back/Contracts/Repositories/IUserRepo.cs

@@ -7,6 +7,6 @@ public interface IUserRepo
 {
     public Task<UserDto?> Get(UserSearch search);
     public Task<UserDto> Create(UserDto user);
-    public Task<UserDto> Update(UserDto user);
-    public Task<UserDto> Delete(UserSearch search);
+    public Task<UserDto?> Update(UserDto user);
+    public Task<UserDto?> Delete(UserSearch search);
 }

back/Infrastructure/DatabaseContext.cs

@@ -0,0 +1,15 @@
+using Infrastructure.Models;
+using Microsoft.EntityFrameworkCore;
+
+namespace Infrastructure;
+
+public class DatabaseContext : DbContext
+{
+    public DatabaseContext(DbContextOptions<DatabaseContext> options)
+        : base(options)
+    {
+        Database.EnsureCreated();
+    }
+
+    public DbSet<User> Users { get; set; } = null!;
+}

back/Infrastructure/DbContextFactory.cs

@@ -0,0 +1,20 @@
+using Microsoft.EntityFrameworkCore;
+using Microsoft.Extensions.DependencyInjection;
+
+namespace Infrastructure;
+
+public class DbContextFactory : IDbContextFactory<DatabaseContext>
+{
+    private readonly IServiceProvider _serviceProvider;
+
+    public DbContextFactory(IServiceProvider serviceProvider)
+    {
+        _serviceProvider = serviceProvider;
+    }
+
+    public DatabaseContext CreateDbContext()
+    {
+        var scope = _serviceProvider.CreateScope();
+        return scope.ServiceProvider.GetRequiredService<DatabaseContext>();
+    }
+}

back/Infrastructure/Infrastructure.csproj

@@ -1,5 +1,17 @@
 <Project Sdk="Microsoft.NET.Sdk">
 
+  <ItemGroup>
+    <ProjectReference Include="..\Contracts\Contracts.csproj" />
+  </ItemGroup>
+
+  <ItemGroup>
+    <PackageReference Include="Microsoft.EntityFrameworkCore.Design" Version="9.0.0">
+      <IncludeAssets>runtime; build; native; contentfiles; analyzers; buildtransitive</IncludeAssets>
+      <PrivateAssets>all</PrivateAssets>
+    </PackageReference>
+    <PackageReference Include="Npgsql.EntityFrameworkCore.PostgreSQL" Version="9.0.1" />
+  </ItemGroup>
+
   <PropertyGroup>
     <TargetFramework>net8.0</TargetFramework>
     <ImplicitUsings>enable</ImplicitUsings>

back/Infrastructure/Models/User.cs

@@ -0,0 +1,25 @@
+using System.Reflection.Metadata.Ecma335;
+using Contracts.DTO;
+
+namespace Infrastructure.Models;
+
+public class User
+{
+    public Guid Id { get; set; }
+    public string Name { get; set; } = null!;
+    public string Password { get; set; } = null!;
+    public decimal Balance { get; set; }
+
+    public void Update(UserDto userDto)
+    {
+        Id = userDto.Id;
+        if (!string.IsNullOrWhiteSpace(userDto.Name)) 
+        {
+            Name = userDto.Name;
+        }
+        if (!string.IsNullOrWhiteSpace(userDto.Password))
+        {
+            Password = userDto.Password;
+        }
+    }
+}

back/Infrastructure/Repositories/UserRepo.cs

@@ -0,0 +1,72 @@
+using Contracts.DTO;
+using Contracts.Repositories;
+using Contracts.SearchModels;
+using Infrastructure.Support.Mappers;
+using Microsoft.EntityFrameworkCore;
+
+namespace Infrastructure.Repositories;
+
+public class UserRepo : IUserRepo
+{
+    public readonly DbContextFactory _factory;
+
+    public UserRepo(DbContextFactory factory)
+    {
+        _factory = factory;
+    }
+
+    public async Task<UserDto> Create(UserDto user)
+    {
+        using var context = _factory.CreateDbContext();
+
+        var createdUser = await context.Users.AddAsync(user.ToModel());
+
+        await context.SaveChangesAsync();
+        return createdUser.Entity.ToDto();
+    }
+
+    public async Task<UserDto?> Delete(UserSearch search)
+    {
+        using var context = _factory.CreateDbContext();
+
+        var user = await context.Users
+            .FirstOrDefaultAsync(x => x.Id == search.Id 
+                || x.Name == search.Name);
+        if (user == null)
+        {
+            return null;
+        }
+
+        context.Users.Remove(user);
+        await context.SaveChangesAsync();
+        return user.ToDto();
+    }
+
+    public async Task<UserDto?> Get(UserSearch search)
+    {
+        using var context = _factory.CreateDbContext();
+
+        var user = await context.Users
+            .FirstOrDefaultAsync(x => x.Id == search.Id 
+                || x.Name == search.Name);
+
+        return user?.ToDto();
+    }
+
+    public async Task<UserDto?> Update(UserDto user)
+    {
+        using var context = _factory.CreateDbContext();
+
+        var existingUser = await context.Users.FirstOrDefaultAsync(x => x.Id == user.Id);
+
+        if (existingUser == null)
+        {
+            return null;
+        }
+
+        existingUser.Update(user);
+        context.Users.Update(existingUser);
+        await context.SaveChangesAsync();
+        return existingUser.ToDto();
+    }
+}

back/Infrastructure/Support/Mappers/UserMapper.cs

@@ -0,0 +1,25 @@
+using Contracts.DTO;
+using Infrastructure.Models;
+
+namespace Infrastructure.Support.Mappers;
+
+public static class UserMapper
+{
+    public static UserDto ToDto(this User user) 
+        => new() 
+        {
+            Id = user.Id,
+            Name = user.Name,
+            Balance = user.Balance,
+            Password = user.Password
+        };
+    
+    public static User ToModel(this UserDto user)
+        => new()
+        {
+            Id = user.Id,
+            Name = user.Name,
+            Balance = user.Balance,
+            Password = user.Password
+        };
+}