<?php
/**
 * @file
 * Implementation of Migration for relations.
 */

/**
 * Handling relations.
 */
abstract class CustomRelationMigration extends DrupalMigration {
  /**
   * Translation from field names assigned when executing the query to our
   * subfield notation.
   *
   * @var array
   *  key: DB-compatible name (e.g., field_buy_link_title).
   *  value: Subfield notation (e.g., field_buy_link:title).
   */
  protected $fixFieldNames = array();

  /**
   * The source and destination content types (bundles) we're dealing with.
   */
  protected $destinationType;

  protected $endpointSourceType;
  protected $endpointDestinationType;

  protected $relationTable;
  protected $relationTableSourceID;
  protected $relationTableDestinationID;

  /**
   * @param array $arguments
   */
  public function __construct(array $arguments) {
    if (!empty($arguments['default_language'])) {
      $this->defaultLanguage = $arguments['default_language'];
    }

    $this->destinationType = $arguments['destination_type'];

    $this->relationTable = $arguments['relation_table'];
    $this->relationTableSourceID = $arguments['relation_table_source_id'];
    $this->relationTableDestinationID = $arguments['relation_table_destination_id'];

    $this->endpointSourceType = $arguments['endpoint_source_type'];
    $this->endpointDestinationType = $arguments['endpoint_destination_type'];

    parent::__construct($arguments);

    $query = $this->query();

    $this->sourceOptions['fix_field_names'] = $this->fixFieldNames;

    $this->source = new MigrateDrupal5SourceSQL($query, $this->sourceFields, NULL,
      $this->sourceOptions);

    $this->destination = new MigrateDestinationRelation($this->destinationType);

    $this->map = new MigrateSQLMap($this->machineName,
      array(
        $this->relationTableSourceID => array(
          'type' => 'int',
          'unsigned' => TRUE,
          'not null' => TRUE,
          'description' => 'Relation Source ID',
          'alias' => 'r',
        ),
        $this->relationTableDestinationID => array(
          'type' => 'int',
          'unsigned' => TRUE,
          'not null' => TRUE,
          'description' => 'Relation Destination ID',
          'alias' => 'r',
        ),
      ),
      MigrateDestinationRelation::getKeySchema()
    );

    $this->addFieldMapping('is_new')
         ->defaultValue(1);

    $this->addFieldMapping('endpoints')
         ->description('Handled in prepare()');

    $this->addFieldMapping('entity_id_source', 'relation_source_nid')
         ->sourceMigration($arguments['relation_source_migration']);
    $this->addFieldMapping('entity_id_destination', 'relation_destination_nid')
         ->sourceMigration($arguments['relation_destination_migration']);

    $this->addUnmigratedDestinations(array(
      'migrate_redirects',
      'path',
      'pathauto', 'uid', 'changed', 'created',
      // Relation
      'endpoints:entity_id', 'endpoints:r_index',
    ));
  }

  /**
   * Query for basic node fields from Drupal 5.
   *
   * @return QueryConditionInterface
   */
  protected function query() {
    $query = Database::getConnection('default', $this->sourceConnection)
             ->select($this->relationTable, 'r');
    $query->addField('r', $this->relationTableSourceID);
    $query->addField('r', $this->relationTableDestinationID);

    return $query;
  }

  public function prepare(stdClass $relation, stdClass $row) {
    if (!empty($relation->entity_id_source) && !empty($relation->entity_id_destination)) {
      $relation->endpoints[LANGUAGE_NONE] = array(
        // Relation Source
        array('entity_type' => $this->endpointSourceType, 'entity_id' => $relation->entity_id_source),
        // Relation Destination:
        array('entity_type' => $this->endpointDestinationType, 'entity_id' => $relation->entity_id_destination),
      );
    }
  }
}