WiFiConnectLegacyUseCase.kt

class WiFiConnectLegacyUseCase(private val context: Context) {

    private var wifiManager =
        context.applicationContext.getSystemService(Context.WIFI_SERVICE) as WifiManager

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

    private val wifiSSID = "My Network"
    private val wifiPassword = "password1234"

    operator fun invoke(): Single<Network> {
        return connect()
            .delay(5, TimeUnit.SECONDS)
            .timeout(20, TimeUnit.SECONDS)
            .andThen(Single.defer { initNetwork() })
    }

    private fun connect(): Completable {
        return Completable.create { emitter ->
            val intentFilter = IntentFilter(WifiManager.NETWORK_STATE_CHANGED_ACTION)
            val receiver = object : BroadcastReceiver() {
                override fun onReceive(context: Context?, intent: Intent?) {
                    if (isConnectedToCorrectSSID()) {
                        Timber.v("Successfully connected to the device.")
                        emitter.onComplete()
                    } else {
                        Timber.w("Still not connected to ${wifiSSID}. Waiting a little bit more...")
                    }
                }
            }
            Timber.v("Registering connection receiver...")
            context.registerReceiver(receiver, intentFilter)
            emitter.setCancellable {
                Timber.v("Unregistering connection receiver...")
                context.unregisterReceiver(receiver)
            }
            addNetwork(emitter)
        }
    }

    private fun initNetwork(): Single<Network> {
        Timber.v("Initializing network...")
        return Single.just(connectivityManager.allNetworks.find {
            if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.M) {
                connectivityManager.getNetworkCapabilities(it)
                    .hasTransport(NetworkCapabilities.TRANSPORT_WIFI)
            } else {
                connectivityManager.getNetworkInfo(it).extraInfo == wifiSSID
            }
        })
    }

    private fun addNetwork(emitter: CompletableEmitter) {
        Timber.v("Connecting to ${wifiSSID}...")
        val wc = WifiConfiguration()
        wc.SSID = "\"" + wifiSSID + "\""
        wc.preSharedKey = "\"" + wifiPassword + "\""
        wc.allowedKeyManagement.set(WifiConfiguration.KeyMgmt.WPA_PSK)
        val netId = wifiManager.addNetwork(wc)
        if (netId != -1) {
            if (!wifiManager.enableNetwork(netId, true)) {
                Timber.e("Failed to connect to the device.")
                emitter.tryOnError(IllegalArgumentException("Failed to connect to the device"))
            }
        } else {
            Timber.e("Failed to connect to the device. addNetwork() returned -1")
            emitter.tryOnError(IllegalArgumentException("Failed to connect to the device. addNetwork() returned -1"))
        }
    }

    private fun isConnectedToCorrectSSID(): Boolean {
        val currentSSID = wifiManager.connectionInfo.ssid ?: return false
        Timber.v("Connected to $currentSSID")
        return currentSSID == "\"${wifiSSID}\""
    }
}