try

Webshop.Infrastructure/Repositories/CustomerRepository.cs

@@ -1,13 +1,15 @@
+// src/Webshop.Infrastructure/Repositories/CustomerRepository.cs
 using Microsoft.EntityFrameworkCore;
 using Webshop.Domain.Entities;
 using Webshop.Domain.Interfaces;
 using Webshop.Infrastructure.Data;
 using System;
+using System.Collections.Generic;
 using System.Threading.Tasks;
 
 namespace Webshop.Infrastructure.Repositories
 {
-    public class CustomerRepository : ICustomerRepository
+    public class CustomerRepository : ICustomerRepository // MUSS public sein
     {
         private readonly ApplicationDbContext _context;
 
@@ -16,15 +18,17 @@ namespace Webshop.Infrastructure.Repositories
             _context = context;
         }
 
-        public async Task<Customer?> GetByUserIdAsync(string userId)
-        {
-            return await _context.Customers.FirstOrDefaultAsync(c => c.AspNetUserId == userId);
-        }
+        // Beispiel-Implementierungen (wenn nicht schon vorhanden):
+        public async Task<IEnumerable<Customer>> GetAllAsync() => await _context.Customers.ToListAsync();
+        public async Task<Customer?> GetByIdAsync(Guid id) => await _context.Customers.FindAsync(id);
+        public async Task AddAsync(Customer entity) { _context.Customers.Add(entity); await _context.SaveChangesAsync(); }
+        public async Task UpdateAsync(Customer entity) { _context.Customers.Update(entity); await _context.SaveChangesAsync(); }
+        public async Task DeleteAsync(Guid id) { var entity = await _context.Customers.FindAsync(id); if (entity != null) { _context.Customers.Remove(entity); await _context.SaveChangesAsync(); } }
 
-        public async Task UpdateAsync(Customer customer)
+        // KORREKTE IMPLEMENTIERUNG F<>R GetByUserIdAsync
+        public async Task<Customer?> GetByUserIdAsync(string aspNetUserId)
         {
-            _context.Customers.Update(customer);
-            await _context.SaveChangesAsync();
+            return await _context.Customers.FirstOrDefaultAsync(c => c.AspNetUserId == aspNetUserId);
         }
     }
 }