// SavedStateHandle State Preservation Across Process Death
import androidx.lifecycle.SavedStateHandle
import androidx.lifecycle.ViewModel
import kotlinx.coroutines.flow.StateFlow

class RegistrationViewModel(private val savedStateHandle: SavedStateHandle) : ViewModel() {

    // Automatically persisted across Activity recreation & Low-Memory process death!
    val email: StateFlow<String> = savedStateHandle.getStateFlow("user_email", "")

    fun updateEmail(newEmail: String) {
        savedStateHandle["user_email"] = newEmail
    }
}

// Responsive Material 3 Adaptive Scaffold in Jetpack Compose
import androidx.compose.material3.*
import androidx.compose.material3.adaptive.navigation.suite.NavigationSuiteScaffold
import androidx.compose.runtime.*
import androidx.compose.ui.Modifier

@Composable
fun MainAdaptiveScreen(currentDestination: String, onNavigate: (String) -> Unit) {
    NavigationSuiteScaffold(
        navigationSuiteItems = {
            item(
                selected = currentDestination == "home",
                onClick = { onNavigate("home") },
                icon = { Icon(Icons.Default.Home, contentDescription = "Home") },
                label = { Text("Home") }
            )
            item(
                selected = currentDestination == "analytics",
                onClick = { onNavigate("analytics") },
                icon = { Icon(Icons.Default.Analytics, contentDescription = "Analytics") },
                label = { Text("Analytics") }
            )
        }
    ) {
        // Content area self-adapts between compact mobile, tablet navigation rail, & desktop bar!
        HomeScreenContent()
    }
}

// Battery-Optimized Persistent Background Work with WorkManager
import android.content.Context
import androidx.work.*
import java.util.concurrent.TimeUnit

class TelemetryUploadWorker(context: Context, params: WorkerParameters) : CoroutineWorker(context, params) {
    override suspend fun doWork(): Result {
        return try {
            uploadCrashLogsToCloud()
            Result.success()
        } catch (e: Exception) {
            Result.retry()
        }
    }
}

fun schedulePeriodicTelemetry(context: Context) {
    val constraints = Constraints.Builder()
        .setRequiredNetworkType(NetworkType.UNMETERED) // Only upload on Wi-Fi!
        .setRequiresBatteryNotLow(true)               // Don't drain low battery!
        .setRequiresCharging(true)                    // Defer until device is plugged in!
        .build()

    val request = PeriodicWorkRequestBuilder<TelemetryUploadWorker>(6, TimeUnit.HOURS)
        .setConstraints(constraints)
        .setBackoffCriteria(BackoffPolicy.EXPONENTIAL, 15, TimeUnit.MINUTES)
        .build()

    WorkManager.getInstance(context).enqueueUniquePeriodicWork(
        "telemetry_sync",
        ExistingPeriodicWorkPolicy.KEEP,
        request
    )
}