public async Task <IReadOnlyList <WifiLedBulb> > Scan(int millisecondsTimeout)
{
//Delete old bulb list
m_discoveredBulbs.Clear();
//Create UDP Client for discovery broadcast
using (UdpClient discovery_client = new UdpClient())
{
//Send magic packet to get controllers to announce themselves
IPEndPoint ip = new IPEndPoint(IPAddress.Broadcast, DISCOVERY_PORT);
byte[] bytes = Encoding.ASCII.GetBytes("HF-A11ASSISTHREAD");
discovery_client.Send(bytes, bytes.Length, ip);
//Listen for their return packets
IPEndPoint endPoint = new IPEndPoint(IPAddress.Any, DISCOVERY_PORT);
m_cancelScanSource = new CancellationTokenSource(millisecondsTimeout);
while (true)
{
//Hack in a way to allow a CancellationToken for ReceiveAsync
//Based heavily on https://stackoverflow.com/questions/19404199/how-to-to-make-udpclient-receiveasync-cancelable
var receive_task = discovery_client.ReceiveAsync();
var tcs = new TaskCompletionSource <bool>();
using (m_cancelScanSource.Token.Register(s => tcs.TrySetResult(true), null))
{
if (await Task.WhenAny(receive_task, tcs.Task) == receive_task)
{
//ReceiveAsync was successful, parse the reply
string message = Encoding.ASCII.GetString(receive_task.Result.Buffer);
string[] bulb_data = message.Split(',');
var bulb = new WifiLedBulb(bulb_data[0], bulb_data[1], bulb_data[2]);
m_discoveredBulbs.Add(bulb);
DiscoveredBulb?.Invoke(bulb);
}
else
{
//Cancelled (or timed out), close out socket
discovery_client.Close();
m_cancelScanSource.Dispose();
m_cancelScanSource = null;
break;
}
}
}
}
return(m_discoveredBulbs.AsReadOnly());
}
/*Scan
* Sends out a UDP packet over the network and listens for response
* returns a Task... still need to investigate how this works
* assuming it returns null until an actual return value is sent,
* in this case a List of Bulb objects.
*
* @params:
* millisecondsTimeout: timeout for each individual bulb if no response is received. (non functional)
* maxRetries: retries after not hearing from a single bulb (non functional)
*/
public async Task <List <Bulb> > Scan(int millisecondsTimeout = 2000, int maxRetries = 2)
{
//Delete old bulb list
m_discoveredBulbs.Clear();
//Create UDP Client for discovery broadcast
using (UdpClient discovery_client = new UdpClient())
{
//Send magic packet to get controllers to announce themselves
IPEndPoint ip = new IPEndPoint(IPAddress.Broadcast, DISCOVERY_PORT);
m_cancelScanSource = new CancellationTokenSource(millisecondsTimeout);
Console.WriteLine("sending magic packet");
discovery_client.Send(MAGIC_UDP_PACKET, MAGIC_UDP_PACKET.Length, ip); //Send magic packet to get controllers to announce themselves
IPEndPoint endPoint = new IPEndPoint(IPAddress.Any, DISCOVERY_PORT); //Listen for their return packets
while (true)
{
//Hack in a way to allow a CancellationToken for ReceiveAsync
//Based heavily on https://stackoverflow.com/questions/19404199/how-to-to-make-udpclient-receiveasync-cancelable
var receive_task = discovery_client.ReceiveAsync();
var tcs = new TaskCompletionSource <bool>();
//??? confused about the using identifier and wrapping curly brackets
using (m_cancelScanSource.Token.Register(s => tcs.TrySetResult(true), null))
{
//if the cancellation token isn't true continue, else break the loop
if (await Task.WhenAny(receive_task, tcs.Task) == receive_task)
{
//ReceiveAsync was successful, encode the reply into ASCII and parse
string message = Encoding.ASCII.GetString(receive_task.Result.Buffer);
Console.WriteLine(message);
//When encoded to ASCII and converted to a string, data arrives in this pattern:
// 'ipaddress,macaddress,typeid'
// for example "192.168.1.21,6001940ED006,ZJ2101"
// split the data and save to variables
string[] bulb_data = message.Split(',');
string ipAddress = bulb_data[0];
string macAddress = bulb_data[1];
string typeID = bulb_data[2];
//instantiate a bulb object in "BulbsFactory" Class. Could just as easily be a...
//BulbsFactory method.
var bulb = BulbsFactory.CreateBulb(ipAddress, macAddress, typeID);
// If BulbsFactory can't figure out what the bulb type is, it will set to null
// We dont add null bulbs to our list of Bulb objects. So we 'continue',
// skipping bulbList.Add(bulb);
if (bulb == null)
{
continue;
}
//add our newly created Bulb object to a list so that we may access it later
m_discoveredBulbs.Add(bulb);
DiscoveredBulb?.Invoke(bulb);
}
else //Cancelled (or timed out), close out socket
{
Console.WriteLine(m_discoveredBulbs.Count);
//close our port so it doesn't timeout causing errors
discovery_client.Close();
//??? destroy our cancelationsource
m_cancelScanSource.Dispose();
//??? set our cancelationsource to null. This may be why scanRetry isn't working
m_cancelScanSource = null;
//break out of the first 'while (true)' loop as we have no more bulbs to add
break;
}
}
}
}
return(m_discoveredBulbs);
}