From 3ba755d872986f5d8b31c1bcc90f8d9e02e29b0f Mon Sep 17 00:00:00 2001
From: Claudiu Farcas <claudiu.farcas@cgm.com>
Date: Tue, 20 Apr 2021 08:38:50 +0300
Subject: [PATCH] adapter sample pattern

---
 Program.cs                          |  6 ++-
 structural/adapter/AdapterSample.cs | 76 +++++++++++++++++++++++++++++
 2 files changed, 81 insertions(+), 1 deletion(-)
 create mode 100644 structural/adapter/AdapterSample.cs

diff --git a/Program.cs b/Program.cs
index df6fd59..1f4f950 100644
--- a/Program.cs
+++ b/Program.cs
@@ -7,6 +7,7 @@ using design_patterns.creational.factory;
 using design_patterns.creational.facadebuilder;
 using design_patterns.creational.singleton;
 using design_patterns.creational.prototype;
+using design_patterns.structural.adapter;
 
 namespace design_patterns
 {
@@ -23,7 +24,10 @@ namespace design_patterns
                 // await FunctionalBuilderSample.Run();
                 // await FacadeBuilderSample.Run();
                 // await SingletonSample.Run();
-                await PrototypeSample.Run();
+                // await PrototypeSample.Run();
+
+                // structural
+                await AdapterSample.Run();
             }
             catch (System.Exception ex)
             {
diff --git a/structural/adapter/AdapterSample.cs b/structural/adapter/AdapterSample.cs
new file mode 100644
index 0000000..f536f75
--- /dev/null
+++ b/structural/adapter/AdapterSample.cs
@@ -0,0 +1,76 @@
+using System;
+using System.Threading.Tasks;
+
+namespace design_patterns.structural.adapter
+{
+    /// <summary>
+    /// Adapter is a structural design pattern that 
+    /// allows objects with incompatible interfaces to collaborate.
+    /// 
+    /// This is a special object that converts the interface
+    /// of one object so that another object can understand it.
+    /// 
+    /// An adapter wraps one of the objects to hide the complexity 
+    /// of conversion happening behind the scenes. 
+    /// The wrapped object isn’t even aware of the adapter.
+    /// 
+    /// It’s very often used in systems based on some legacy code.
+    /// </summary>
+    public class AdapterSample
+    {
+        public static async Task Run()
+        {
+            Console.WriteLine("Structural - Adapter");
+
+            var person = new Person {
+                ID = Guid.NewGuid().ToString(),
+                Name = "Test person"
+            };
+            ExternalService service = new ExternalService();
+
+            ExternalServiceAdapter adapter = new ExternalServiceAdapter();
+            var status = adapter.GetStatus(person, service);
+
+            Console.WriteLine($"Status of {status.ID} - {status.PersonStatus}");
+        }
+    }
+
+    // client DDD models - we don't want to modify their structure
+    // to match external system and inherit unwanted data and behavior
+    public class Person {
+        public string Name { get; set; }
+        public string ID { get; set; }
+    }
+    public class PersonInfo {
+        public string ID { get; set; }
+        public string PersonStatus { get; set; }
+    }
+
+    // defined inside client DDD core
+    // interface for adapting external service
+    public interface IExternalService {
+        PersonInfo GetStatus(Person person, ExternalService service);
+    }
+
+    // (legacy) external Service
+    public class ExternalService {
+        public string GetPersonStatus(string id) {
+            return $"Status OK";
+        }
+    }
+
+    // adapter implementation, we can have 
+    // multiple adapter implementations if needed
+    public class ExternalServiceAdapter : IExternalService
+    {
+        public PersonInfo GetStatus(Person person, ExternalService service)
+        {
+            return new PersonInfo {
+                ID = person.ID,
+                PersonStatus = service.GetPersonStatus(person.ID)
+            };
+        }
+    }
+
+
+}
\ No newline at end of file