taxbaik/src/TaxBaik.Web/Endpoints/Auth/LoginEndpoint.cs

using FastEndpoints;
using TaxBaik.Web.Services;

namespace TaxBaik.Web.Endpoints.Auth;

public class LoginRequest
{
    public string Username { get; set; } = string.Empty;
    public string Password { get; set; } = string.Empty;
}

public class TokenPairResponse
{
    public string Token { get; set; } = string.Empty;
    public string AccessToken { get; set; } = string.Empty;
    public string RefreshToken { get; set; } = string.Empty;
    public int ExpiresIn { get; set; }
}

public class LoginEndpoint : Endpoint<LoginRequest, TokenPairResponse>
{
    private readonly AuthService _authService;

    public LoginEndpoint(AuthService authService)
    {
        _authService = authService;
    }

    public override void Configure()
    {
        Post("/api/auth/login");
        AllowAnonymous();
    }

    public override async Task HandleAsync(LoginRequest request, CancellationToken ct)
    {
        if (string.IsNullOrWhiteSpace(request.Username) || string.IsNullOrWhiteSpace(request.Password))
        {
            ThrowError("로그인 정보가 필요합니다.");
        }

        var authResult = await _authService.AuthenticateAndGenerateTokenPairAsync(request.Username, request.Password);
        if (!authResult.IsSuccess || authResult.TokenPair is null)
        {
            ThrowError(authResult.FailureReason == AuthFailureReason.DatabaseUnavailable
                ? "로그인 서비스를 일시적으로 사용할 수 없습니다."
                : "아이디 또는 비밀번호가 올바르지 않습니다.");
        }

        await SendAsync(new TokenPairResponse
        {
            Token = authResult.TokenPair!.AccessToken,
            AccessToken = authResult.TokenPair.AccessToken,
            RefreshToken = authResult.TokenPair.RefreshToken,
            ExpiresIn = authResult.TokenPair.ExpiresIn
        }, 200, cancellation: ct);
    }
}