<?php
/**
 * @file
 * Main methods of Replicate module.
 */

/**
 * Replicate the entity corresponding to the type and id passed in argument and save it.
 *
 * @param string $entity_type
 *   The entity type.
 * @param int $id
 *   The unique entity identifier.
 *
 * @return mixed
 *   The newly created entity id if the clone has been created and saved,
 *   else FALSE.
 *
 * @see replicate_entity()
 */
function replicate_entity_by_id($entity_type, $id) {
  $original = entity_load_single($entity_type, $id);
  return replicate_entity($entity_type, $original);
}

/**
 * Replicate the entity passed in argument and save it.
 *
 * @param string $entity_type
 *   The entity type.
 * @param object $entity
 *   The entity to replicate.
 *
 * @return mixed
 *   The newly created entity id if the clone has been created and saved,
 *   else FALSE.
 */
function replicate_entity($entity_type, $entity) {
  $clone = replicate_clone_entity($entity_type, $entity);
  if ($clone) {
    entity_save($entity_type, $clone);
    $entity_id = array_shift(entity_extract_ids($entity_type, $clone));

    if (isset($entity_id)) {
      return $entity_id;
    }
  }

  return FALSE;
}

/**
 * Replicate the entity corresponding to the type and id passed in argument.
 *
 * Do not save the replicated entity.
 *
 * @param string $entity_type
 *   The entity type.
 * @param int $id
 *   The unique entity identifier.
 *
 * @return object
 *   A new replicated entity.
 *
 * @see replicate_clone_entity()
 */
function replicate_clone_entity_by_id($entity_type, $id) {
  $original = entity_load_single($entity_type, $id);
  return replicate_clone_entity($entity_type, $original);
}

/**
 * Replicate the entity passed in argument.
 *
 * This function do not save the replicated entity.
 *
 * @param string $entity_type
 *   The entity type.
 * @param object $entity
 *   The entity to replicate.
 *
 * @return object
 *   A new replicated entity.
 */
function replicate_clone_entity($entity_type, $entity) {
  $clone = clone $entity;

  if ($clone) {
    // Let other modules manage the cleaning of the entity.
    foreach (module_implements('replicate_entity_' . $entity_type) as $module) {
      $function = $module . '_replicate_entity_' . $entity_type;
      $function($clone);
    }

    // Set the entity as new entity.
    $clone->is_new = TRUE;

    // Let other modules do special actions on each field.
    replicate_clone_fields($clone, $entity_type);

    // Let other modules do special actions on the global entity.
    drupal_alter('replicate_entity', $clone, $entity_type, $entity);
  }

  return $clone;
}

/**
 * Replicate the fields of an entity.
 *
 * @param object $entity
 *   The entity for which to clone the fields.
 * @param string $entity_type
 *   The entity type.
 */
function replicate_clone_fields(&$entity, $entity_type) {
  foreach (field_info_fields() as $field_name => $field) {
    if (isset($entity->$field_name)) {
      // Here call hook functions. Doesn't use module_invoke because we
      // want to pass the clone by reference.
      foreach (module_implements('replicate_field_' . $field['type']) as $module) {
        $function = $module . '_replicate_field_' . $field['type'];
        $function($entity, $entity_type, $field_name);
      }
    }
  }
}

/**
 * Implements hook_help().
 */
function replicate_help($path, $arg) {
  switch ($path) {
    case 'admin/help#replicate':
      // Return a line-break version of the module README.txt.
      return check_markup(file_get_contents(dirname(__FILE__) . "/README.txt"));
  }
}

/**
 * Implements hook_replicate_entity_ENTITY_TYPE().
 */
function replicate_replicate_entity_node(&$entity) {
  $entity->nid = NULL;
  $entity->tnid = NULL;
  $entity->vid = NULL;
  $entity->created = NULL;
  $entity->changed = NULL;
  $entity->path = NULL;
  $entity->revision_timestamp = NULL;
}

/**
 * Implements hook_replicate_entity_ENTITY_TYPE().
 */
function replicate_replicate_entity_taxonomy_vocabulary(&$entity) {
  $entity->vid = NULL;
}

/**
 * Implements hook_replicate_entity_ENTITY_TYPE().
 */
function replicate_replicate_entity_taxonomy_term(&$entity) {
  $entity->tid = NULL;
}

/**
 * Implements hook_replicate_entity_ENTITY_TYPE().
 */
function replicate_replicate_entity_user(&$entity) {
  $entity->uid = NULL;
}

/**
 * Implements hook_replicate_entity_ENTITY_TYPE().
 */
function replicate_replicate_entity_comment(&$entity) {
  $entity->cid = NULL;
  $entity->created = NULL;
  $entity->changed = NULL;
}

/**
 * Implements hook_replicate_entity_ENTITY_TYPE().
 */
function replicate_replicate_entity_file(&$entity) {
  $entity->fid = NULL;
}