<?php
// $Id$

/**
 * @file
 * Provides Rules intregration for the Voting API module
 */

/**
 * Implements hook_votingapi_insert().
 */
function voting_rules_votingapi_insert($votes) {
  _voting_rules_votingapi_op($votes, 'insert');
}

/**
 * Implements hook_votingapi_results().
 */
function voting_rules_votingapi_delete($votes) {
  _voting_rules_votingapi_op($votes, 'delete');
}

function _voting_rules_votingapi_op($votes, $op) {
  foreach ($votes as $vote) {
    $entity = voting_rules_load_entity($vote['entity_type'], $vote['entity_id']);

    if ($entity) {
      if (in_array($vote['entity_type'], array_keys(voting_rules_get_types()))) {
      	rules_invoke_event('voting_rules_' . $op . '_' . $vote['entity_type'], $vote, $entity);
      }
      else {
      	rules_invoke_event('voting_rules_' . $op . '_entity', $vote, $entity);
      }
    }
  }
}

/**
 * Implements hook_votingapi_results().
 */
function voting_rules_votingapi_results($cached, $entity_type, $entity_id) {
  $entity = voting_rules_load_entity($entity_type, $entity_id);
  foreach ($cached as $result) {
    $vote_results[$result['function']] = $result;
  }
  
  if ($entity) {
    rules_invoke_event('voting_rules_results_' . $entity_type, $vote_results, $entity);
  }
}

/**
 * Helper function that loads content of the specified type. Since Voting API is
 * built to support client defined content types, while Rules requires content 
 * types to be pre-defined, we use this helper function to encapsulate the 
 * loading of new content based on supported types (currently nodes, users, and
 * comments) and the entity API for unknown entities.
 *
 * @param $entity_type
 *   The entity type.
 * @param $entity_id
 *   The entity ID.
 */
function voting_rules_load_entity($entity_type, $entity_id) {
  switch ($entity_type) {
    case 'node':
      return node_load($entity_id);

    case 'user':
      return user_load($entity_id);

    case 'comment':
      return comment_load($entity_id);

    default:
    	$entity_key = voting_rules_get_entity_key($entity_type);
    	$entities = entity_load($entity_type, array($entity_id));
    	$entity = reset($entities);
    	return $entity;
  }
}

/**
 * Helper function to get Voting API entity types that should be used by rules.
 *
 * @return
 *   A keyed array of entity types.
 */
function voting_rules_get_types() {
  $types = array('node' => t('Node'), 'user' => t('User'), 'comment' => t('Comment'), 'entity' => t('Entity'));
	drupal_alter('voting_rules_types', $types);
	return $types;
}

/**
 * Helper function to get the primary key used by an entity.
 *
 * @return
 *   An entity key.
 */
function voting_rules_get_entity_key($entity_type) {
  switch ($entity_type) {
    case 'node':
      return 'nid';

    case 'user':
      return 'uid';

    case 'comment':
      return 'cid';

    default:
    	$entity_info = entity_get_info($entity_type);
    	return $entity_info['entity keys']['id'];
  }
}

/**
 * Rules callback for user and entities.
 */
function voting_rules_get_property($data, array $options, $name, $entity_type) {
  switch ($name) {
    case 'user':
      return user_load($data['uid']);

    case 'entity':
    	return voting_rules_load_entity($data['entity_type'], $data['entity_id']);
  }
}

/**
 * Rules callback to get votes on an entity.
 */
function voting_rules_get_votes($entity, array $options, $name, $entity_type) {
  $entity_key = voting_rules_get_entity_key($entity_type);

  $votes = votingapi_select_votes(array(
    'entity_id' => $entity->$entity_key,
    'entity_type' => $entity_type
  ));

  return $votes;
}

/**
 * Rules callback to get vote results on an entity.
 */
function voting_rules_get_vote_results($entity, array $options, $name, $entity_type) {
  $entity_key = voting_rules_get_entity_key($entity_type);
  $results = array();

  $select_results = votingapi_select_results(array(
    'entity_id' => $entity->$entity_key,
    'entity_type' => $entity_type
  ));

  foreach ($select_results as $select_result) {
    $results[$select_result['function']] = $select_result;
  }

  return $results;
}