Ch4PizzaStore: last part with AbstractFactory. This example in the book is really TERRIBLE.

Ch4PizzaStore/Pizza.cs

@@ -1,17 +1,15 @@
 namespace Ch4PizzaStore;
 
-public abstract class Pizza(string name, string dough, string sauce, List<string> toppings) {
-    public string Name { get; } = name;
+public abstract class Pizza(string name) {
+    public string Name { get; internal set; } = name;
+    public IDough? Dough { get; internal set; } = null;
+    public ISauce? Sauce { get; internal set; } = null;
+    public IVeggies[]? VeggiesArray { get; internal set; } = null;
+    public ICheese? Cheese { get; internal set; } = null;
+    public IPepperoni? Pepperoni { get; internal set; } = null;
+    public IClams? Clams { get; internal set; } = null;
 
-    internal void Prepare() {
-        Console.WriteLine($"Preparing {Name}");
-        Console.WriteLine($"Tossing {dough} dough...");
-        Console.WriteLine($"Adding {sauce} sauce...");
-        Console.WriteLine("Adding toppings:");
-        foreach (var topping in toppings) {
-            Console.WriteLine($"\t{topping}");
-        }
-    }
+    internal abstract void Prepare();
 
     // While in Java all methods are by default `virtual`, C# is the same as C++,
     // all methods are final/selaed until explicitly marked as virtual.
@@ -26,15 +24,28 @@ public abstract class Pizza(string name, string dough, string sauce, List<string
     internal virtual void Box() {
         Console.WriteLine("Place pizza in official PizzaStore box");
     }
+
+    public override string ToString() {
+        return "Pizza!"; // TODO: code to print the pizza here
+    }
 }
 
-public class NYStyleCheesePizza() : Pizza("NY Style Sauce and Cheese Pizza", "Thin Crust Dough", "Marinara Sauce",
-    ["Grated Reggiano Cheese"]);
+public class CheesePizza(IPizzaIngredientFactory ingredientFactory, string name) : Pizza(name) {
+    internal override void Prepare() {
+        Console.WriteLine($"Preparing {Name}");
+        Dough = ingredientFactory.CreateDough();
+        Sauce = ingredientFactory.CreateSauce();
+        Cheese = ingredientFactory.CreateCheese();
+    }
+}
 
-public class ChicagoStyleCheesePizza() : Pizza("Chicago Style Deep Dish Cheese Pizza", "Extra Thick Crust Dough",
-    "Plum Tomato Sauce", ["Shredded Mozzarella Cheese"]) {
-    internal override void Cut() {
-        Console.WriteLine("Cutting the pizza into square slices");
+public class ClamPizza(IPizzaIngredientFactory ingredientFactory, string name) : Pizza(name) {
+    internal override void Prepare() {
+        Console.WriteLine($"Preparing {Name}");
+        Dough = ingredientFactory.CreateDough();
+        Sauce = ingredientFactory.CreateSauce();
+        Cheese = ingredientFactory.CreateCheese();
+        Clams = ingredientFactory.CreateClams();
     }
 }
 
@@ -53,18 +64,76 @@ public abstract class PizzaStore {
 
 public class NYPizzaStore : PizzaStore {
     protected override Pizza CreatePizza(string type) {
+        var ingredientFactory = new NYPizzaIngredientFactory();
         return type switch {
-            "cheese" => new NYStyleCheesePizza(),
+            "cheese" => new CheesePizza(ingredientFactory, "New York Style Cheese Pizza"),
+            "clam" => new ClamPizza(ingredientFactory, "New York Style Clam Pizza"),
             _ => throw new ArgumentOutOfRangeException(nameof(type), type, null)
         };
     }
 }
 
-public class ChicagoPizzaStore : PizzaStore {
-    protected override Pizza CreatePizza(string type) {
-        return type switch {
-            "cheese" => new ChicagoStyleCheesePizza(),
-            _ => throw new ArgumentOutOfRangeException(nameof(type), type, null)
-        };
+public interface IDough;
+
+public interface ISauce;
+
+public interface ICheese;
+
+public interface IVeggies;
+
+public interface IPepperoni;
+
+public interface IClams;
+
+public interface IPizzaIngredientFactory {
+    public IDough CreateDough();
+    public ISauce CreateSauce();
+    public ICheese CreateCheese();
+    public IVeggies[] CreateVeggies();
+    public IPepperoni CreatePepperoni();
+    public IClams CreateClams();
+}
+
+public class ThinCrustDough : IDough;
+
+public class MarinaraSauce : ISauce;
+
+public class ReggianoCheese : ICheese;
+
+public class Garlic : IVeggies;
+
+public class Onion : IVeggies;
+
+public class Mushroom : IVeggies;
+
+public class RedPepper : IVeggies;
+
+public class SlicedPepperoni : IPepperoni;
+
+public class FreshClams : IClams;
+
+public class NYPizzaIngredientFactory : IPizzaIngredientFactory {
+    public IDough CreateDough() {
+        return new ThinCrustDough();
+    }
+
+    public ISauce CreateSauce() {
+        return new MarinaraSauce();
+    }
+
+    public ICheese CreateCheese() {
+        return new ReggianoCheese();
+    }
+
+    public IVeggies[] CreateVeggies() {
+        return [new Garlic(), new Onion(), new Mushroom(), new RedPepper()];
+    }
+
+    public IPepperoni CreatePepperoni() {
+        return new SlicedPepperoni();
+    }
+
+    public IClams CreateClams() {
+        return new FreshClams();
     }
 }

Ch4PizzaStore/Program.cs

@@ -3,9 +3,8 @@
 using Ch4PizzaStore;
 
 PizzaStore nyStore = new NYPizzaStore();
-PizzaStore chicagoStore = new ChicagoPizzaStore();
 
 var pizza = nyStore.OrderPizza("cheese");
 Console.WriteLine($"Ethan ordered a {pizza.Name}\n");
-pizza = chicagoStore.OrderPizza("cheese");
+pizza = nyStore.OrderPizza("clam");
 Console.WriteLine($"Joel ordered a {pizza.Name}\n");