NetworkStatusTracker_stage4.kt

class NetworkStatusTracker(context: Context) {

    private val connectivityManager =
        context.getSystemService(Context.CONNECTIVITY_SERVICE) as ConnectivityManager

    private val networks = mutableSetOf<Network>()

    val networkStatus = callbackFlow<NetworkStatus> {
        val networkStatusCallback = object : ConnectivityManager.NetworkCallback() {
            override fun onUnavailable() {
                println("onUnavailable")
                offer(NetworkStatus.Unavailable)
            }

            override fun onAvailable(network: Network) {
                println("onAvailable")
                networks += network
                checkConnection()
            }

            override fun onLost(network: Network) {
                println("onLost")
                networks -= network
                checkConnection()
            }

            fun checkConnection() {
                if (networks.isEmpty()) offer(NetworkStatus.Unavailable)
                else offer(NetworkStatus.Available)
            }
        }

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

        awaitClose {
            connectivityManager.unregisterNetworkCallback(networkStatusCallback)
        }
    }
}