it/backend/HardwarePerformance.Infrastructure/Data/AppDbContext.cs

using Microsoft.EntityFrameworkCore;
using HardwarePerformance.Core.Entities;

namespace HardwarePerformance.Infrastructure.Data
{
    /// <summary>
    /// 应用程序数据库上下文
    /// </summary>
    public class AppDbContext : DbContext
    {
        public AppDbContext(DbContextOptions<AppDbContext> options) : base(options)
        {
        }

        // DbSets
        public DbSet<Category> Categories { get; set; }
        public DbSet<Product> Products { get; set; }
        public DbSet<PerformanceScore> PerformanceScores { get; set; }
        public DbSet<Specification> Specifications { get; set; }
        public DbSet<DataSource> DataSources { get; set; }
        public DbSet<RankingHistory> RankingHistories { get; set; }

        protected override void OnModelCreating(ModelBuilder modelBuilder)
        {
            base.OnModelCreating(modelBuilder);

            // 配置Category实体
            modelBuilder.Entity<Category>(entity =>
            {
                entity.HasKey(e => e.Id);
                
                entity.Property(e => e.Name)
                    .IsRequired()
                    .HasMaxLength(100);
                
                entity.Property(e => e.Description)
                    .HasMaxLength(500);
                
                entity.Property(e => e.IconUrl)
                    .HasMaxLength(500);
                
                entity.Property(e => e.CreatedAt)
                    .HasDefaultValueSql("UTC_TIMESTAMP()");
                
                entity.Property(e => e.UpdatedAt)
                    .HasDefaultValueSql("UTC_TIMESTAMP()");
                
                entity.HasIndex(e => e.Name).IsUnique();
                entity.HasIndex(e => e.SortOrder);
            });

            // 配置Product实体
            modelBuilder.Entity<Product>(entity =>
            {
                entity.HasKey(e => e.Id);
                
                entity.Property(e => e.Name)
                    .IsRequired()
                    .HasMaxLength(200);
                
                entity.Property(e => e.Model)
                    .IsRequired()
                    .HasMaxLength(200);
                
                entity.Property(e => e.Manufacturer)
                    .IsRequired()
                    .HasMaxLength(100);
                
                entity.Property(e => e.ImageUrl)
                    .HasMaxLength(500);
                
                entity.Property(e => e.Description)
                    .HasMaxLength(2000);
                
                entity.Property(e => e.CreatedAt)
                    .HasDefaultValueSql("UTC_TIMESTAMP()");
                
                entity.Property(e => e.UpdatedAt)
                    .HasDefaultValueSql("UTC_TIMESTAMP()");
                
                // 配置外键关系
                entity.HasOne(e => e.Category)
                    .WithMany(c => c.Products)
                    .HasForeignKey(e => e.CategoryId)
                    .OnDelete(DeleteBehavior.Cascade);
                
                // 配置索引
                entity.HasIndex(e => e.Name);
                entity.HasIndex(e => e.Model);
                entity.HasIndex(e => e.CategoryId);
                entity.HasIndex(e => e.PerformanceScore);
                entity.HasIndex(e => e.CurrentRank);
                entity.HasIndex(e => e.Manufacturer);
                entity.HasIndex(e => e.ReleaseYear);
                entity.HasIndex(e => new { e.CategoryId, e.CurrentRank });
            });

            // 配置PerformanceScore实体
            modelBuilder.Entity<PerformanceScore>(entity =>
            {
                entity.HasKey(e => e.Id);
                
                entity.Property(e => e.TestName)
                    .IsRequired()
                    .HasMaxLength(100);
                
                entity.Property(e => e.Unit)
                    .HasMaxLength(20);
                
                entity.Property(e => e.TestVersion)
                    .HasMaxLength(50);
                
                entity.Property(e => e.CreatedAt)
                    .HasDefaultValueSql("UTC_TIMESTAMP()");
                
                // 配置外键关系
                entity.HasOne(e => e.Product)
                    .WithMany(p => p.PerformanceScores)
                    .HasForeignKey(e => e.ProductId)
                    .OnDelete(DeleteBehavior.Cascade);
                
                entity.HasOne(e => e.DataSource)
                    .WithMany(d => d.PerformanceScores)
                    .HasForeignKey(e => e.DataSourceId)
                    .OnDelete(DeleteBehavior.Restrict);
                
                // 配置索引
                entity.HasIndex(e => new { e.ProductId, e.TestName });
                entity.HasIndex(e => e.Score);
                entity.HasIndex(e => e.TestDate);
            });

            // 配置Specification实体
            modelBuilder.Entity<Specification>(entity =>
            {
                entity.HasKey(e => e.Id);
                
                entity.Property(e => e.GroupName)
                    .IsRequired()
                    .HasMaxLength(100);
                
                entity.Property(e => e.Name)
                    .IsRequired()
                    .HasMaxLength(100);
                
                entity.Property(e => e.Value)
                    .IsRequired()
                    .HasMaxLength(500);
                
                entity.Property(e => e.Unit)
                    .HasMaxLength(20);
                
                entity.Property(e => e.CreatedAt)
                    .HasDefaultValueSql("UTC_TIMESTAMP()");
                
                entity.Property(e => e.UpdatedAt)
                    .HasDefaultValueSql("UTC_TIMESTAMP()");
                
                // 配置外键关系
                entity.HasOne(e => e.Product)
                    .WithMany(p => p.Specifications)
                    .HasForeignKey(e => e.ProductId)
                    .OnDelete(DeleteBehavior.Cascade);
                
                // 配置索引
                entity.HasIndex(e => new { e.ProductId, e.GroupName });
                entity.HasIndex(e => new { e.ProductId, e.Name });
                entity.HasIndex(e => e.IsKeySpecification);
            });

            // 配置DataSource实体
            modelBuilder.Entity<DataSource>(entity =>
            {
                entity.HasKey(e => e.Id);
                
                entity.Property(e => e.Name)
                    .IsRequired()
                    .HasMaxLength(100);
                
                entity.Property(e => e.Description)
                    .HasMaxLength(500);
                
                entity.Property(e => e.Url)
                    .HasMaxLength(500);
                
                entity.Property(e => e.Type)
                    .IsRequired()
                    .HasMaxLength(50);
                
                entity.Property(e => e.CreatedAt)
                    .HasDefaultValueSql("UTC_TIMESTAMP()");
                
                entity.Property(e => e.UpdatedAt)
                    .HasDefaultValueSql("UTC_TIMESTAMP()");
                
                // 配置索引
                entity.HasIndex(e => e.Name).IsUnique();
                entity.HasIndex(e => e.Type);
            });

            // 配置RankingHistory实体
            modelBuilder.Entity<RankingHistory>(entity =>
            {
                entity.HasKey(e => e.Id);
                
                entity.Property(e => e.CreatedAt)
                    .HasDefaultValueSql("UTC_TIMESTAMP()");
                
                // 配置外键关系
                entity.HasOne(e => e.Product)
                    .WithMany(p => p.RankingHistories)
                    .HasForeignKey(e => e.ProductId)
                    .OnDelete(DeleteBehavior.Cascade);
                
                // 配置索引
                entity.HasIndex(e => new { e.ProductId, e.RecordDate });
                entity.HasIndex(e => e.Rank);
                entity.HasIndex(e => e.RecordDate);
            });
        }

        public override int SaveChanges()
        {
            UpdateTimestamps();
            return base.SaveChanges();
        }

        public override Task<int> SaveChangesAsync(CancellationToken cancellationToken = default)
        {
            UpdateTimestamps();
            return base.SaveChangesAsync(cancellationToken);
        }

        private void UpdateTimestamps()
        {
            var entries = ChangeTracker.Entries()
                .Where(e => e.Entity is BaseEntity && (e.State == EntityState.Added || e.State == EntityState.Modified));

            foreach (var entry in entries)
            {
                if (entry.State == EntityState.Added)
                {
                    ((BaseEntity)entry.Entity).CreatedAt = DateTime.UtcNow;
                }
                
                ((BaseEntity)entry.Entity).UpdatedAt = DateTime.UtcNow;
            }
        }
    }
}