feat: map routes/tielines at startup and new console commands

* visualizeroutes allows visualizing configured routes based on tielines and signal type
  * can be filtered by source key, destination key, and type, along with partial matches for source & destination keys
* visualizecurrentroutes visualizes what Essentials says is currently routed by type
  * uses same filtering as visualizeroutes
* improvements to how the routing algorithm works

src/PepperDash.Essentials.Core/Routing/Extensions.cs

@@ -18,6 +18,20 @@ namespace PepperDash.Essentials.Core
     /// </summary>
     public static class Extensions
     {
+
+        /// <summary>
+        /// A collection of RouteDescriptors for each signal type.
+        /// </summary>
+        public static readonly Dictionary<eRoutingSignalType, RouteDescriptorCollection> RouteDescriptors = new Dictionary<eRoutingSignalType, RouteDescriptorCollection>()
+        {
+            { eRoutingSignalType.Audio, new RouteDescriptorCollection() },
+            { eRoutingSignalType.Video, new RouteDescriptorCollection() },
+            { eRoutingSignalType.SecondaryAudio, new RouteDescriptorCollection() },
+            { eRoutingSignalType.AudioVideo, new RouteDescriptorCollection() },
+            { eRoutingSignalType.UsbInput, new RouteDescriptorCollection() },
+            { eRoutingSignalType.UsbOutput, new RouteDescriptorCollection() }
+        };
+
         /// <summary>
         /// Stores pending route requests, keyed by the destination device key.
         /// Used primarily to handle routing requests while a device is cooling down.
@@ -29,6 +43,105 @@ namespace PepperDash.Essentials.Core
         /// </summary>
         private static readonly GenericQueue routeRequestQueue = new GenericQueue("routingQueue");
 
+        /// <summary>
+        /// Indexed lookup of TieLines by destination device key for faster queries.
+        /// </summary>
+        private static Dictionary<string, List<TieLine>> _tieLinesByDestination;
+
+        /// <summary>
+        /// Indexed lookup of TieLines by source device key for faster queries.
+        /// </summary>
+        private static Dictionary<string, List<TieLine>> _tieLinesBySource;
+
+        /// <summary>
+        /// Cache of failed route attempts to avoid re-checking impossible paths.
+        /// Format: "sourceKey|destKey|signalType"
+        /// </summary>
+        private static readonly HashSet<string> _impossibleRoutes = new HashSet<string>();
+
+        /// <summary>
+        /// Indexes all TieLines by source and destination device keys for faster lookups.
+        /// Should be called once at system startup after all TieLines are created.
+        /// </summary>
+        public static void IndexTieLines()
+        {
+            try
+            {
+                Debug.LogMessage(LogEventLevel.Information, "Indexing TieLines for faster route discovery");
+
+                _tieLinesByDestination = TieLineCollection.Default
+                    .GroupBy(t => t.DestinationPort.ParentDevice.Key)
+                    .ToDictionary(g => g.Key, g => g.ToList());
+
+                _tieLinesBySource = TieLineCollection.Default
+                    .GroupBy(t => t.SourcePort.ParentDevice.Key)
+                    .ToDictionary(g => g.Key, g => g.ToList());
+
+                Debug.LogMessage(LogEventLevel.Information, "TieLine indexing complete. {0} destination keys, {1} source keys",
+                    null, _tieLinesByDestination.Count, _tieLinesBySource.Count);
+            }
+            catch (Exception ex)
+            {
+                Debug.LogError("Exception indexing TieLines: {exception}", ex.Message);
+                Debug.LogDebug(ex, "Stack Trace: ");
+            }
+        }
+
+        /// <summary>
+        /// Gets TieLines connected to a destination device.
+        /// Uses indexed lookup if available, otherwise falls back to LINQ query.
+        /// </summary>
+        /// <param name="destinationKey">The destination device key</param>
+        /// <returns>List of TieLines connected to the destination</returns>
+        private static IEnumerable<TieLine> GetTieLinesForDestination(string destinationKey)
+        {
+            if (_tieLinesByDestination != null && _tieLinesByDestination.TryGetValue(destinationKey, out List<TieLine> tieLines))
+            {
+                return tieLines;
+            }
+
+            // Fallback to LINQ if index not available
+            return TieLineCollection.Default.Where(t => t.DestinationPort.ParentDevice.Key == destinationKey);
+        }
+
+        /// <summary>
+        /// Gets TieLines connected to a source device.
+        /// Uses indexed lookup if available, otherwise falls back to LINQ query.
+        /// </summary>
+        /// <param name="sourceKey">The source device key</param>
+        /// <returns>List of TieLines connected to the source</returns>
+        private static IEnumerable<TieLine> GetTieLinesForSource(string sourceKey)
+        {
+            if (_tieLinesBySource != null && _tieLinesBySource.TryGetValue(sourceKey, out List<TieLine> tieLines))
+            {
+                return tieLines;
+            }
+
+            // Fallback to LINQ if index not available
+            return TieLineCollection.Default.Where(t => t.SourcePort.ParentDevice.Key == sourceKey);
+        }
+
+        /// <summary>
+        /// Creates a cache key for route impossibility tracking.
+        /// </summary>
+        /// <param name="sourceKey">Source device key</param>
+        /// <param name="destKey">Destination device key</param>
+        /// <param name="type">Signal type</param>
+        /// <returns>Cache key string</returns>
+        private static string GetRouteKey(string sourceKey, string destKey, eRoutingSignalType type)
+        {
+            return string.Format("{0}|{1}|{2}", sourceKey, destKey, type);
+        }
+
+        /// <summary>
+        /// Clears the impossible routes cache. Should be called if TieLines are added/removed at runtime.
+        /// </summary>
+        public static void ClearImpossibleRoutesCache()
+        {
+            _impossibleRoutes.Clear();
+            Debug.LogMessage(LogEventLevel.Information, "Impossible routes cache cleared");
+        }
+
         /// <summary>
         /// Gets any existing RouteDescriptor for a destination, clears it using ReleaseRoute
         /// and then attempts a new Route and if sucessful, stores that RouteDescriptor
@@ -173,8 +286,9 @@ namespace PepperDash.Essentials.Core
             if (!audioSuccess && !videoSuccess)
                 return (null, null);
 
-
-            return (audioRouteDescriptor, videoRouteDescriptor);
+            // Return null for descriptors that have no routes
+            return (audioSuccess && audioRouteDescriptor.Routes.Count > 0 ? audioRouteDescriptor : null,
+                    videoSuccess && videoRouteDescriptor.Routes.Count > 0 ? videoRouteDescriptor : null);
         }
 
         /// <summary>
@@ -245,6 +359,90 @@ namespace PepperDash.Essentials.Core
             routeRequestQueue.Enqueue(new RouteRequestQueueItem(RunRouteRequest, routeRequest));
         }
 
+        /// <summary>
+        /// Maps destination input ports to source output ports for all routing devices.
+        /// </summary>
+        public static void MapDestinationsToSources()
+        {
+            try
+            {
+                // Index TieLines before mapping if not already done
+                if (_tieLinesByDestination == null || _tieLinesBySource == null)
+                {
+                    IndexTieLines();
+                }
+
+                var sinks = DeviceManager.AllDevices.OfType<IRoutingInputs>().Where(d => !(d is IRoutingInputsOutputs));
+                var sources = DeviceManager.AllDevices.OfType<IRoutingOutputs>().Where(d => !(d is IRoutingInputsOutputs));
+
+                foreach (var sink in sinks)
+                {
+                    foreach (var source in sources)
+                    {
+                        foreach (var inputPort in sink.InputPorts)
+                        {
+                            foreach (var outputPort in source.OutputPorts)
+                            {
+                                var (audioOrSingleRoute, videoRoute) = sink.GetRouteToSource(source, inputPort.Type, inputPort, outputPort);
+
+                                if (audioOrSingleRoute == null && videoRoute == null)
+                                {
+                                    continue;
+                                }
+
+                                if (audioOrSingleRoute != null)
+                                {
+                                    // Only add routes that have actual switching steps
+                                    if (audioOrSingleRoute.Routes == null || audioOrSingleRoute.Routes.Count == 0)
+                                    {
+                                        continue;
+                                    }
+
+                                    // Add to the appropriate collection(s) based on signal type
+                                    // Note: A single route descriptor with combined flags (e.g., AudioVideo) will be added once per matching signal type
+                                    if (audioOrSingleRoute.SignalType.HasFlag(eRoutingSignalType.Audio))
+                                    {
+                                        RouteDescriptors[eRoutingSignalType.Audio].AddRouteDescriptor(audioOrSingleRoute);
+                                    }
+                                    if (audioOrSingleRoute.SignalType.HasFlag(eRoutingSignalType.Video))
+                                    {
+                                        RouteDescriptors[eRoutingSignalType.Video].AddRouteDescriptor(audioOrSingleRoute);
+                                    }
+                                    if (audioOrSingleRoute.SignalType.HasFlag(eRoutingSignalType.SecondaryAudio))
+                                    {
+                                        RouteDescriptors[eRoutingSignalType.SecondaryAudio].AddRouteDescriptor(audioOrSingleRoute);
+                                    }
+                                    if (audioOrSingleRoute.SignalType.HasFlag(eRoutingSignalType.UsbInput))
+                                    {
+                                        RouteDescriptors[eRoutingSignalType.UsbInput].AddRouteDescriptor(audioOrSingleRoute);
+                                    }
+                                    if (audioOrSingleRoute.SignalType.HasFlag(eRoutingSignalType.UsbOutput))
+                                    {
+                                        RouteDescriptors[eRoutingSignalType.UsbOutput].AddRouteDescriptor(audioOrSingleRoute);
+                                    }
+                                }
+                                if (videoRoute != null)
+                                {
+                                    // Only add routes that have actual switching steps
+                                    if (videoRoute.Routes == null || videoRoute.Routes.Count == 0)
+                                    {
+                                        continue;
+                                    }
+
+                                    RouteDescriptors[eRoutingSignalType.Video].AddRouteDescriptor(videoRoute);
+                                }
+                            }
+                        }
+                    }
+                }
+            }
+            catch (Exception ex)
+            {
+                Debug.LogError("Exception mapping routes: {exception}", ex.Message);
+                Debug.LogDebug(ex, "Stack Trace: ");
+            }
+        }
+
         /// <summary>
         /// Executes the actual routing based on a <see cref="RouteRequest"/>.
         /// Finds the route path, adds it to the collection, and executes the switches.
@@ -257,7 +455,51 @@ namespace PepperDash.Essentials.Core
                 if (request.Source == null)
                     return;
 
-                var (audioOrSingleRoute, videoRoute) = request.Destination.GetRouteToSource(request.Source, request.SignalType, request.DestinationPort, request.SourcePort);
+                RouteDescriptor audioOrSingleRoute = null;
+                RouteDescriptor videoRoute = null;
+
+                // Try to use pre-loaded route descriptors first
+                if (request.SignalType.HasFlag(eRoutingSignalType.AudioVideo))
+                {
+                    // For AudioVideo routes, check both Audio and Video collections
+                    if (RouteDescriptors.TryGetValue(eRoutingSignalType.Audio, out RouteDescriptorCollection audioCollection))
+                    {
+                        audioOrSingleRoute = audioCollection.Descriptors.FirstOrDefault(d =>
+                            d.Source.Key == request.Source.Key &&
+                            d.Destination.Key == request.Destination.Key &&
+                            (request.DestinationPort == null || d.InputPort?.Key == request.DestinationPort.Key));
+                    }
+
+                    if (RouteDescriptors.TryGetValue(eRoutingSignalType.Video, out RouteDescriptorCollection videoCollection))
+                    {
+                        videoRoute = videoCollection.Descriptors.FirstOrDefault(d =>
+                            d.Source.Key == request.Source.Key &&
+                            d.Destination.Key == request.Destination.Key &&
+                            (request.DestinationPort == null || d.InputPort?.Key == request.DestinationPort.Key));
+                    }
+                }
+                else
+                {
+                    // For single signal type routes
+                    var signalTypeToCheck = request.SignalType.HasFlag(eRoutingSignalType.SecondaryAudio)
+                        ? eRoutingSignalType.SecondaryAudio
+                        : request.SignalType;
+
+                    if (RouteDescriptors.TryGetValue(signalTypeToCheck, out RouteDescriptorCollection collection))
+                    {
+                        audioOrSingleRoute = collection.Descriptors.FirstOrDefault(d =>
+                            d.Source.Key == request.Source.Key &&
+                            d.Destination.Key == request.Destination.Key &&
+                            (request.DestinationPort == null || d.InputPort?.Key == request.DestinationPort.Key));
+                    }
+                }
+
+                // If no pre-loaded route found, build it dynamically
+                if (audioOrSingleRoute == null && videoRoute == null)
+                {
+                    Debug.LogMessage(LogEventLevel.Debug, "No pre-loaded route found, building dynamically", request.Destination);
+                    (audioOrSingleRoute, videoRoute) = request.Destination.GetRouteToSource(request.Source, request.SignalType, request.DestinationPort, request.SourcePort);
+                }
 
                 if (audioOrSingleRoute == null && videoRoute == null)
                     return;
@@ -321,11 +563,13 @@ namespace PepperDash.Essentials.Core
         /// </summary>
         /// <param name="destination"></param>
         /// <param name="source"></param>
-        /// <param name="destinationPort">The RoutingOutputPort whose link is being checked for a route</param>
+        /// <param name="outputPortToUse">The RoutingOutputPort whose link is being checked for a route</param>
         /// <param name="alreadyCheckedDevices">Prevents Devices from being twice-checked</param>
         /// <param name="signalType">This recursive function should not be called with AudioVideo</param>
         /// <param name="cycle">Just an informational counter</param>
         /// <param name="routeTable">The RouteDescriptor being populated as the route is discovered</param>
+        /// <param name="destinationPort">The RoutingOutputPort whose link is being checked for a route</param>
+        /// <param name="sourcePort">The source output port (optional)</param>
         /// <returns>true if source is hit</returns>
         private static bool GetRouteToSource(this IRoutingInputs destination, IRoutingOutputs source,
             RoutingOutputPort outputPortToUse, List<IRoutingInputsOutputs> alreadyCheckedDevices,
@@ -333,42 +577,54 @@ namespace PepperDash.Essentials.Core
         {
             cycle++;
 
+            // Check if this route has already been determined to be impossible
+            var routeKey = GetRouteKey(source.Key, destination.Key, signalType);
+            if (_impossibleRoutes.Contains(routeKey))
+            {
+                Debug.LogMessage(LogEventLevel.Verbose, "Route {0} is cached as impossible, skipping", null, routeKey);
+                return false;
+            }
+
             Debug.LogMessage(LogEventLevel.Verbose, "GetRouteToSource: {cycle} {sourceKey}:{sourcePortKey}--> {destinationKey}:{destinationPortKey} {type}", null, cycle, source.Key, sourcePort?.Key ?? "auto", destination.Key, destinationPort?.Key ?? "auto", signalType.ToString());
 
             RoutingInputPort goodInputPort = null;
 
+            // Use indexed lookup instead of LINQ query
+            var allDestinationTieLines = GetTieLinesForDestination(destination.Key);
+
             IEnumerable<TieLine> destinationTieLines;
             TieLine directTie = null;
 
             if (destinationPort == null)
             {
-                destinationTieLines = TieLineCollection.Default.Where(t =>
-                    t.DestinationPort.ParentDevice.Key == destination.Key && (t.Type.HasFlag(signalType) || signalType == eRoutingSignalType.AudioVideo));
+                destinationTieLines = allDestinationTieLines.Where(t =>
+                    t.Type.HasFlag(signalType) || signalType == eRoutingSignalType.AudioVideo);
             }
             else
             {
-                destinationTieLines = TieLineCollection.Default.Where(t => t.DestinationPort.ParentDevice.Key == destination.Key && t.DestinationPort.Key == destinationPort.Key && (t.Type.HasFlag(signalType)));
+                destinationTieLines = allDestinationTieLines.Where(t =>
+                    t.DestinationPort.Key == destinationPort.Key && t.Type.HasFlag(signalType));
             }
 
             // find the TieLine without a port
             if (destinationPort == null && sourcePort == null)
             {
-                directTie = destinationTieLines.FirstOrDefault(t => t.DestinationPort.ParentDevice.Key == destination.Key && t.SourcePort.ParentDevice.Key == source.Key);
+                directTie = destinationTieLines.FirstOrDefault(t => t.SourcePort.ParentDevice.Key == source.Key);
             }
             // find a tieLine to a specific destination port without a specific source port
             else if (destinationPort != null && sourcePort == null)
             {
-                directTie = destinationTieLines.FirstOrDefault(t => t.DestinationPort.ParentDevice.Key == destination.Key && t.DestinationPort.Key == destinationPort.Key && t.SourcePort.ParentDevice.Key == source.Key);
+                directTie = destinationTieLines.FirstOrDefault(t => t.DestinationPort.Key == destinationPort.Key && t.SourcePort.ParentDevice.Key == source.Key);
             }
             // find a tieline to a specific source port without a specific destination port
             else if (destinationPort == null & sourcePort != null)
             {
-                directTie = destinationTieLines.FirstOrDefault(t => t.DestinationPort.ParentDevice.Key == destination.Key && t.SourcePort.ParentDevice.Key == source.Key && t.SourcePort.Key == sourcePort.Key);
+                directTie = destinationTieLines.FirstOrDefault(t => t.SourcePort.ParentDevice.Key == source.Key && t.SourcePort.Key == sourcePort.Key);
             }
             // find a tieline to a specific source port and destination port
             else if (destinationPort != null && sourcePort != null)
             {
-                directTie = destinationTieLines.FirstOrDefault(t => t.DestinationPort.ParentDevice.Key == destination.Key && t.DestinationPort.Key == destinationPort.Key && t.SourcePort.ParentDevice.Key == source.Key && t.SourcePort.Key == sourcePort.Key);
+                directTie = destinationTieLines.FirstOrDefault(t => t.DestinationPort.Key == destinationPort.Key && t.SourcePort.ParentDevice.Key == source.Key && t.SourcePort.Key == sourcePort.Key);
             }
 
             if (directTie != null) // Found a tie directly to the source
@@ -423,6 +679,10 @@ namespace PepperDash.Essentials.Core
             if (goodInputPort == null)
             {
                 Debug.LogMessage(LogEventLevel.Verbose, "No route found to {0}", destination, source.Key);
+
+                // Cache this as an impossible route
+                _impossibleRoutes.Add(routeKey);
+
                 return false;
             }
 

src/PepperDash.Essentials.Core/Routing/RouteDescriptor.cs

@@ -95,15 +95,15 @@ namespace PepperDash.Essentials.Core
         /// Releases the usage tracking for the route and optionally clears the route on the switching devices.
         /// </summary>
         /// <param name="clearRoute">If true, attempts to clear the route on the switching devices (e.g., set input to null/0).</param>
-        
-        
+
+
         public void ReleaseRoutes(bool clearRoute = false)
         {
             foreach (var route in Routes.Where(r => r.SwitchingDevice is IRouting))
             {
                 if (route.SwitchingDevice is IRouting switchingDevice)
                 {
-                    if(clearRoute)
+                    if (clearRoute)
                     {
                         try
                         {
@@ -137,98 +137,11 @@ namespace PepperDash.Essentials.Core
         /// Returns a string representation of the route descriptor, including source, destination, and individual route steps.
         /// </summary>
         /// <returns>A string describing the route.</returns>
-        
-        
-        
         public override string ToString()
         {
             var routesText = Routes.Select(r => r.ToString()).ToArray();
-            return string.Format("Route table from {0} to {1}:\r{2}", Source.Key, Destination.Key, string.Join("\r", routesText));
+            return $"Route table from {Source.Key} to {Destination.Key} for {SignalType}:\r\n    {string.Join("\r\n    ", routesText)}";
         }
     }
 
-    /*/// <summary>
-    /// Represents an collection of individual route steps between Source and Destination
-    /// </summary>
-    /// <summary>
-    /// Represents a RouteDescriptor
-    /// </summary>
-    public class RouteDescriptor<TInputSelector, TOutputSelector>
-    {
-        /// <summary>
-        /// Gets or sets the Destination
-        /// </summary>
-        public IRoutingInputs<TInputSelector> Destination { get; private set; }
-        /// <summary>
-        /// Gets or sets the Source
-        /// </summary>
-        public IRoutingOutputs<TOutputSelector> Source { get; private set; }
-        /// <summary>
-        /// Gets or sets the SignalType
-        /// </summary>
-        public eRoutingSignalType SignalType { get; private set; }
-        public List<RouteSwitchDescriptor<TInputSelector, TOutputSelector>> Routes { get; private set; }
-
-
-        public RouteDescriptor(IRoutingOutputs<TOutputSelector> source, IRoutingInputs<TInputSelector> destination, eRoutingSignalType signalType)
-        {
-            Destination = destination;
-            Source = source;
-            SignalType = signalType;
-            Routes = new List<RouteSwitchDescriptor<TInputSelector, TOutputSelector>>();
-        }
-
-        /// <summary>
-        /// ExecuteRoutes method
-        /// </summary>
-        public void ExecuteRoutes()
-        {
-            foreach (var route in Routes)
-            {
-                Debug.LogMessage(LogEventLevel.Verbose, "ExecuteRoutes: {0}", null, route.ToString());
-
-                if (route.SwitchingDevice is IRoutingSinkWithSwitching<TInputSelector> sink)
-                {
-                    sink.ExecuteSwitch(route.InputPort.Selector);
-                    continue;
-                }
-
-                if (route.SwitchingDevice is IRouting switchingDevice)
-                {
-                    switchingDevice.ExecuteSwitch(route.InputPort.Selector, route.OutputPort.Selector, SignalType);
-
-                    route.OutputPort.InUseTracker.AddUser(Destination, "destination-" + SignalType);
-
-                    Debug.LogMessage(LogEventLevel.Verbose, "Output port {0} routing. Count={1}", null, route.OutputPort.Key, route.OutputPort.InUseTracker.InUseCountFeedback.UShortValue);
-                }
-            }
-        }
-
-        /// <summary>
-        /// ReleaseRoutes method
-        /// </summary>
-        public void ReleaseRoutes()
-        {
-            foreach (var route in Routes)
-            {
-                if (route.SwitchingDevice is IRouting<TInputSelector, TOutputSelector>)
-                {
-                    // Pull the route from the port.  Whatever is watching the output's in use tracker is
-                    // responsible for responding appropriately.
-                    route.OutputPort.InUseTracker.RemoveUser(Destination, "destination-" + SignalType);
-                    Debug.LogMessage(LogEventLevel.Verbose, "Port {0} releasing. Count={1}", null, route.OutputPort.Key, route.OutputPort.InUseTracker.InUseCountFeedback.UShortValue);
-                }
-            }
-        }
-
-        /// <summary>
-        /// ToString method
-        /// </summary>
-        /// <inheritdoc />
-        public override string ToString()
-        {
-            var routesText = Routes.Select(r => r.ToString()).ToArray();
-            return string.Format("Route table from {0} to {1}:\r{2}", Source.Key, Destination.Key, string.Join("\r", routesText));
-        }
-    }*/
 }

src/PepperDash.Essentials.Core/Routing/RouteDescriptorCollection.cs

@@ -1,7 +1,7 @@
-using PepperDash.Core;
-using Serilog.Events;
-using System.Collections.Generic;
+using System.Collections.Generic;
 using System.Linq;
+using PepperDash.Core;
+using Serilog.Events;
 
 
 namespace PepperDash.Essentials.Core
@@ -11,6 +11,9 @@ namespace PepperDash.Essentials.Core
     /// </summary>
     public class RouteDescriptorCollection
     {
+        /// <summary>
+        /// Gets the default collection of RouteDescriptors.
+        /// </summary>
         public static RouteDescriptorCollection DefaultCollection
         {
             get
@@ -24,6 +27,11 @@ namespace PepperDash.Essentials.Core
 
         private readonly List<RouteDescriptor> RouteDescriptors = new List<RouteDescriptor>();
 
+        /// <summary>
+        /// Gets an enumerable collection of all RouteDescriptors in this collection.
+        /// </summary>
+        public IEnumerable<RouteDescriptor> Descriptors => RouteDescriptors.AsReadOnly();
+
         /// <summary>
         /// Adds a RouteDescriptor to the list.  If an existing RouteDescriptor for the
         /// destination exists already, it will not be added - in order to preserve
@@ -37,13 +45,29 @@ namespace PepperDash.Essentials.Core
                 return;
             }
 
-            if (RouteDescriptors.Any(t => t.Destination == descriptor.Destination)
-                && RouteDescriptors.Any(t => t.Destination == descriptor.Destination && t.InputPort != null && descriptor.InputPort != null && t.InputPort.Key == descriptor.InputPort.Key))
+            // Check if a route already exists with the same source, destination, input port, AND signal type
+            var existingRoute = RouteDescriptors.FirstOrDefault(t =>
+                t.Source == descriptor.Source &&
+                t.Destination == descriptor.Destination &&
+                t.SignalType == descriptor.SignalType &&
+                ((t.InputPort == null && descriptor.InputPort == null) ||
+                 (t.InputPort != null && descriptor.InputPort != null && t.InputPort.Key == descriptor.InputPort.Key)));
+
+            if (existingRoute != null)
             {
-                Debug.LogMessage(LogEventLevel.Debug, descriptor.Destination,
-                    "Route to [{0}] already exists in global routes table", descriptor?.Source?.Key);
+                Debug.LogMessage(LogEventLevel.Information, descriptor.Destination,
+                    "Route from {0} to {1}:{2} ({3}) already exists in this collection",
+                    descriptor?.Source?.Key,
+                    descriptor?.Destination?.Key,
+                    descriptor?.InputPort?.Key ?? "auto",
+                    descriptor?.SignalType);
                 return;
             }
+            Debug.LogMessage(LogEventLevel.Verbose, "Adding route descriptor: {0} -> {1}:{2} ({3})",
+                descriptor?.Source?.Key,
+                descriptor?.Destination?.Key,
+                descriptor?.InputPort?.Key ?? "auto",
+                descriptor?.SignalType);
             RouteDescriptors.Add(descriptor);
         }
 
@@ -57,6 +81,12 @@ namespace PepperDash.Essentials.Core
             return RouteDescriptors.FirstOrDefault(rd => rd.Destination == destination);
         }
 
+        /// <summary>
+        /// Gets the route descriptor for a specific destination and input port
+        /// </summary>
+        /// <param name="destination">The destination device</param>
+        /// <param name="inputPortKey">The input port key</param>
+        /// <returns>The matching RouteDescriptor or null if not found</returns>
         public RouteDescriptor GetRouteDescriptorForDestinationAndInputPort(IRoutingInputs destination, string inputPortKey)
         {
             Debug.LogMessage(LogEventLevel.Information, "Getting route descriptor for '{destination}':'{inputPortKey}'", destination?.Key ?? null, string.IsNullOrEmpty(inputPortKey) ? "auto" : inputPortKey);
@@ -73,7 +103,7 @@ namespace PepperDash.Essentials.Core
         {
             Debug.LogMessage(LogEventLevel.Information, "Removing route descriptor for '{destination}':'{inputPortKey}'", destination.Key ?? null, string.IsNullOrEmpty(inputPortKey) ? "auto" : inputPortKey);
 
-            var descr = string.IsNullOrEmpty(inputPortKey) 
+            var descr = string.IsNullOrEmpty(inputPortKey)
                 ? GetRouteDescriptorForDestination(destination)
                 : GetRouteDescriptorForDestinationAndInputPort(destination, inputPortKey);
             if (descr != null)
@@ -84,70 +114,4 @@ namespace PepperDash.Essentials.Core
             return descr;
         }
     }
-
-    /*/// <summary>
-    /// A collection of RouteDescriptors - typically the static DefaultCollection is used
-    /// </summary>
-    /// <summary>
-    /// Represents a RouteDescriptorCollection
-    /// </summary>
-    public class RouteDescriptorCollection<TInputSelector, TOutputSelector>
-	{
-		public static RouteDescriptorCollection<TInputSelector, TOutputSelector> DefaultCollection
-		{
-			get
-			{
-				if (_DefaultCollection == null)
-					_DefaultCollection = new RouteDescriptorCollection<TInputSelector, TOutputSelector>();
-				return _DefaultCollection;
-			}
-		}
-		private static RouteDescriptorCollection<TInputSelector, TOutputSelector> _DefaultCollection;
-
-		private readonly List<RouteDescriptor> RouteDescriptors = new List<RouteDescriptor>();
-
-		/// <summary>
-		/// Adds a RouteDescriptor to the list.  If an existing RouteDescriptor for the
-		/// destination exists already, it will not be added - in order to preserve
-		/// proper route releasing.
-		/// </summary>
-		/// <param name="descriptor"></param>
-  /// <summary>
-  /// AddRouteDescriptor method
-  /// </summary>
-		public void AddRouteDescriptor(RouteDescriptor descriptor)
-		{
-			if (RouteDescriptors.Any(t => t.Destination == descriptor.Destination))
-			{
-				Debug.LogMessage(LogEventLevel.Debug, descriptor.Destination, 
-					"Route to [{0}] already exists in global routes table", descriptor.Source.Key);
-				return;
-			}
-			RouteDescriptors.Add(descriptor);
-		}
-
-		/// <summary>
-		/// Gets the RouteDescriptor for a destination
-		/// </summary>
-		/// <returns>null if no RouteDescriptor for a destination exists</returns>
-  /// <summary>
-  /// GetRouteDescriptorForDestination method
-  /// </summary>
-		public RouteDescriptor GetRouteDescriptorForDestination(IRoutingInputs<TInputSelector> destination)
-		{
-			return RouteDescriptors.FirstOrDefault(rd => rd.Destination == destination);
-		}
-
-		/// <summary>
-		/// Returns the RouteDescriptor for a given destination AND removes it from collection.
-		/// Returns null if no route with the provided destination exists.
-		/// </summary>
-		public RouteDescriptor RemoveRouteDescriptor(IRoutingInputs<TInputSelector> destination)
-		{
-			var descr = GetRouteDescriptorForDestination(destination);
-			if (descr != null)
-				RouteDescriptors.Remove(descr);
-			return descr;
-		}
-	}*/
 }

src/PepperDash.Essentials.Core/Routing/RouteSwitchDescriptor.cs

@@ -4,96 +4,51 @@
     /// Represents a RouteSwitchDescriptor
     /// </summary>
     public class RouteSwitchDescriptor
-	{
-  /// <summary>
-  /// Gets or sets the SwitchingDevice
-  /// </summary>
-		public IRoutingInputs SwitchingDevice { get { return InputPort?.ParentDevice; } }
-		/// <summary>
-		/// The output port being switched from (relevant for matrix switchers). Null for sink devices.
-		/// </summary>
-		public RoutingOutputPort OutputPort { get; set; }
-		/// <summary>
-		/// The input port being switched to.
-		/// </summary>
-		public RoutingInputPort InputPort { get; set; }
-
-		/// <summary>
-		/// Initializes a new instance of the <see cref="RouteSwitchDescriptor"/> class for sink devices (no output port).
-		/// </summary>
-		/// <param name="inputPort">The input port being switched to.</param>
-		public RouteSwitchDescriptor(RoutingInputPort inputPort)
-		{
-			InputPort = inputPort;
-		}
-
-		/// <summary>
-		/// Initializes a new instance of the <see cref="RouteSwitchDescriptor"/> class for matrix switchers.
-		/// </summary>
-		/// <param name="outputPort">The output port being switched from.</param>
-		/// <param name="inputPort">The input port being switched to.</param>
-		public RouteSwitchDescriptor(RoutingOutputPort outputPort, RoutingInputPort inputPort)
-		{
-			InputPort = inputPort;
-			OutputPort = outputPort;
-		}
-
-		/// <summary>
-		/// Returns a string representation of the route switch descriptor.
-		/// </summary>
-		/// <returns>A string describing the switch operation.</returns>
-  /// <inheritdoc />
-		public override string ToString()
-		{
-            if (SwitchingDevice is IRouting)
-                return $"{(SwitchingDevice != null ? SwitchingDevice.Key : "No Device")} switches output {(OutputPort != null ? OutputPort.Key : "No output port")} to input {(InputPort != null ? InputPort.Key : "No input port")}";
-            else
-                return $"{(SwitchingDevice != null ? SwitchingDevice.Key : "No Device")} switches to input {(InputPort != null ? InputPort.Key : "No input port")}";
-		}
-	}
-
-    /*/// <summary>
-    /// Represents an individual link for a route
-    /// </summary>
-    /// <summary>
-    /// Represents a RouteSwitchDescriptor
-    /// </summary>
-    public class RouteSwitchDescriptor<TInputSelector, TOutputSelector>
     {
         /// <summary>
         /// Gets or sets the SwitchingDevice
         /// </summary>
-        public IRoutingInputs<TInputSelector> SwitchingDevice { get { return InputPort.ParentDevice; } }
+        public IRoutingInputs SwitchingDevice { get { return InputPort?.ParentDevice; } }
         /// <summary>
-        /// Gets or sets the OutputPort
+        /// The output port being switched from (relevant for matrix switchers). Null for sink devices.
         /// </summary>
-        public RoutingOutputPort<TOutputSelector> OutputPort { get; set; }
+        public RoutingOutputPort OutputPort { get; set; }
         /// <summary>
-        /// Gets or sets the InputPort
+        /// The input port being switched to.
         /// </summary>
-        public RoutingInputPort<TInputSelector> InputPort { get; set; }
+        public RoutingInputPort InputPort { get; set; }
 
-        public RouteSwitchDescriptor(RoutingInputPort<TInputSelector> inputPort)
+        /// <summary>
+        /// Initializes a new instance of the <see cref="RouteSwitchDescriptor"/> class for sink devices (no output port).
+        /// </summary>
+        /// <param name="inputPort">The input port being switched to.</param>
+        public RouteSwitchDescriptor(RoutingInputPort inputPort)
         {
             InputPort = inputPort;
         }
 
-        public RouteSwitchDescriptor(RoutingOutputPort<TOutputSelector> outputPort, RoutingInputPort<TInputSelector> inputPort)
+        /// <summary>
+        /// Initializes a new instance of the <see cref="RouteSwitchDescriptor"/> class for matrix switchers.
+        /// </summary>
+        /// <param name="outputPort">The output port being switched from.</param>
+        /// <param name="inputPort">The input port being switched to.</param>
+        public RouteSwitchDescriptor(RoutingOutputPort outputPort, RoutingInputPort inputPort)
         {
             InputPort = inputPort;
             OutputPort = outputPort;
         }
 
         /// <summary>
-        /// ToString method
+        /// Returns a string representation of the route switch descriptor.
         /// </summary>
+        /// <returns>A string describing the switch operation.</returns>
         /// <inheritdoc />
         public override string ToString()
         {
             if (SwitchingDevice is IRouting)
-                return string.Format("{0} switches output '{1}' to input '{2}'", SwitchingDevice.Key, OutputPort.Selector, InputPort.Selector);
+                return $"{(SwitchingDevice != null ? SwitchingDevice.Key : "No Device")} switches output {(OutputPort != null ? OutputPort.Key : "No output port")} to input {(InputPort != null ? InputPort.Key : "No input port")}";
             else
-                return string.Format("{0} switches to input '{1}'", SwitchingDevice.Key, InputPort.Selector);
+                return $"{(SwitchingDevice != null ? SwitchingDevice.Key : "No Device")} switches to input {(InputPort != null ? InputPort.Key : "No input port")}";
         }
-    }*/
+    }
 }

src/PepperDash.Essentials/ControlSystem.cs

@@ -1,4 +1,5 @@
 using System;
+using System.Collections.Generic;
 using System.IO.Compression;
 using System.Linq;
 using System.Reflection;
@@ -92,12 +93,16 @@ namespace PepperDash.Essentials
 
             CrestronConsole.AddNewConsoleCommand(s => Debug.LogMessage(LogEventLevel.Information, "CONSOLE MESSAGE: {0}", s), "appdebugmessage", "Writes message to log", ConsoleAccessLevelEnum.AccessOperator);
 
-            CrestronConsole.AddNewConsoleCommand(s =>
-            {
-                foreach (var tl in TieLineCollection.Default)
-                    CrestronConsole.ConsoleCommandResponse("  {0}{1}", tl, CrestronEnvironment.NewLine);
-            },
-            "listtielines", "Prints out all tie lines", ConsoleAccessLevelEnum.AccessOperator);
+            CrestronConsole.AddNewConsoleCommand(ListTieLines,
+            "listtielines", "Prints out all tie lines. Usage: listtielines [signaltype]", ConsoleAccessLevelEnum.AccessOperator);
+
+            CrestronConsole.AddNewConsoleCommand(VisualizeRoutes, "visualizeroutes",
+                "Visualizes routes by signal type",
+                ConsoleAccessLevelEnum.AccessOperator);
+
+            CrestronConsole.AddNewConsoleCommand(VisualizeCurrentRoutes, "visualizecurrentroutes",
+                "Visualizes current active routes from DefaultCollection",
+                ConsoleAccessLevelEnum.AccessOperator);
 
             CrestronConsole.AddNewConsoleCommand(s =>
             {
@@ -443,6 +448,282 @@ namespace PepperDash.Essentials
 
             Debug.LogMessage(LogEventLevel.Information, "All Tie Lines Loaded.");
 
+            Extensions.MapDestinationsToSources();
+
+            Debug.LogMessage(LogEventLevel.Information, "All Routes Mapped.");
+        }
+
+
+
+        /// <summary>
+        /// Visualizes routes in a tree format for better understanding of signal paths
+        /// </summary>
+        private void ListTieLines(string args)
+        {
+            try
+            {
+                if (args.Contains("?"))
+                {
+                    CrestronConsole.ConsoleCommandResponse("Usage: listtielines [signaltype]\r\n");
+                    CrestronConsole.ConsoleCommandResponse("Signal types: Audio, Video, SecondaryAudio, AudioVideo, UsbInput, UsbOutput\r\n");
+                    return;
+                }
+
+                eRoutingSignalType? signalTypeFilter = null;
+                if (!string.IsNullOrEmpty(args))
+                {
+                    eRoutingSignalType parsedType;
+                    if (Enum.TryParse(args.Trim(), true, out parsedType))
+                    {
+                        signalTypeFilter = parsedType;
+                    }
+                    else
+                    {
+                        CrestronConsole.ConsoleCommandResponse("Invalid signal type: {0}\r\n", args.Trim());
+                        CrestronConsole.ConsoleCommandResponse("Valid types: Audio, Video, SecondaryAudio, AudioVideo, UsbInput, UsbOutput\r\n");
+                        return;
+                    }
+                }
+
+                var tielines = signalTypeFilter.HasValue
+                    ? TieLineCollection.Default.Where(tl => tl.Type.HasFlag(signalTypeFilter.Value))
+                    : TieLineCollection.Default;
+
+                var count = 0;
+                foreach (var tl in tielines)
+                {
+                    CrestronConsole.ConsoleCommandResponse("  {0}{1}", tl, CrestronEnvironment.NewLine);
+                    count++;
+                }
+
+                CrestronConsole.ConsoleCommandResponse("\r\nTotal: {0} tieline{1}{2}", count, count == 1 ? "" : "s", CrestronEnvironment.NewLine);
+            }
+            catch (Exception ex)
+            {
+                CrestronConsole.ConsoleCommandResponse("Error listing tielines: {0}\r\n", ex.Message);
+            }
+        }
+
+        private void VisualizeRoutes(string args)
+        {
+            try
+            {
+                if (args.Contains("?"))
+                {
+                    CrestronConsole.ConsoleCommandResponse("Usage: visualizeroutes [signaltype] [-s source] [-d destination]\r\n");
+                    CrestronConsole.ConsoleCommandResponse("  signaltype: Audio, Video, AudioVideo, etc.\r\n");
+                    CrestronConsole.ConsoleCommandResponse("  -s: Filter by source key (partial match)\r\n");
+                    CrestronConsole.ConsoleCommandResponse("  -d: Filter by destination key (partial match)\r\n");
+                    return;
+                }
+
+                ParseRouteFilters(args, out eRoutingSignalType? signalTypeFilter, out string sourceFilter, out string destFilter);
+
+                CrestronConsole.ConsoleCommandResponse("\r\n+===========================================================================+\r\n");
+                CrestronConsole.ConsoleCommandResponse("|                         ROUTE VISUALIZATION                               |\r\n");
+                CrestronConsole.ConsoleCommandResponse("+===========================================================================+\r\n\r\n");
+
+                foreach (var descriptorCollection in Extensions.RouteDescriptors.Where(kv => kv.Value.Descriptors.Count() > 0))
+                {
+                    // Filter by signal type if specified
+                    if (signalTypeFilter.HasValue && descriptorCollection.Key != signalTypeFilter.Value)
+                        continue;
+
+                    CrestronConsole.ConsoleCommandResponse("\r\n+--- Signal Type: {0} ({1} routes) ---\r\n",
+                        descriptorCollection.Key,
+                        descriptorCollection.Value.Descriptors.Count());
+
+                    foreach (var descriptor in descriptorCollection.Value.Descriptors)
+                    {
+                        // Filter by source/dest if specified
+                        if (sourceFilter != null && !descriptor.Source.Key.ToLower().Contains(sourceFilter))
+                            continue;
+                        if (destFilter != null && !descriptor.Destination.Key.ToLower().Contains(destFilter))
+                            continue;
+
+                        VisualizeRouteDescriptor(descriptor);
+                    }
+                }
+
+                CrestronConsole.ConsoleCommandResponse("\r\n");
+            }
+            catch (Exception ex)
+            {
+                CrestronConsole.ConsoleCommandResponse("Error visualizing routes: {0}\r\n", ex.Message);
+            }
+        }
+
+        private void VisualizeCurrentRoutes(string args)
+        {
+            try
+            {
+                if (args.Contains("?"))
+                {
+                    CrestronConsole.ConsoleCommandResponse("Usage: visualizecurrentroutes [signaltype] [-s source] [-d destination]\r\n");
+                    CrestronConsole.ConsoleCommandResponse("  signaltype: Audio, Video, AudioVideo, etc.\r\n");
+                    CrestronConsole.ConsoleCommandResponse("  -s: Filter by source key (partial match)\r\n");
+                    CrestronConsole.ConsoleCommandResponse("  -d: Filter by destination key (partial match)\r\n");
+                    return;
+                }
+
+                ParseRouteFilters(args, out eRoutingSignalType? signalTypeFilter, out string sourceFilter, out string destFilter);
+
+                CrestronConsole.ConsoleCommandResponse("\r\n+===========================================================================+\r\n");
+                CrestronConsole.ConsoleCommandResponse("|                    CURRENT ROUTES VISUALIZATION                            |\r\n");
+                CrestronConsole.ConsoleCommandResponse("+===========================================================================+\r\n\r\n");
+
+                var hasRoutes = false;
+
+                // Get all descriptors from DefaultCollection
+                var allDescriptors = RouteDescriptorCollection.DefaultCollection.Descriptors;
+
+                // Group by signal type
+                var groupedByType = allDescriptors.GroupBy(d => d.SignalType);
+
+                foreach (var group in groupedByType)
+                {
+                    var signalType = group.Key;
+
+                    // Filter by signal type if specified
+                    if (signalTypeFilter.HasValue && signalType != signalTypeFilter.Value)
+                        continue;
+
+                    var filteredDescriptors = group.Where(d =>
+                    {
+                        if (sourceFilter != null && !d.Source.Key.ToLower().Contains(sourceFilter))
+                            return false;
+                        if (destFilter != null && !d.Destination.Key.ToLower().Contains(destFilter))
+                            return false;
+                        return true;
+                    }).ToList();
+
+                    if (filteredDescriptors.Count == 0)
+                        continue;
+
+                    hasRoutes = true;
+                    CrestronConsole.ConsoleCommandResponse("\r\n+--- Signal Type: {0} ({1} routes) ---\r\n",
+                        signalType,
+                        filteredDescriptors.Count);
+
+                    foreach (var descriptor in filteredDescriptors)
+                    {
+                        VisualizeRouteDescriptor(descriptor);
+                    }
+                }
+
+                if (!hasRoutes)
+                {
+                    CrestronConsole.ConsoleCommandResponse("\r\nNo active routes found in current state.\r\n");
+                }
+
+                CrestronConsole.ConsoleCommandResponse("\r\n");
+            }
+            catch (Exception ex)
+            {
+                CrestronConsole.ConsoleCommandResponse("Error visualizing current state: {0}\r\n", ex.Message);
+            }
+        }
+
+        /// <summary>
+        /// Parses route filter arguments from command line
+        /// </summary>
+        /// <param name="args">Command line arguments</param>
+        /// <param name="signalTypeFilter">Parsed signal type filter (if any)</param>
+        /// <param name="sourceFilter">Parsed source filter (if any)</param>
+        /// <param name="destFilter">Parsed destination filter (if any)</param>
+        private void ParseRouteFilters(string args, out eRoutingSignalType? signalTypeFilter, out string sourceFilter, out string destFilter)
+        {
+            signalTypeFilter = null;
+            sourceFilter = null;
+            destFilter = null;
+
+            if (string.IsNullOrEmpty(args))
+                return;
+
+            var parts = args.Split(new[] { ' ' }, StringSplitOptions.RemoveEmptyEntries);
+
+            for (int i = 0; i < parts.Length; i++)
+            {
+                var part = parts[i];
+
+                // Check for flags
+                if (part == "-s" && i + 1 < parts.Length)
+                {
+                    sourceFilter = parts[++i].ToLower();
+                }
+                else if (part == "-d" && i + 1 < parts.Length)
+                {
+                    destFilter = parts[++i].ToLower();
+                }
+                // Try to parse as signal type if not a flag and no signal type set yet
+                else if (!part.StartsWith("-") && !signalTypeFilter.HasValue)
+                {
+                    if (Enum.TryParse(part, true, out eRoutingSignalType parsedType))
+                    {
+                        signalTypeFilter = parsedType;
+                    }
+                }
+            }
+        }
+
+        /// <summary>
+        /// Visualizes a single route descriptor in a tree format
+        /// </summary>
+        private void VisualizeRouteDescriptor(RouteDescriptor descriptor)
+        {
+            CrestronConsole.ConsoleCommandResponse("|\r\n");
+            CrestronConsole.ConsoleCommandResponse("|-- {0} --> {1}\r\n",
+                descriptor.Source.Key,
+                descriptor.Destination.Key);
+
+            if (descriptor.Routes == null || descriptor.Routes.Count == 0)
+            {
+                CrestronConsole.ConsoleCommandResponse("|   +-- (No switching steps)\r\n");
+                return;
+            }
+
+            for (int i = 0; i < descriptor.Routes.Count; i++)
+            {
+                var route = descriptor.Routes[i];
+                var isLast = i == descriptor.Routes.Count - 1;
+                var prefix = isLast ? "+" : "|";
+                var continuation = isLast ? " " : "|";
+
+                if (route.SwitchingDevice != null)
+                {
+                    CrestronConsole.ConsoleCommandResponse("|   {0}-- [{1}] {2}\r\n",
+                        prefix,
+                        route.SwitchingDevice.Key,
+                        GetSwitchDescription(route));
+
+                    // Add visual connection line for non-last items
+                    if (!isLast)
+                        CrestronConsole.ConsoleCommandResponse("|   {0}      |\r\n", continuation);
+                }
+                else
+                {
+                    CrestronConsole.ConsoleCommandResponse("|   {0}-- {1}\r\n", prefix, route.ToString());
+                }
+            }
+        }
+
+        /// <summary>
+        /// Gets a readable description of the switching operation
+        /// </summary>
+        private string GetSwitchDescription(RouteSwitchDescriptor route)
+        {
+            if (route.OutputPort != null && route.InputPort != null)
+            {
+                return string.Format("{0} -> {1}", route.OutputPort.Key, route.InputPort.Key);
+            }
+            else if (route.InputPort != null)
+            {
+                return string.Format("-> {0}", route.InputPort.Key);
+            }
+            else
+            {
+                return "(passthrough)";
+            }
         }
 
         /// <summary>