set up google sign in

app/src/main/java/com/samuelokello/kazihub/presentation/shared/authentication/SignIn/Google/GoogleAuthUiClient.kt

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+package com.samuelokello.kazihub.presentation.shared.authentication.SignIn.Google
+
+import android.content.Context
+import android.content.Intent
+import android.content.IntentSender
+import com.google.android.gms.auth.api.identity.BeginSignInRequest
+import com.google.android.gms.auth.api.identity.BeginSignInRequest.GoogleIdTokenRequestOptions
+import com.google.android.gms.auth.api.identity.SignInClient
+import com.google.firebase.auth.GoogleAuthProvider
+import com.google.firebase.auth.ktx.auth
+import com.google.firebase.ktx.Firebase
+import com.samuelokello.kazihub.R
+import com.samuelokello.kazihub.presentation.shared.authentication.SignIn.SignInResult
+import com.samuelokello.kazihub.presentation.shared.authentication.SignIn.UserData
+import kotlinx.coroutines.CancellationException
+import kotlinx.coroutines.tasks.await
+
+class GoogleAuthUiClient(
+    private val context: Context,
+    private val oneTapClient: SignInClient
+) {
+    private val auth = Firebase.auth
+
+    suspend fun signIn(): IntentSender? {
+        val result = try {
+            oneTapClient.beginSignIn(
+                buildSignInRequest()
+            ).await()
+        } catch(e: Exception) {
+            e.printStackTrace()
+            if(e is CancellationException) throw e
+            null
+        }
+        return result?.pendingIntent?.intentSender
+    }
+
+    suspend fun signInWithIntent(intent: Intent): SignInResult {
+        val credential = oneTapClient.getSignInCredentialFromIntent(intent)
+        val googleIdToken = credential.googleIdToken
+        val googleCredentials = GoogleAuthProvider.getCredential(googleIdToken, null)
+        return try {
+            val user = auth.signInWithCredential(googleCredentials).await().user
+            SignInResult(
+                data = user?.run {
+                    UserData(
+                        userId = uid,
+                        username = displayName,
+                        profilePictureUrl = photoUrl?.toString()
+                    )
+                },
+                errorMessage = null
+            )
+        } catch(e: Exception) {
+            e.printStackTrace()
+            if(e is CancellationException) throw e
+            SignInResult(
+                data = null,
+                errorMessage = e.message
+            )
+        }
+    }
+
+    suspend fun signOut() {
+        try {
+            oneTapClient.signOut().await()
+            auth.signOut()
+        } catch(e: Exception) {
+            e.printStackTrace()
+            if(e is CancellationException) throw e
+        }
+    }
+
+    fun getSignedInUser(): UserData? = auth.currentUser?.run {
+        UserData(
+            userId = uid,
+            username = displayName,
+            profilePictureUrl = photoUrl?.toString()
+        )
+    }
+
+    private fun buildSignInRequest(): BeginSignInRequest {
+        return BeginSignInRequest.Builder()
+            .setGoogleIdTokenRequestOptions(
+                GoogleIdTokenRequestOptions.builder()
+                    .setSupported(true)
+                    .setFilterByAuthorizedAccounts(false)
+                    .setServerClientId(context.getString(R.string.web_client_id))
+                    .build()
+            )
+            .setAutoSelectEnabled(true)
+            .build()
+    }
+}

app/src/main/java/com/samuelokello/kazihub/presentation/shared/authentication/SignIn/SignInEvent.kt

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+package com.samuelokello.kazihub.presentation.shared.authentication.SignIn
+
+sealed interface SignInEvent {
+    data class onEmailChanged(val email: String): SignInEvent
+    data class onPasswordChanged(val password: String): SignInEvent
+}

app/src/main/java/com/samuelokello/kazihub/presentation/shared/authentication/SignIn/SignInResult.kt

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+package com.samuelokello.kazihub.presentation.shared.authentication.SignIn
+
+data class SignInResult(
+    val data: UserData?,
+    val errorMessage: String?
+)
+
+data class UserData(
+    val userId: String,
+    val username: String?,
+    val profilePictureUrl: String?
+)

app/src/main/java/com/samuelokello/kazihub/presentation/shared/authentication/SignIn/SignInViewModel.kt

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+package com.samuelokello.kazihub.presentation.shared.authentication.SignIn
+
+import androidx.lifecycle.ViewModel
+import kotlinx.coroutines.flow.MutableStateFlow
+import kotlinx.coroutines.flow.asStateFlow
+import kotlinx.coroutines.flow.update
+
+class SignInViewModel : ViewModel() {
+
+    private val _state = MutableStateFlow(SignInState())
+    val state = _state.asStateFlow()
+
+    fun onSignInResult(result: SignInResult) {
+        _state.update {
+            it.copy(
+                isSignInSuccessful = result.data != null,
+                signInError = result.errorMessage
+            )
+        }
+    }
+
+    fun resetState() {
+        _state.update { SignInState() }
+    }
+
+    fun onSignInClicked() {
+
+    }
+
+    fun onEvent(event: SignInEvent) {
+        when (event) {
+            is SignInEvent.onEmailChanged -> {
+                _state.update {
+                    it.copy(email = event.email)
+                }
+            }
+
+            is SignInEvent.onPasswordChanged -> {
+                _state.update {
+                    it.copy(password = event.password)
+                }
+            }
+        }
+    }
+}