facade design pattern

Program.cs

@@ -11,6 +11,7 @@ using design_patterns.structural.adapter;
 using design_patterns.structural.bridge;
 using design_patterns.structural.composite;
 using design_patterns.structural.decorator;
+using design_patterns.structural.facade;
 
 namespace design_patterns
 {
@@ -33,7 +34,8 @@ namespace design_patterns
                 // await AdapterSample.Run();
                 // await BridgeSample.Run();
                 // await CompositeSample.Run();
-                await DecoratorSample.Run();
+                // await DecoratorSample.Run();
+                await FacadeSample.Run();
             }
             catch (System.Exception ex)
             {

structural/facade/FacadeSample.cs

@@ -0,0 +1,82 @@
+using System;
+using System.Threading.Tasks;
+
+namespace design_patterns.structural.facade
+{
+    /// <summary>
+    /// Facade is a structural design pattern that provides 
+    /// a simplified interface to a library, a framework, 
+    /// or any other complex set of classes.
+    /// 
+    /// - exposing several components through a single interface
+    /// - hide inner complexity
+    /// </summary>
+    public class FacadeSample
+    {
+        public static async Task Run()
+        {
+            Console.WriteLine("Structural - Facade");
+
+            var service = new ProcessingService();
+            var result = service.ProcessData("start data");
+            System.Console.WriteLine(result);
+        }
+    }
+
+    /// <summary>
+    /// expose simple interface 
+    /// hiding inside complexity
+    /// </summary>
+    public interface IProcessingService
+    {
+        string ProcessData(string input);
+    }
+
+    public class ProcessingService : IProcessingService
+    {
+        private Component1 c1 = new();
+        private Component2 c2 = new(); 
+        private Component3 c3 = new();
+        public string ProcessData(string input)
+        {
+            c1.LogInfo(input);
+            var handler = c2.StartSubsystem(input);
+            var res1 = c2.GetSubsystemData(handler);
+            c1.LogInfo(res1);
+            var res2 = c3.FilterInfo(res1);
+            c1.LogInfo(res2);
+            return res2;
+        }
+
+        public class Component1
+        {
+            internal void LogInfo(string input)
+            {
+                System.Console.WriteLine($"Logging: {input}");
+            }
+        }
+
+        public class Component2
+        {
+            Guid handler;
+            internal string GetSubsystemData(Guid handler)
+            {
+                return $"{handler}_{Guid.NewGuid()}";
+            }
+
+            internal Guid StartSubsystem(string input)
+            {
+                handler = Guid.NewGuid();
+                return handler;
+            }
+        }
+
+        public class Component3
+        {
+            internal string FilterInfo(string res1)
+            {
+                return $"{res1} with filters";
+            }
+        }
+    }
+}