ActivityStuff.kt

package il.co.galex.alexpizzapp.utils

import android.app.Activity
import android.content.Context
import android.content.ContextWrapper
import androidx.activity.result.ActivityResultLauncher
import androidx.activity.result.ActivityResultRegistry
import androidx.activity.result.contract.ActivityResultContract
import androidx.compose.*
import androidx.ui.core.ContextAmbient
import com.google.android.gms.auth.api.signin.GoogleSignInAccount
import com.google.android.gms.auth.api.signin.GoogleSignInClient
import com.google.firebase.auth.GoogleAuthProvider
import com.google.firebase.auth.ktx.auth
import com.google.firebase.ktx.Firebase
import il.co.galex.alexpizzapp.feature.user.UserRepository

@OptIn(ExperimentalComposeApi::class)
@Composable
fun <I, O> ActivityResultRegistry.activityResultLauncher(
    requestContract: ActivityResultContract<I, O>,
    onResult: (O) -> Unit
): ActivityResultLauncher<I> {
    val key = currentComposer.currentCompoundKeyHash.toString()
    val launcher = remember(requestContract, onResult) {
        register(key, requestContract, onResult)
    }
    onDispose {
        launcher.unregister()
    }
    return launcher
}

fun Context.findActivity(): Activity? {
    var context = this
    while (context is ContextWrapper) {
        if (context is Activity) return context
        context = context.baseContext
    }
    return null
}

class GoogleSignInState(private val googleSignInClient: GoogleSignInClient,
                        val signInState: State<GoogleSignInAccount?>,
                        private val launcher: ActivityResultLauncher<GoogleSignInClient>) {

    fun launchSignInRequest() = launcher.launch(googleSignInClient)
}

@Composable
fun ActivityResultRegistry.googleSignIn(googleSignInClient: GoogleSignInClient): GoogleSignInState {
    val context = ContextAmbient.current
    val activity = context.findActivity()
    val signInState = mutableStateOf<GoogleSignInAccount?>( null )

    val launcher = activityResultLauncher(GoogleSignInContract()) {
        signInState.value = it
    }
    return remember(launcher) {
        GoogleSignInState(googleSignInClient, signInState ,launcher)
    }
}

// How can I integrate into this composable the following code?
private fun firebaseAuthWithGoogle(account: GoogleSignInAccount) {
    val credential = GoogleAuthProvider.getCredential(account.idToken, null)
    Firebase.auth.signInWithCredential(credential).addOnCompleteListener { task ->

        if (task.isSuccessful) {
            // Sign in success, update UI with the signed-in user's information
            val firebaseUser = Firebase.auth.currentUser

            val repo = UserRepository()
            account.toUser(firebaseUser!!.uid).let {
                repo.add(it) {
                    // TODO something nice to show to the user when he is officially in the Firebase User table
                }
            }

        } else {
            // If sign in fails, display a message to the user.
        }

    }
}