firebase

Firebase for Android

Setup — always use BoM for version management

[versions]
firebaseBom = "33.5.1"
googleServices = "4.4.2"

// build.gradle.kts
plugins { alias(libs.plugins.google.services) }
dependencies {
    implementation(platform(libs.firebase.bom))
    implementation(libs.firebase.auth.ktx)
    implementation(libs.firebase.firestore.ktx)
    implementation(libs.firebase.storage.ktx)
    implementation(libs.firebase.analytics.ktx)
    implementation(libs.firebase.crashlytics.ktx)
    implementation(libs.firebase.messaging.ktx)
}

Firebase Auth

// ✅ Auth repository
class AuthRepositoryImpl @Inject constructor(
    private val auth: FirebaseAuth
) : AuthRepository {

    override val currentUser: Flow<User?> = callbackFlow {
        val listener = FirebaseAuth.AuthStateListener { auth ->
            trySend(auth.currentUser?.toDomain())
        }
        auth.addAuthStateListener(listener)
        awaitClose { auth.removeAuthStateListener(listener) }
    }

    override suspend fun signInWithEmail(email: String, password: String): Result<User> =
        runCatching {
            auth.signInWithEmailAndPassword(email, password).await()
                .user?.toDomain() ?: throw IllegalStateException("User is null after sign in")
        }

    override suspend fun createAccount(email: String, password: String): Result<User> =
        runCatching {
            auth.createUserWithEmailAndPassword(email, password).await()
                .user?.toDomain() ?: throw IllegalStateException("User is null after creation")
        }

    override suspend fun signInWithGoogle(idToken: String): Result<User> = runCatching {
        val credential = GoogleAuthProvider.getCredential(idToken, null)
        auth.signInWithCredential(credential).await()
            .user?.toDomain() ?: throw IllegalStateException("User is null")
    }

    override fun signOut() = auth.signOut()

    override fun isSignedIn(): Boolean = auth.currentUser != null
}

fun FirebaseUser.toDomain() = User(uid, email ?: "", displayName ?: "", photoUrl?.toString())