Computer_Hardware_Store/HardwareShop/HardwareShopDatabaseImplement/Models/Build.cs

using HardwareShopContracts.BindingModels;
using HardwareShopContracts.ViewModels;
using HardwareShopDataModels.Models;
using System.ComponentModel;
using System.ComponentModel.DataAnnotations;
using System.ComponentModel.DataAnnotations.Schema;

namespace HardwareShopDatabaseImplement.Models
{
    public class Build : IBuildModel
    {
        public int Id { get; set; }

        [Required]
        public decimal Price { get; set; }

        [Required]
        public string BuildName { get; set; } = string.Empty;

        [Required]
        public int UserID { get; set; }

        public virtual User User { get; set; }

        [ForeignKey("BuildId")]
        public virtual List<Comment>? Comments { get; set; }

        [ForeignKey("BuildId")]
        public virtual List<BuildComponent>? Components { get; set; }


        [ForeignKey("BuildId")]
        public virtual List<PurchaseBuild>? Purchases { get; set; }


        private Dictionary<int, (IComponentModel, int)>? _buildComponents = null;

        [NotMapped]
        public Dictionary<int, (IComponentModel, int)> BuildComponents
        {
            get
            {
                if (_buildComponents == null)
                {
                    _buildComponents = Components.ToDictionary(recBC => recBC.ComponentId, recBC => (recBC.Component as IComponentModel, recBC.Count));
                }
                return _buildComponents;
            }
        }

        public static Build Create(HardwareShopDatabase context, BuildBindingModel model)
        {
            return new Build()
            {
                Id = model.Id,
                Price = model.Price,
                BuildName = model.BuildName,
                UserID = model.UserID,
                Components = model.BuildComponents.Select(x => new BuildComponent
                {
                    Component = context.Components.First(y => y.Id == x.Key),
                    Count = x.Value.Item2
                }).ToList()
            };
        }

        public void Update(BuildBindingModel model)
        {
            BuildName = model.BuildName;
            Price = model.Price;
        }

        public BuildViewModel GetViewModel => new()
        {
            Id = Id,
            BuildName = BuildName,
            Price = Price,
            UserEmail = User.Email,
            UserID = UserID,
            BuildComponents = BuildComponents
        };

        public void UpdateComponents(HardwareShopDatabase context, BuildBindingModel model)
        {
            var buildComponents = context.BuildsComponents.Where(rec => rec.BuildID == model.Id).ToList();
            if (buildComponents != null && buildComponents.Count > 0)
            {   // удалили те в бд, которых нет в модели
                context.BuildsComponents.RemoveRange(buildComponents.Where(rec => !model.BuildComponents.ContainsKey(rec.ComponentId)));
                context.SaveChanges();
                // обновили количество у существующих записей
                foreach (var updateComponent in buildComponents)
                {
                    updateComponent.Count = model.BuildComponents[updateComponent.ComponentId].Item2;
                    model.BuildComponents.Remove(updateComponent.ComponentId);
                }
                context.SaveChanges();
            }
            var build = context.Builds.First(x => x.Id == Id);
            //добавляем в бд блюда которые есть в моделе, но ещё нет в бд
            foreach (var dc in model.BuildComponents)
            {
                context.BuildsComponents.Add(new BuildComponent
                {
                    Build = build,
                    Component = context.Components.First(x => x.Id == dc.Key),
                    Count = dc.Value.Item2
                });
                context.SaveChanges();
            }
            _buildComponents = null;
        }

    }
}