<?php
// $Id: rules_admin.rule_forms.inc,v 1.1.2.11 2011-01-05 13:59:43 fago Exp $


/**
 * @file Rules Admin UI
 *   Implements rule management and configuration screens.
 */

rules_include('rules_admin');

/**
 * Lists the available rules.
 */
function rules_admin_form_overview(&$form_state) {
  // Check if token module is present.
  rules_admin_check_token();
  $form['filter'] = array(
    '#type' => 'fieldset',
    '#title' => t('Filter'),
    '#collapsible' => TRUE,
    '#collapsed' => isset($form_state['values']) || count(rules_get_configured_items('rules')) < 20,
  );
  $form['filter']['set'] = array(
    '#type' => 'select',
    '#title' => t('Filter by event'),
    '#options' => array(0 => '<All>') + rules_admin_get_grouped_labels(rules_get_events()),
    '#default_value' => isset($form_state['values']['set']) ? $form_state['values']['set'] : 0,
  );
  $form['filter']['category'] = array(
    '#type' => 'select',
    '#title' => t('Filter by category'),
    '#options' => array(0 => '<All>') + rules_admin_get_categories('rules'),
    '#default_value' => isset($form_state['values']['category']) ? $form_state['values']['category'] : 0,
  );
  $form['filter']['submit'] = array('#type' => 'submit', '#value' => t('Filter'));

  $category = !empty($form_state['values']['category']) ? $form_state['values']['category'] : FALSE;
  $set = !empty($form_state['values']['set']) ? 'event_'. $form_state['values']['set'] : FALSE;

  $form['active_header'] = array('#value' => '<h3>'. t('Active rules') .'</h3>');
  $form['active'] = rules_admin_overview_table(array('category' => $category, 'set' => $set, 'active' => TRUE));
  $form['active']['#suffix'] = '<br />';
  $form['inactive_header'] = array('#value' => '<h3>'. t('Inactive rules') .'</h3>');
  $form['inactive'] = rules_admin_overview_table(array('category' => $category, 'set' => $set, 'active' => FALSE));

  if (variable_get('rules_show_fixed', FALSE)) {
    $form['fixed_header'] = array('#value' => '<h3>'. t('Fixed rules') .'</h3>');
    $form['fixed'] = rules_admin_overview_table(array('category' => $category, 'set' => $set, 'active' => TRUE, 'fixed' => TRUE));
  }
  return $form;
}

function rules_admin_form_overview_submit($form_id, &$form_state) {
  $form_state['rebuild'] = TRUE;
}

/**
 * Check to see if the token module is installed, and if not put up
 * a message.
 *
 * Only call this function if the user is already in a position for this to
 * be useful.
 */
function rules_admin_check_token() {
  if (!variable_get('rules_hide_token_message', FALSE) && !module_exists('token')) {
    drupal_set_message(t('If you install the token module from !href, token replacements will be supported. <a href="@hide">Hide this message.</a>', array('!href' => l('http://drupal.org/project/token', 'http://drupal.org/project/token'), '@hide' => url('admin/rules/settings'))));
  }
}

/**
 * Returns the add rule form
 */
function rules_admin_form_add_rule(&$form_state, $set_info = FALSE) {
  drupal_add_js(drupal_get_path('module', 'rules_admin') . '/rules_admin.js');
  $form = rules_admin_form_rule_settings(array(), (boolean)$set_info);
  $form['settings']['set']['#default_value'] = $set_info['name'];
  return $form;
}

function rules_admin_form_add_rule_validate($form_id, &$form_state) {
  rules_admin_validate_machine_name('rules', 'name', $form_state['values']['name']);
}

function rules_admin_form_add_rule_submit($form_id, &$form_state) {
  $rule = isset($form_state['proxy']) ? $form_state['proxy']->get_rule() : array('#type' => 'rule');

  foreach (array('set', 'label', 'active', 'weight') as $key) {
    $rule['#'. $key] = $form_state['values'][$key];
  }
  $rule['#categories'] = array_filter(array_map('trim', explode(',', $form_state['values']['categories'])));
  $rule['#status'] = 'custom';

  // Get the name of the rule.
  $rule_name = 'rules_' . $form_state['values']['name'];

  rules_item_save('rules', $rule_name, $rule);
  rules_clear_cache();
  drupal_set_message(t("The rule %label has been added. You can start adding some conditions or actions now.", array('%label' => $rule['#label'])));
  $form_state['redirect'] = RULES_ADMIN_RULE_PATH .'/'. $rule_name;
}

/**
 * Returns the form for the settings of a rule
 *
 * @param $is_set
 *   When adding a new rule for a rule set, TRUE.
 */
function rules_admin_form_rule_settings($rule, $is_set = FALSE, $changable_name = TRUE) {
  $form['settings'] = array(
    '#type' => 'fieldset',
    '#title' => t('Rule settings'),
    '#collapsible' => TRUE,
  );
  $form['settings']['label'] = array(
    '#title' => t('Label'),
    '#type' => 'textfield',
    '#description' => t('Choose an appropriate label for this rule.'),
    '#default_value' => isset($rule['#label']) ? $rule['#label'] : '',
    '#required' => TRUE,
  );
  $form['settings']['name'] = array(
    '#title' => t('Machine readable name'),
    '#type' => 'textfield',
    '#description' => t('Specify a unique name containing only alphanumeric characters, and underscores.'),
    '#default_value' => isset($rule['#name']) ? $rule['#name'] : '',
    '#disabled' => !$changable_name,
    '#required' => TRUE,
  );
  // Only set the value if name isn't changable.
  if (!$changable_name) {
    $form['settings']['name']['#value'] = $rule['#name'];
  }
  $form['settings']['set'] = array(
    '#type' => 'select',
    '#default_value' => isset($rule['#set']) ? $rule['#set'] : '',
    '#required' => TRUE,
  );
  if ($is_set) {
    $form['settings']['set'] += array(
      '#title' => t('Rule set'),
      '#options' => rules_admin_get_grouped_labels(rules_admin_get_compatible_sets($rule, rules_get_configured_items('rule_sets'))),
      '#description' => t('Select to which rule set this rule should belong.'),
    );
  }
  else {
    $form['settings']['set'] += array(
      '#title' => t('Event'),
      '#options' => rules_admin_get_grouped_labels(rules_admin_get_compatible_sets($rule, rules_get_event_sets())),
      '#description' => t('Select the event on which you want to evaluate this rule.'),
    );
  };
  $form['settings']['categories'] = array(
    '#type' => 'textfield',
    '#title' => t('Categories'),
    '#default_value' => isset($rule['#categories']) ? implode(', ', $rule['#categories']) : '',
    '#description' => t('A comma-separated list of terms describing this rule. Example: funny, bungee jumping.'),
    '#autocomplete_path' => RULES_ADMIN_PATH .'/autocomplete',
  );
  $form['settings']['active'] = array(
    '#title' => t('This rule is active and should be evaluated when the associated event occurs.'),
    '#type' => 'checkbox',
    '#default_value' => isset($rule['#active']) ? $rule['#active'] : 1,
  );
  $form['settings']['weight'] = array(
    '#title' => t('Weight'),
    '#type' => 'weight',
    '#description' => t('Adjust the weight to customize the evaluation order of rules.'),
    '#default_value' => isset($rule['#weight']) ? $rule['#weight'] : 0,
  );
  $form['settings']['button'] = array('#type' => 'submit', '#weight' => 10, '#value' => t('Save changes'));
  return $form;
}

/**
 * Returns the form for editing a rule
 */
function rules_admin_form_edit_rule(&$form_state, $proxy) {
  $form_state['proxy'] = &$proxy;
  $rule = $proxy->get_rule();
  _rules_element_defaults($rule);
  $rule['#name'] = drupal_substr($proxy->get_rule_name(), drupal_strlen('rules_'));
  $is_set = strpos($rule['#set'], 'event_') !== 0;
  $form = rules_admin_form_rule_settings($rule, $is_set, $rule['#status'] == 'custom');
  $form['settings']['#collapsed'] = TRUE;

  // Add help
  rules_admin_element_help($form, $proxy->get_set_info());

  // Show a warning when editing custom rules form other modules
  if ($rule['#status'] == 'custom' && strpos($proxy->get_rule_name(), 'rules_') !== 0) {
    drupal_set_message(t('<em>Warning</em>: This rule has been provided by another module. <br />Be aware that any changes made through this interface might be overwritten once the providing module updates the rule.'));
  }

  $form['elements'] = array(
    '#type' => 'fieldset',
    '#title' => t('Rule elements'),
    '#collapsible' => TRUE,
  );

  //this will render the whole rule with the help of drupal_render(),
  //see rules_admin.render.inc
  $form['elements']['rule'] = $proxy->get_indexed_rule();
  $form['elements']['rule']['#name'] = $proxy->get_rule_name();
  $form['elements']['rule']['#theme'] = array('rules_admin_rule_render');

  return $form;
}

function rules_admin_form_edit_rule_validate($form, &$form_state) {
  // Get the name of the rule.
  $name = $form_state['proxy']->get_rule_name();
  // We only need to check this if the name differs.
  if ('rules_' . $form_state['values']['name'] != $name) {
    rules_admin_validate_machine_name('rules', 'name', $form_state['values']['name']);
  }
}

function rules_admin_form_edit_rule_submit(&$form, &$form_state) {
  $rule_ref = &$form_state['proxy']->get_rule();
  foreach (array('label', 'active', 'weight', 'set') as $key) {
    $rule_ref['#'. $key] = $form_state['values'][$key];
  }
  $rule_ref['#categories'] = array_filter(array_map('trim', explode(',', $form_state['values']['categories'])));
  // Set the new rule name if needed.
  if ($rule_ref['#status'] == 'custom' && $form_state['values']['name'] != $form_state['proxy']->get_rule_name()) {
    $name = 'rules_' . $form_state['values']['name'];
    $form_state['proxy']->set_rule_name($name);
    $form_state['redirect'] = 'admin/rules/rules/' . $name . '/edit';
  }
  $form_state['proxy']->save_changes();
  drupal_set_message(t("The rule %label has been updated.", array('%label' => $rule_ref['#label'])));
}

/**
 * Returns the form for the add operation
 * This handles adding conditions and actions
 *
 * @param $type Either 'action' or 'condition' or 'op'
 * @param $parent_id The id of the the element where the condition / action is to be added
 */
function rules_admin_form_add(&$form_state, $proxy, $type, $parent_id = NULL) {
  $form_state['proxy'] = &$proxy;
  $rule = $proxy->get_rule();
  _rules_element_defaults($rule);

  if (in_array($type, array('action', 'condition', 'op'))) {
    if (!isset($form_state['element'])) {
      //initial step!
      $form_state += array('element' => array('#type' => $type), 'step' => 0);
    }
    $element = &$form_state['element'];
    $element += array('#id' => NULL, '#settings' => array());

    // Due to adding storage during the form build, the form will be rebuilt
    // immediately. So be sure to increase the step only out of a #submit callback.
    // Also see http://drupal.org/node/302240.

    if ($form_state['step'] == 0) {
      if (isset($parent_id) && is_array($parent = $proxy->get_element(intval($parent_id)))) {
        if (function_exists($function = 'rules_admin_form_add_'. $element['#type'])) {
          $form_state['parent_id'] = intval($parent_id);
          _rules_element_defaults($parent);
          $form = $function($form_state, $element, $parent);
          return rules_admin_form_pack_storage($form, $form_state);
        }
      }
    }
    else {
      if (function_exists($function = 'rules_admin_form_edit_'. $type)) {
        $form = $function($form_state, $element);
        return rules_admin_form_pack_storage($form, $form_state);
      }
    }
  }
  drupal_not_found();
  exit;
}

/**
 * Returns the form for the first action add page
 */
function rules_admin_form_add_action(&$form_state, &$element) {
  $vars = $form_state['proxy']->get_available_variables();
  $all_actions = rules_get_actions();
  $satisfied_actions = rules_admin_filter_info($vars, $all_actions);
  $unsatisfied_actions = array_filter(array_diff_assoc($all_actions, $satisfied_actions), 'rules_admin_element_filter');
  $form['name'] = array(
    '#type' => 'select',
    '#title' => t('Select an action to add'),
    '#options' => rules_admin_get_grouped_labels($satisfied_actions),
    '#required' => TRUE,
  );
  if (!empty($unsatisfied_actions)) {
    // Hold all the actions that are disabled because argument(s) are missing.
    $form['unsatisfied'] = array(
      '#type' => 'fieldset',
      '#title' => format_plural(count($unsatisfied_actions), '1 action is not configurable', '@count actions are not configurable'),
      '#description' => t("The following actions aren't available in this context because they require arguments that don't exist in your rule. If you want to use any of these actions, you must first add some action that adds variables of this kind, or have an event that passes the required variables."),
      '#collapsible' => TRUE,
      '#collapsed' => TRUE,
    );
    $form['unsatisfied']['items'] = array(
      '#type' => 'item',
      '#unsatisfied_grouped_options' => $unsatisfied_actions,
      '#theme' => 'rules_admin_unsatisfied_elements',
    );
  }
  $form['submit'] = array(
    '#type' => 'submit',
    '#weight' => 10,
    '#value' => t('Next'),
    '#submit' => array('rules_admin_form_add_submit'),
  );
  return $form;
}

/**
 * Returns the form for the first condition add page
 */
function rules_admin_form_add_condition(&$form_state, &$element, $parent) {

  if (!isset($parent['#type']) || isset($parent['#logical_op']) && $parent['#logical_op']) {
    $vars = $form_state['proxy']->get_available_variables(0);
    $all_conditions = rules_get_conditions();
    $satisfied_conditions = rules_admin_filter_info($vars, $all_conditions);
    $unsatisfied_conditions = array_filter(array_diff_assoc($all_conditions, $satisfied_conditions), 'rules_admin_element_filter');
    $form['name'] = array(
      '#type' => 'select',
      '#title' => t('Select the condition to add'),
      '#options' => rules_admin_get_grouped_labels($satisfied_conditions),
      '#required' => TRUE,
    );
    if (!empty($unsatisfied_conditions)) {
      // Hold all the actions that are disabled because argument(s) are missing.
      $form['unsatisfied'] = array(
        '#type' => 'fieldset',
        '#title' => format_plural(count($unsatisfied_conditions), '1 condition is not configurable', '@count conditions are not configurable'),
        '#description' => t("The following conditions aren't available in this context because they require arguments that don't exist in your rule. If you want to use any of these conditions, you must first add some action that adds variables of this kind in a previous rule, or have an event that passes the required variables."),
        '#collapsible' => TRUE,
        '#collapsed' => TRUE,
      );
      $form['unsatisfied']['items'] = array(
        '#type' => 'item',
        '#unsatisfied_grouped_options' => $unsatisfied_conditions,
        '#theme' => 'rules_admin_unsatisfied_elements',
      );
    }
    $form['submit'] = array(
      '#type' => 'submit',
      '#weight' => 10,
      '#value' => t('Next'),
      '#submit' => array('rules_admin_form_add_submit'),
    );
    return $form;
  }
}

/**
 * Indenting a condition
 * Adds a logical operation and place the given condition element inside. We automatically
 * determine which operation is to be added.
 */
function rules_admin_form_add_op(&$form_state, $element, $parent) {
  $parent_ref = &$form_state['proxy']->get_element($form_state['parent_id']);

  //determine the appropriate operation and apply it
  $op = rules_admin_determine_operation($form_state['proxy'], $form_state['parent_id']);
  if (isset($parent_ref['#weight'])) {
    $weight = $parent_ref['#weight'];
    unset($parent_ref['#weight']);
  }
  $parent_ref = rules_configure($op, $parent_ref);

  if (isset($weight)) {
    //apply the weight of the element to the op
    $parent_ref['#weight'] = $weight;
  }

  //and save
  $form_state['proxy']->save_changes();
  drupal_goto(RULES_ADMIN_RULE_PATH .'/'. $form_state['proxy']->get_rule_name());
}

function rules_admin_form_add_submit($form, &$form_state) {
  $form_state['element']['#name'] = $form_state['values']['name'];
  $form_state['step']++;
  rules_init_element_info($form_state['element']);
}

/**
 * Use this function when there should be a further step.
 * It puts all variables needed into the form storage
 */
function rules_admin_form_pack_storage($form, &$form_state) {
  foreach (array('proxy', 'step', 'element', 'parent_id') as $key) {
    if (isset($form_state[$key])) {
      $form_state['storage'][$key] = &$form_state[$key];
    }
  }
  // Add a mechanism that includes arbitrary files needed by the form.
  // This can be used by configuration forms that need to rely on other files.
  $form['#after_build'][] = 'rules_after_build_include_files';

  // Register an after build callback that unpacks the storage.
  // However let the rules_admin.rule_forms.inc file be included previously, so that
  // #ahah callbacks from other modules keep working.
  $form['#includes'][] = "./". drupal_get_path('module', 'rules_admin') ."/rules_admin.rule_forms.inc";
  $form['#after_build'][] = 'rules_admin_form_unpack_storage';
  return $form;
}

/**
 * Puts the variables out of storage on their usual place. Invoked through
 * #after_build, which is set by rules_admin_form_pack_storage().
 */
function rules_admin_form_unpack_storage($form, &$form_state) {
  if (!isset($form_state['unpacked'])) {
    foreach (array('proxy', 'step', 'element', 'parent_id') as $key) {
      if (isset($form_state['storage'][$key]) && !isset($form_state[$key])) {
        $form_state[$key] = &$form_state['storage'][$key];
      }
    }
    $form_state['unpacked'] = TRUE;
  }

  return $form;
}

/**
 * Returns the form for the edit operation
 * This handles editing conditions and actions
 *
 * @param $id The id of the the element where the condition / action is to be added
 */
function rules_admin_form_edit(&$form_state, $proxy, $element) {
  if (!isset($form_state['element'])) {
    //initial step!
    $form_state += array('element' => $element, 'step' => 1);
  }
  //just call the add form with the appropriate step.
  $type = in_array($element['#type'], array('action', 'condition')) ? $element['#type'] : 'op';
  return rules_admin_form_add($form_state, $proxy, $type);
}

/**
 * Returns the edit form for an action
 */
function rules_admin_form_edit_action(&$form_state, $element) {
  $label = rules_get_element_label($element);
  $form['label'] = array(
    '#title' => t('Label'),
    '#type' => 'textfield',
    '#description' => t('Customize the label for this action.'),
    '#default_value' => isset($form_state['values']['label']) ? $form_state['values']['label'] : $label,
    '#required' => TRUE,
    '#weight' => -5,
  );
  if ($label) {
    drupal_set_title(t('Editing action %label', array('%label' => $label)));
  }
  $form['weight'] = array(
    '#title' => t('Weight'),
    '#type' => 'weight',
    '#description' => t('Adjust the weight to customize the ordering of actions.'),
    '#default_value' => isset($element['#weight']) ? $element['#weight'] : 0,
    '#weight' => 8,
  );
  $form['submit'] = array(
    '#type' => 'submit',
    '#weight' => 10,
    '#value' => t('Save'),
    '#submit' => array('rules_admin_form_edit_action_submit', 'rules_admin_form_edit_save'),
  );
  if (isset($element['#id'])) {
    $form['delete'] = array(
      '#type' => 'submit',
      '#weight' => 11,
      '#value' => t('Delete'),
      '#submit' => array('rules_admin_form_edit_delete_submit'),
    );
  }
  rules_admin_element_help($form, $element);
  $form['help']['#weight'] = -4; // Move upwards
  rules_admin_default_argument_form($form, $form_state, $element);
  rules_admin_new_variables_form($form, $form_state, $element);
  rules_admin_element_alter_form($form, $form_state, $element);
  return $form;
}

/*
 * Apply the changes to the element
 */
function rules_admin_form_edit_action_submit($form, &$form_state) {
  $element = &$form_state['element'];
  $element['#weight'] = $form_state['values']['weight'];
  rules_admin_default_argument_form_submit($form, $form_state, $element);
  rules_admin_new_variables_form_submit($form, $form_state, $element);
  rules_admin_save_element_label($form, $form_state, $element);
  rules_admin_element_alter_form_submit($form, $form_state, $element);
  drupal_set_message(t('The action %label has been saved.', array('%label' => rules_get_element_label($element))));
}

/**
 * Returns the edit form for a condition
 */
function rules_admin_form_edit_condition(&$form_state, $element) {
  $label = rules_get_element_label($element);
  $form['label'] = array(
    '#title' => t('Label'),
    '#type' => 'textfield',
    '#description' => t('Customize the label for this condition.'),
    '#default_value' => isset($form_state['values']['label']) ? $form_state['values']['label'] : $label,
    '#required' => TRUE,
    '#weight' => -5,
  );
  if ($label) {
    drupal_set_title(t('Editing condition %label', array('%label' => $label)));
  }
  $form['negate'] = array(
    '#title' => t('Negate'),
    '#type' => 'checkbox',
    '#description' => t('If checked, the condition returns TRUE, if it evaluates to FALSE.'),
    '#default_value' => isset($element['#negate']) ? $element['#negate'] : 0,
  );
  $form['weight'] = array(
    '#title' => t('Weight'),
    '#type' => 'weight',
    '#description' => t('Adjust the weight to customize the ordering of conditions.'),
    '#default_value' => isset($element['#weight']) ? $element['#weight'] : 0,
    '#weight' => 8,
  );
  $form['submit'] = array(
    '#type' => 'submit',
    '#weight' => 10,
    '#value' => t('Save'),
    '#submit' => array('rules_admin_form_edit_condition_submit', 'rules_admin_form_edit_save'),
  );
  if (isset($element['#id'])) {
    $form['delete'] = array(
      '#type' => 'submit',
      '#weight' => 11,
      '#value' => t('Delete'),
      '#submit' => array('rules_admin_form_edit_delete_submit'),
    );
  }
  else {
    // For conditions we set the id to 0, so new variables of this rules aren't shown
    // in argument mapping forms.
    $element['#id'] = 0;
  }
  rules_admin_element_help($form, $element);
  rules_admin_default_argument_form($form, $form_state, $element);
  rules_admin_element_alter_form($form, $form_state, $element);
  return $form;
}

/**
 * Apply the changes to the element
 */
function rules_admin_form_edit_condition_submit($form, &$form_state) {
  $element = &$form_state['element'];
  foreach (array('negate', 'weight') as $key) {
    $element['#'. $key] = $form_state['values'][$key];
  }
  rules_admin_default_argument_form_submit($form, $form_state, $element);
  rules_admin_save_element_label($form, $form_state, $element);
  rules_admin_element_alter_form_submit($form, $form_state, $element);
  drupal_set_message(t('The condition %label has been saved.', array('%label' => rules_get_element_label($element))));
}

/**
 * Returns the edit form of a logical operation
 */
function rules_admin_form_edit_op(&$form_state, $element) {
  drupal_set_title(t('Editing condition group %label', array('%label' => rules_get_element_label($element))));
  $form['negate'] = array(
    '#title' => t('Negate'),
    '#type' => 'checkbox',
    '#description' => t('If checked, the operation will be negated. E.g. AND would be handled as NOT AND.'),
    '#default_value' => isset($element['#negate']) ? $element['#negate'] : 0,
  );
  $form['operation'] = array(
    '#title' => t('Operation'),
    '#type' => 'select',
    '#description' => t('The logical operation of this condition group. E.g. if you select AND, this condition group will only evaluate to TRUE if all conditions of this group evaluate to TRUE.'),
    '#default_value' => $element['#type'],
    '#options' => rules_admin_elements_get_logical_ops(),
    '#required' => TRUE,
  );
  $form['weight'] = array(
    '#title' => t('Weight'),
    '#type' => 'weight',
    '#description' => t('Adjust the weight to customize the ordering.'),
    '#default_value' => isset($element['#weight']) ? $element['#weight'] : 0,
  );
  $form['submit'] = array(
    '#type' => 'submit',
    '#weight' => 10,
    '#value' => t('Save'),
    '#submit' => array('rules_admin_form_edit_op_submit', 'rules_admin_form_edit_save'),
  );
  if (isset($element['#id'])) {
    $form['delete'] = array(
      '#type' => 'submit',
      '#weight' => 10,
      '#value' => t('Delete'),
      '#submit' => array('rules_admin_form_edit_delete_submit'),
    );
  }
  return $form;
}

/**
 * Apply the changes to the element
 */
function rules_admin_form_edit_op_submit($form, &$form_state) {
  $element = &$form_state['element'];
  foreach (array('negate', 'weight') as $key) {
    $element['#'. $key] = $form_state['values'][$key];
  }
  $element['#type'] = $form_state['values']['operation'];
  drupal_set_message(t('The condition group %label has been saved.', array('%label' => $element['#type'])));
}

/**
 * Actually saves the element. Note that this handles also saving newly added elements.
 */
function rules_admin_form_edit_save($form, &$form_state) {
  $element = &$form_state['element'];
  //remove empty values
  $element = array_filter($element);

  if (isset($element['#id']) && $element['#id']) {
    //save edited element
    $element_ref = &$form_state['proxy']->get_element($element['#id']);
    $element_ref = $element;
    unset($element_ref['#id']);
  }
  else {
    $parent_ref = &$form_state['proxy']->get_element($form_state['parent_id']);
    //just add the element to the parent
    unset($element['#id']);
    $parent_ref = rules_configure($parent_ref, $element);
  }
  $form_state['proxy']->save_changes();
  $form_state['redirect'] = RULES_ADMIN_RULE_PATH .'/'. $form_state['proxy']->get_rule_name();
  unset($form_state['storage']);
}

/**
 * Just redirect to the delete form
 */
function rules_admin_form_edit_delete_submit($form, &$form_state) {
  $element = &$form_state['element'];
  $base_path = RULES_ADMIN_RULE_PATH .'/'. $form_state['proxy']->get_rule_name();
  unset($_REQUEST['destination']);
  $form_state['redirect'] = array(
    'path' => $base_path .'/delete/'. $element['#id'],
    'query' => 'destination='. $base_path,
  );
  // We need to empty the storage or there will be no redirect.
  $form_state['storage'] = NULL;
}

/**
 * Allows the element to alter the default configuration form
 */
function rules_admin_element_alter_form(&$form, &$form_state, $element) {
  rules_include('rules_forms');
  $element += array('#settings' => array());

  rules_element_invoke($element, 'form', array($element['#settings'], &$form, &$form_state), FALSE);
  $form['submit']['#validate'][] = 'rules_admin_element_alter_form_validate';
}

function rules_admin_element_alter_form_validate(&$form, &$form_state) {
  rules_include('rules_forms');
  rules_element_invoke($form_state['element'], 'validate', array(&$form, &$form_state), FALSE);
}

function rules_admin_element_alter_form_submit(&$form, &$form_state, &$element) {
  rules_include('rules_forms');
  rules_element_invoke($element, 'submit', array(&$element['#settings'], &$form, &$form_state), FALSE);

  // After altering we can apply the input evaluators.
  rules_prepare_input_evaluators($element, $form_state['proxy']->get_available_variables($form_state['element']['#id']));
}

/**
 * Returns form elements for new variables
 */
function rules_admin_new_variables_form(&$form, &$form_state, $element) {
  $info = rules_get_element_info($element);

  if (isset($info['new variables']) && count($info['new variables'])) {
    $form['new'] = array('#tree' => TRUE);
    foreach ($info['new variables'] as $name => $var) {
      $form['new'][$name] = array(
        '#type' => 'fieldset',
        '#title' => t('Variable @label settings', array('@label' => $var['label'])),
        '#collapsible' => TRUE,
      );
      // Make sure the variable label is in lower case.
      $var['label'] = drupal_strtolower(drupal_substr($var['label'], 0, 1)) . drupal_substr($var['label'], 1);
      $form['new'][$name]['label'] = array(
        '#type' => 'textfield',
        '#title' => t('Label'),
        '#default_value' => $var['label'],
        '#required' => TRUE,
      );
      $form['new'][$name]['name'] = array(
        '#type' => 'textfield',
        '#title' => t('Machine readable variable name'),
        '#description' => t('Specify a unique name containing only alphanumeric characters, and underscores.'),
        '#default_value' => $name,
        '#required' => TRUE,
      );
      // Preserve its old argument map value or initialize the map
      $element['#settings'] += array('#argument map' => array());
      $default_name = array_search($name, $element['#settings']['#argument map']);
      $default_name = $default_name === FALSE ? $name : $default_name;
      $form['map'][$default_name] = array('#type' => 'value', '#value' => $name);
    }
    $form['submit']['#validate'][] = 'rules_admin_new_variables_form_validate';
  }
}

function rules_admin_new_variables_form_validate($form, &$form_state) {
  $variables = $form_state['proxy']->get_defined_variables();
  foreach ($form_state['values']['new'] as $old_name => $values) {
    // If the variable name changed or we add a new element we have to ensure
    // that the variable name is not taken yet.
    if (isset($variables[ $values['name'] ]) && ($values['name'] != $old_name || !isset($form_state['element']['#id']))) {
      form_set_error(implode('][', array('new', $old_name, 'name')), t('A variable with this name does already exist. Please choose another name.'));
    }
    if (!preg_match('/^[0-9a-zA-Z_]*$/', $values['name'])) {
      form_set_error(implode('][', array('new', $old_name, 'name')), t('The name contains not allowed characters.'));
    }
  }
}

function rules_admin_new_variables_form_submit(&$form, &$form_state, &$element) {
  if (isset($form_state['values']['new'])) {
    foreach ($form_state['values']['new'] as $old_name => $values) {

      //handle the label
      $info = &$element['#info']['new variables'][$old_name];
      $info = _rules_admin_get_label($form_state, $info, $element, $values['label'], FALSE) + $info;

      if ($old_name != $values['name']) {
        //add it to the argument map
        $default_name = array_search($old_name, $element['#settings']['#argument map']);
        $element['#settings']['#argument map'][$default_name] = $values['name'];
        //and alter the info about the variable to reflect the name change
        $element['#info']['new variables'][ $values['name'] ] = $element['#info']['new variables'][$old_name];
        unset($element['#info']['new variables'][$old_name]);
      }
    }
  }
}

/**
 * Returns the argument form for the given element
 */
function rules_admin_default_argument_form(&$form, &$form_state, $element) {
  $form['input_help'] = rules_input_evaluators_help($element, $form_state['proxy']->get_available_variables($form_state['element']['#id']));
  $form['settings'] = array('#tree' => TRUE);
  $form['map'] = array('#tree' => TRUE);

  $function = $element['#name'] .'_form';
  $info = rules_retrieve_element_info($element);

  if (isset($info['arguments']) && count($info['arguments'])) {
    $variables = $form_state['proxy']->get_available_variables($element['#id']);

    foreach ($info['arguments'] as $name => $arg_info) {
      $arg = rules_get_data_object($arg_info);
      if ($arg->uses_input_form()) {
        $value = isset($element['#settings'][$name]) ? $element['#settings'][$name] : NULL;
        $form['settings'][$name] = $arg->get_default_input_form($arg_info, $value, $form_state);
      }
      else {
        $args = rules_admin_map_get_possible_arguments($arg_info, $variables);
        $form['map'][$name] = array(
          '#type' => 'select',
          '#title' => $arg_info['label'],
          '#options' => $args,
          '#default_value' => rules_admin_element_map_variable_name($name, $element),
          '#description' => isset($arg_info['description']) ? $arg_info['description'] : '',
        );
      }
    }
    if (element_children($form['map'])) {
      $form['map'] += array(
        '#type' => 'fieldset',
        '#title' => t('Arguments configuration'),
        '#weight' => -2,
      );
    }
  }
}

function rules_admin_default_argument_form_submit($form, &$form_state, &$element) {
  //save the argument map
  if (isset($form_state['values']['map'])) {
    $element['#settings']['#argument map'] = $form_state['values']['map'];
  }
  //add in values of not identifiable variables
  if (isset($form_state['values']['settings'])) {
    $element['#settings'] = $form_state['values']['settings'] + $element['#settings'];
  }
}

/**
 * Shows the delete form for elements (conditions, actions, ..)
 */
function rules_admin_form_delete(&$form_state, $proxy, $element) {
  $form_state['proxy'] = &$proxy;

  //get the item assocaited with $id
  $form_state['id'] = $element['#id'];
  _rules_element_defaults($element);

  $form = array();
  $path = array();
  $path['path'] = isset($_GET['destination']) ? $_GET['destination'] : RULES_ADMIN_PATH;

  if (isset($element['#logical_op']) && $element['#logical_op']) {
    $form_state['is_op'] = TRUE;
    $text = t('Are you sure you want to delete the logical operation %label?', array('%label' => rules_get_element_label($element)));
  }
  else {
    $text = t('Are you sure you want to delete %label?', array('%label' => rules_get_element_label($element)));
  }
  return confirm_form($form, $text, $path, t('This action cannot be undone.'), t('Delete'), t('Cancel'));
}

function rules_admin_form_delete_submit($form_id, $form_state) {
  $rule = $form_state['proxy']->get_rule();
  //get a reference on the element
  $element = &$form_state['proxy']->get_element(intval($form_state['id']));

  if (isset($form_state['is_op']) && $form_state['is_op']) {
    drupal_set_message(t("The logical operation %label has been deleted.", array('%label' => rules_get_element_label($element))));
    //just unset the type, so that containing conditions are not deleted
    unset($element['#type']);
  }
  else {
    drupal_set_message(t("%label has been deleted.", array('%label' => rules_get_element_label($element))));
    $element = NULL;
    //remove the elements key by cleaning the rule
  }
  $form_state['proxy']->clean_rule();
  $form_state['proxy']->save_changes();
  $form_state['redirect'] = RULES_ADMIN_PATH;
}

/**
 * Clones a rule
 */
function rules_admin_form_clone(&$form_state, $proxy) {
  drupal_add_js(drupal_get_path('module', 'rules_admin') . '/rules_admin.js');
  $form_state['proxy'] = &$proxy;
  $rule = $proxy->get_rule();
  _rules_element_defaults($rule);
  $rule['#name'] = drupal_substr($proxy->get_rule_name(), drupal_strlen('rules_')) . '_cloned';
  if (!$form_state['post']) {
    drupal_set_message(t('Alter the settings for the cloned rule.'));
  }

  $form_state['set'] = strpos($rule['#set'], 'event_') !== 0;

  $form = rules_admin_form_rule_settings($rule, $form_state['set']);
  $form['#submit'] = array('rules_admin_form_add_rule_submit');
  return $form;
}

/**
 * Determines which operation should be added
 * If the parent operation is an AND, we add an OR, and vice versa.
 */
function rules_admin_determine_operation(&$proxy, $id) {
  $parent = $proxy->get_element($proxy->get_element_parent_id($id)) + array('#type' => '');
  switch ($parent['#type']) {
    default:
    case 'rule':
    case 'AND':
      return 'OR';

    case 'OR':
      return 'AND';
  }
}

/**
 * Returns a list of available logical operations suitable for use with #options
 */
function rules_admin_elements_get_logical_ops() {
  $elements = rules_gather_data('elements');
  $labels = array_map('rules_get_element_label', array_filter($elements, '_rules_admin_element_is_logical_op'));
  asort($labels);
  return $labels;
}

function _rules_admin_element_is_logical_op($element) {
  return isset($element['#logical_op']) && $element['#logical_op'];
}

/**
 * Themes the a list of actions or conditions, that are not satisfiable.
 */
function theme_rules_admin_unsatisfied_elements($element) {
  $output = '';
  $output .= '<div class="rules-unsatisfied-arguments">';
  foreach (rules_admin_get_grouped_labels($element['#unsatisfied_grouped_options']) as $grouped_rules) {
    $output .= theme('rules_admin_unsatisfied_elements_group', $grouped_rules, $element['#unsatisfied_grouped_options']);
  }
  $output .= '</div>';
  return $output;
}

/**
 * Themes not satisifable elements of a group.
 */
function theme_rules_admin_unsatisfied_elements_group($grouped_rules, $elements) {
  $output = '<dl>';
  foreach ($grouped_rules as $name => $value) {
    $fieldset = array(
      '#type' => 'fieldset',
      '#title' => t('@group module', array('@group' => $elements[$name]['module'])),
      '#collapsible' => FALSE,
    );
    $output .= '<dt>'. check_plain($elements[$name]['label']) .'</dt>';
    $output .= '<dd><em>'. format_plural(count($elements[$name]['unsatisfied arguments']), 'Unavailable argument: @arguments', 'Unavailable arguments: @arguments', array('@arguments' => implode(', ', $elements[$name]['unsatisfied arguments']))) .'</em></dd>';
  }
  $output .= '</dl>';
  $fieldset['items'] = array(
    '#type' => 'markup',
    '#value' => $output,
  );
  return drupal_render($fieldset);
}

/**
 * Menu callback for the autocompletion of categories.
 */
function rules_admin_categories_autocomplete($string) {
  // The user enters a comma-separated list of tags. We only autocomplete the last tag.
  $array = array_filter(drupal_explode_tags($string));
  // Fetch last tag
  $last_string = drupal_strtolower(trim(array_pop($array)));
  $prefix = count($array) ? implode(', ', $array) .', ' : '';
  $tags = rules_admin_get_categories('rules') + rules_admin_get_categories('rule_sets');

  $matches = array();
  foreach ($tags as $tag) {
    if ($last_string && strpos(drupal_strtolower($tag), $last_string) !== FALSE) {
      $matches[$prefix . $tag] = check_plain($tag);
    }
  }
  drupal_json($matches);
}

/**
 * Saves the element label.
 */
function rules_admin_save_element_label($form, &$form_state, &$element) {
  $info = _rules_admin_get_label($form_state, rules_get_element_info($element), $element, $form_state['values']['label'], TRUE);
  $element['#info'] = $info + $element['#info'];
}

/**
 * Defines the rules settings form
 */
function rules_admin_settings(&$form_state) {
  $form['rules_debug'] = array(
    '#type' => 'checkbox',
    '#title' => t('Debug rule evaluation'),
    '#default_value' => variable_get('rules_debug', FALSE),
    '#description' => t('When activated, debugging information is shown when rules are evaluated.'),
  );
  $form['rules_show_fixed'] = array(
    '#type' => 'checkbox',
    '#title' => t('Show fixed rules and rule sets'),
    '#default_value' => variable_get('rules_show_fixed', FALSE),
    '#description' => t('When activated, fixed items provided by modules are shown in the admin center too.'),
  );
  $form['rules_hide_token_message'] = array(
    '#type' => 'checkbox',
    '#title' => t('Ignore missing token module'),
    '#default_value' => variable_get('rules_hide_token_message', FALSE),
    '#description' => t('Rules can use the token module to provide token replacements; if this module is not present rules will complain, unless this setting is checked.'),
  );
  return system_settings_form($form);
}