Added optimization in the execution context not it is handler driven approach, event driven approach added

Examples/Nodify.Calculator/Execution/Handlers/NodeHandlers.cs

@@ -0,0 +1,373 @@
+using System;
+using System.Collections.Generic;
+using System.IO;
+using System.Linq;
+using Newtonsoft.Json;
+using Newtonsoft.Json.Linq;
+
+namespace Nodify.Calculator.Execution.Handlers
+{
+    // ─────────────────────────────────────────────────────────────────────────────
+    // Sentinel / trivial handlers
+    // ─────────────────────────────────────────────────────────────────────────────
+
+    /// <summary>Skips Begin/End sentinel nodes. </summary>
+    internal sealed class BeginEndHandler : INodeExecutionHandler
+    {
+        public bool CanHandle(OperationViewModel node, ExecutionContext ctx)
+            => string.Equals(node.Title, "begin", StringComparison.OrdinalIgnoreCase)
+            || string.Equals(node.Title, "end", StringComparison.OrdinalIgnoreCase);
+
+        public void Execute(OperationViewModel node, ExecutionContext ctx)
+            => ctx.Log("Begin or End node found. skipping it");
+    }
+
+    /// <summary>Auth node: configuration is resolved before execution, so this is a no-op log.</summary>
+    internal sealed class AuthHandler : INodeExecutionHandler
+    {
+        public bool CanHandle(OperationViewModel node, ExecutionContext ctx)
+            => node is AuthOperationViewModel
+            || string.Equals(node.Title, "auth", StringComparison.OrdinalIgnoreCase);
+
+        public void Execute(OperationViewModel node, ExecutionContext ctx)
+            => ctx.Log($"Auth node reached: {node.Title}");
+    }
+
+    /// <summary>Knot/Reroute: forwards the single data input to the node's output.</summary>
+    internal sealed class KnotHandler : INodeExecutionHandler
+    {
+        public bool CanHandle(OperationViewModel node, ExecutionContext ctx)
+            => node is KnotOperationViewModel;
+
+        public void Execute(OperationViewModel node, ExecutionContext ctx)
+        {
+            var inputCon = ctx.Connections.FirstOrDefault(
+                c => c.Input.Operation == node && c.Input.Shape != ConnectorShape.Triangle);
+            if (inputCon?.Output?.Operation?.NodeId is string srcId
+                && ctx.Outputs.TryGetValue(srcId, out var srcVal))
+            {
+                ctx.Outputs[node.NodeId] = srcVal;
+            }
+        }
+    }
+
+    // ─────────────────────────────────────────────────────────────────────────────
+    // System-op handlers
+    // ─────────────────────────────────────────────────────────────────────────────
+
+    internal sealed class DebugHandler : INodeExecutionHandler
+    {
+        public bool CanHandle(OperationViewModel node, ExecutionContext ctx)
+            => node is SystemOperationViewModel sys && sys.SystemOperationType == SystemOperations.DEBUG;
+
+        public void Execute(OperationViewModel node, ExecutionContext ctx)
+        {
+            var input = node.Input.FirstOrDefault(i => i.Shape != ConnectorShape.Triangle);
+            var hasConnection = input != null && ctx.Connections.Any(c => c.Input == input);
+            var val = ctx.ReadInput(input);
+
+            if (!hasConnection)
+                ctx.Log("[DEBUG] No input connected", logType.Warning);
+            else if (val != null)
+                ctx.Log($"[DEBUG] {val}");
+            else
+                ctx.Log("[DEBUG] (no value)", logType.Warning);
+        }
+    }
+
+    internal sealed class NewObjectHandler : INodeExecutionHandler
+    {
+        public bool CanHandle(OperationViewModel node, ExecutionContext ctx)
+            => node is SystemOperationViewModel sys && sys.SystemOperationType == SystemOperations.NEW_OBJECT;
+
+        public void Execute(OperationViewModel node, ExecutionContext ctx)
+        {
+            ctx.Log($"Constructing new object: {node.Title}");
+            var jObj = new JObject();
+
+            foreach (var inp in node.Input)
+            {
+                if (inp.Shape == ConnectorShape.Triangle || inp.Shape == ConnectorShape.Square) continue;
+
+                var propName = inp.Title ?? "";
+                var parenIdx = propName.IndexOf(" (", StringComparison.Ordinal);
+                if (parenIdx > 0) propName = propName.Substring(0, parenIdx);
+
+                var val = ctx.ReadInput(inp);
+                if (val != null)
+                {
+                    try { jObj[propName] = JToken.Parse(val); }
+                    catch { jObj[propName] = val; }
+                }
+                else
+                {
+                    jObj[propName] = null;
+                }
+            }
+
+            var json = jObj.ToString(Formatting.None);
+            ctx.Outputs[node.NodeId] = json;
+            ctx.Variables[node.NodeId] = json;
+            ctx.Log($"Object constructed: {json}");
+        }
+    }
+
+    internal sealed class AssertHandler : INodeExecutionHandler
+    {
+        public bool CanHandle(OperationViewModel node, ExecutionContext ctx)
+            => node is AssertOperationViewModel;
+
+        public void Execute(OperationViewModel node, ExecutionContext ctx)
+        {
+            ctx.Log($"[ASSERT] Evaluating assertion: {node.Title}");
+            string actualVal = "", expectedVal = "";
+
+            foreach (var inp in node.Input)
+            {
+                if (inp.Shape == ConnectorShape.Triangle) continue;
+                var title = inp.Title?.Trim() ?? "";
+                var val = ctx.ReadInput(inp) ?? "";
+
+                if (title.StartsWith("Actual", StringComparison.OrdinalIgnoreCase)) actualVal = val;
+                else if (title.StartsWith("Expected", StringComparison.OrdinalIgnoreCase)) expectedVal = val;
+            }
+
+            var passed = string.Equals(actualVal.Trim(), expectedVal.Trim(), StringComparison.OrdinalIgnoreCase);
+            ctx.Outputs[node.NodeId] = passed.ToString();
+
+            if (passed)
+                ctx.Log($"[ASSERT] ✅ PASSED — Actual: \"{actualVal}\" == Expected: \"{expectedVal}\"");
+            else
+                ctx.Log($"[ASSERT] ❌ FAILED — Actual: \"{actualVal}\" != Expected: \"{expectedVal}\"", logType.Error);
+        }
+    }
+
+    internal sealed class ForEachHandler : INodeExecutionHandler
+    {
+        public bool CanHandle(OperationViewModel node, ExecutionContext ctx)
+            => node is ForEachOperationViewModel;
+
+        public void Execute(OperationViewModel node, ExecutionContext ctx)
+        {
+            ctx.Log($"[FOREACH] Starting loop: {node.Title}");
+
+            var listInput = node.Input.FirstOrDefault(i => i.Shape != ConnectorShape.Triangle);
+            var listJson = ctx.ReadInput(listInput) ?? "";
+            if (string.IsNullOrEmpty(listJson))
+            {
+                ctx.Log("[FOREACH] No list data found. Skipping loop.", logType.Warning);
+                return;
+            }
+
+            JArray array;
+            try
+            {
+                var token = JToken.Parse(listJson);
+                if (token is JArray arr) array = arr;
+                else
+                {
+                    ctx.Log("[FOREACH] Input is not an array. Wrapping as single-element array.", logType.Warning);
+                    array = new JArray(token);
+                }
+            }
+            catch
+            {
+                ctx.Log("[FOREACH] Failed to parse input as JSON array.", logType.Error);
+                return;
+            }
+
+            var loopBodyOutput = node.Output.FirstOrDefault(o => o.Title == "Loop Body");
+            var currentItemOutput = node.Output.FirstOrDefault(o => o.Title == "Current Item");
+            var indexOutput = node.Output.FirstOrDefault(o => o.Title == "Index");
+            var loopBodyConnection = loopBodyOutput != null
+                ? ctx.Connections.FirstOrDefault(c => c.Output == loopBodyOutput)
+                : null;
+
+            ctx.Log($"[FOREACH] Iterating over {array.Count} items...");
+            for (int i = 0; i < array.Count; i++)
+            {
+                var itemStr = array[i].ToString(Formatting.None);
+                var preview = itemStr.Length > 80 ? itemStr.Substring(0, 80) + "..." : itemStr;
+                ctx.Log($"[FOREACH] Iteration {i}: {preview}");
+
+                ctx.Outputs[node.NodeId] = itemStr;
+                if (currentItemOutput != null)
+                    currentItemOutput.Value = double.TryParse(itemStr, out var dv) ? dv : 0;
+                if (indexOutput != null)
+                    indexOutput.Value = i;
+
+                var bodyNode = loopBodyConnection?.Input?.Operation;
+                if (bodyNode != null)
+                    ctx.Executor.TraverseChainPublic(bodyNode, "end", ctx.Connections, new HashSet<string>(), true);
+            }
+            ctx.Log($"[FOREACH] Loop completed. {array.Count} iterations executed.");
+        }
+    }
+
+    internal sealed class FunctionHandler : INodeExecutionHandler
+    {
+        public bool CanHandle(OperationViewModel node, ExecutionContext ctx)
+            => node is FunctionOperationViewModel;
+
+        public void Execute(OperationViewModel node, ExecutionContext ctx)
+        {
+            var funcOp = (FunctionOperationViewModel)node;
+            ctx.Log($"Executing function: {funcOp.FunctionName}");
+            ctx.Executor.ExecuteFunctionPublic(funcOp, ctx.Connections);
+        }
+    }
+
+    // ─────────────────────────────────────────────────────────────────────────────
+    // Title-matched handlers (legacy string-based behavior preserved)
+    // ─────────────────────────────────────────────────────────────────────────────
+
+    internal sealed class CreateModelHandler : INodeExecutionHandler
+    {
+        public bool CanHandle(OperationViewModel node, ExecutionContext ctx)
+            => node.Title != null
+            && node.Title.IndexOf("create model", StringComparison.OrdinalIgnoreCase) >= 0;
+
+        public void Execute(OperationViewModel node, ExecutionContext ctx)
+        {
+            var url = node.Title ?? "";
+            var conByTitle = ctx.Connections
+                .Where(c => c.Input.Operation.Title != null
+                            && c.Input.Operation.Title.IndexOf("create model", StringComparison.OrdinalIgnoreCase) >= 0)
+                .ToList();
+            var flowConnection = conByTitle.FirstOrDefault(c => c.Input.Shape != ConnectorShape.Triangle);
+            if (flowConnection == null)
+            {
+                ctx.Log("No input found", logType.Error);
+                throw new Exception("Input connection missig for : " + url);
+            }
+
+            if (!ctx.Outputs.TryGetValue(flowConnection.InputNodeId, out var outputValue))
+                return;
+
+            var customModelDir = Path.Combine(ProjectManager.ProjectDirectory, "CustomModels");
+            Directory.CreateDirectory(customModelDir);
+            const string className = "Class1";
+            var classStruct = Executor.GenerateClassFromJson(outputValue, className);
+            File.WriteAllText(Path.Combine(customModelDir, $"{className}.cs"), classStruct);
+
+            ctx.Executor.AddNewModelPublic(new OperationInfoViewModel
+            {
+                Title = className,
+                IsModelNode = true,
+                Type = OperationType.System,
+                sysOp = SystemOperations.GET_SET,
+                ClassName = className,
+            });
+        }
+    }
+
+    /// <summary>
+    /// Handles SET nodes — both "SET myVar (type)" simple variables and
+    /// legacy "SET ClassName" parse-JSON variants.
+    /// </summary>
+    internal sealed class SetHandler : INodeExecutionHandler
+    {
+        public bool CanHandle(OperationViewModel node, ExecutionContext ctx)
+            => node.Title != null
+            && node.Title.IndexOf("set", StringComparison.OrdinalIgnoreCase) >= 0;
+
+        public void Execute(OperationViewModel node, ExecutionContext ctx)
+        {
+            var url = node.Title ?? "";
+
+            // Simple variable SET: "SET myVar (string)"
+            if (node is SystemOperationViewModel && url.Contains("(") && url.Contains(")"))
+            {
+                var parts = url.Split(new[] { ' ' }, StringSplitOptions.RemoveEmptyEntries);
+                if (parts.Length < 2) return;
+                var varName = parts[1];
+
+                var sourceConn = ctx.Connections.FirstOrDefault(
+                    c => c.Input.Operation == node && c.Input.Shape != ConnectorShape.Triangle);
+                if (sourceConn != null)
+                {
+                    var sourceNodeId = sourceConn.Output.Operation.NodeId;
+                    if (ctx.Outputs.TryGetValue(sourceNodeId, out var sourceVal))
+                    {
+                        ctx.Variables[varName] = sourceVal;
+                        ctx.Log($"Variable '{varName}' SET to: {sourceVal}");
+                    }
+                    else
+                    {
+                        ctx.Variables[varName] = sourceConn.Output.Value.ToString();
+                        ctx.Log($"Variable '{varName}' SET to connector value: {sourceConn.Output.Value}");
+                    }
+                }
+                else
+                {
+                    var valueInput = node.Input.FirstOrDefault(i => i.Title == "Value");
+                    if (valueInput != null)
+                    {
+                        ctx.Variables[varName] = valueInput.Value.ToString();
+                        ctx.Log($"Variable '{varName}' SET to default: {valueInput.Value}");
+                    }
+                }
+                ctx.Outputs[node.NodeId] = ctx.Variables.TryGetValue(varName, out var v)
+                    ? v?.ToString() ?? "" : "";
+                return;
+            }
+
+            // Legacy "SET ClassName" parse-json variant
+            var inputConnection = ctx.Connections.FirstOrDefault(
+                c => c.Input.Operation.Title == url && c.Input.Shape != ConnectorShape.Triangle);
+            if (inputConnection == null)
+            {
+                ctx.Log("No input found", logType.Error);
+                throw new Exception("Input connection missig for : " + url);
+            }
+            var outPutNode = inputConnection.Output
+                ?? throw new Exception("Output connection missig for : " + url);
+
+            if (outPutNode.Operation.Title?.IndexOf("parse json", StringComparison.OrdinalIgnoreCase) >= 0)
+            {
+                var inputNodeForParseJson = ctx.Connections.FirstOrDefault(c => c.Input.Operation.Title == outPutNode.Title);
+                if (inputNodeForParseJson == null)
+                {
+                    ctx.Log("No input found", logType.Error);
+                    throw new Exception("Input connection missig for : " + url);
+                }
+                if (ctx.Outputs.TryGetValue(inputNodeForParseJson.InputNodeId, out var inputNodeOutput)
+                    && inputNodeOutput != null)
+                {
+                    ctx.Variables[node.NodeId] = JsonConvert.DeserializeObject(inputNodeOutput);
+                }
+            }
+        }
+    }
+
+    // ─────────────────────────────────────────────────────────────────────────────
+    // Default / fallback: API call
+    // ─────────────────────────────────────────────────────────────────────────────
+
+    internal sealed class ApiRequestHandler : INodeExecutionHandler
+    {
+        public bool CanHandle(OperationViewModel node, ExecutionContext ctx) => true; // final fallback
+
+        public void Execute(OperationViewModel node, ExecutionContext ctx)
+        {
+            var url = node.Title ?? "";
+            ctx.Log($"Starting Execution : {url}");
+
+            var httpMethod = (node is APIOperationViewModel apiVm)
+                ? apiVm.OperationType?.ToLower() ?? "get"
+                : "get";
+
+            var res = ctx.Executor.GetResponsePublic(url, httpMethod);
+            if (!string.IsNullOrEmpty(res))
+            {
+                ctx.Outputs[node.NodeId] = res;
+                if (node is APIOperationViewModel apiOp && !string.IsNullOrEmpty(apiOp.ResponseModelClassName))
+                {
+                    ctx.Variables[node.NodeId] = res;
+                    ctx.Log($"Response auto-parsed as {apiOp.ResponseModelClassName}");
+                }
+            }
+            ctx.Log($"Response Result : {res}");
+        }
+    }
+}