Implement Firebase Google sign-in with enum-based auth contracts.

Refactor AuthService to use AuthProvider and User, add Firebase-backed auth wiring for login/manage flows, and fix app-level Google services configuration so Credential Manager sign-in works reliably.

Made-with: Cursor

app/build.gradle.kts

@@ -5,6 +5,8 @@ plugins {
     alias(libs.plugins.hilt.android)
     alias(libs.plugins.ksp)
     alias(libs.plugins.kotlin.compose)
+    alias(libs.plugins.google.services)
+    alias(libs.plugins.firebase.crashlytics)
 }
 
 fun gitCommitCount(): String {
@@ -81,6 +83,9 @@ dependencies {
     implementation(libs.androidx.navigation.compose)
     implementation(libs.hilt.android)
     implementation(libs.androidx.hilt.navigation.compose)
+    implementation(libs.androidx.credentials)
+    implementation(libs.androidx.credentials.play.services.auth)
+    implementation(libs.googleid)
     ksp(libs.hilt.compiler)
 
     // Tests

app/google-services.json

@@ -0,0 +1,84 @@
+{
+  "project_info": {
+    "project_number": "223884730019",
+    "project_id": "db3-airmq-debug",
+    "storage_bucket": "db3-airmq-debug.firebasestorage.app"
+  },
+  "client": [
+    {
+      "client_info": {
+        "mobilesdk_app_id": "1:223884730019:android:ebe25591cd4c41c2562916",
+        "android_client_info": {
+          "package_name": "org.db3.airmq"
+        }
+      },
+      "oauth_client": [
+        {
+          "client_id": "223884730019-0ddlndpmfesrt1vk5vdsqgeudkmoanls.apps.googleusercontent.com",
+          "client_type": 3
+        }
+      ],
+      "api_key": [
+        {
+          "current_key": "AIzaSyCcgdvdp8xec2dKUqlQHl9peQAyOWRVga4"
+        }
+      ],
+      "services": {
+        "appinvite_service": {
+          "other_platform_oauth_client": [
+            {
+              "client_id": "223884730019-0ddlndpmfesrt1vk5vdsqgeudkmoanls.apps.googleusercontent.com",
+              "client_type": 3
+            }
+          ]
+        }
+      }
+    },
+    {
+      "client_info": {
+        "mobilesdk_app_id": "1:223884730019:android:1345a64a13459de7562916",
+        "android_client_info": {
+          "package_name": "org.db3.airmq.debug"
+        }
+      },
+      "oauth_client": [
+        {
+          "client_id": "223884730019-0cobqn6haoga9n5o60lqcke9uglqihea.apps.googleusercontent.com",
+          "client_type": 1,
+          "android_info": {
+            "package_name": "org.db3.airmq.debug",
+            "certificate_hash": "38547bbc27af278e820c78fc012227a40f64505f"
+          }
+        },
+        {
+          "client_id": "223884730019-p44o1v2t3g6v0kmopsa65f0umf60ksif.apps.googleusercontent.com",
+          "client_type": 1,
+          "android_info": {
+            "package_name": "org.db3.airmq.debug",
+            "certificate_hash": "195356c67cabf18c9ab0a8ccfcec45c3346b6b6c"
+          }
+        },
+        {
+          "client_id": "223884730019-0ddlndpmfesrt1vk5vdsqgeudkmoanls.apps.googleusercontent.com",
+          "client_type": 3
+        }
+      ],
+      "api_key": [
+        {
+          "current_key": "AIzaSyCcgdvdp8xec2dKUqlQHl9peQAyOWRVga4"
+        }
+      ],
+      "services": {
+        "appinvite_service": {
+          "other_platform_oauth_client": [
+            {
+              "client_id": "223884730019-0ddlndpmfesrt1vk5vdsqgeudkmoanls.apps.googleusercontent.com",
+              "client_type": 3
+            }
+          ]
+        }
+      }
+    }
+  ],
+  "configuration_version": "1"
+}

app/src/main/kotlin/org/db3/airmq/features/login/LoginScreen.kt

@@ -1,6 +1,18 @@
 package org.db3.airmq.features.login
 
+import android.app.Activity
+import android.content.Context
+import android.content.ContextWrapper
+import android.util.Log
 import android.widget.Toast
+import androidx.credentials.CredentialManager
+import androidx.credentials.CustomCredential
+import androidx.credentials.GetCredentialRequest
+import androidx.credentials.exceptions.GetCredentialCancellationException
+import androidx.credentials.exceptions.GetCredentialException
+import androidx.credentials.exceptions.GetCredentialInterruptedException
+import androidx.credentials.exceptions.GetCredentialProviderConfigurationException
+import androidx.credentials.exceptions.NoCredentialException
 import androidx.compose.foundation.background
 import androidx.compose.foundation.layout.Arrangement
 import androidx.compose.foundation.BorderStroke
@@ -53,6 +65,10 @@ import androidx.compose.runtime.collectAsState
 import androidx.compose.ui.geometry.Offset
 import androidx.compose.ui.platform.LocalContext
 import androidx.hilt.navigation.compose.hiltViewModel
+import com.google.android.libraries.identity.googleid.GetGoogleIdOption
+import com.google.android.libraries.identity.googleid.GetSignInWithGoogleOption
+import com.google.android.libraries.identity.googleid.GoogleIdTokenCredential
+import com.google.android.libraries.identity.googleid.GoogleIdTokenParsingException
 import kotlinx.coroutines.flow.collectLatest
 import org.db3.airmq.R
 import org.db3.airmq.features.login.LoginScreenContract.Action
@@ -63,6 +79,7 @@ import org.db3.airmq.ui.theme.AirMQTheme
 private val LegacyLoginGradientStart = Color(0xFF449CF5)
 private val LegacyLoginGradientEnd = Color(0xFF5CE4BB)
 private val LegacyFacebookBlue = Color(0xFF3B5998)
+private const val LOGIN_TAG = "LoginScreen"
 
 @Composable
 fun LoginScreen(
@@ -77,6 +94,15 @@ fun LoginScreen(
         viewModel.actions.collectLatest { action ->
             when (action) {
                 Action.OpenManage -> onLogInToManage()
+                Action.LaunchGoogleSignIn -> {
+                    val result = launchGoogleSignIn(context)
+                    result.fold(
+                        onSuccess = { viewModel.onEvent(Event.GoogleTokenReceived(it)) },
+                        onFailure = { error ->
+                            viewModel.onEvent(Event.GoogleSignInFailed(error.message))
+                        }
+                    )
+                }
                 Action.ShowContinueAnonymousDialog -> showContinueAnonymousDialog = true
                 Action.OpenPrivacyPolicy -> {
                     Toast.makeText(context, context.getString(R.string.coming_soon), Toast.LENGTH_SHORT).show()
@@ -362,6 +388,59 @@ private fun PrivacyAndTermsFooter(onEvent: (Event) -> Unit) {
     )
 }
 
+private suspend fun launchGoogleSignIn(context: Context): Result<String> = runCatching {
+    val activity = context.findActivity()
+    val request = GetCredentialRequest.Builder()
+        .addCredentialOption(
+            GetSignInWithGoogleOption.Builder(context.getString(R.string.default_web_client_id))
+                .build()
+        )
+        .build()
+    val response = CredentialManager.create(context).getCredential(
+        context = activity,
+        request = request
+    )
+    val credential = response.credential
+    if (credential is CustomCredential &&
+        credential.type == GoogleIdTokenCredential.TYPE_GOOGLE_ID_TOKEN_CREDENTIAL
+    ) {
+        GoogleIdTokenCredential.createFrom(credential.data).idToken
+    } else {
+        error("Unsupported credential type for Google sign-in.")
+    }
+}.recoverCatching {
+    when (it) {
+        is GetCredentialException -> {
+            logGoogleSignInError(it)
+            throw IllegalStateException(context.getString(R.string.toast_oauth_failed), it)
+        }
+        is GoogleIdTokenParsingException -> {
+            Log.e(LOGIN_TAG, "Google ID token parsing failed", it)
+            throw IllegalStateException(context.getString(R.string.toast_oauth_failed), it)
+        }
+        else -> throw it
+    }
+}
+
+private fun logGoogleSignInError(exception: GetCredentialException) {
+    val message = when (exception) {
+        is GetCredentialCancellationException -> "Google sign-in cancelled by user"
+        is NoCredentialException -> "No Google credential available on device"
+        is GetCredentialProviderConfigurationException -> "Credential provider is not configured correctly"
+        is GetCredentialInterruptedException -> "Credential flow interrupted; try again"
+        else -> "CredentialManager returned an unknown sign-in error"
+    }
+    Log.e(LOGIN_TAG, message, exception)
+}
+
+private tailrec fun Context.findActivity(): Activity {
+    return when (this) {
+        is Activity -> this
+        is ContextWrapper -> baseContext.findActivity()
+        else -> error("Unable to find Activity context for Google sign-in.")
+    }
+}
+
 @Preview(showBackground = true)
 @Composable
 private fun LoginScreenPreview() {

app/src/main/kotlin/org/db3/airmq/features/login/LoginScreenContract.kt

@@ -8,6 +8,7 @@ object LoginScreenContract {
 
     sealed interface Action {
         data object OpenManage : Action
+        data object LaunchGoogleSignIn : Action
         data object ShowContinueAnonymousDialog : Action
         data object OpenPrivacyPolicy : Action
         data object OpenTermsAndConditions : Action
@@ -16,6 +17,8 @@ object LoginScreenContract {
 
     sealed interface Event {
         data object GoogleClicked : Event
+        data class GoogleTokenReceived(val idToken: String) : Event
+        data class GoogleSignInFailed(val message: String? = null) : Event
         data object FacebookClicked : Event
         data object ContinueAnonymousClicked : Event
         data object ContinueAnonymousConfirmed : Event

app/src/main/kotlin/org/db3/airmq/features/login/LoginViewModel.kt

@@ -2,9 +2,11 @@ package org.db3.airmq.features.login
 
 import android.content.Context
 import androidx.lifecycle.ViewModel
+import androidx.lifecycle.viewModelScope
 import dagger.hilt.android.lifecycle.HiltViewModel
 import dagger.hilt.android.qualifiers.ApplicationContext
 import javax.inject.Inject
+import kotlinx.coroutines.launch
 import kotlinx.coroutines.flow.MutableSharedFlow
 import kotlinx.coroutines.flow.MutableStateFlow
 import kotlinx.coroutines.flow.SharedFlow
@@ -15,10 +17,13 @@ import org.db3.airmq.R
 import org.db3.airmq.features.login.LoginScreenContract.Action
 import org.db3.airmq.features.login.LoginScreenContract.Event
 import org.db3.airmq.features.login.LoginScreenContract.State
+import org.db3.airmq.sdk.auth.AuthService
+import org.db3.airmq.sdk.auth.model.AuthProvider
 
 @HiltViewModel
 class LoginViewModel @Inject constructor(
-    @ApplicationContext private val appContext: Context
+    @ApplicationContext private val appContext: Context,
+    private val authService: AuthService
 ) : ViewModel() {
 
     private val _uiState = MutableStateFlow(State())
@@ -30,7 +35,19 @@ class LoginViewModel @Inject constructor(
     fun onEvent(event: Event) {
         when (event) {
             Event.GoogleClicked -> {
-                _actions.tryEmit(Action.ShowMessage(appContext.getString(R.string.coming_soon)))
+                _uiState.value = _uiState.value.copy(isLoading = true)
+                _actions.tryEmit(Action.LaunchGoogleSignIn)
+            }
+            is Event.GoogleTokenReceived -> {
+                signInWithGoogle(event.idToken)
+            }
+            is Event.GoogleSignInFailed -> {
+                _uiState.value = _uiState.value.copy(isLoading = false)
+                _actions.tryEmit(
+                    Action.ShowMessage(
+                        event.message ?: appContext.getString(R.string.toast_oauth_failed)
+                    )
+                )
             }
             Event.FacebookClicked -> {
                 _actions.tryEmit(Action.ShowMessage(appContext.getString(R.string.coming_soon)))
@@ -50,4 +67,16 @@ class LoginViewModel @Inject constructor(
             }
         }
     }
+
+    private fun signInWithGoogle(idToken: String) {
+        viewModelScope.launch {
+            val signInResult = authService.signIn(provider = AuthProvider.GOOGLE, token = idToken)
+            _uiState.value = _uiState.value.copy(isLoading = false)
+            if (signInResult.isSuccess) {
+                _actions.tryEmit(Action.OpenManage)
+            } else {
+                _actions.tryEmit(Action.ShowMessage(appContext.getString(R.string.toast_oauth_failed)))
+            }
+        }
+    }
 }

app/src/main/kotlin/org/db3/airmq/features/manage/ManageViewModel.kt

@@ -2,9 +2,11 @@ package org.db3.airmq.features.manage
 
 import android.content.Context
 import androidx.lifecycle.ViewModel
+import androidx.lifecycle.viewModelScope
 import dagger.hilt.android.lifecycle.HiltViewModel
 import dagger.hilt.android.qualifiers.ApplicationContext
 import javax.inject.Inject
+import kotlinx.coroutines.launch
 import kotlinx.coroutines.flow.MutableSharedFlow
 import kotlinx.coroutines.flow.MutableStateFlow
 import kotlinx.coroutines.flow.SharedFlow
@@ -17,21 +19,25 @@ import org.db3.airmq.features.manage.ManageScreenContract.DeviceItem
 import org.db3.airmq.features.manage.ManageScreenContract.Event
 import org.db3.airmq.features.manage.ManageScreenContract.State
 import org.db3.airmq.features.manage.ManageScreenContract.UserMode
+import org.db3.airmq.sdk.auth.AuthService
+import org.db3.airmq.sdk.auth.model.User
 
 @HiltViewModel
 class ManageViewModel @Inject constructor(
-    @ApplicationContext private val appContext: Context
+    @ApplicationContext private val appContext: Context,
+    private val authService: AuthService
 ) : ViewModel() {
 
-    // Temporary migration stub: keep screen in anonymous mode.
-    private val forceAnonymous = true
-
     private val _uiState = MutableStateFlow(initialState())
     val uiState: StateFlow<State> = _uiState.asStateFlow()
 
     private val _actions = MutableSharedFlow<Action>(extraBufferCapacity = 1)
     val actions: SharedFlow<Action> = _actions.asSharedFlow()
 
+    init {
+        refreshAuthState()
+    }
+
     fun onEvent(event: Event) {
         when (event) {
             Event.SettingsClicked -> _actions.tryEmit(Action.OpenSettings)
@@ -42,39 +48,44 @@ class ManageViewModel @Inject constructor(
         }
     }
 
-    private fun initialState(): State {
-        val mode = if (forceAnonymous) {
-            UserMode.ANONYMOUS
-        } else {
-            UserMode.AUTHORIZED
-        }
-        return when (mode) {
-            UserMode.ANONYMOUS -> State(
-                userMode = UserMode.ANONYMOUS,
-                userName = appContext.getString(R.string.text_anonymous_user),
-                userEmail = appContext.getString(R.string.text_please_sign_in),
-                devicesLabel = appContext.getString(R.string.text_sign_in_small)
-            )
-            UserMode.AUTHORIZED -> State(
-                userMode = UserMode.AUTHORIZED,
-                userName = appContext.getString(R.string.mock_user_name),
-                userEmail = appContext.getString(R.string.mock_user_email),
-                devicesLabel = appContext.getString(R.string.text_your_devices),
-                devices = listOf(
-                    DeviceItem(
-                        id = "device-1",
-                        name = appContext.getString(R.string.mock_device_name_42),
-                        status = appContext.getString(R.string.map_status_online),
-                        hasLocation = true
-                    ),
-                    DeviceItem(
-                        id = "device-2",
-                        name = appContext.getString(R.string.mock_device_name_17),
-                        status = appContext.getString(R.string.map_status_offline),
-                        hasLocation = false
-                    )
-                )
-            )
+    private fun initialState(): State = anonymousState()
+
+    private fun refreshAuthState() {
+        viewModelScope.launch {
+            val session = authService.getCurrentSession()
+            _uiState.value = if (session?.isAuthenticated == true) {
+                authorizedState(session)
+            } else {
+                anonymousState()
+            }
         }
     }
+
+    private fun anonymousState(): State = State(
+        userMode = UserMode.ANONYMOUS,
+        userName = appContext.getString(R.string.text_anonymous_user),
+        userEmail = appContext.getString(R.string.text_please_sign_in),
+        devicesLabel = appContext.getString(R.string.text_sign_in_small)
+    )
+
+    private fun authorizedState(user: User): State = State(
+        userMode = UserMode.AUTHORIZED,
+        userName = user.displayName ?: appContext.getString(R.string.text_anonymous_user),
+        userEmail = user.email ?: "",
+        devicesLabel = appContext.getString(R.string.text_your_devices),
+        devices = listOf(
+            DeviceItem(
+                id = "device-1",
+                name = appContext.getString(R.string.mock_device_name_42),
+                status = appContext.getString(R.string.map_status_online),
+                hasLocation = true
+            ),
+            DeviceItem(
+                id = "device-2",
+                name = appContext.getString(R.string.mock_device_name_17),
+                status = appContext.getString(R.string.map_status_offline),
+                hasLocation = false
+            )
+        )
+    )
 }

app/src/main/res/values/strings.xml

@@ -142,7 +142,6 @@
     <string name="toast_copied">Copied</string>
     <string name="snackbar_not_registered">Device requires registration</string>
 
-    <string name="oauth_token" translatable="false" tools:ignore="Typos">21688843933-n04t4s1h7rjad12tdj1pc9j6kajgh2ka.apps.googleusercontent.com</string>
     <string name="facebook_app_id" translatable="false">356744979027664</string>
     <string name="fb_login_protocol_scheme" translatable="false">fb356744979027664</string>
     <string name="text_air_quality">Air quality</string>