reorganization of database layer

UserService.DatabaseLayer/Repository/BaseRepository.cs

@@ -0,0 +1,53 @@
+using System;
+using System.Collections.Generic;
+using System.Linq.Expressions;
+using System.Threading;
+using System.Threading.Tasks;
+using Microsoft.EntityFrameworkCore;
+using UserService.DatabaseLayer.DataModels;
+
+namespace UserService.DatabaseLayer.Repository
+{
+    public class BaseRepository<T> where T : class
+    {
+        private readonly Func<UserServiceDbContext, DbSet<T>> _context;
+
+        protected BaseRepository(Func<UserServiceDbContext, DbSet<T>> context)
+        {
+            _context = context;
+        }
+
+        public async Task<IReadOnlyList<T>> GetAllAsync(CancellationToken token = default)
+        {
+            await using var db = new UserServiceDbContext();
+            return await _context(db).ToListAsync(token);
+        }
+
+        public async Task<T?> GetAsync(Expression<Func<T, bool>> predicate, CancellationToken token = default)
+        {
+            await using var db = new UserServiceDbContext();
+            return await _context(db).FirstOrDefaultAsync(predicate, token);
+        }
+
+        public async Task AddAsync(T entity, CancellationToken token = default)
+        {
+            await using var db = new UserServiceDbContext();
+            await _context(db).AddAsync(@entity, token);
+            await db.SaveChangesAsync(token);
+        }
+
+        public async Task UpdateAsync(T entity, CancellationToken token = default)
+        {
+            await using var db = new UserServiceDbContext();
+            _context(db).Update(entity);
+            await db.SaveChangesAsync(token);
+        }
+
+        public async Task DeleteAsync(T entity, CancellationToken token = default)
+        {
+            await using var db = new UserServiceDbContext();
+            _context(db).Remove(entity);
+            await db.SaveChangesAsync(token);
+        }
+    }
+}