using Domain.Exceptions;
using Features.Auth.Dtos;
using Features.Auth.Repository;
using Features.Auth.Services;
using MediatR;

namespace Features.Auth.Commands.ConfirmUser;

/// <summary>
/// Handles <see cref="ConfirmUserCommand"/> by validating the confirmation token and marking the
/// corresponding user account as confirmed.
/// </summary>
/// <param name="authRepository">Repository used to look up and confirm user accounts.</param>
/// <param name="tokenService">Service used to validate the confirmation token.</param>
public class ConfirmUserHandler(
    IAuthRepository authRepository,
    ITokenService tokenService
) : IRequestHandler<ConfirmUserCommand, ConfirmationPayload>
{
    /// <exception cref="UnauthorizedException">
    /// Thrown when the confirmation token is invalid or expired, or when the associated user account cannot be found.
    /// </exception>
    public async Task<ConfirmationPayload> Handle(ConfirmUserCommand request, CancellationToken cancellationToken)
    {
        var validatedToken = await tokenService.ValidateConfirmationTokenAsync(request.Token);

        var user = await authRepository.ConfirmUserAccountAsync(validatedToken.UserId);

        if (user == null)
        {
            throw new UnauthorizedException("User account not found");
        }

        return new ConfirmationPayload(user.UserAccountId, DateTime.UtcNow);
    }
}