exos-polymorphism/TicketSystem/Order.cs

using System.Collections.Generic;
using System.Diagnostics;
using TicketSystem.Tickets;

namespace TicketSystem
{
    public class Order
    {
        private List<Ticket> tickets;
        private int price;
        public int Price => price;
        
        public Order()
        {
            tickets = new List<Ticket>();
            price = 0;
        }
        
        public void AddTicket(Ticket ticket)
        {
            tickets.Add(ticket);
            price += ticket.price;
        }

        public void AddTicket(TicketType type)
        {
            Ticket t;
            switch (type)
            {
                case TicketType.Child:
                    t = new Child();
                    tickets.Add(t);
                    price += t.price;
                    break;
                case TicketType.Student:
                    t = new Student();
                    tickets.Add(t);
                    price += t.price;
                    break;
                case TicketType.Adult:
                    t = new Adult();
                    tickets.Add(t);
                    price += t.price;
                    break;
            }
        }

        public void ApplyReduction()
        {
            price = 0;
            foreach (var ticket in tickets)
            {
                price += ticket.PriceWithReduction();
            }
        }
    }
}