PIbd-22-Ismailov_SUBD/BlogDataModels/BlogDatabaseImplement/Model/News.cs

using BlogDataModels.Model;
using System;
using System.Collections.Generic;
using System.Diagnostics;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.ComponentModel.DataAnnotations.Schema;
using BlogContracts.BindingModel;

namespace BlogDatabaseImplement.Model
{
    public class News : INews
    {
        public string Title { get; set; } = string.Empty;

        public string Text { get; set; } = string.Empty;

        public int UserId { get; set; } 

        public int Id { get; set; }
        public virtual User User { get; set; }

        private Dictionary<int, (ITag, int)>? _NewsTag = null;
        [NotMapped]
        public Dictionary<int, (ITag, int)> NewsTag
        {
            get
            {
                if (_NewsTag == null)
                {
                    _NewsTag = Tags.ToDictionary(recPC => recPC.TagId, recPC => (recPC.Tag as ITag, recPC.Count));

                }
                return _NewsTag;

            }
        }
        [ForeignKey("NewsId")]
        public virtual List<NewsTag> Tags { get; set; } = new();

        [ForeignKey("NewsId")]
        public virtual List<Comment> Comments { get; set; } = new();


        public static News Create(BlogDatabase context, NewsBindingModel model)
        {
            var news = new News()
            {
                Id = model.Id,
                Title = model.Title,
                Text = model.Text,
                UserId = model.UserId
            };

            news.Tags = model.NewsTag.Select(x => new NewsTag
            {
                Tag = context.Tags.First(y => y.Id == x.Key),
                Count = x.Value.Item2
            }).ToList();

            return news;
        }


        public void Update(NewsBindingModel model)
        {
            Title = model.Title;
            Text = model.Text;
            UserId = model.UserId;
        }
        public BlogContracts.ViewModels.NewsViewModel GetViewModel => new()
        {
            Id = Id,
            Title = Title,
            Text = Text,
            UserId = UserId
        };

        public void UpdateTags(BlogDatabase context, NewsBindingModel model)
        {
            var NewsTags = context.NewsTags.Where(rec => rec.NewsId == model.Id).ToList();
            if (NewsTags != null && NewsTags.Count > 0)
            {   // удалили те, которых нет в модели
                context.NewsTags.RemoveRange(NewsTags.Where(rec => !model.NewsTag.ContainsKey(rec.TagId)));
                context.SaveChanges();
                // обновили количество у существующих записей
                foreach (var updateTag in NewsTags)
                {
                    updateTag.Count = model.NewsTag[updateTag.TagId].Item2;
                    model.NewsTag.Remove(updateTag.TagId);
                }
                context.SaveChanges();
            }
            var News = context.News.First(x => x.Id == Id);
            foreach (var pc in model.NewsTag)
            {
                context.NewsTags.Add(new NewsTag
                {
                    News = News,
                    Tag = context.Tags.First(x => x.Id == pc.Key),
                    Count = pc.Value.Item2
                });
                context.SaveChanges();
            }
            _NewsTag = null;
        }
    }
}