<?php
// $Id: votingapi_actions.module,v 1.8 2006-10-14 02:01:43 eaton Exp $

/**
 * Lets users directly control the votingapi's integration with the actions module.
 */
 
 /**
 * Implementation of hook_perm().
 */
function votingapi_actions_perm() {
  return array('administer voting actions');
}

/*
 * Implementation of hook_menu()
 */
function votingapi_actions_menu($may_cache) {
  $items = array();
  require_once('votingapi_actions.inc');
  require_once('votingapi_actions_ui.inc');

  if ($may_cache) {
    $items[] = array('path' => 'admin/voting/actions', 
      'title' => t('voting actions'),
      'description' => t('Vote-driven triggers and actions for your site'),
      'callback' => 'votingapi_actions_admin_page',
      'access' => user_access('administer voting actions'),
      'type' => MENU_NORMAL_ITEM);
    $items[] = array('path' => 'admin/voting/actions/list', 
      'title' => t('list'),
      'callback' => 'votingapi_actions_admin_page',
      'access' => user_access('administer voting actions'),
      'type' => MENU_DEFAULT_LOCAL_TASK,
      'weight' => '-1');
    $items[] = array('path' => 'admin/voting/actions/add', 
      'title' => t('add'),
      'callback' => 'drupal_get_form',
      'callback arguments' => array('votingapi_actions_admin_edit_page', 'add'),
      'access' => user_access('administer voting actions'),
      'type' => MENU_LOCAL_TASK);
    $items[] = array('path' => 'admin/voting/actions/edit', 
      'title' => t('edit action set'),
      'callback' => 'drupal_get_form',
      'callback arguments' => array('votingapi_actions_admin_edit_page', 'edit'),
      'type' => MENU_CALLBACK);
    $items[] = array('path' => 'admin/voting/actions/import', 
      'title' => t('import'),
      'callback' => 'drupal_get_form',
      'callback arguments' => array('votingapi_actions_admin_import_page'),
      'access' => user_access('administer voting actions'),
      'type' => MENU_LOCAL_TASK);
    $items[] = array('path' => 'admin/voting/actions/export', 
      'title' => t('export action set'),
      'callback' => 'drupal_get_form',
      'callback arguments' => array('votingapi_actions_admin_export_page'),
      'access' => user_access('administer voting actions'),
      'type' => MENU_CALLBACK);
    $items[] = array('path' => 'admin/voting/actions/delete', 
      'title' => t('edit action set'),
      'callback' => 'drupal_get_form',
      'callback arguments' => array('votingapi_actions_admin_delete_page'),
      'access' => user_access('administer voting actions'),
      'type' => MENU_CALLBACK);
    $items[] = array('path' => 'admin/voting/actions/enable', 
      'callback' => 'votingapi_actions_admin_enable_page',
      'access' => user_access('administer voting actions'),
      'type' => MENU_CALLBACK);
    $items[] = array('path' => 'admin/voting/actions/disable', 
      'callback' => 'votingapi_actions_admin_disable_page',
      'access' => user_access('administer voting actions'),
      'type' => MENU_CALLBACK);
  }
  return $items;
}

function votingapi_actions_votingapi_recalculate($cached, $votes, $content_type, $content_id) {
  _votingapi_process_actions($content_id, $content_type, $votes, $cached);
}

/**
 * Functions that integrate VotingAPI with the Actions module.
 * Allows VotingAPI-based modules to insert nested sets of conditionals
 * and actions to be executed whenever a voting result is fired off.
 */

// Called by the Voting API whenever a result is calculated.
// Other helper functions build the actions cache from the database.

function _votingapi_process_actions($content_id, $content_type, $votes, $results) {
  $data = cache_get('votingapi_action_sets');
  $action_sets = unserialize($data->data);

  if (!is_array($action_sets)) {
    return;
  }

  $content = _votingapi_load_content($content_id, $content_type);
  if ($content == NULL) {
    return;
  }

  foreach ($action_sets as $action_set) {
    if ($action_set['content_type'] == $content_type) {
      $actions = array();
      _votingapi_process_action_set($content, $votes, $results, $action_set, $actions);
      foreach ($actions as $action) {
        actions_do($action, $content);
      }
    }
  }
}

// An internal utility function that calls itself recursively to evaluate a
// tree of voting action sets. $actions is passed in by references, and accumulates
// actions-to-initiate. The calling function is responsible for firing them off.

function _votingapi_process_action_set($content = NULL, $votes = array(), $results = array(), $action_set = NULL, &$actions) {
  // a little safety code to catch malformed sets.
  if (!isset($action_set['conditions'])) {
    $action_set['conditions'] = array();
  }
  if (!isset($action_set['actions'])) {
    $action_set['actions'] = array();
  }
  if (!isset($action_set['subsets'])) {
    $action_set['subsets'] = array();
  }

  // Here, we iterate through every rule. The value starts as true,
  // and a single false will trip it to failure state.
  foreach($action_set['conditions'] as $condition) {
    $function = $condition['handler'];
    if (function_exists($function)) {
      // this calls a handler with several ops. 'process' and 'input' are the two i've thought of.
      $conditions_result = $function('process', $content, $votes, $results, $condition);
    }
    else {
      $conditions_result = FALSE;
    }
    if ($action_set['condition_mask'] == 'AND') {
      if ($conditions_result === FALSE) {
        // bail out to avoid unecessary processing.
        return FALSE;
      }
      else {
        // AND the set result and rule result together.
        if (isset($set_result)) {
          $set_result = $set_result && $conditions_result;
        }
        else {
          $set_result = $conditions_result;
        }
      }
    }
    else if ($action_set['condition_mask'] == 'OR') {
      // OR the set result and rule result together.
      $set_result = $set_result || $conditions_result;
    }
  }
 
  if ($set_result == TRUE) {
    // Now check sub-actions.

    foreach($action_set['subsets'] as $subset) {
      // check the required flag of the subset. if it is, evaluate it.
      if ($subset['required'] == TRUE) {
        $set_result = $set_result && _votingapi_process_action_set($content, $votes, $results, $subset, $actions);
        if ($set_result == FALSE) {
          return FALSE;
        }
      }
    }

    if ($set_result == TRUE) {
      // It's still true after executing required subsets. Add the actions, then process optional subsets.
      foreach ($action_set['actions'] as $action) {
        $actions[] = $action;
      }
      
      foreach($action_set['subsets'] as $subset) {
        // now handle the non-required subsets
        if ($subset['required'] == FALSE) {
          _votingapi_process_action_set($content, $votes, $results, $subset, $actions);
        }
      }
    }
  }

  return $set_result;
}

/**
 * Utility functions that manage the raw voting actions data..
 */

function votingapi_rebuild_action_cache() {
  // This builds a live cache of all the currently enabled sets,
  // first from the database, then from module 'defaults'. Any
  // set saved in the DB is assumed to be enabled, and any DB
  // set overrides a module set with the same name.

  $sets = _votingapi_load_action_sets_from_db();
  $module_sets = _votingapi_load_action_sets_from_modules();
  
  foreach($sets as $name => $set) {
    $active_sets[$name] = $set;
  }

  $status_list = variable_get('votingapi_action_status', array());
  foreach($module_sets as $name => $set) {
    if (!in_array($name, array_keys($sets))) {
      if ($status_list[$name]) {
        $sets[$name] = $set;
      }
    }
  }
  cache_set("votingapi_action_sets", 'cache', serialize($sets));
}

function _votingapi_get_action_status($set_name) {
  $status_list = variable_get('votingapi_action_status', array());
  return $status_list[$set_name];
}

function _votingapi_set_action_status($set_name, $status) {
  $status_list = variable_get('votingapi_action_status', array());
  $status_list[$set_name] = $status;
  variable_set('votingapi_action_status', $status_list);
  votingapi_rebuild_action_cache();
}

function _votingapi_load_action_sets_from_modules() {
  $sets = array();
  $status_list = variable_get('votingapi_action_status', array());

  $set_data = module_invoke_all('votingapi_action_sets');
  foreach ($set_data as $name => $set) {
    $sets[$name] = $set;
    if (!isset($status_list[$name])) {
      $status_list[$name] = $set['enabled'];
    }
  }
  
  variable_set('votingapi_action_status', $status_list);
  return $sets;
}

function _votingapi_load_action_sets_from_db($parent = '') {
  $sets = array();
  $result = db_query("SELECT * FROM {votingapi_action_set} WHERE parent_name = '%s' ORDER BY weight, name ASC", $parent);   

  while ($set = db_fetch_array($result)) {
    $set_name = $set['name'];
    unset($set['name']);

    $condition_result = db_query("SELECT * FROM {votingapi_action_condition} WHERE parent_name = '%s' ORDER BY weight ASC", $set_name);
    while ($condition = db_fetch_array($condition_result)) {
      $condition['data'] = unserialize($condition['data']);
      $name = $condition['name'];
      unset($condition['name']);
      $set['conditions'][$name] = $condition;
    }

    $action_result = db_query("SELECT * FROM {votingapi_action} WHERE parent_name = '%s' ORDER BY aid ASC", $set_name);
    while ($action = db_fetch_array($action_result)) {
      $set['actions'][] = $action['aid'];
    }

    $set->subsets = _votingapi_load_action_sets_from_db($set_name);
    $sets[$set_name] = $set;
  }
  
  return $sets;
}

function _votingapi_insert_set($name, $set) {
  $sql = "INSERT INTO {votingapi_action_set} ";
  $sql .= "(name, parent_name, content_type, source, description, condition_mask, required, weight)";
  $sql .= "VALUES ('%s', '%s', '%s', '%s', '%s', '%s', %d, %d)";
  
  db_query($sql, $name, $set['parent_name'], $set['content_type'],
    $set['source'], $set['description'], $set['condition_mask'], 
    $set['required'], $set['weight']);
  
  if (is_array($set['conditions'])) {
    foreach ($set['conditions'] as $cname => $condition) {
      $condition['parent_name'] = $name;
      _votingapi_insert_condition($cname, $condition);
    }
  }
  
  if (is_array($set['actions'])) {
    foreach ($set['actions'] as $action) {
      db_query("INSERT INTO {votingapi_action} (parent_name, aid) VALUES ('%s', '%s')", $name, $action);
    }
  }

  if (is_array($set['sets'])) {
    foreach ($set['sets'] as $sname => $subset) {
      $subset['parent_name'] = $name;
      _votingapi_insert_set($sname, $subset);
    }
  }
}

function _votingapi_insert_condition($name, $condition) {
  $sql = "INSERT INTO {votingapi_action_condition} ";
  $sql .= "(name, parent_name, description, data, handler, weight)";
  $sql .= "VALUES ('%s', '%s', '%s', '%s', '%s', %d)";

  db_query($sql, $name, $condition['parent_name'], $condition['description'],
    serialize($condition['data']), $condition['handler'], $condition['weight']);
}

function _votingapi_update_set($name, $old_name, $set) {
  $sql = "UPDATE {votingapi_action_set} SET ";
  $sql .= "name = '%s', parent_name = '%s', content_type = '%s', source = '%s', description = '%s', condition_mask = '%s', ";
  $sql .= "required = %d, weight = %d ";
  $sql .= "WHERE name = '%s'";
  
  db_query($sql, $name, $set['parent_name'], $set['content_type'],
    $set['source'], $set['description'], $set['condition_mask'], 
    $set['required'], $set['weight'], $old_name);

  db_query("DELETE FROM {votingapi_action_condition} WHERE parent_name = '%s'", $old_name);
  if (is_array($set['conditions'])) {
    foreach ($set['conditions'] as $cname => $condition) {
      $condition['parent_name'] = $name;
      _votingapi_insert_condition($cname, $condition);
    }
  }

  db_query("DELETE FROM {votingapi_action} WHERE parent_name = '%s'", $old_name);
  if (is_array($set['actions'])) {
    foreach ($set['actions'] as $action) {
      db_query("INSERT INTO {votingapi_action} (parent_name, aid) VALUES ('%s', '%s')", $name, $action);
    }
  }
  
  if (is_array($set['sets'])) {
    foreach ($set['sets'] as $sname => $subset) {
      $subset['parent_name'] = $name;
      if ($subset['new']) {
        _votingapi_insert_set($sname , $subset);
      }
      else {
        _votingapi_update_set($sname , $subset);
      }
    }
  }

  if (is_array($set['deleted_sets'])) {
    foreach ($set['deleted_sets'] as $sname => $subset) {
      $subset['parent_name'] = $name;
      _votingapi_delete_set($sname , $subset);
    }
  }
}

function _votingapi_update_condition($name, $condition) {
  $sql = "UPDATE {votingapi_action_condition} SET ";
  $sql .= "name = '%s', parent_name = '%s', description = '%s', data = '%s', handler = '%s', weight = %d ";
  $sql .= "WHERE name = '%s' AND parent_name = '%s'";
  
  db_query($sql, $name, $condition['parent_name'], $condition['description'],
    serialize($condition['data']), $condition['handler'], $condition['weight'], 
    $name, $condition['parent_name']);
}

function _votingapi_delete_set($name, $set) {
  if (is_array($set['sets'])) {
    foreach ($set['sets'] as $sname => $subset) {
      $subset['parent_name'] = $name;
      _votingapi_delete_set($sname, $subset);
    }
  }

  db_query("DELETE FROM {votingapi_action_condition} WHERE parent_name = '%s'", $name);
  db_query("DELETE FROM {votingapi_action} WHERE parent_name = '%s'", $name);
  db_query("DELETE FROM {votingapi_action_set} WHERE name = '%s'", $name);
}

function _votingapi_validate_action_set($name, $set) {
  $errors = array();

  if (!is_array($set)) {
    $errors[] = "The set '$name' is not an array!";
    return $errors;
  }
  
  if (!isset($set['content_type']) && !isset($set['parent_name'])) {
    $errors[] = "The set '$name' must have a content_type.";
  }

  if ($set['condition_mask'] != 'AND' && $set['condition_mask'] != 'OR') {
    $errors[] = "The set '$name' must define a condition_mask of 'AND' or 'OR'.";
  }

  if (!isset($set['conditions'])) {
    $errors[] = "The set '$name' has no conditions defined.";
  }
  else {
    if (count($set['conditions']) == 0) {
      $errors[] = "The set '$name' has no conditions defined.";
    }
  }

  if (is_array($set['conditions'])) {
    foreach ($set['conditions'] as $cname => $condition) {
      $errors = array_merge($errors, _votingapi_validate_action_condition($cname, $condition));
    }
  }

  if (is_array($set['sets'])) {
    foreach ($set['sets'] as $subname => $subset) {
      $errors = array_merge($errors, _votingapi_validate_action_set($subname, $subset));
    }
  }
  return $errors;
}

function _votingapi_validate_action_condition($name, $condition) {
  $errors = array();
  if (!is_array($condition)) {
    $errors[] = "The condition '$name' is not an array!";
    return $errors;
  }

  if (!isset($condition['handler'])) {
    $errors[] = "The condition '$name' has no handler.";
  }

  if (!function_exists($condition['handler'])) {
    $handler = $condition['handler'];
    $errors[] = "The condition '$name' has an invalid handler ($handler).";
  }

  return $errors;
}