using System;

namespace DoFactory.GangOfFour.Abstract.RealWorld
{
  /// <summary>
  /// MainApp startup class for Real-World
  /// Abstract Factory Design Pattern.
  /// </summary>
  class MainApp
  {
    /// <summary>
    /// Entry point into console application.
    /// </summary>
    public static void Main()
    {
      // Create and run the African animal world
      ContinentFactory africa = new AfricaFactory();
      AnimalWorld world = new AnimalWorld(africa);
      world.RunFoodChain();

      // Create and run the American animal world
      ContinentFactory america = new AmericaFactory();
      world = new AnimalWorld(america);
      world.RunFoodChain();

      // Wait for user input
      Console.ReadKey();
    }
  }


  /// <summary>
  /// The 'AbstractFactory' abstract class
  /// </summary>
  abstract class ContinentFactory
  {
    public abstract Herbivore CreateHerbivore();
    public abstract Carnivore CreateCarnivore();
  }

  /// <summary>
  /// The 'ConcreteFactory1' class
  /// </summary>
  class AfricaFactory : ContinentFactory
  {
    public override Herbivore CreateHerbivore()
    {
      return new Wildebeest();
    }
    public override Carnivore CreateCarnivore()
    {
      return new Lion();
    }
  }

  /// <summary>
  /// The 'ConcreteFactory2' class
  /// </summary>
  class AmericaFactory : ContinentFactory
  {
    public override Herbivore CreateHerbivore()
    {
      return new Bison();
    }
    public override Carnivore CreateCarnivore()
    {
      return new Wolf();
    }
  }

  /// <summary>
  /// The 'AbstractProductA' abstract class
  /// </summary>
  abstract class Herbivore
  {
  }

  /// <summary>
  /// The 'AbstractProductB' abstract class
  /// </summary>
  abstract class Carnivore
  {
    public abstract void Eat(Herbivore h);
  }

  /// <summary>
  /// The 'ProductA1' class
  /// </summary>
  class Wildebeest : Herbivore
  {
  }

  /// <summary>
  /// The 'ProductB1' class
  /// </summary>
  class Lion : Carnivore
  {
    public override void Eat(Herbivore h)
    {
      // Eat Wildebeest
      Console.WriteLine(this.GetType().Name +
        " eats " + h.GetType().Name);
    }
  }

  /// <summary>
  /// The 'ProductA2' class
  /// </summary>
  class Bison : Herbivore
  {
  }

  /// <summary>
  /// The 'ProductB2' class
  /// </summary>
  class Wolf : Carnivore
  {
    public override void Eat(Herbivore h)
    {
      // Eat Bison
      Console.WriteLine(this.GetType().Name +
        " eats " + h.GetType().Name);
    }
  }

  /// <summary>
  /// The 'Client' class
  /// </summary>
  class AnimalWorld
  {
    private Herbivore _herbivore;
    private Carnivore _carnivore;

    // Constructor
    public AnimalWorld(ContinentFactory factory)
    {
      _carnivore = factory.CreateCarnivore();
      _herbivore = factory.CreateHerbivore();
    }

    public void RunFoodChain()
    {
      _carnivore.Eat(_herbivore);
    }
  }
}