If the resturaunt is dirty and the ambiance is that bad, you should report it to the manager. That is the person responsible for everyone else in the establishment. However, you chose the resturaunt and chose to stay. If the service was good, then yes you should tip.
If the resturaunt is dirty and the ambiance is that bad, you should report it to the manager. That is the person responsible for everyone else in the establishment. However, you chose the resturaunt and chose to stay. If the service was good, then yes you should tip.