ShopSolution-backend/Webshop.Infrastructure/Data/ApplicationDbContext.cs

using Microsoft.AspNetCore.Identity;
using Microsoft.AspNetCore.Identity.EntityFrameworkCore;
using Microsoft.EntityFrameworkCore;
using Webshop.Domain.Entities;
using Webshop.Domain.Identity;

namespace Webshop.Infrastructure.Data
{
    public class ApplicationDbContext : IdentityDbContext<ApplicationUser>
    {
        public ApplicationDbContext(DbContextOptions<ApplicationDbContext> options) : base(options)
        {
        }

        public DbSet<Product> Products { get; set; } = default!;
        public DbSet<ProductVariant> ProductVariants { get; set; } = default!;
        public DbSet<Categorie> categories { get; set; } = default!;
        public DbSet<Customer> Customers { get; set; } = default!;
        public DbSet<Address> Addresses { get; set; } = default!;
        public DbSet<Order> Orders { get; set; } = default!;
        public DbSet<OrderItem> OrderItems { get; set; } = default!;
        public DbSet<Review> Reviews { get; set; } = default!;
        public DbSet<Discount> Discounts { get; set; } = default!;
        public DbSet<Supplier> Suppliers { get; set; } = default!;
        public DbSet<ShippingMethod> ShippingMethods { get; set; } = default!;
        public DbSet<PaymentMethod> PaymentMethods { get; set; } = default!;
        public DbSet<Setting> Settings { get; set; } = default!;

        public DbSet<Productcategorie> Productcategories { get; set; } = default!;
        public DbSet<ProductDiscount> ProductDiscounts { get; set; } = default!;
        public DbSet<CategorieDiscount> categorieDiscounts { get; set; } = default!;


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

            foreach (var entity in modelBuilder.Model.GetEntityTypes())
            {
                var tableName = entity.GetTableName();

                if (tableName != null && tableName.StartsWith("AspNet"))
                {
                    entity.SetTableName(tableName.Substring(6));
                }
            }

            modelBuilder.Entity<Productcategorie>().HasKey(pc => new { pc.ProductId, pc.categorieId });
            modelBuilder.Entity<ProductDiscount>().HasKey(pd => new { pd.ProductId, pd.DiscountId });
            modelBuilder.Entity<CategorieDiscount>().HasKey(cd => new { cd.categorieId, cd.DiscountId });

            modelBuilder.Entity<Product>().HasIndex(p => p.SKU).IsUnique();
            modelBuilder.Entity<Product>().HasIndex(p => p.Slug).IsUnique();
            modelBuilder.Entity<Categorie>().HasIndex(c => c.Slug).IsUnique();
            modelBuilder.Entity<Discount>().HasIndex(d => d.CouponCode).IsUnique().HasFilter("\"CouponCode\" IS NOT NULL");
            modelBuilder.Entity<Setting>().HasIndex(s => s.Key).IsUnique();
            modelBuilder.Entity<Order>().HasIndex(o => o.OrderNumber).IsUnique();

            modelBuilder.Entity<Product>(e =>
            {
                e.Property(p => p.Price).HasPrecision(18, 2);
                e.Property(p => p.OldPrice).HasPrecision(18, 2);
                e.Property(p => p.PurchasePrice).HasPrecision(18, 2);
                e.Property(p => p.Weight).HasPrecision(18, 3);
                e.Property(p => p.Width).HasPrecision(18, 2);
                e.Property(p => p.Height).HasPrecision(18, 2);
                e.Property(p => p.Length).HasPrecision(18, 2);
            });

            modelBuilder.Entity<ProductVariant>()
                .Property(pv => pv.PriceAdjustment).HasPrecision(18, 2);

            modelBuilder.Entity<Order>(e =>
            {
                e.Property(o => o.OrderTotal).HasPrecision(18, 2);
                e.Property(o => o.ShippingCost).HasPrecision(18, 2);
                e.Property(o => o.TaxAmount).HasPrecision(18, 2);
                e.Property(o => o.DiscountAmount).HasPrecision(18, 2);
            });

            modelBuilder.Entity<OrderItem>(e =>
            {
                e.Property(oi => oi.UnitPrice).HasPrecision(18, 2);
                e.Property(oi => oi.TotalPrice).HasPrecision(18, 2);
            });

            modelBuilder.Entity<Discount>(e =>
            {
                e.Property(d => d.DiscountValue).HasPrecision(18, 2);
                e.Property(d => d.MinimumOrderAmount).HasPrecision(18, 2);
            });

            modelBuilder.Entity<ShippingMethod>(e =>
            {
                e.Property(sm => sm.BaseCost).HasPrecision(18, 2);
                e.Property(sm => sm.MinimumOrderAmount).HasPrecision(18, 2);
            });

            modelBuilder.Entity<PaymentMethod>()
                .Property(pm => pm.ProcessingFee).HasPrecision(18, 2);

            modelBuilder.Entity<Categorie>()
                .HasOne(c => c.Parentcategorie)
                .WithMany(c => c.Subcategories)
                .HasForeignKey(c => c.ParentcategorieId)
                .OnDelete(DeleteBehavior.Restrict);

            modelBuilder.Entity<OrderItem>()
                .HasOne(oi => oi.Product)
                .WithMany()
                .HasForeignKey(oi => oi.ProductId)
                .OnDelete(DeleteBehavior.SetNull);

            modelBuilder.Entity<OrderItem>()
                .HasOne(oi => oi.ProductVariant)
                .WithMany()
                .HasForeignKey(oi => oi.ProductVariantId)
                .OnDelete(DeleteBehavior.SetNull);

            modelBuilder.Entity<Order>()
                .HasOne(o => o.BillingAddress)
                .WithMany()
                .HasForeignKey(o => o.BillingAddressId)
                .OnDelete(DeleteBehavior.Restrict);

            modelBuilder.Entity<Order>()
                .HasOne(o => o.ShippingAddress)
                .WithMany()
                .HasForeignKey(o => o.ShippingAddressId)
                .OnDelete(DeleteBehavior.Restrict);

            modelBuilder.Entity<ApplicationUser>()
                .HasOne(a => a.Customer) // Ein ApplicationUser hat ein optionales Customer-Profil
                .WithOne(c => c.User)     // Ein Customer-Profil ist mit genau einem User verknüpft
                .HasForeignKey<Customer>(c => c.AspNetUserId);
        }
    }
}