rule-engine part first example fixed.

Behavioral/ChainOfResponsibility/RuleEngine/Abstraction/RequestHandler.cs

@@ -0,0 +1,27 @@
+using Thisisnabi.DesignPattern.Behavioral.ChainOfResponsibility.RuleEngine.Interface;
+using Thisisnabi.DesignPattern.Behavioral.ChainOfResponsibility.RuleEngine.Model;
+
+namespace Thisisnabi.DesignPattern.Behavioral.ChainOfResponsibility.RuleEngine.Abstraction
+{
+    public abstract class RequestHandler : IRequestHandler
+    {
+        private IRequestHandler _nextHandler;
+
+        public void SetNextHandler(IRequestHandler handler)
+        {
+            _nextHandler = handler;
+        }
+
+        public void HandleRequest(Request request)
+        {
+            ProcessRequest(request);
+
+            if (_nextHandler != null)
+            {
+                _nextHandler.HandleRequest(request);
+            }
+        }
+
+        protected abstract void ProcessRequest(Request request);
+    }
+}

Behavioral/ChainOfResponsibility/RuleEngine/Interface/IRequestHandler.cs

@@ -0,0 +1,10 @@
+using Thisisnabi.DesignPattern.Behavioral.ChainOfResponsibility.RuleEngine.Model;
+
+namespace Thisisnabi.DesignPattern.Behavioral.ChainOfResponsibility.RuleEngine.Interface
+{
+    public interface IRequestHandler
+    {
+        void SetNextHandler(IRequestHandler handler);
+        void HandleRequest(Request request);
+    }
+}

Behavioral/ChainOfResponsibility/RuleEngine/Model/Request.cs

@@ -0,0 +1,16 @@
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using System.Text;
+using System.Threading.Tasks;
+
+namespace Thisisnabi.DesignPattern.Behavioral.ChainOfResponsibility.RuleEngine.Model
+{
+    public class Request
+    {
+        public string Username { get; set; }
+        public string Password { get; set; }
+
+        // Other  properties
+    }
+}

Behavioral/ChainOfResponsibility/RuleEngine/Program.cs

@@ -1,2 +1,26 @@
-// See https://aka.ms/new-console-template for more information
-Console.WriteLine("Hello, World!");
+
+using Thisisnabi.DesignPattern.Behavioral.ChainOfResponsibility.RuleEngine.Model;
+using Thisisnabi.DesignPattern.Behavioral.ChainOfResponsibility.RuleEngine.Providers;
+
+
+// Create the request handlers
+var validationHandler = new ValidationHandler();
+var authenticationHandler = new AuthenticationHandler();
+var authorizationHandler = new AuthorizationHandler();
+
+
+
+// Set the chain of responsibility
+validationHandler.SetNextHandler(authenticationHandler);
+authenticationHandler.SetNextHandler(authorizationHandler);
+
+
+// Create a request
+var request = new Request { Username = "hwpro"  , Password = "123"};
+
+
+// Process the request
+validationHandler.HandleRequest(request);
+
+
+Console.ReadLine();

Behavioral/ChainOfResponsibility/RuleEngine/Providers/AuthenticationHandler.cs

@@ -0,0 +1,14 @@
+using Thisisnabi.DesignPattern.Behavioral.ChainOfResponsibility.RuleEngine.Abstraction;
+using Thisisnabi.DesignPattern.Behavioral.ChainOfResponsibility.RuleEngine.Model;
+
+namespace Thisisnabi.DesignPattern.Behavioral.ChainOfResponsibility.RuleEngine.Providers
+{
+    public class AuthenticationHandler : RequestHandler
+    {
+        protected override void ProcessRequest(Request request)
+        {
+            Console.WriteLine("Authentication handler processing request");
+            // Perform authentication logic
+        }
+    }
+}

Behavioral/ChainOfResponsibility/RuleEngine/Providers/AuthorizationHandler.cs

@@ -0,0 +1,15 @@
+using Thisisnabi.DesignPattern.Behavioral.ChainOfResponsibility.RuleEngine.Abstraction;
+using Thisisnabi.DesignPattern.Behavioral.ChainOfResponsibility.RuleEngine.Model;
+
+namespace Thisisnabi.DesignPattern.Behavioral.ChainOfResponsibility.RuleEngine.Providers
+{
+    public class AuthorizationHandler : RequestHandler
+    {
+        protected override void ProcessRequest(Request request)
+        {
+            Console.WriteLine("Authorization handler processing request");
+            // Perform authorization logic
+        }
+
+    }
+}

Behavioral/ChainOfResponsibility/RuleEngine/Providers/ValidationHandler.cs

@@ -0,0 +1,14 @@
+using Thisisnabi.DesignPattern.Behavioral.ChainOfResponsibility.RuleEngine.Abstraction;
+using Thisisnabi.DesignPattern.Behavioral.ChainOfResponsibility.RuleEngine.Model;
+
+namespace Thisisnabi.DesignPattern.Behavioral.ChainOfResponsibility.RuleEngine.Providers
+{
+    public class ValidationHandler : RequestHandler
+    {
+        protected override void ProcessRequest(Request request)
+        {
+            Console.WriteLine("Validation handler processing request");
+            // Perform validation logic
+        }
+    }
+}