Add local node help lookup as fallback for DNA

Author: johnpierson

src/DynamoCore/Models/DynamoModel.cs

@@ -2431,7 +2431,7 @@ private void SetPeriodicEvaluation(WorkspaceModel ws)
             }
         }
 
-        private bool OpenJsonFile(
+        internal bool OpenJsonFile(
           string filePath,
           string fileContents,
           DynamoPreferencesData dynamoPreferences,

src/DynamoUtilities/Properties/AssemblyInfo.cs

@@ -31,3 +31,4 @@
 [assembly: InternalsVisibleTo("LibraryViewExtensionWebView2")]
 [assembly: InternalsVisibleTo("Notifications")]
 [assembly: InternalsVisibleTo("SystemTestServices")]
+[assembly: InternalsVisibleTo("NodeAutoCompleteViewExtension")]

src/NodeAutoCompleteViewExtension/ViewModels/NodeAutoCompleteBarViewModel.cs

@@ -546,7 +546,8 @@ private IEnumerable<SingleResultItem> GetNodeAutocompleMLResults()
                 AutocompleteMLTitle = Resources.AutocompleteNoRecommendationsTitle;
                 AutocompleteMLMessage = Resources.AutocompleteNoRecommendationsMessage;
                 Analytics.TrackEvent(Actions.View, Categories.NodeAutoCompleteOperations, "NoRecommendation");
-                return new List<SingleResultItem>();
+
+                return TryGetLocalAutoCompleteResult();
             }
             ServiceVersion = MLresults.Version;
             var results = new List<SingleResultItem>();
@@ -619,6 +620,90 @@ private IEnumerable<SingleResultItem> GetNodeAutocompleMLResults()
 
             return results;
         }
+
+        /// <summary>
+        /// Use local node help files to at least return one result that will work.
+        /// </summary>
+        /// <returns></returns>
+        private List<SingleResultItem> TryGetLocalAutoCompleteResult()
+        {
+            var dynamoModel = this.dynamoViewModel.Model;
+
+            var nodeHelpDocPath = new DirectoryInfo(Path.Combine(new FileInfo(Assembly.GetExecutingAssembly().Location).DirectoryName,
+                Configurations.DynamoNodeHelpDocs));
+
+            var selectedNode = this.PortViewModel.NodeViewModel.NodeModel;
+            var selectedPortModel = this.PortViewModel.PortModel;
+
+            string nodeFullName;
+
+            switch (selectedNode)
+            {
+                case DSFunction dsFunction:
+                    string fullSignature = dsFunction.FunctionSignature;
+                    nodeFullName = fullSignature.Split('@')[0];
+                    break;
+                case Function function:
+                    string fullFunctionSignature = function.FunctionSignature.ToString();
+                    nodeFullName = fullFunctionSignature.Split('@')[0];
+                    break;
+                default:
+                    nodeFullName = selectedNode.GetType().ToString();
+                    break;
+            }
+
+            string sampleDynPath = Path.Combine(nodeHelpDocPath.FullName, $"{nodeFullName}.dyn");
+
+            if (!File.Exists(sampleDynPath))
+            {
+                var minimumQualifiedName = dynamoViewModel.GetMinimumQualifiedName(selectedNode);
+                var shortName = Hash.GetHashFilenameFromString(minimumQualifiedName);
+                sampleDynPath = Path.Combine(nodeHelpDocPath.FullName, $"{shortName}.dyn");
+            }
+
+            //no help file found, return nothing
+            if (!File.Exists(sampleDynPath))
+            {
+                return new List<SingleResultItem>();
+            }
+
+            Exception ex;
+            DynamoUtilities.PathHelper.isValidJson(sampleDynPath, out var fileContents, out ex);
+
+            //get the workspace model from the sample to lookup the node
+            var workspace = WorkspaceModel.FromJson(fileContents, dynamoModel.LibraryServices,
+                dynamoModel.EngineController, dynamoModel.Scheduler,
+                dynamoModel.NodeFactory, false, false,
+                dynamoModel.CustomNodeManager,
+                dynamoModel.LinterManager);
+
+            var matchingNode = workspace.Nodes
+                .FirstOrDefault(n => n.CreationName == selectedNode.CreationName);
+
+            //no matching node found, return nothing
+            if (matchingNode is null) return new List<SingleResultItem>();
+            
+            //find the port model and the node to place
+            NodeModel predictedNode = null;
+            PortModel matchingPortModel = null;
+            switch (selectedPortModel.PortType)
+            {
+                case PortType.Input:
+                    matchingPortModel = matchingNode.InPorts[selectedPortModel.Index];
+                    predictedNode = matchingPortModel.Connectors.First().Start.Owner;
+                    break;
+                case PortType.Output:
+                    matchingPortModel = matchingNode.OutPorts[selectedPortModel.Index];
+                    predictedNode = matchingPortModel.Connectors.First().End.Owner;
+                    break;
+            }
+
+            if (predictedNode is null) return new List<SingleResultItem>();
+
+            SingleResultItem singleResultItem = new SingleResultItem(predictedNode, matchingPortModel.Index);
+            return [singleResultItem];
+        }
+
         private T GetGenericAutocompleteResult<T>(string endpoint)
         {   
             var requestDTO = GenerateRequestForMLAutocomplete();

src/NodeAutoCompleteViewExtension/ViewModels/SingleResultItem.cs

@@ -1,3 +1,4 @@
+using Dynamo.Graph.Nodes;
 using Dynamo.Search.SearchElements;
 using Dynamo.Wpf.ViewModels;
 
@@ -17,6 +18,16 @@ public SingleResultItem(NodeSearchElement model, double score = 1.0)
             Score = score;
         }
 
+        public SingleResultItem(NodeModel nodeModel, int portToConnect, double score = 1.0)
+        {
+            Assembly = nodeModel.GetType().Assembly.GetName().Name;
+            IconName = nodeModel.GetType().Name;
+            Description = nodeModel.Name;
+            CreationName = nodeModel.CreationName;
+            PortToConnect = portToConnect;
+            Score = score;
+        }
+
         public SingleResultItem(NodeSearchElementViewModel x) : this(x.Model)
         {
             //Convert percent to probability