PIAPS_CW/DatabaseImplement/Models/Purchase.cs

using Contracts.BindingModels;
using Contracts.ViewModels;
using DataModels.Enums;
using DataModels.Models;
using Microsoft.EntityFrameworkCore.Metadata.Internal;
using System;
using System.Collections.Generic;
using System.ComponentModel.DataAnnotations;
using System.ComponentModel.DataAnnotations.Schema;
using System.Linq;
using System.Runtime.Serialization;
using System.Text;
using System.Threading.Tasks;

namespace DatabaseImplement.Models
{
	public class Purchase : IPurchase
	{
		public Guid Id { get; set; }
		[Required]
		public DateTime DatePurchase { get; set; }
        [Required]
		public Guid UserId { get; set; }
        [Required]
		public PurchaseStatus Status { get; private set; } = PurchaseStatus.Unknown;
        private Dictionary<Guid, (IProduct, int)>? _purchaseProducts = null;
        public virtual User? User { get; set; }
		[DataMember]
        [NotMapped]
        public Dictionary<Guid, (IProduct, int)> PurchaseProducts
        {
            get
            {
                if (_purchaseProducts == null)
                {
                    _purchaseProducts = Products.ToDictionary(e => e.ProductId, e => (e.Product as IProduct, e.Count));
                }
                return _purchaseProducts;
            }
            set { }
        }
		[ForeignKey("PurchaseId")]
		public virtual List<PurchaseProducts> Products { get; set; } = new();
        public PurchaseBindingModel GetBindingModel() => new()
		{
			Id = Id,
			DatePurchase = DatePurchase,
			UserId = UserId,
			PurchaseProducts = PurchaseProducts,
			Status = Status
		};

        public PurchaseViewModel GetViewModel() => new()
        {
            Id = Id,
            DatePurchase = DatePurchase,
            UserId = UserId,
            PurchaseProducts = PurchaseProducts,
            Status = Status
        };

        public static Purchase ToPurchaseFromView(PurchaseViewModel model, Purchase purchase) => new()
		{
			Id = model.Id,
			DatePurchase = model.DatePurchase,
            UserId = model.UserId,
            PurchaseProducts = model.PurchaseProducts,
            Status = model.Status
        };

		public static Purchase ToPurchaseFromBinding(PurchaseBindingModel model, Purchase purchase) => new()
		{
			Id = model.Id,
			DatePurchase = model.DatePurchase,
            UserId = model.UserId,
            PurchaseProducts = model.PurchaseProducts,
            Status = model.Status
        };

		public void Update(PurchaseBindingModel model, Purchase purchase)
		{
			if (model is null)
			{
				throw new ArgumentNullException("Update purchase: binding model is null");
			}

			DatePurchase = purchase.DatePurchase;
		}
	}
}