dotNetStudyWithGPT/MySolution/EF_ChangeLog/Controller/StockDbContext.cs

using EF_ChangeLog.Model;
using Microsoft.EntityFrameworkCore;
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;

namespace EF_ChangeLog.Controller
{
    internal class StockDbContext : DbContext
    {
        public DbSet<Stock> Stocks { get; set; }
        public DbSet<StockChangeLog> StockChangeLogs { get; set; }
        public DbSet<StockLog> stockLogs { get; set; }

        protected override void OnConfiguring(DbContextOptionsBuilder optionsBuilder)
        {
            optionsBuilder.UseSqlServer(@"Data Source=peacecloud.synology.me,21433;Initial Catalog=Study;User ID=study;Password=Study1234;Encrypt=false");
            base.OnConfiguring(optionsBuilder);
        }

        public override int SaveChanges()
        {
            var modifiedEntities = ChangeTracker.Entries().ToList();

            for (var i = 0; i < modifiedEntities.Count; i++)
            {
                var entry = modifiedEntities[i];
                var entitiy = entry.Entity;

                if (entitiy.GetType() != typeof(Stock))
                    continue;

                if (entitiy is Stock stock && entry.State != EntityState.Added)
                {
                    StockLog stockLog = new StockLog()
                    {
                        OriginalId = (int)entry.OriginalValues[nameof(Stock.Id)],
                        Name = (string)entry.OriginalValues[nameof(Stock.Name)],
                        Price = (decimal)entry.OriginalValues[nameof(Stock.Price)],
                        LoggedAt = DateTime.Now
                    };

                    this.stockLogs.Add(stockLog);
                }

                var changeLog = new StockChangeLog()
                {
                    EntityName = entitiy.GetType().Name,
                    EntityId = (int)entitiy.GetType().GetProperty("Id").GetValue(entitiy),
                    ChangeBy = "User",
                    ChangeDate = DateTime.Now,
                    ActionType = entry.State.ToString(),
                    OriginalSnapshot = (string)entitiy.GetType().GetProperty("OriginalSnapshot").GetValue(entitiy)
                };

                StockChangeLogs.Add(changeLog);
            }

            return base.SaveChanges();
        }
    }
}