카카오, 구글 소셜 로그인입니다.

composeApp/build.gradle.kts

@@ -1,13 +1,20 @@
 import org.jetbrains.compose.desktop.application.dsl.TargetFormat
 import org.jetbrains.kotlin.gradle.dsl.JvmTarget
+import java.util.Properties
+import kotlin.apply
 
 plugins {
     alias(libs.plugins.kotlinMultiplatform)
     alias(libs.plugins.androidApplication)
     alias(libs.plugins.composeMultiplatform)
     alias(libs.plugins.composeCompiler)
 }
-
+val localProperties = Properties().apply {
+    val localPropertiesFile = rootProject.file("local.properties")
+    if (localPropertiesFile.exists()) {
+        localPropertiesFile.inputStream().use { load(it) }
+    }
+}
 kotlin {
     androidTarget {
         compilerOptions {
@@ -29,6 +36,11 @@ kotlin {
         androidMain.dependencies {
             implementation(compose.preview)
             implementation(libs.androidx.activity.compose)
+            // 카카오 소셜 로그인
+            implementation(libs.kakao.user)
+
+            // Android Credential Manager (구글 소셜 로그인) - 번들 사용 시
+            implementation(libs.bundles.social.login.google)
         }
         commonMain.dependencies {
             implementation(compose.runtime)
@@ -46,6 +58,8 @@ kotlin {
             implementation(projects.core.ui)
 
             implementation(projects.feature.settings.impl)
+            // Coroutines (버전 카탈로그 사용)
+            implementation(libs.kotlinx.coroutines.core)
         }
         commonTest.dependencies {
             implementation(libs.kotlin.test)
@@ -56,13 +70,24 @@ kotlin {
 android {
     namespace = "com.yourssu.pingpong"
     compileSdk = libs.versions.android.compileSdk.get().toInt()
-
+    buildFeatures {
+        buildConfig = true
+    }
     defaultConfig {
         applicationId = "com.yourssu.pingpong"
         minSdk = libs.versions.android.minSdk.get().toInt()
         targetSdk = libs.versions.android.targetSdk.get().toInt()
         versionCode = 1
         versionName = "1.0"
+        buildConfigField("String", "KAKAO_NATIVE_APP_KEY", "\"${localProperties.getProperty("KAKAO_NATIVE_APP_KEY")}\"")
+        manifestPlaceholders["KAKAO_NATIVE_APP_KEY"] = localProperties.getProperty("KAKAO_NATIVE_APP_KEY") ?: ""
+
+        testInstrumentationRunner = "androidx.test.runner.AndroidJUnitRunner"
+        // local.properties에서 읽어와서 BuildConfig에 등록
+        val googleClientId = localProperties.getProperty("GOOGLE_SERVER_CLIENT_ID") ?: ""
+        buildConfigField("String", "GOOGLE_SERVER_CLIENT_ID", "\"$googleClientId\"")
+        manifestPlaceholders["GOOGLE_SERVER_CLIENT_ID"] = googleClientId
+
     }
     packaging {
         resources {

composeApp/src/androidMain/AndroidManifest.xml

@@ -1,6 +1,6 @@
 <?xml version="1.0" encoding="utf-8"?>
 <manifest xmlns:android="http://schemas.android.com/apk/res/android">
-
+    <uses-permission android:name="android.permission.INTERNET" />
     <application
         android:allowBackup="true"
         android:icon="@mipmap/ic_launcher"
@@ -17,6 +17,18 @@
                 <category android:name="android.intent.category.LAUNCHER" />
             </intent-filter>
         </activity>
+        <activity
+            android:name="com.kakao.sdk.auth.AuthCodeHandlerActivity"
+            android:exported="true">
+            <intent-filter>
+                <action android:name="android.intent.action.VIEW" />
+                <category android:name="android.intent.category.DEFAULT" />
+                <category android:name="android.intent.category.BROWSABLE" />
+
+                <data android:host="oauth"
+                    android:scheme="kakao${KAKAO_NATIVE_APP_KEY}" />
+            </intent-filter>
+        </activity>
     </application>
 
 </manifest>

composeApp/src/androidMain/kotlin/auth/AuthManager.kt

@@ -0,0 +1,53 @@
+// composeApp/src/androidMain/kotlin/auth/AuthManager.kt
+package auth
+
+import android.content.Context
+import androidx.credentials.ClearCredentialStateRequest
+import androidx.credentials.CredentialManager
+import androidx.credentials.GetCredentialRequest
+import com.google.android.libraries.identity.googleid.GetGoogleIdOption
+import com.google.android.libraries.identity.googleid.GoogleIdTokenCredential
+import kotlinx.coroutines.Dispatchers
+import kotlinx.coroutines.withContext
+
+actual class GoogleAuthManager(private val context: Context) {
+    private val credentialManager = CredentialManager.create(context)
+
+    actual suspend fun signIn(): GoogleUser? = withContext(Dispatchers.IO) {
+        try {
+            val googleIdOption = GetGoogleIdOption.Builder()
+                .setFilterByAuthorizedAccounts(false)
+                .setServerClientId(com.yourssu.pingpong.BuildConfig.GOOGLE_SERVER_CLIENT_ID)
+                .setAutoSelectEnabled(false)
+                .build()
+
+            val request = GetCredentialRequest.Builder()
+                .addCredentialOption(googleIdOption)
+                .build()
+
+            val result = credentialManager.getCredential(context, request)
+            val credential = result.credential
+
+            if (credential.type == GoogleIdTokenCredential.TYPE_GOOGLE_ID_TOKEN_CREDENTIAL) {
+                // credential.data(Bundle)로부터 객체를 명시적으로 생성합니다.
+                val googleIdTokenCredential = GoogleIdTokenCredential.createFrom(credential.data)
+
+                GoogleUser(
+                    idToken = googleIdTokenCredential.idToken,
+                    displayName = googleIdTokenCredential.displayName,
+                    email = googleIdTokenCredential.id
+                )
+            } else {
+                println("DEBUG: 예상치 못한 크리덴셜 타입: ${credential.type}")
+                null
+            }
+        } catch (e: Exception) {
+            e.printStackTrace()
+            null
+        }
+    }
+
+    actual suspend fun signOut() {
+        credentialManager.clearCredentialState(ClearCredentialStateRequest())
+    }
+}

composeApp/src/androidMain/kotlin/com/yourssu/pingpong/AndroidSocialLoginHandler.kt

@@ -0,0 +1,28 @@
+package com.yourssu.pingpong
+
+import android.content.Context
+import com.kakao.sdk.user.UserApiClient
+
+class AndroidSocialLoginHandler(private val context: Context) : SocialLoginHandler {
+
+    override fun loginWithKakao(onSuccess: (String) -> Unit, onFailure: (Throwable) -> Unit) {
+        if (UserApiClient.instance.isKakaoTalkLoginAvailable(context)) {
+            UserApiClient.instance.loginWithKakaoTalk(context) { token, error ->
+                if (error != null) onFailure(error)
+                else if (token != null) onSuccess(token.accessToken)
+            }
+        } else {
+            UserApiClient.instance.loginWithKakaoAccount(context) { token, error ->
+                if (error != null) onFailure(error)
+                else if (token != null) onSuccess(token.accessToken)
+            }
+        }
+    }
+
+    override fun logout(onResult: (Throwable?) -> Unit) {
+        // 카카오 SDK 로그아웃 호출
+        UserApiClient.instance.logout { error ->
+            onResult(error)
+        }
+    }
+}

composeApp/src/androidMain/kotlin/com/yourssu/pingpong/MainActivity.kt

@@ -1,25 +1,60 @@
 package com.yourssu.pingpong
 
+import android.content.pm.PackageManager
+import android.os.Build
 import android.os.Bundle
+import android.util.Base64
+import android.util.Log
 import androidx.activity.ComponentActivity
 import androidx.activity.compose.setContent
 import androidx.activity.enableEdgeToEdge
 import androidx.compose.runtime.Composable
+import androidx.compose.runtime.remember
 import androidx.compose.ui.tooling.preview.Preview
+import auth.GoogleAuthManager
+import java.security.MessageDigest
+import com.kakao.sdk.common.KakaoSdk //카카오용
+import com.yourssu.pingpong.BuildConfig
 
 class MainActivity : ComponentActivity() {
     override fun onCreate(savedInstanceState: Bundle?) {
         enableEdgeToEdge()
         super.onCreate(savedInstanceState)
-
+        // 카카오 SDK 초기화 (네이티브 앱 키 입력)
+        KakaoSdk.init(this, BuildConfig.KAKAO_NATIVE_APP_KEY)
         setContent {
-            App()
+            val _loginHandler = remember { AndroidSocialLoginHandler(this) }
+            val googleAuthManager = GoogleAuthManager(this) // Context 전달
+            App(
+                loginHandler = _loginHandler,
+                googleAuthManager = googleAuthManager
+            )
         }
     }
 }
 
 @Preview
 @Composable
 fun AppAndroidPreview() {
-    App()
+    // 1. 카카오 로그인용 가짜 핸들러 (기존)
+    val previewHandler = object : SocialLoginHandler {
+        override fun loginWithKakao(onSuccess: (String) -> Unit, onFailure: (Throwable) -> Unit) {
+            println("Preview: 카카오 로그인 클릭됨")
+        }
+        override fun logout(onResult: (Throwable?) -> Unit) {
+            onResult(null)
+        }
+    }
+
+    // 2. 구글 로그인용 가짜 매니저
+    // 현재 클래스 형태라면, Context가 필요한 actual class 구조상
+    // 프리뷰 전용으로 null이나 더미 Context를 넣은 인스턴스가 필요할 수 있습니다.
+    // 여기서는 로직 연결을 위해 '임시'로 생성하는 코드를 예시로 듭니다.
+    val context = androidx.compose.ui.platform.LocalContext.current
+    val previewGoogleManager = remember { GoogleAuthManager(context) }
+
+    App(
+        loginHandler = previewHandler,
+        googleAuthManager = previewGoogleManager
+    )
 }

composeApp/src/commonMain/kotlin/auth/AuthManager.kt

@@ -0,0 +1,14 @@
+package auth
+
+// 사용자 정보를 담을 데이터 클래스!
+data class GoogleUser(
+    val idToken: String,
+    val displayName: String?,
+    val email: String?
+)
+
+// 플랫폼별 구현을 위한 expect 클래스
+expect class GoogleAuthManager {
+    suspend fun signIn(): GoogleUser?
+    suspend fun signOut()
+}

composeApp/src/commonMain/kotlin/auth/AuthViewModel.kt

@@ -0,0 +1,51 @@
+package com.yourssu.pingpong
+
+import androidx.compose.runtime.getValue
+import androidx.compose.runtime.mutableStateOf
+import androidx.compose.runtime.setValue
+import androidx.lifecycle.ViewModel
+import androidx.lifecycle.viewModelScope
+import auth.GoogleAuthManager
+import kotlinx.coroutines.launch
+
+class AuthViewModel : ViewModel() {
+    // UI에서 관찰할 상태 (내부에서만 수정 가능하도록 private set 설정)
+    var isLoggedIn by mutableStateOf(false)
+        private set
+
+    var userName by mutableStateOf("")
+        private set
+
+    // 카카오 로그인 로직
+    fun loginWithKakao(loginHandler: SocialLoginHandler) {
+        loginHandler.loginWithKakao(
+            onSuccess = {
+                isLoggedIn = true
+            },
+            onFailure = { error ->
+                println("카카오 로그인 실패: ${error.message}")
+            }
+        )
+    }
+
+    // 구글 로그인 로직 (코루틴 사용)
+    fun loginWithGoogle(googleAuthManager: GoogleAuthManager) {
+        viewModelScope.launch {
+            val user = googleAuthManager.signIn()
+            if (user != null) {
+                userName = user.displayName ?: "구글 사용자"
+                isLoggedIn = true
+            }
+        }
+    }
+
+    // 로그아웃 로직
+    fun logout(loginHandler: SocialLoginHandler, googleAuthManager: GoogleAuthManager) {
+        viewModelScope.launch {
+            loginHandler.logout { }
+            googleAuthManager.signOut()
+            isLoggedIn = false
+            userName = ""
+        }
+    }
+}