Implement user existence check and repository pattern for user management

Author: TranHuyThang9999

Common/Exceptions/UserAlreadyExistsException.cs

@@ -22,8 +22,12 @@ public UsersController(IMediator mediator)
     [AllowAnonymous] // Cho phép tạo user mà không cần authentication
     public async Task<IActionResult> Create([FromBody] CreateUserCommand command)
     {
-        var user = await _mediator.Send(command);
-        return Ok(user);
+        var result = await _mediator.Send(command);
+        if (result == null)
+        {
+            return ErrorResponse("Username already exists");
+        }
+        return SuccessResponse(result);
     }
 
     [HttpGet("profile")]

Controllers/UsersController.cs

@@ -0,0 +1,10 @@
+using System.Linq.Expressions;
+
+namespace PaymentCoreServiceApi.Core.Interfaces.Repositories.Read;
+
+public interface IBaseReadRepository<TEntity> where TEntity : class
+{
+    Task<TEntity> GetByIdAsync(int id);
+    Task<IEnumerable<TEntity>> GetAllAsync();
+    Task<(IEnumerable<TEntity> Items, int TotalCount)> GetPagedAsync(int pageIndex, int pageSize, Expression<Func<TEntity, bool>> predicate);
+}

Core/Interfaces/Repositories/Read/IBaseReadRepository.cs

@@ -2,5 +2,5 @@ namespace PaymentCoreServiceApi.Core.Interfaces.Repositories.Read;
 
 public interface IUserReadRepository
 {
-    
+    Task<bool> ExistsAsync(string username);
 }

Core/Interfaces/Repositories/Read/IUserReadRepository.cs

@@ -1,20 +1,26 @@
 using MediatR;
 using PaymentCoreServiceApi.Core.Entities.UserGenerated;
+using PaymentCoreServiceApi.Core.Interfaces.Repositories.Read;
 using PaymentCoreServiceApi.Core.Interfaces.Repositories.Write;
 
 namespace PaymentCoreServiceApi.Features.Users.Commands;
 
 public class CreateUserCommandHandler : IRequestHandler<CreateUserCommand, User>
 {
     private readonly IUserWriteRepository _userWriteRepository;
-
-    public CreateUserCommandHandler(IUserWriteRepository userWriteRepository)
+    private readonly IUserReadRepository _userReadRepository;
+    public CreateUserCommandHandler(IUserWriteRepository userWriteRepository, IUserReadRepository userReadRepository)
     {
         _userWriteRepository = userWriteRepository;
+        _userReadRepository = userReadRepository;
     }
 
     public async Task<User> Handle(CreateUserCommand request, CancellationToken cancellationToken)
     {
+        if (await _userReadRepository.ExistsAsync(request.UserName))
+        {
+            return null;
+        }
         try
         {
             var user = new User
@@ -26,13 +32,12 @@ public async Task<User> Handle(CreateUserCommand request, CancellationToken canc
                 Age = request.Age,
                 Email = request.Email,
                 UserName = request.UserName,
-                Password = request.Password, // Note: In production, hash this password
+                Password = request.Password,
                 PhoneNumber = request.PhoneNumber,
                 Address = request.Address,
                 Active = true
             };
 
-            // Add the user without auto-commit
             var result = await _userWriteRepository.AddAsync(user);
             await _userWriteRepository.CommitAsync();
             return result;

Features/Users/Commands/CreateUserCommandHandler.cs

@@ -3,8 +3,10 @@
 using Microsoft.Extensions.Configuration;
 using Microsoft.Extensions.DependencyInjection;
 using Microsoft.IdentityModel.Tokens;
+using PaymentCoreServiceApi.Core.Interfaces.Repositories.Read;
 using PaymentCoreServiceApi.Core.Interfaces.Repositories.Write;
 using PaymentCoreServiceApi.Features.Auth;
+using PaymentCoreServiceApi.Infrastructure.Repositories.Read;
 using PaymentCoreServiceApi.Infrastructure.Repositories.Write;
 using PaymentCoreServiceApi.Middlewares;
 using PaymentCoreServiceApi.Services;
@@ -20,7 +22,7 @@ public static IServiceCollection AddRepositories(this IServiceCollection service
 
         // Register Domain Specific Repositories
         services.AddScoped<IUserWriteRepository, UserWriteRepository>();
-        
+        services.AddScoped<IUserReadRepository, UserReadRepository>();
         return services;
     }
 

Infrastructure/Extensions/ServiceCollectionExtensions.cs

@@ -0,0 +1,44 @@
+using PaymentCoreServiceApi.Core.Entities.BaseModel;
+using PaymentCoreServiceApi.Core.Interfaces.Repositories.Read;
+using PaymentCoreServiceApi.Infrastructure.DbContexts;
+using Microsoft.EntityFrameworkCore;
+using System.Linq.Expressions;
+
+namespace PaymentCoreServiceApi.Infrastructure.Repositories.Read;
+
+public class EfBaseReadOnlyRepository<TEntity> : IBaseReadRepository<TEntity> where TEntity : EntityBase
+{
+    private readonly AppDbContext _context;
+    private readonly DbSet<TEntity> _dbSet;
+
+    public EfBaseReadOnlyRepository(AppDbContext context)
+    {
+        _context = context;
+        _dbSet = context.Set<TEntity>();
+    }
+
+    public async Task<TEntity> GetByIdAsync(int id)
+    {
+        return await _dbSet.FindAsync(id);
+    }
+
+    public async Task<IEnumerable<TEntity>> GetAllAsync()
+    {
+        return await _dbSet.ToListAsync();
+    }
+
+    public async Task<(IEnumerable<TEntity> Items, int TotalCount)> GetPagedAsync(int pageIndex, int pageSize, Expression<Func<TEntity, bool>> predicate)
+    {
+        var query = _dbSet.Where(predicate);
+        var totalCount = await query.CountAsync();
+        var items = await query
+            .Skip((pageIndex - 1) * pageSize)
+            .Take(pageSize)
+            .ToListAsync();
+
+        return (items, totalCount);
+    }
+    
+    
+    
+}

Infrastructure/Repositories/Read/EfBaseReadOnlyRepository.cs

@@ -1,6 +1,21 @@
+using Microsoft.EntityFrameworkCore;
+using PaymentCoreServiceApi.Core.Entities.UserGenerated;
+using PaymentCoreServiceApi.Core.Interfaces.Repositories.Read;
+using PaymentCoreServiceApi.Infrastructure.DbContexts;
+
 namespace PaymentCoreServiceApi.Infrastructure.Repositories.Read;
 
-public class UserReadRepository
+public class UserReadRepository : EfBaseReadOnlyRepository<User>, IUserReadRepository
 {
-    
+    private readonly AppDbContext _context;
+
+    public UserReadRepository(AppDbContext context) : base(context)
+    {
+        _context = context;
+    }
+
+    public async Task<bool> ExistsAsync(string username)
+    {
+        return await _context.Users.AnyAsync(u => u.UserName == username);
+    }
 }