<?php

/**

 * @file

 * This is the actions engine for executing stored actions.

 */

/**

 * @defgroup actions Actions

 * @{

 * Functions that perform an action on a certain system object.

 *

 * Action functions are declared by modules by implementing hook_action_info().

 * Modules can cause action functions to run by calling actions_do(), and

 * trigger.module provides a user interface that lets administrators define

 * events that cause action functions to run.

 *

 * Each action function takes two to four arguments:

 * - $entity: The object that the action acts on, such as a node, comment, or

 *   user.

 * - $context: Array of additional information about what triggered the action.

 * - $a1, $a2: Optional additional information, which can be passed into

 *   actions_do() and will be passed along to the action function.

 *

 * @}

 */

/**

 * Performs a given list of actions by executing their callback functions.

 *

 * Given the IDs of actions to perform, this function finds out what the

 * callback functions for the actions are by querying the database. Then

 * it calls each callback using the function call $function($object, $context,

 * $a1, $a2), passing the input arguments of this function (see below) to the

 * action function.

 *

 * @param $action_ids

 *   The IDs of the actions to perform. Can be a single action ID or an array

 *   of IDs. IDs of configurable actions must be given as numeric action IDs;

 *   IDs of non-configurable actions may be given as action function names.

 * @param $object

 *   The object that the action will act on: a node, user, or comment object.

 * @param $context

 *   Associative array containing extra information about what triggered

 *   the action call, with $context['hook'] giving the name of the hook

 *   that resulted in this call to actions_do().

 * @param $a1

 *   Passed along to the callback.

 * @param $a2

 *   Passed along to the callback.

 *

 * @return

 *   An associative array containing the results of the functions that

 *   perform the actions, keyed on action ID.

 *

 * @ingroup actions

 */

function actions_do($action_ids, $object = NULL, $context = NULL, $a1 = NULL, $a2 = NULL) {

  // $stack tracks the number of recursive calls.

  static $stack;

  $stack++;

  if ($stack > variable_get('actions_max_stack', 35)) {

    watchdog('actions', 'Stack overflow: too many calls to actions_do(). Aborting to prevent infinite recursion.', array(), WATCHDOG_ERROR);

    return;

  }

  $actions = array();

  $available_actions = actions_list();

  $actions_result = array();

  if (is_array($action_ids)) {

    $conditions = array();

    foreach ($action_ids as $action_id) {

      if (is_numeric($action_id)) {

        $conditions[] = $action_id;

      }

      elseif (isset($available_actions[$action_id])) {

        $actions[$action_id] = $available_actions[$action_id];

      }

    }

    // When we have action instances we must go to the database to retrieve

    // instance data.

    if (!empty($conditions)) {

      $query = db_select('actions');

      $query->addField('actions', 'aid');

      $query->addField('actions', 'type');

      $query->addField('actions', 'callback');

      $query->addField('actions', 'parameters');

      $query->condition('aid', $conditions, 'IN');

      $result = $query->execute();

      foreach ($result as $action) {

        $actions[$action->aid] = $action->parameters ? unserialize($action->parameters) : array();

        $actions[$action->aid]['callback'] = $action->callback;

        $actions[$action->aid]['type'] = $action->type;

      }

    }

    // Fire actions, in no particular order.

    foreach ($actions as $action_id => $params) {

      // Configurable actions need parameters.

      if (is_numeric($action_id)) {

        $function = $params['callback'];

        if (function_exists($function)) {

          $context = array_merge($context, $params);

          $actions_result[$action_id] = $function($object, $context, $a1, $a2);

        }

        else {

          $actions_result[$action_id] = FALSE;

        }

      }

      // Singleton action; $action_id is the function name.

      else {

        $actions_result[$action_id] = $action_id($object, $context, $a1, $a2);

      }

    }

  }

  // Optimized execution of a single action.

  else {

    // If it's a configurable action, retrieve stored parameters.

    if (is_numeric($action_ids)) {

      $action = db_query("SELECT callback, parameters FROM {actions} WHERE aid = :aid", array(':aid' => $action_ids))->fetchObject();

      $function = $action->callback;

      if (function_exists($function)) {

        $context = array_merge($context, unserialize($action->parameters));

        $actions_result[$action_ids] = $function($object, $context, $a1, $a2);

      }

      else {

        $actions_result[$action_ids] = FALSE;

      }

    }

    // Singleton action; $action_ids is the function name.

    else {

      if (function_exists($action_ids)) {

        $actions_result[$action_ids] = $action_ids($object, $context, $a1, $a2);

      }

      else {

        // Set to avoid undefined index error messages later.

        $actions_result[$action_ids] = FALSE;

      }

    }

  }

  $stack--;

  return $actions_result;

}

/**

 * Discovers all available actions by invoking hook_action_info().

 *

 * This function contrasts with actions_get_all_actions(); see the

 * documentation of actions_get_all_actions() for an explanation.

 *

 * @param $reset

 *   Reset the action info static cache.

 *

 * @return

 *   An associative array keyed on action function name, with the same format

 *   as the return value of hook_action_info(), containing all

 *   modules' hook_action_info() return values as modified by any

 *   hook_action_info_alter() implementations.

 *

 * @see hook_action_info()

 */

function actions_list($reset = FALSE) {

  $actions = &drupal_static(__FUNCTION__);

  if (!isset($actions) || $reset) {

    $actions = module_invoke_all('action_info');

    drupal_alter('action_info', $actions);

  }

  // See module_implements() for an explanation of this cast.

  return (array) $actions;

}

/**

 * Retrieves all action instances from the database.

 *

 * This function differs from the actions_list() function, which gathers

 * actions by invoking hook_action_info(). The actions returned by this

 * function and the actions returned by actions_list() are partially

 * synchronized. Non-configurable actions from hook_action_info()

 * implementations are put into the database when actions_synchronize() is

 * called, which happens when admin/config/system/actions is visited.

 * Configurable actions are not added to the database until they are configured

 * in the user interface, in which case a database row is created for each

 * configuration of each action.

 *

 * @return

 *   Associative array keyed by numeric action ID. Each value is an associative

 *   array with keys 'callback', 'label', 'type' and 'configurable'.

 */

function actions_get_all_actions() {

  $actions = db_query("SELECT aid, type, callback, parameters, label FROM {actions}")->fetchAllAssoc('aid', PDO::FETCH_ASSOC);

  foreach ($actions as &$action) {

    $action['configurable'] = (bool) $action['parameters'];

    unset($action['parameters']);

    unset($action['aid']);

  }

  return $actions;

}

/**

 * Creates an associative array keyed by hashes of function names or IDs.

 *

 * Hashes are used to prevent actual function names from going out into HTML

 * forms and coming back.

 *

 * @param $actions

 *   An associative array with function names or action IDs as keys

 *   and associative arrays with keys 'label', 'type', etc. as values.

 *   This is usually the output of actions_list() or actions_get_all_actions().

 *

 * @return

 *   An associative array whose keys are hashes of the input array keys, and

 *   whose corresponding values are associative arrays with components

 *   'callback', 'label', 'type', and 'configurable' from the input array.

 */

function actions_actions_map($actions) {

  $actions_map = array();

  foreach ($actions as $callback => $array) {

    $key = drupal_hash_base64($callback);

    $actions_map[$key]['callback']     = isset($array['callback']) ? $array['callback'] : $callback;

    $actions_map[$key]['label']        = $array['label'];

    $actions_map[$key]['type']         = $array['type'];

    $actions_map[$key]['configurable'] = $array['configurable'];

  }

  return $actions_map;

}

/**

 * Returns an action array key (function or ID), given its hash.

 *

 * Faster than actions_actions_map() when you only need the function name or ID.

 *

 * @param $hash

 *   Hash of a function name or action ID array key. The array key

 *   is a key into the return value of actions_list() (array key is the action

 *   function name) or actions_get_all_actions() (array key is the action ID).

 *

 * @return

 *   The corresponding array key, or FALSE if no match is found.

 */

function actions_function_lookup($hash) {

  // Check for a function name match.

  $actions_list = actions_list();

  foreach ($actions_list as $function => $array) {

    if (drupal_hash_base64($function) == $hash) {

      return $function;

    }

  }

  $aid = FALSE;

  // Must be a configurable action; check database.

  $result = db_query("SELECT aid FROM {actions} WHERE parameters <> ''")->fetchAll(PDO::FETCH_ASSOC);

  foreach ($result as $row) {

    if (drupal_hash_base64($row['aid']) == $hash) {

      $aid = $row['aid'];

      break;

    }

  }

  return $aid;

}

/**

 * Synchronizes actions that are provided by modules in hook_action_info().

 *

 * Actions provided by modules in hook_action_info() implementations are

 * synchronized with actions that are stored in the actions database table.

 * This is necessary so that actions that do not require configuration can

 * receive action IDs.

 *

 * @param $delete_orphans

 *   If TRUE, any actions that exist in the database but are no longer

 *   found in the code (for example, because the module that provides them has

 *   been disabled) will be deleted.

 */

function actions_synchronize($delete_orphans = FALSE) {

  $actions_in_code = actions_list(TRUE);

  $actions_in_db = db_query("SELECT aid, callback, label FROM {actions} WHERE parameters = ''")->fetchAllAssoc('callback', PDO::FETCH_ASSOC);

  // Go through all the actions provided by modules.

  foreach ($actions_in_code as $callback => $array) {

    // Ignore configurable actions since their instances get put in when the

    // user adds the action.

    if (!$array['configurable']) {

      // If we already have an action ID for this action, no need to assign aid.

      if (isset($actions_in_db[$callback])) {

        unset($actions_in_db[$callback]);

      }

      else {

        // This is a new singleton that we don't have an aid for; assign one.

        db_insert('actions')

          ->fields(array(

            'aid' => $callback,

            'type' => $array['type'],

            'callback' => $callback,

            'parameters' => '',

            'label' => $array['label'],

            ))

          ->execute();

        watchdog('actions', "Action '%action' added.", array('%action' => $array['label']));

      }

    }

  }

  // Any actions that we have left in $actions_in_db are orphaned.

  if ($actions_in_db) {

    $orphaned = array_keys($actions_in_db);

    if ($delete_orphans) {

      $actions = db_query('SELECT aid, label FROM {actions} WHERE callback IN (:orphaned)', array(':orphaned' => $orphaned))->fetchAll();

      foreach ($actions as $action) {

        actions_delete($action->aid);

        watchdog('actions', "Removed orphaned action '%action' from database.", array('%action' => $action->label));

      }

    }

    else {

      $link = l(t('Remove orphaned actions'), 'admin/config/system/actions/orphan');

      $count = count($actions_in_db);

      $orphans = implode(', ', $orphaned);

      watchdog('actions', '@count orphaned actions (%orphans) exist in the actions table. !link', array('@count' => $count, '%orphans' => $orphans, '!link' => $link), WATCHDOG_INFO);

    }

  }

}

/**

 * Saves an action and its user-supplied parameter values to the database.

 *

 * @param $function

 *   The name of the function to be called when this action is performed.

 * @param $type

 *   The type of action, to describe grouping and/or context, e.g., 'node',

 *   'user', 'comment', or 'system'.

 * @param $params

 *   An associative array with parameter names as keys and parameter values as

 *   values.

 * @param $label

 *   A user-supplied label of this particular action, e.g., 'Send e-mail

 *   to Jim'.

 * @param $aid

 *   The ID of this action. If omitted, a new action is created.

 *

 * @return

 *   The ID of the action.

 */

function actions_save($function, $type, $params, $label, $aid = NULL) {

  // aid is the callback for singleton actions so we need to keep a separate

  // table for numeric aids.

  if (!$aid) {

    $aid = db_next_id();

  }

  db_merge('actions')

    ->key(array('aid' => $aid))

    ->fields(array(

      'callback' => $function,

      'type' => $type,

      'parameters' => serialize($params),

      'label' => $label,

    ))

    ->execute();

  watchdog('actions', 'Action %action saved.', array('%action' => $label));

  return $aid;

}

/**

 * Retrieves a single action from the database.

 *

 * @param $aid

 *   The ID of the action to retrieve.

 *

 * @return

 *   The appropriate action row from the database as an object.

 */

function actions_load($aid) {

  return db_query("SELECT aid, type, callback, parameters, label FROM {actions} WHERE aid = :aid", array(':aid' => $aid))->fetchObject();

}

/**

 * Deletes a single action from the database.

 *

 * @param $aid

 *   The ID of the action to delete.

 */

function actions_delete($aid) {

  db_delete('actions')

    ->condition('aid', $aid)

    ->execute();

  module_invoke_all('actions_delete', $aid);

}