Enhance discovery process with configurable timeout and continuous search

Key improvements:

- Added a configurable timeout for the device discovery process (defaulting to 60 seconds).
- Modified StartDiscovery method in DiscoveryService to accept the timeout value.
- Implemented a continuous device search loop with periodic searches based on the timeout.
- Added logging messages to indicate when device searches are initiated.
- Minor code formatting adjustments for readability.

Author: Ibrahim Ethem Gursoy

Services/CheckerService.cs

@@ -39,8 +39,11 @@ public CheckerService(ILogger<CheckerService> logger, IConfiguration configurati
                     var iface = _configuration.GetValue<string>("AppConfiguration:NetworkInterface");
                     var bindIp = Helper.GetIPAddress(iface);
 
+                    var timeout = _configuration.GetValue<int>("AppConfiguration:DiscoveryTimeout");
+                    if (timeout <= 0)
+                        timeout = 60000;
                     _discoveryService = new DiscoveryService();
-                    _discoveryService.StartDiscovery(bindIp?.ToString() ?? "", OnDiscoveredDevice);
+                    _discoveryService.StartDiscovery(bindIp?.ToString() ?? "", OnDiscoveredDevice, timeout);
                 }
 
                 var devicesFile = _configuration.GetValue<string>("AppConfiguration:DefaultDeviceJsonPath");

Services/DiscoveryService.cs

@@ -6,15 +6,19 @@ public class DiscoveryService : IDisposable
     {
         private SsdpDeviceLocator? _deviceLocator;
 
-        public void StartDiscovery(string bindIp, EventHandler<DeviceAvailableEventArgs> cb)
+        public void StartDiscovery(string bindIp, EventHandler<DeviceAvailableEventArgs> cb, int timeout = 60000)
         {
             _deviceLocator = new SsdpDeviceLocator(bindIp) { NotificationFilter = "upnp:rootdevice" };
             _deviceLocator.DeviceAvailable += cb;
+            _deviceLocator.StartListeningForNotifications();
 
             new Thread(() =>
             {
-                _deviceLocator.StartListeningForNotifications();
-                _deviceLocator.SearchAsync();
+                while (true) {
+                    Console.WriteLine("***************************\n** Searching for devices **\n***************************");
+                    _ = _deviceLocator.SearchAsync();
+                    Thread.Sleep(timeout);
+                }
             }).Start();
         }
 

appsettings.json

@@ -33,6 +33,7 @@
     "EnableCheckPort": true,
     "EnableCheckOnvifMedia": true,
     "EnableCheckRTSPLinks": true,
+    "DiscoveryTimeout": 6000,
     "ThumbnailsPath": "/tmp/thumbnails/",
     "DefaultDeviceJsonPath": "device_list.json",
     "NetworkInterface": "eth0",