using DinerContracts.BindingModels;
using DinerContracts.ViewModels;
using DinerDataModels.Models;
using System;
using System.Collections.Generic;
using System.Linq;
using System.Runtime.InteropServices;
using System.Text;
using System.Threading.Tasks;
using System.Xml.Linq;
using System.Xml.XPath;

namespace DinerFileImplement.Models
{
    internal class Snack : ISnackModel
    {
        public string ProductName { get; private set; } = string.Empty;

        public double Price { get; private set; }

        public int ID { get; private set; }

        public Dictionary<int, int> Components { get; private set; } = new();
        private Dictionary<int, (IFoodModel, int)>? _productComponents = null;
        public Dictionary<int, (IFoodModel, int)> ProductComponents
        {
            get
            {
                if (_productComponents == null) {
                    var source = DataFileSingleton.GetInstance();
                    _productComponents = Components.ToDictionary(x => x.Key, y => ((source.Foods.FirstOrDefault(z => z.ID ==
                                                                    y.Key) as IFoodModel)!, y.Value));
                }
                return _productComponents;
            }
        }

        public static Snack? Create(SnackBindingModel? model)
        {
            if (model == null) return null;
            return new Snack()
            {
                ID = model.ID,
                ProductName = model.ProductName,
                Price = model.Price,
                Components = model.ProductComponents.ToDictionary(x => x.Key, x => x.Value.Item2)
            };
        }
        public static Snack? Create(XElement element)
        {
            if (element == null) return null;
            return new Snack()
            {
                ID = Convert.ToInt32(element.Attribute("ID")!.Value),
                ProductName = element.Element("ProductName")!.Value,
                Price = Convert.ToDouble(element.Element("Price")!.Value),
                Components = element.Element("ProductComponents")!.Elements("ProductComponent")
                                .ToDictionary(x => Convert.ToInt32(x.Element("Key")?.Value), x => Convert.ToInt32(x.Element("Value")?.Value))
            };
        }
        public void Update(SnackBindingModel? model)
        {
            if (model == null) return;
            ProductName = model.ProductName;
            Price = model.Price;
            Components = model.ProductComponents.ToDictionary(x => x.Key, x => x.Value.Item2);
            _productComponents = null;
        }
        public SnackViewModel GetViewModel => new()
        {
            ID = ID,
            ProductName = ProductName,
            Price = Price,
            ProductComponents = ProductComponents
        };
        public XElement GetXElement => new("Snack", new XAttribute("ID", ID),
                                        new XElement("ProductName", ProductName),
                                        new XElement("Price", Price.ToString()),
                                        new XElement("ProductComponents", Components.Select(x => new XElement("ProductComponent",
                                                                                                    new XElement("Key", x.Key),
                                                                                                    new XElement("Value", x.Value))).ToArray()));
    }
}