bitforum-backend/Application/Features/Api/Auth/Logout/Handler.cs

using Application.Abstractions.Data;
using Application.Abstractions.Messaging;
using Microsoft.EntityFrameworkCore;
using Microsoft.Extensions.Logging;
using SharedKernel.Results;

namespace Application.Features.Api.Auth.Logout;

internal sealed class Handler(IAppDbContext db, ILogger<Handler> logger) : ICommandHandler<Command, Result>
{
    public async Task<Result> Handle(Command request, CancellationToken ct)
    {
        if (string.IsNullOrWhiteSpace(request.RefreshToken))
        {
            return Result.Failure(Error.Problem("Auth.TokenRequired", "리프레시 토큰은 필수입니다."));
        }

        var refreshToken = await db.RefreshToken.FirstOrDefaultAsync(t => t.Token == request.RefreshToken && t.MemberID == request.MemberID, ct);

        if (refreshToken is null)
        {
            return Result.Failure(Error.NotFound("Auth.TokenNotFound", "유효하지 않은 리프레시 토큰입니다."));
        }

        if (refreshToken.IsRevoked)
        {
            return Result.Success();
        }

        refreshToken.Revoke();

        await db.SaveChangesAsync(ct);

        logger.LogInformation("로그아웃 완료");

        return Result.Success();
    }
}