_Button
               text="홈으로"
-              link="/mainpage"
+              onClick={() => navigate("/mainpage", { replace: true })}
               color="orange"
               size="compact"
             />
@@ -259,9 +268,29 @@ export function LoginPage() {
             key={ui.footerKey}
             className={`mx-auto max-w-sm ${ui.footerAnim}`}
           >
-            <div className="flex flex-col gap-2">
-              {!isAndroidApp() && (
-                <AppleButton onClick={apple.login} disabled={apple.isPending} />
+            <div className="flex flex-col gap-3">
+              {recentLoginProvider === "APPLE" && !isAndroidApp() && (
+                <RecentLoginDialog />
+              )}
+              <div
+                className={
+                  recentLoginProvider === "KAKAO" && !isAndroidApp()
+                    ? "relative"
+                    : undefined
+                }
+              >
+                {!isAndroidApp() && (
+                  <AppleButton
+                    onClick={apple.login}
+                    disabled={apple.isPending}
+                  />
+                )}
+                {recentLoginProvider === "KAKAO" && !isAndroidApp() && (
+                  <RecentLoginDialog className="absolute bottom-0 left-1/2 -translate-x-1/2 translate-y-1/4" />
+                )}
+              </div>
+              {recentLoginProvider === "KAKAO" && isAndroidApp() && (
+                <RecentLoginDialog />
               )}
               <KakaoButton onClick={handleKakaoLogin} />
             </div>

src/pages/auth/OnBoarding.tsx

@@ -3,6 +3,7 @@ import { useLocation, useNavigate } from "react-router";
 import { formatMMSS } from "@/utils/time";
 import { ActionButton, InputForm } from "@/components/auth";
 import { Collapse, CTA_Button } from "@/components/common";
+import { DialogBox } from "@/components/common/DialogBox";
 import { useOnBoardingForm } from "@/hooks/auth/onBoarding";
 import type { TermsType } from "@/types/auth";
 
@@ -121,6 +122,15 @@ export function OnBoardingPage() {
           onClick={f.handleSubmit}
         />
       </footer>
+
+      <DialogBox
+        isOpen={f.isDuplicatePhone}
+        title="이미 가입한 회원입니다"
+        description="이전에 가입한 계정으로 로그인해주세요."
+        confirmText="확인"
+        onConfirm={() => navigate("/auth/login", { replace: true })}
+        onCancel={f.closeDuplicatePhoneDialog}
+      />
     </div>
   );
 }

src/pages/auth/TermsAgreementPage.tsx

@@ -19,7 +19,10 @@ export function TermsAgreementPage() {
 
   const handleConfirm = () => {
     if (!requiredAllChecked) return;
-    navigate("/auth/onboarding", { state: { agreedTermTypes } });
+    navigate("/auth/onboarding", {
+      state: { agreedTermTypes },
+      replace: true,
+    });
   };
 
   return (

src/router/Router.tsx

@@ -267,7 +267,7 @@ const router = createBrowserRouter([
   {
     Component: RootLayout,
     children: [
-      { index: true, element: <Navigate to="/auth/login" /> },
+      { index: true, element: <Navigate to="/auth/login" replace /> },
 
       // auth prefix를 한 번만
       { path: "auth", children: authRoutes },

src/utils/auth/recentLoginProvider.ts

@@ -0,0 +1,21 @@
+import type { SocialProvider } from "@/types/auth";
+
+const RECENT_LOGIN_PROVIDER_KEY = "finders:recentLoginProvider";
+
+// 로그아웃과 무관하게 남아야 해서 useAuthStore(persist)와 분리된 별도 키로 관리
+export function setRecentLoginProvider(provider: SocialProvider) {
+  try {
+    localStorage.setItem(RECENT_LOGIN_PROVIDER_KEY, provider);
+  } catch (e) {
+    console.error("최근 로그인 정보 저장에 실패했습니다.", e);
+  }
+}
+
+export function getRecentLoginProvider(): SocialProvider | null {
+  try {
+    const value = localStorage.getItem(RECENT_LOGIN_PROVIDER_KEY);
+    return value === "KAKAO" || value === "APPLE" ? value : null;
+  } catch {
+    return null;
+  }
+}