FirebaseAuthStateUserDataSource.kt

/* Copyright 2019 Google LLC.	
   SPDX-License-Identifier: Apache-2.0 */
class FirebaseAuthStateUserDataSource(...) : AuthStateUserDataSource {

    private val channel = ConflatedBroadcastChannel<Result<AuthenticatedUserInfo>>()

    private val listener: ((FirebaseAuth) -> Unit) = { auth ->
        // Data processing logic

        // Send the current user for observers
        if (!channel.isClosedForSend) {
            channel.offer(Success(FirebaseUserInfo(auth.currentUser)))
        } else {
            unregisterListener()
        }
    }
    
    @Synchronized
    override fun getBasicUserInfo(): Flow<Result<AuthenticatedUserInfo>> {
        if (!isListening) {
            firebase.addAuthStateListener(listener)
            isListening = true
        }
        return channel.asFlow()
    }
}