using SIGCM2.Application.Abstractions;
using SIGCM2.Application.Abstractions.Persistence;
using SIGCM2.Application.Roles.Dtos;
using SIGCM2.Domain.Entities;
using SIGCM2.Domain.Exceptions;

namespace SIGCM2.Application.Roles.Create;

public sealed class CreateRolCommandHandler : ICommandHandler<CreateRolCommand, RolCreatedDto>
{
    private readonly IRolRepository _repository;

    public CreateRolCommandHandler(IRolRepository repository)
    {
        _repository = repository;
    }

    public async Task<RolCreatedDto> Handle(CreateRolCommand command)
    {
        // Check-then-insert: explicit check produces a clear 409 message.
        // SqlException 2627 (UQ violation) acts as race-condition fallback — caught in ExceptionFilter.
        var existing = await _repository.GetByCodigoAsync(command.Codigo);
        if (existing is not null)
            throw new RolAlreadyExistsException(command.Codigo);

        var rol = Rol.ForCreation(command.Codigo, command.Nombre, command.Descripcion);
        var newId = await _repository.AddAsync(rol);

        return new RolCreatedDto(
            Id: newId,
            Codigo: rol.Codigo,
            Nombre: rol.Nombre,
            Descripcion: rol.Descripcion,
            Activo: rol.Activo);
    }
}