SIG-CM2.0/tests/SIGCM2.Application.Tests/Auth/Login/LoginCommandHandlerTests.cs

using NSubstitute;
using SIGCM2.Application.Abstractions.Persistence;
using SIGCM2.Application.Abstractions.Security;
using SIGCM2.Application.Auth.Login;
using SIGCM2.Domain.Entities;
using SIGCM2.Domain.Exceptions;

namespace SIGCM2.Application.Tests.Auth.Login;

public class LoginCommandHandlerTests
{
    private readonly IUsuarioRepository _repository = Substitute.For<IUsuarioRepository>();
    private readonly IPasswordHasher _hasher = Substitute.For<IPasswordHasher>();
    private readonly IJwtService _jwtService = Substitute.For<IJwtService>();
    private readonly LoginCommandHandler _handler;

    public LoginCommandHandlerTests()
    {
        _handler = new LoginCommandHandler(_repository, _hasher, _jwtService);
    }

    // Scenario: valid credentials → returns token response with usuario populated
    [Fact]
    public async Task Handle_ValidCredentials_ReturnsTokenResponse()
    {
        var usuario = new Usuario(1, "admin", "$2a$12$hash", "Admin", "Sys", null, "admin", "[\"*\"]", true);
        _repository.GetByUsernameAsync("admin").Returns(usuario);
        _hasher.Verify("@Diego550@", "$2a$12$hash").Returns(true);
        _jwtService.GenerateAccessToken(usuario).Returns("jwt.token.here");

        var command = new LoginCommand("admin", "@Diego550@");
        var result = await _handler.Handle(command);

        Assert.Equal("jwt.token.here", result.AccessToken);
        Assert.False(string.IsNullOrWhiteSpace(result.RefreshToken));
        Assert.Equal(3600, result.ExpiresIn);

        // Contract: Usuario must be populated
        Assert.NotNull(result.Usuario);
        Assert.Equal(1, result.Usuario.Id);
        Assert.Equal("Admin Sys", result.Usuario.Nombre);
        Assert.Equal("admin", result.Usuario.Rol);
        Assert.NotNull(result.Usuario.Permisos);
        Assert.Contains("*", result.Usuario.Permisos);
    }

    // Triangulation: Usuario object maps id/nombre/rol/permisos from authenticated user
    [Fact]
    public async Task Handle_ValidCredentials_UsuarioMatchesAuthenticatedUser()
    {
        var usuario = new Usuario(42, "cajero1", "$2a$12$hash3", "María", "González", null, "Cajero",
            "[\"ventas:contado:create\",\"ventas:contado:read\"]", true);
        _repository.GetByUsernameAsync("cajero1").Returns(usuario);
        _hasher.Verify("pass123", "$2a$12$hash3").Returns(true);
        _jwtService.GenerateAccessToken(usuario).Returns("jwt.cajero.token");

        var command = new LoginCommand("cajero1", "pass123");
        var result = await _handler.Handle(command);

        Assert.Equal(42, result.Usuario.Id);
        Assert.Equal("María González", result.Usuario.Nombre);
        Assert.Equal("Cajero", result.Usuario.Rol);
        Assert.Equal(2, result.Usuario.Permisos.Length);
        Assert.Contains("ventas:contado:create", result.Usuario.Permisos);
        Assert.Contains("ventas:contado:read", result.Usuario.Permisos);
    }

    // Scenario: user does not exist → throws InvalidCredentialsException
    [Fact]
    public async Task Handle_UserNotFound_ThrowsInvalidCredentialsException()
    {
        _repository.GetByUsernameAsync("noexiste").Returns((Usuario?)null);

        var command = new LoginCommand("noexiste", "anything");

        await Assert.ThrowsAsync<InvalidCredentialsException>(() => _handler.Handle(command));
    }

    // Scenario: user is inactive → throws InvalidCredentialsException
    [Fact]
    public async Task Handle_InactiveUser_ThrowsInvalidCredentialsException()
    {
        var inactive = new Usuario(2, "operador", "$2a$12$hash2", "Juan", "Pérez", null, "vendedor", "[]", false);
        _repository.GetByUsernameAsync("operador").Returns(inactive);

        var command = new LoginCommand("operador", "correctpassword");

        await Assert.ThrowsAsync<InvalidCredentialsException>(() => _handler.Handle(command));
    }

    // Scenario: wrong password → throws InvalidCredentialsException
    [Fact]
    public async Task Handle_WrongPassword_ThrowsInvalidCredentialsException()
    {
        var usuario = new Usuario(1, "admin", "$2a$12$hash", "Admin", "Sys", null, "admin", "[\"*\"]", true);
        _repository.GetByUsernameAsync("admin").Returns(usuario);
        _hasher.Verify("WrongPass1", "$2a$12$hash").Returns(false);

        var command = new LoginCommand("admin", "WrongPass1");

        await Assert.ThrowsAsync<InvalidCredentialsException>(() => _handler.Handle(command));
    }
}