Add Factory Method Pattern

Author: akazad13

DesignPatterns/A - Creational Patterns/FactoryMethod/BurgerFactoryMethod.cs

@@ -0,0 +1,75 @@
+namespace FactoryMethod
+{
+    /// <summary>
+    /// Product
+    /// </summary>
+    public abstract class Burger
+    {
+        public int ProductId { get; set; }
+
+        public abstract void Prepare();
+    }
+
+    /// <summary>
+    /// Concreate Product A
+    /// </summary>
+    public class BeefBurger : Burger
+    {
+        public bool Angus { get; set; }
+
+        public override void Prepare()
+        {
+            Console.WriteLine("Preparing Beef Burger");
+        }
+    }
+
+    /// <summary>
+    /// Concreate Product B
+    /// </summary>
+    public class VeggieBurger : Burger
+    {
+        public bool Combo { get; set; }
+
+        public override void Prepare()
+        {
+            Console.WriteLine("Preparing Veggie Burger");
+        }
+    }
+
+    /// <summary>
+    /// Creator
+    /// </summary>
+    public abstract class Restaurant
+    {
+        public Burger OrderBurger()
+        {
+            Burger burger = CreateBurger();
+            burger.Prepare();
+            return burger;
+        }
+
+        public abstract Burger CreateBurger();
+    }
+
+    /// <summary>
+    /// Concreate Creator A
+    /// </summary>
+    public class BeefBurgerRestaurant : Restaurant
+    {
+        public override Burger CreateBurger()
+        {
+            return new BeefBurger();
+        }
+    }
+
+    /// <summary>
+    /// Concreate Creator B
+    /// </summary>
+    public class VeggieBurgerRestaurant : Restaurant
+    {
+        public override Burger CreateBurger()
+        {
+            return new VeggieBurger();
+        }
+    }
+}

DesignPatterns/A - Creational Patterns/FactoryMethod/DiscountFactoryMethod.cs

@@ -0,0 +1,87 @@
+namespace FactoryMethod
+{
+    public abstract class DiscountService
+    {
+        public abstract int DiscountPercentage { get; }
+
+        public override string ToString() => GetType().Name;
+    }
+
+    public class CountryDiscountService : DiscountService
+    {
+        private readonly string _countryIdentifier;
+
+        public CountryDiscountService(string countryIdentifier)
+        {
+            _countryIdentifier = countryIdentifier;
+        }
+
+        public override int DiscountPercentage
+        {
+            get
+            {
+                switch (_countryIdentifier)
+                {
+                    case "USA":
+                        return 10;
+                    case "UK":
+                        return 15;
+                    case "GER":
+                        return 20;
+                    default:
+                        return 0; // No discount for other countries
+                }
+            }
+        }
+    }
+
+    public class CodeDiscountService : DiscountService
+    {
+        private readonly Guid _code;
+
+        public CodeDiscountService(Guid code)
+        {
+            _code = code;
+        }
+
+        public override int DiscountPercentage
+        {
+            get => 10;
+        }
+    }
+
+    public abstract class DiscountFactory
+    {
+        public abstract DiscountService CreateDiscountService();
+    }
+
+    public class CountryDiscountFactory : DiscountFactory
+    {
+        public readonly string _countryIdentifier;
+
+        public CountryDiscountFactory(string countryIdentifier)
+        {
+            _countryIdentifier = countryIdentifier;
+        }
+
+        public override DiscountService CreateDiscountService()
+        {
+            return new CountryDiscountService(_countryIdentifier);
+        }
+    }
+
+    public class CodeDiscountFactory : DiscountFactory
+    {
+        public readonly Guid _code;
+
+        public CodeDiscountFactory(Guid code)
+        {
+            _code = code;
+        }
+
+        public override DiscountService CreateDiscountService()
+        {
+            return new CodeDiscountService(_code);
+        }
+    }
+}

DesignPatterns/A - Creational Patterns/FactoryMethod/FactoryMethod.csproj

@@ -0,0 +1,10 @@
+<Project Sdk="Microsoft.NET.Sdk">
+
+  <PropertyGroup>
+    <OutputType>Exe</OutputType>
+    <TargetFramework>net8.0</TargetFramework>
+    <ImplicitUsings>enable</ImplicitUsings>
+    <Nullable>enable</Nullable>
+  </PropertyGroup>
+
+</Project>

DesignPatterns/A - Creational Patterns/FactoryMethod/Program.cs

@@ -0,0 +1,21 @@
+using FactoryMethod;
+
+Restaurant beefBurgerFactory = new BeefBurgerRestaurant();
+Burger beefBurger = beefBurgerFactory.OrderBurger();
+
+Restaurant veggieBurgerFactory = new VeggieBurgerRestaurant();
+Burger veggieBurger = veggieBurgerFactory.OrderBurger();
+
+var factories = new List<DiscountFactory>
+{
+    new CodeDiscountFactory(Guid.NewGuid()),
+    new CountryDiscountFactory("GER")
+};
+
+foreach (var factory in factories)
+{
+    var discountService = factory.CreateDiscountService();
+    Console.WriteLine(
+        $"Percentage {discountService.DiscountPercentage} " + $"coming from {discountService}"
+    );
+}

README.md

@@ -118,7 +118,7 @@ namespace Singleton
 
 ```
 
-### 2. Factory Pattern
+### 2. Factory Method Pattern
 
 ### 3. Abstract Factory Pattern