using System;
using System.Collections.Generic;
 
namespace DoFactory.GangOfFour.Visitor.RealWorld
{
	/// 

	/// MainApp startup class for Real-World 
	/// Visitor Design Pattern.
	/// 
  class MainApp
  {
	/// 

	/// Entry point into console application.
	/// 
    static void Main()
    {
      // Setup employee collection
      Employees e = new Employees();
      e.Attach(new Clerk());
      e.Attach(new Director());
      e.Attach(new President());
 
      // Employees are 'visited'
      e.Accept(new IncomeVisitor());
      e.Accept(new VacationVisitor());
 
      // Wait for user
      Console.ReadKey();
    }
  }
 
	/// 

	/// The 'Visitor' interface
	/// 
  interface IVisitor
  {
    void Visit(Element element);
  }
 
	/// 

	/// A 'ConcreteVisitor' class
	/// 
  class IncomeVisitor : IVisitor
  {
    public void Visit(Element element)
    {
      Employee employee = element as Employee;
 
      // Provide 10% pay raise
      employee.Income *= 1.10;
      Console.WriteLine("{0} {1}'s new income: {2:C}",
        employee.GetType().Name, employee.Name,
        employee.Income);
    }
  }
 
	/// 

	/// A 'ConcreteVisitor' class
	/// 
  class VacationVisitor : IVisitor
  {
    public void Visit(Element element)
    {
      Employee employee = element as Employee;
 
      // Provide 3 extra vacation days
      employee.VacationDays += 3;
      Console.WriteLine("{0} {1}'s new vacation days: {2}",
        employee.GetType().Name, employee.Name,
        employee.VacationDays);
    }
  }
 
	/// 

	/// The 'Element' abstract class
	/// 
  abstract class Element
  {
    public abstract void Accept(IVisitor visitor);
  }
 
	/// 

	/// The 'ConcreteElement' class
	/// 
  class Employee : Element
  {
    private string _name;
    private double _income;
    private int _vacationDays;
 
    // Constructor
    public Employee(string name, double income, int vacationDays)
    {
      this._name = name;
      this._income = income;
      this._vacationDays = vacationDays;
    }
 
    // Gets or sets the name
    public string Name
    {
      get { return _name; }
      set { _name = value; }
    }
 
    // Gets or sets income
    public double Income
    {
      get { return _income; }
      set { _income = value; }
    }
 
    // Gets or sets number of vacation days
    public int VacationDays
    {
      get { return _vacationDays; }
      set { _vacationDays = value; }
    }
 
    public override void Accept(IVisitor visitor)
    {
      visitor.Visit(this);
    }
  }
 
	/// 

	/// The 'ObjectStructure' class
	/// 
  class Employees
  {
    private List _employees = new List();

    public void Attach(Employee employee)
    {
      _employees.Add(employee);
    }
 
    public void Detach(Employee employee)
    {
      _employees.Remove(employee);
    }
 
    public void Accept(IVisitor visitor)
    {
      foreach (Employee e in _employees)
      {
        e.Accept(visitor);
      }
      Console.WriteLine();
    }
  }
 
  // Three employee types
  class Clerk : Employee
  {
    // Constructor
    public Clerk() : base("Hank", 25000.0, 14)
    {
    }
  }
 
  class Director : Employee
  {
    // Constructor
    public Director() : base("Elly", 35000.0, 16)
    {
    }
  }
 
  class President : Employee
  {
    // Constructor
    public President() : base("Dick", 45000.0, 21)
    {
    }
  }
}