NetworkStatusTracker_stage3.kt

class NetworkStatusTracker(context: Context) {
    
    private val connectivityManager =
        context.getSystemService(Context.CONNECTIVITY_SERVICE) as ConnectivityManager

    val networkStatus = callbackFlow<NetworkStatus> {
        val networkStatusCallback = object : ConnectivityManager.NetworkCallback() {
            override fun onUnavailable() {
                offer(NetworkStatus.Unavailable)
            }
            
            override fun onAvailable(network: Network) {
                offer(NetworkStatus.Available)
            }
            
            override fun onLost(network: Network) {
                offer(NetworkStatus.Unavailable)
            }
        }

        val request = NetworkRequest.Builder()
            .addCapability(NetworkCapabilities.NET_CAPABILITY_INTERNET)
            .build()
        connectivityManager.registerNetworkCallback(request, networkStatusCallback)

        awaitClose {
            connectivityManager.unregisterNetworkCallback(networkStatusCallback)
        }
    }
}

inline fun <Result> Flow<NetworkStatus>.map(
    crossinline onUnavailable: suspend () -> Result,
    crossinline onAvailable: suspend () -> Result,
): Flow<Result> = map { status ->
    when (status) {
        NetworkStatus.Unavailable -> onUnavailable()
        NetworkStatus.Available -> onAvailable()
    }
}