wire up google auth for android

android/Omnivore/app/build.gradle

@@ -121,6 +121,8 @@ dependencies {
 
     implementation 'androidx.compose.material3:material3:1.0.0-alpha16'
     implementation 'androidx.compose.material3:material3-window-size-class:1.0.0-alpha16'
+
+    implementation 'com.google.android.gms:play-services-auth:20.2.0'
 }
 
 apollo {

android/Omnivore/app/src/main/java/app/omnivore/omnivore/LoginViewModel.kt

@@ -1,9 +1,14 @@
 package app.omnivore.omnivore
 
+import android.content.ContentValues
+import android.util.Log
 import androidx.compose.runtime.getValue
 import androidx.compose.runtime.mutableStateOf
 import androidx.compose.runtime.setValue
 import androidx.lifecycle.*
+import com.google.android.gms.auth.api.signin.GoogleSignInAccount
+import com.google.android.gms.common.api.ApiException
+import com.google.android.gms.tasks.Task
 import dagger.hilt.android.lifecycle.HiltViewModel
 import kotlinx.coroutines.flow.distinctUntilChanged
 import kotlinx.coroutines.launch
@@ -65,4 +70,11 @@ class LoginViewModel @Inject constructor(
   fun resetErrorMessage() {
     errorMessage = null
   }
+
+  fun handleGoogleAuthTask(task: Task<GoogleSignInAccount>) {
+    val googleIdToken = task?.getResult(ApiException::class.java).idToken
+    Log.d(ContentValues.TAG, "Google Result?: $googleIdToken")
+    // TODO: submit id token to backend
+    // If token is missing then set the error message
+  }
 }

android/Omnivore/app/src/main/java/app/omnivore/omnivore/MainActivity.kt

@@ -1,11 +1,16 @@
 package app.omnivore.omnivore
 
 import android.annotation.SuppressLint
+import android.app.Activity
+import android.content.Context
 import android.os.Bundle
 import android.view.View
 import android.widget.Toast
 import androidx.activity.ComponentActivity
+import androidx.activity.compose.rememberLauncherForActivityResult
 import androidx.activity.compose.setContent
+import androidx.activity.result.ActivityResult
+import androidx.activity.result.contract.ActivityResultContracts
 import androidx.activity.viewModels
 import androidx.compose.foundation.background
 import androidx.compose.foundation.clickable
@@ -27,6 +32,13 @@ import androidx.compose.runtime.livedata.observeAsState
 import androidx.core.view.ViewCompat
 import androidx.core.view.WindowCompat
 import androidx.core.view.WindowInsetsCompat
+import com.google.android.gms.auth.api.signin.GoogleSignIn
+import com.google.android.gms.auth.api.signin.GoogleSignInAccount
+import com.google.android.gms.auth.api.signin.GoogleSignInClient
+import com.google.android.gms.auth.api.signin.GoogleSignInOptions
+import com.google.android.gms.common.GoogleApiAvailability
+import com.google.android.gms.common.GooglePlayServicesUtil.isGooglePlayServicesAvailable
+import com.google.android.gms.tasks.Task
 import dagger.hilt.android.AndroidEntryPoint
 import kotlinx.coroutines.launch
 
@@ -41,7 +53,7 @@ class MainActivity : ComponentActivity() {
       OmnivoreTheme {
         // A surface container using the 'background' color from the theme
         Surface(modifier = Modifier.fillMaxSize(), color = MaterialTheme.colorScheme.background) {
-          PrimaryView(viewModel)
+          WelcomeView(viewModel)
         }
       }
     }
@@ -58,7 +70,7 @@ class MainActivity : ComponentActivity() {
 }
 
 @Composable
-fun PrimaryView(viewModel: LoginViewModel) {
+fun WelcomeView(viewModel: LoginViewModel) {
   val hasAuthToken: Boolean by viewModel.hasAuthTokenLiveData.observeAsState(false)
 
   if (hasAuthToken) {
@@ -68,6 +80,26 @@ fun PrimaryView(viewModel: LoginViewModel) {
   }
 }
 
+@Composable
+fun LoginView(viewModel: LoginViewModel) {
+  val isGoogleAuthAvailable: Boolean = GoogleApiAvailability
+    .getInstance()
+    .isGooglePlayServicesAvailable(LocalContext.current) == 0
+
+  Column(
+    verticalArrangement = Arrangement.Center,
+    horizontalAlignment = Alignment.CenterHorizontally,
+    modifier = Modifier
+      .background(MaterialTheme.colorScheme.background)
+      .fillMaxSize()
+  ) {
+    if (isGoogleAuthAvailable) {
+      GoogleAuthButton(viewModel)
+    }
+    EmailLoginView(viewModel)
+  }
+}
+
 @Composable
 fun LoggedInView(viewModel: LoginViewModel) {
   Column(
@@ -89,7 +121,7 @@ fun LoggedInView(viewModel: LoginViewModel) {
 
 @SuppressLint("CoroutineCreationDuringComposition")
 @Composable
-fun LoginView(viewModel: LoginViewModel) {
+fun EmailLoginView(viewModel: LoginViewModel) {
   var email by rememberSaveable { mutableStateOf("") }
   var password by rememberSaveable { mutableStateOf("") }
   val focusManager = LocalFocusManager.current

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

@@ -1,3 +1,4 @@
 <resources>
     <string name="app_name">Omnivore</string>
-</resources>
+    <string name="gcp_id">590528454690-ovh9ku5r3fojgr1pp5kgaimr43o96btb.apps.googleusercontent.com</string>
+</resources>