Returns the default form state for the given entity and operation.
EntityInterface $entity: The entity to be created or edited.
$operation: (optional) The operation identifying the form to be processed.
A $form_state array already filled the entity form controller.
function entity_form_state_defaults(EntityInterface $entity, $operation = 'default', $langcode = NULL) {
$form_state = array();
$controller = entity_form_controller($entity
->entityType(), $operation);
$form_state['build_info']['callback'] = array(
$controller,
'build',
);
$form_state['build_info']['base_form_id'] = $entity
->entityType() . '_form';
$form_state['build_info']['args'] = array(
$entity,
);
$form_state['langcode'] = $langcode;
return $form_state;
}