using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;

namespace Domain.Entities
{
    public class Order
    {
        private List<Item> items = new List<Item>();
        public IList<Item> Items { get { return items.AsReadOnly(); } }

        public void AddItem(Film film, int quantity) 
        {
            var item = items.FirstOrDefault(x => x.Film.FilmID == film.FilmID);
            if (item == null)
                items.Add(new Item { Film = film, Quantity = quantity });
            else
                item.Quantity += quantity;
        }

        public void RemoveItem(Film film)
        {
            items.RemoveAll(x => x.Film.FilmID == film.FilmID);
        }
        
        public void Clear() 
        {
            items.Clear();
        }

        public decimal TotalCost()
        {
            return items.Sum(x => x.Film.RentalPrice * x.Quantity);
        }
    }

    public class Item
    {
        public Film Film{ get; set; }
        public int Quantity { get; set; }
    }
}