구글 로그인 구현

.idea/.gitignore

@@ -0,0 +1,3 @@
+# Default ignored files
+/shelf/
+/workspace.xml

.idea/deviceManager.xml

@@ -0,0 +1,13 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<project version="4">
+  <component name="DeviceTable">
+    <option name="columnSorters">
+      <list>
+        <ColumnSorterState>
+          <option name="column" value="Name" />
+          <option name="order" value="ASCENDING" />
+        </ColumnSorterState>
+      </list>
+    </option>
+  </component>
+</project>

.idea/misc.xml

@@ -0,0 +1,5 @@
+<project version="4">
+  <component name="ProjectRootManager">
+    <output url="file://$PROJECT_DIR$/out" />
+  </component>
+</project>

.idea/modules.xml

@@ -0,0 +1,8 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<project version="4">
+  <component name="ProjectModuleManager">
+    <modules>
+      <module fileurl="file://$PROJECT_DIR$/.idea/rup.iml" filepath="$PROJECT_DIR$/.idea/rup.iml" />
+    </modules>
+  </component>
+</project>

.idea/rup.iml

@@ -0,0 +1,13 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<module type="JAVA_MODULE" version="4">
+  <component name="NewModuleRootManager" inherit-compiler-output="true">
+    <exclude-output />
+    <content url="file://$MODULE_DIR$">
+      <excludeFolder url="file://$MODULE_DIR$/app/.dart_tool" />
+      <excludeFolder url="file://$MODULE_DIR$/app/.pub" />
+      <excludeFolder url="file://$MODULE_DIR$/app/build" />
+    </content>
+    <orderEntry type="inheritedJdk" />
+    <orderEntry type="sourceFolder" forTests="false" />
+  </component>
+</module>

.idea/vcs.xml

@@ -0,0 +1,6 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<project version="4">
+  <component name="VcsDirectoryMappings">
+    <mapping directory="" vcs="Git" />
+  </component>
+</project>

app/android/app/build.gradle.kts

@@ -3,6 +3,7 @@ plugins {
     id("kotlin-android")
     // The Flutter Gradle Plugin must be applied after the Android and Kotlin Gradle plugins.
     id("dev.flutter.flutter-gradle-plugin")
+    id("com.google.gms.google-services")
 }
 
 android {
@@ -21,7 +22,7 @@ android {
 
     defaultConfig {
         // TODO: Specify your own unique Application ID (https://developer.android.com/studio/build/application-id.html).
-        applicationId = "com.example.app"
+        applicationId = "com.example.rup"
         // You can update the following values to match your application needs.
         // For more information, see: https://flutter.dev/to/review-gradle-config.
         minSdk = flutter.minSdkVersion

app/android/app/google-services.json

@@ -0,0 +1,47 @@
+{
+  "project_info": {
+    "project_number": "379988243470",
+    "project_id": "rup-project-9d4c4",
+    "storage_bucket": "rup-project-9d4c4.firebasestorage.app"
+  },
+  "client": [
+    {
+      "client_info": {
+        "mobilesdk_app_id": "1:379988243470:android:b4a4761b906eb44a1cb85f",
+        "android_client_info": {
+          "package_name": "com.example.rup"
+        }
+      },
+      "oauth_client": [
+        {
+          "client_id": "379988243470-jd0c59ci9ksr36er7sjkrkc4rtgmll1a.apps.googleusercontent.com",
+          "client_type": 1,
+          "android_info": {
+            "package_name": "com.example.rup",
+            "certificate_hash": "7bda16a71840f93ab7c41fecc24da2bde3702424"
+          }
+        },
+        {
+          "client_id": "379988243470-g6490l8gucc3ljras93i28c3l4qlroi4.apps.googleusercontent.com",
+          "client_type": 3
+        }
+      ],
+      "api_key": [
+        {
+          "current_key": "AIzaSyAql00w1JB6n5wb4StXi9eyixVyIuT3-Hg"
+        }
+      ],
+      "services": {
+        "appinvite_service": {
+          "other_platform_oauth_client": [
+            {
+              "client_id": "379988243470-g6490l8gucc3ljras93i28c3l4qlroi4.apps.googleusercontent.com",
+              "client_type": 3
+            }
+          ]
+        }
+      }
+    }
+  ],
+  "configuration_version": "1"
+}

app/android/app/src/main/AndroidManifest.xml

@@ -1,4 +1,5 @@
 <manifest xmlns:android="http://schemas.android.com/apk/res/android">
+    <uses-permission android:name="android.permission.INTERNET"/>
     <application
         android:label="app"
         android:name="${applicationName}"

app/android/build.gradle.kts

@@ -1,3 +1,13 @@
+buildscript {
+    repositories {
+        google()
+        mavenCentral()
+    }
+    dependencies {
+        classpath("com.google.gms:google-services:4.3.15")
+    }
+}
+
 allprojects {
     repositories {
         google()

app/lib/main.dart

@@ -1,7 +1,15 @@
 import 'package:flutter/material.dart';
+import 'package:firebase_core/firebase_core.dart';
 import 'screens/splash_screen.dart';
+import 'dart:developer';
 
-void main() {
+void main() async {
+  WidgetsFlutterBinding.ensureInitialized();
+  try {
+    await Firebase.initializeApp();
+  } catch (e) {
+    log('Firebase initialization failed: $e');
+  }
   runApp(RupApp());
 }
 

app/lib/screens/login_screen.dart

@@ -1,119 +1,176 @@
 import 'package:flutter/material.dart';
 import 'package:flutter_svg/flutter_svg.dart';
+import '../services/auth_service.dart';
+import 'home_screen.dart';
 
-class LoginScreen extends StatelessWidget {
+class LoginScreen extends StatefulWidget {
   const LoginScreen({super.key});
 
+  @override
+  State<LoginScreen> createState() => _LoginScreenState();
+}
+
+class _LoginScreenState extends State<LoginScreen> {
+  bool _isLoading = false;
+
+  Future<void> _handleGoogleLogin() async {
+    setState(() {
+      _isLoading = true;
+    });
+
+    try {
+      final authService = AuthService();
+      final user = await authService.signInWithGoogle();
+
+      if (!mounted) return;
+
+      if (user != null) {
+        Navigator.pushReplacement(
+          context,
+          MaterialPageRoute(builder: (context) => const HomeScreen()),
+        );
+      } else {
+        ScaffoldMessenger.of(
+          context,
+        ).showSnackBar(const SnackBar(content: Text('로그인이 취소되었습니다.')));
+      }
+    } catch (e) {
+      if (!mounted) return;
+      ScaffoldMessenger.of(
+        context,
+      ).showSnackBar(SnackBar(content: Text('로그인 실패: $e')));
+    } finally {
+      if (mounted) {
+        setState(() {
+          _isLoading = false;
+        });
+      }
+    }
+  }
+
   @override
   Widget build(BuildContext context) {
-    return Scaffold(
+    return Stack(
-      backgroundColor: Colors.white,
+      children: [
-      appBar: AppBar(
+        Scaffold(
-        backgroundColor: Colors.white,
+          backgroundColor: Colors.white,
-        elevation: 0,
+          appBar: AppBar(
-        leading: IconButton(
+            backgroundColor: Colors.white,
-          icon: const Icon(Icons.arrow_back_ios, color: Colors.black, size: 20),
+            elevation: 0,
-          onPressed: () => Navigator.pop(context),
+            leading: IconButton(
-        ),
+              icon: const Icon(
-        title: const Text(
+                Icons.arrow_back_ios,
-          '로그인',
+                color: Colors.black,
-          style: TextStyle(
+                size: 20,
-            fontSize: 15,
+              ),
-            fontFamily: 'SCDream',
+              onPressed: () => Navigator.pop(context),
-            fontWeight: FontWeight.w500,
-            color: Colors.black,
-          ),
-        ),
-        centerTitle: true,
-      ),
-      body: Padding(
-        padding: const EdgeInsets.fromLTRB(20, 0, 20, 240),
-        child: Column(
-          crossAxisAlignment: CrossAxisAlignment.start,
-          children: [
-            SizedBox(height: 20),
-            Row(
-              mainAxisAlignment: MainAxisAlignment.start,
-              children: [
-                Image.asset('assets/img/foot.png', width: 30),
-                SizedBox(width: 10),
-                Text(
-                  '로그인',
-                  style: TextStyle(
-                    fontSize: 24,
-                    fontFamily: 'SCDream',
-                    fontWeight: FontWeight.bold,
-                    color: Colors.black,
-                  ),
-                ),
-              ],
             ),
-            SizedBox(height: 10),
+            title: const Text(
-            Text(
+              '로그인',
-              'RUP에 어서오세요!\n지금 로그인하고 다양한 서비스를 이용해보세요.',
               style: TextStyle(
-                fontSize: 14,
+                fontSize: 15,
                 fontFamily: 'SCDream',
                 fontWeight: FontWeight.w500,
                 color: Colors.black,
               ),
-              textAlign: TextAlign.start,
             ),
-            Spacer(),
+            centerTitle: true,
-            Align(
+          ),
-              alignment: Alignment.centerRight,
+          body: Padding(
-              child: Image.asset('assets/img/cat.png', height: 150),
+            padding: const EdgeInsets.fromLTRB(20, 0, 20, 240),
+            child: Column(
+              crossAxisAlignment: CrossAxisAlignment.start,
+              children: [
+                SizedBox(height: 20),
+                Row(
+                  mainAxisAlignment: MainAxisAlignment.start,
+                  children: [
+                    Image.asset('assets/img/foot.png', width: 30),
+                    SizedBox(width: 10),
+                    Text(
+                      '로그인',
+                      style: TextStyle(
+                        fontSize: 24,
+                        fontFamily: 'SCDream',
+                        fontWeight: FontWeight.bold,
+                        color: Colors.black,
+                      ),
+                    ),
+                  ],
+                ),
+                SizedBox(height: 10),
+                Text(
+                  'RUP에 어서오세요!\n지금 로그인하고 다양한 서비스를 이용해보세요.',
+                  style: TextStyle(
+                    fontSize: 14,
+                    fontFamily: 'SCDream',
+                    fontWeight: FontWeight.w500,
+                    color: Colors.black,
+                  ),
+                  textAlign: TextAlign.start,
+                ),
+                Spacer(),
+                Align(
+                  alignment: Alignment.centerRight,
+                  child: Image.asset('assets/img/cat.png', height: 150),
+                ),
+                SizedBox(height: 10),
+              ],
             ),
-            SizedBox(height: 10),
+          ),
-          ],
+          bottomSheet: Container(
+            color: Colors.white,
+            padding: const EdgeInsets.fromLTRB(20, 20, 20, 40),
+            child: Column(
+              mainAxisSize: MainAxisSize.min,
+              crossAxisAlignment: CrossAxisAlignment.stretch,
+              children: [
+                // Naver Login Button
+                _SocialLoginButton(
+                  text: '네이버 로그인',
+                  textColor: Colors.white,
+                  fontFamily: 'SCDream',
+                  fontWeight: FontWeight.bold,
+                  fontSize: 15,
+                  backgroundColor: const Color(0xFF00D03F),
+                  onPressed: () {},
+                  iconPath: 'assets/icons/navericon.svg',
+                ),
+                const SizedBox(height: 15),
+                // Kakao Login Button
+                _SocialLoginButton(
+                  text: '카카오 로그인',
+                  textColor: const Color(0xFF212121),
+                  fontFamily: 'SCDream',
+                  fontWeight: FontWeight.bold,
+                  fontSize: 15,
+                  backgroundColor: const Color(0xFFFAE100),
+                  onPressed: () {},
+                  iconPath: 'assets/icons/kakaoicon.svg',
+                ),
+                const SizedBox(height: 15),
+                // Google Login Button
+                _SocialLoginButton(
+                  text: '구글 로그인',
+                  textColor: const Color(0xFF17191A),
+                  fontFamily: 'SCDream',
+                  fontWeight: FontWeight.bold,
+                  fontSize: 15,
+                  backgroundColor: Colors.white,
+                  onPressed: _handleGoogleLogin,
+                  iconPath: 'assets/icons/googleicon.svg',
+                  isBordered: true,
+                ),
+              ],
+            ),
+          ),
         ),
-      ),
+        if (_isLoading)
-      bottomSheet: Container(
+          Container(
-        color: Colors.white,
+            color: Colors.black.withOpacity(0.5),
-        padding: const EdgeInsets.fromLTRB(20, 20, 20, 40),
+            child: const Center(child: CircularProgressIndicator()),
-        child: Column(
+          ),
-          mainAxisSize: MainAxisSize.min,
+      ],
-          crossAxisAlignment: CrossAxisAlignment.stretch,
-          children: [
-            // Naver Login Button
-            _SocialLoginButton(
-              text: '네이버 로그인',
-              textColor: Colors.white,
-              fontFamily: 'SCDream',
-              fontWeight: FontWeight.bold,
-              fontSize: 15,
-              backgroundColor: const Color(0xFF00D03F),
-              onPressed: () {},
-              iconPath: 'assets/icons/navericon.svg',
-            ),
-            const SizedBox(height: 15),
-            // Kakao Login Button
-            _SocialLoginButton(
-              text: '카카오 로그인',
-              textColor: const Color(0xFF212121),
-              fontFamily: 'SCDream',
-              fontWeight: FontWeight.bold,
-              fontSize: 15,
-              backgroundColor: const Color(0xFFFAE100),
-              onPressed: () {},
-              iconPath: 'assets/icons/kakaoicon.svg',
-            ),
-            const SizedBox(height: 15),
-            // Google Login Button
-            _SocialLoginButton(
-              text: '구글 로그인',
-              textColor: const Color(0xFF17191A),
-              fontFamily: 'SCDream',
-              fontWeight: FontWeight.bold,
-              fontSize: 15,
-              backgroundColor: Colors.white,
-              onPressed: () {},
-              iconPath: 'assets/icons/googleicon.svg',
-              isBordered: true,
-            ),
-          ],
-        ),
-      ),
     );
   }
 }

app/lib/screens/signup_screen.dart

@@ -1,119 +1,176 @@
 import 'package:flutter/material.dart';
 import 'package:flutter_svg/flutter_svg.dart';
+import '../services/auth_service.dart';
+import 'home_screen.dart';
 
-class SignupScreen extends StatelessWidget {
+class SignupScreen extends StatefulWidget {
   const SignupScreen({super.key});
 
+  @override
+  State<SignupScreen> createState() => _SignupScreenState();
+}
+
+class _SignupScreenState extends State<SignupScreen> {
+  bool _isLoading = false;
+
+  Future<void> _handleGoogleLogin() async {
+    setState(() {
+      _isLoading = true;
+    });
+
+    try {
+      final authService = AuthService();
+      final user = await authService.signInWithGoogle();
+
+      if (!mounted) return;
+
+      if (user != null) {
+        Navigator.pushReplacement(
+          context,
+          MaterialPageRoute(builder: (context) => const HomeScreen()),
+        );
+      } else {
+        ScaffoldMessenger.of(
+          context,
+        ).showSnackBar(const SnackBar(content: Text('로그인이 취소되었습니다.')));
+      }
+    } catch (e) {
+      if (!mounted) return;
+      ScaffoldMessenger.of(
+        context,
+      ).showSnackBar(SnackBar(content: Text('로그인 실패: $e')));
+    } finally {
+      if (mounted) {
+        setState(() {
+          _isLoading = false;
+        });
+      }
+    }
+  }
+
   @override
   Widget build(BuildContext context) {
-    return Scaffold(
+    return Stack(
-      backgroundColor: Colors.white,
+      children: [
-      appBar: AppBar(
+        Scaffold(
-        backgroundColor: Colors.white,
+          backgroundColor: Colors.white,
-        elevation: 0,
+          appBar: AppBar(
-        leading: IconButton(
+            backgroundColor: Colors.white,
-          icon: Icon(Icons.arrow_back_ios, color: Colors.black, size: 20),
+            elevation: 0,
-          onPressed: () => Navigator.pop(context),
+            leading: IconButton(
-        ),
+              icon: const Icon(
-        title: Text(
+                Icons.arrow_back_ios,
-          '회원가입',
+                color: Colors.black,
-          style: TextStyle(
+                size: 20,
-            fontSize: 15,
+              ),
-            fontFamily: 'SCDream',
+              onPressed: () => Navigator.pop(context),
-            fontWeight: FontWeight.w500,
-            color: Colors.black,
-          ),
-        ),
-        centerTitle: true,
-      ),
-      body: Padding(
-        padding: const EdgeInsets.fromLTRB(20, 0, 20, 240),
-        child: Column(
-          crossAxisAlignment: CrossAxisAlignment.start,
-          children: [
-            SizedBox(height: 20),
-            Row(
-              mainAxisAlignment: MainAxisAlignment.start,
-              children: [
-                Image.asset('assets/img/foot.png', width: 30),
-                SizedBox(width: 10),
-                Text(
-                  '서비스 이용 약관',
-                  style: TextStyle(
-                    fontSize: 24,
-                    fontFamily: 'SCDream',
-                    fontWeight: FontWeight.bold,
-                    color: Colors.black,
-                  ),
-                ),
-              ],
             ),
-            SizedBox(height: 10),
+            title: const Text(
-            Text(
+              '회원가입',
-              '똑똑한 반려생활을 위한 첫걸음,\nRUP에 오신것을 환영해요!',
               style: TextStyle(
-                fontSize: 14,
+                fontSize: 15,
                 fontFamily: 'SCDream',
                 fontWeight: FontWeight.w500,
                 color: Colors.black,
               ),
-              textAlign: TextAlign.start,
             ),
-            Spacer(),
+            centerTitle: true,
-            Align(
+          ),
-              alignment: Alignment.centerRight,
+          body: Padding(
-              child: Image.asset('assets/img/cat.png', height: 150),
+            padding: const EdgeInsets.fromLTRB(20, 0, 20, 240),
+            child: Column(
+              crossAxisAlignment: CrossAxisAlignment.start,
+              children: [
+                const SizedBox(height: 20),
+                Row(
+                  mainAxisAlignment: MainAxisAlignment.start,
+                  children: [
+                    Image.asset('assets/img/foot.png', width: 30),
+                    const SizedBox(width: 10),
+                    const Text(
+                      '서비스 이용 약관',
+                      style: TextStyle(
+                        fontSize: 24,
+                        fontFamily: 'SCDream',
+                        fontWeight: FontWeight.bold,
+                        color: Colors.black,
+                      ),
+                    ),
+                  ],
+                ),
+                const SizedBox(height: 10),
+                const Text(
+                  '똑똑한 반려생활을 위한 첫걸음,\nRUP에 오신것을 환영해요!',
+                  style: TextStyle(
+                    fontSize: 14,
+                    fontFamily: 'SCDream',
+                    fontWeight: FontWeight.w500,
+                    color: Colors.black,
+                  ),
+                  textAlign: TextAlign.start,
+                ),
+                const Spacer(),
+                Align(
+                  alignment: Alignment.centerRight,
+                  child: Image.asset('assets/img/cat.png', height: 150),
+                ),
+                const SizedBox(height: 10),
+              ],
             ),
-            SizedBox(height: 10),
+          ),
-          ],
+          bottomSheet: Container(
+            color: Colors.white,
+            padding: const EdgeInsets.fromLTRB(20, 20, 20, 40),
+            child: Column(
+              mainAxisSize: MainAxisSize.min,
+              crossAxisAlignment: CrossAxisAlignment.stretch,
+              children: [
+                // Naver Login Button
+                _SocialLoginButton(
+                  text: '네이버 로그인',
+                  textColor: Colors.white,
+                  fontFamily: 'SCDream',
+                  fontWeight: FontWeight.bold,
+                  fontSize: 15,
+                  backgroundColor: const Color(0xFF00D03F),
+                  onPressed: () {},
+                  iconPath: 'assets/icons/navericon.svg',
+                ),
+                const SizedBox(height: 15),
+                // Kakao Login Button
+                _SocialLoginButton(
+                  text: '카카오로 3초만에 시작하기',
+                  textColor: const Color(0xFF212121),
+                  fontFamily: 'SCDream',
+                  fontWeight: FontWeight.bold,
+                  fontSize: 15,
+                  backgroundColor: const Color(0xFFFAE100),
+                  onPressed: () {},
+                  iconPath: 'assets/icons/kakaoicon.svg',
+                ),
+                const SizedBox(height: 15),
+                // Google Login Button
+                _SocialLoginButton(
+                  text: '구글 로그인',
+                  textColor: const Color(0xFF17191A),
+                  fontFamily: 'SCDream',
+                  fontWeight: FontWeight.bold,
+                  fontSize: 15,
+                  backgroundColor: Colors.white,
+                  onPressed: _handleGoogleLogin,
+                  iconPath: 'assets/icons/googleicon.svg',
+                  isBordered: true,
+                ),
+              ],
+            ),
+          ),
         ),
-      ),
+        if (_isLoading)
-      bottomSheet: Container(
+          Container(
-        color: Colors.white,
+            color: Colors.black.withOpacity(0.5),
-        padding: EdgeInsets.fromLTRB(20, 20, 20, 40),
+            child: const Center(child: CircularProgressIndicator()),
-        child: Column(
+          ),
-          mainAxisSize: MainAxisSize.min,
+      ],
-          crossAxisAlignment: CrossAxisAlignment.stretch,
-          children: [
-            // Naver Login Button
-            _SocialLoginButton(
-              text: '네이버 로그인',
-              textColor: Colors.white,
-              fontFamily: 'SCDream',
-              fontWeight: FontWeight.bold,
-              fontSize: 15,
-              backgroundColor: Color(0xFF00D03F),
-              onPressed: () {},
-              iconPath: 'assets/icons/navericon.svg',
-            ),
-            SizedBox(height: 15),
-            // Kakao Login Button
-            _SocialLoginButton(
-              text: '카카오로 3초만에 시작하기',
-              textColor: Color(0xFF212121),
-              fontFamily: 'SCDream',
-              fontWeight: FontWeight.bold,
-              fontSize: 15,
-              backgroundColor: Color(0xFFFAE100),
-              onPressed: () {},
-              iconPath: 'assets/icons/kakaoicon.svg',
-            ),
-            SizedBox(height: 15),
-            // Google Login Button
-            _SocialLoginButton(
-              text: '구글 로그인',
-              textColor: Color(0xFF17191A),
-              fontFamily: 'SCDream',
-              fontWeight: FontWeight.bold,
-              fontSize: 15,
-              backgroundColor: Colors.white,
-              onPressed: () {},
-              iconPath: 'assets/icons/googleicon.svg',
-              isBordered: true,
-            ),
-          ],
-        ),
-      ),
     );
   }
 }

app/lib/screens/splash_screen.dart

@@ -43,7 +43,7 @@ class _SplashScreenState extends State<SplashScreen> {
   @override
   Widget build(BuildContext context) {
     return Scaffold(
-      backgroundColor: const Color(0xFFFF7500), // Original Brand Color
+      backgroundColor: const Color(0xFFFF7500),
       body: Center(
         child: Column(
           mainAxisAlignment: MainAxisAlignment.center,

app/lib/services/auth_service.dart

@@ -0,0 +1,51 @@
+import 'package:firebase_auth/firebase_auth.dart';
+import 'package:google_sign_in/google_sign_in.dart';
+
+class AuthService {
+  final FirebaseAuth _auth = FirebaseAuth.instance;
+  final GoogleSignIn _googleSignIn = GoogleSignIn();
+
+  // 구글 로그인
+  Future<UserCredential?> signInWithGoogle() async {
+    // 1. 구글 로그인 흐름 시작
+    print('[DEBUG] Google Sign-In: Starting signIn()');
+    final GoogleSignInAccount? googleUser = await _googleSignIn.signIn();
+    print(
+      '[DEBUG] Google Sign-In: signIn() completed, user: ${googleUser?.email}',
+    );
+
+    if (googleUser == null) {
+      // 사용자가 로그인 창을 닫음
+      print('[DEBUG] Google Sign-In: User canceled');
+      return null;
+    }
+
+    // 2. 인증 세부 정보 요청
+    print('[DEBUG] Google Sign-In: Getting authentication...');
+    final GoogleSignInAuthentication googleAuth =
+        await googleUser.authentication;
+    print(
+      '[DEBUG] Google Sign-In: Authentication received. AccessToken: ${googleAuth.accessToken != null}, IDToken: ${googleAuth.idToken != null}',
+    );
+
+    // 3. 자격 증명 생성
+    final OAuthCredential credential = GoogleAuthProvider.credential(
+      accessToken: googleAuth.accessToken,
+      idToken: googleAuth.idToken,
+    );
+
+    // 4. Firebase에 로그인
+    print('[DEBUG] Google Sign-In: Signing in with credential to Firebase...');
+    final userCredential = await _auth.signInWithCredential(credential);
+    print(
+      '[DEBUG] Google Sign-In: Firebase sign-in completed. User: ${userCredential.user?.uid}',
+    );
+    return userCredential;
+  }
+
+  // 로그아웃
+  Future<void> signOut() async {
+    await _googleSignIn.signOut();
+    await _auth.signOut();
+  }
+}

app/macos/Flutter/GeneratedPluginRegistrant.swift

@@ -5,8 +5,14 @@
 import FlutterMacOS
 import Foundation
 
+import firebase_auth
+import firebase_core
+import google_sign_in_ios
 import video_player_avfoundation
 
 func RegisterGeneratedPlugins(registry: FlutterPluginRegistry) {
+  FLTFirebaseAuthPlugin.register(with: registry.registrar(forPlugin: "FLTFirebaseAuthPlugin"))
+  FLTFirebaseCorePlugin.register(with: registry.registrar(forPlugin: "FLTFirebaseCorePlugin"))
+  FLTGoogleSignInPlugin.register(with: registry.registrar(forPlugin: "FLTGoogleSignInPlugin"))
   FVPVideoPlayerPlugin.register(with: registry.registrar(forPlugin: "FVPVideoPlayerPlugin"))
 }

app/pubspec.lock

@@ -1,6 +1,14 @@
 # Generated by pub
 # See https://dart.dev/tools/pub/glossary#lockfile
 packages:
+  _flutterfire_internals:
+    dependency: transitive
+    description:
+      name: _flutterfire_internals
+      sha256: ff0a84a2734d9e1089f8aedd5c0af0061b82fb94e95260d943404e0ef2134b11
+      url: "https://pub.dev"
+    source: hosted
+    version: "1.3.59"
   args:
     dependency: transitive
     description:
@@ -73,6 +81,54 @@ packages:
       url: "https://pub.dev"
     source: hosted
     version: "1.3.3"
+  firebase_auth:
+    dependency: "direct main"
+    description:
+      name: firebase_auth
+      sha256: "0fed2133bee1369ee1118c1fef27b2ce0d84c54b7819a2b17dada5cfec3b03ff"
+      url: "https://pub.dev"
+    source: hosted
+    version: "5.7.0"
+  firebase_auth_platform_interface:
+    dependency: transitive
+    description:
+      name: firebase_auth_platform_interface
+      sha256: "871c9df4ec9a754d1a793f7eb42fa3b94249d464cfb19152ba93e14a5966b386"
+      url: "https://pub.dev"
+    source: hosted
+    version: "7.7.3"
+  firebase_auth_web:
+    dependency: transitive
+    description:
+      name: firebase_auth_web
+      sha256: d9ada769c43261fd1b18decf113186e915c921a811bd5014f5ea08f4cf4bc57e
+      url: "https://pub.dev"
+    source: hosted
+    version: "5.15.3"
+  firebase_core:
+    dependency: "direct main"
+    description:
+      name: firebase_core
+      sha256: "7be63a3f841fc9663342f7f3a011a42aef6a61066943c90b1c434d79d5c995c5"
+      url: "https://pub.dev"
+    source: hosted
+    version: "3.15.2"
+  firebase_core_platform_interface:
+    dependency: transitive
+    description:
+      name: firebase_core_platform_interface
+      sha256: cccb4f572325dc14904c02fcc7db6323ad62ba02536833dddb5c02cac7341c64
+      url: "https://pub.dev"
+    source: hosted
+    version: "6.0.2"
+  firebase_core_web:
+    dependency: transitive
+    description:
+      name: firebase_core_web
+      sha256: "0ed0dc292e8f9ac50992e2394e9d336a0275b6ae400d64163fdf0a8a8b556c37"
+      url: "https://pub.dev"
+    source: hosted
+    version: "2.24.1"
   flutter:
     dependency: "direct main"
     description: flutter
@@ -104,6 +160,54 @@ packages:
     description: flutter
     source: sdk
     version: "0.0.0"
+  google_identity_services_web:
+    dependency: transitive
+    description:
+      name: google_identity_services_web
+      sha256: "5d187c46dc59e02646e10fe82665fc3884a9b71bc1c90c2b8b749316d33ee454"
+      url: "https://pub.dev"
+    source: hosted
+    version: "0.3.3+1"
+  google_sign_in:
+    dependency: "direct main"
+    description:
+      name: google_sign_in
+      sha256: d0a2c3bcb06e607bb11e4daca48bd4b6120f0bbc4015ccebbe757d24ea60ed2a
+      url: "https://pub.dev"
+    source: hosted
+    version: "6.3.0"
+  google_sign_in_android:
+    dependency: transitive
+    description:
+      name: google_sign_in_android
+      sha256: d5e23c56a4b84b6427552f1cf3f98f716db3b1d1a647f16b96dbb5b93afa2805
+      url: "https://pub.dev"
+    source: hosted
+    version: "6.2.1"
+  google_sign_in_ios:
+    dependency: transitive
+    description:
+      name: google_sign_in_ios
+      sha256: "102005f498ce18442e7158f6791033bbc15ad2dcc0afa4cf4752e2722a516c96"
+      url: "https://pub.dev"
+    source: hosted
+    version: "5.9.0"
+  google_sign_in_platform_interface:
+    dependency: transitive
+    description:
+      name: google_sign_in_platform_interface
+      sha256: "5f6f79cf139c197261adb6ac024577518ae48fdff8e53205c5373b5f6430a8aa"
+      url: "https://pub.dev"
+    source: hosted
+    version: "2.5.0"
+  google_sign_in_web:
+    dependency: transitive
+    description:
+      name: google_sign_in_web
+      sha256: "460547beb4962b7623ac0fb8122d6b8268c951cf0b646dd150d60498430e4ded"
+      url: "https://pub.dev"
+    source: hosted
+    version: "0.12.4+4"
   html:
     dependency: transitive
     description:

app/pubspec.yaml

@@ -36,6 +36,9 @@ dependencies:
   cupertino_icons: ^1.0.8
   flutter_svg: ^2.0.10
   video_player: ^2.8.2
+  firebase_core: ^3.0.0 # 파이어베이스 기본 (Updated)
+  firebase_auth: ^5.0.0 # 인증 기능 (Updated)
+  google_sign_in: ^6.2.1 # 구글 로그인 UI/기능 (Updated)
 
 dev_dependencies:
   flutter_test:

app/windows/flutter/generated_plugin_registrant.cc

@@ -6,6 +6,12 @@
 
 #include "generated_plugin_registrant.h"
 
+#include <firebase_auth/firebase_auth_plugin_c_api.h>
+#include <firebase_core/firebase_core_plugin_c_api.h>
 
 void RegisterPlugins(flutter::PluginRegistry* registry) {
+  FirebaseAuthPluginCApiRegisterWithRegistrar(
+      registry->GetRegistrarForPlugin("FirebaseAuthPluginCApi"));
+  FirebaseCorePluginCApiRegisterWithRegistrar(
+      registry->GetRegistrarForPlugin("FirebaseCorePluginCApi"));
 }

app/windows/flutter/generated_plugins.cmake

@@ -3,6 +3,8 @@
 #
 
 list(APPEND FLUTTER_PLUGIN_LIST
+  firebase_auth
+  firebase_core
 )
 
 list(APPEND FLUTTER_FFI_PLUGIN_LIST