<?php

/**
 * @file
 * Implementation of the Hierarchical Select API for the Menu module.
 */


//----------------------------------------------------------------------------
// Drupal core hooks.

/**
 * Implements of hook_menu().
 */
function hs_menu_menu() {
  $items['admin/config/content/hierarchical_select/menu'] = array(
    'title'            => 'Menu',
    'description'      => 'Hierarchical Select configuration for Menu',
    'access arguments' => array('administer site configuration'),
    'page callback'    => 'drupal_get_form',
    'page arguments'   => array('hs_menu_admin_settings'),
    'type'             => MENU_LOCAL_TASK,
  );
  return $items;
}

/**
 * Implements hook_form_FORMID_alter().
 *
 * Alter the node form's menu form.
 */
function hs_menu_form_node_form_alter(&$form, &$form_state) {
  if (isset($form['menu']['link']['parent']) && $form['menu']['#access']) {
    unset($form['menu']['link']['parent']['#options']);
    $form['menu']['link']['parent']['#type'] = 'hierarchical_select';
    _hs_menu_apply_config($form['menu']['link']['parent'], array('type' => $form['type']['#value']));

     // Set custom submit callback.
     array_unshift($form['#submit'], 'hs_menu_node_form_submit');
  }
}

/**
 * Implements hook_form_BASE_FORMID_alter().
 *
 * Alter the widget type form; dynamically add the Hierarchical Select
 * Configuration form when it is needed.
 */
function hs_menu_form_menu_edit_item_alter(&$form, &$form_state) {
  unset($form['parent']['#options']);
  $original_item = $form['original_item']['#value'];
  $form['parent']['#type'] = 'hierarchical_select';
  _hs_menu_apply_config($form['parent'], array('exclude' => array(
    $original_item['menu_name'],
    $original_item['mlid'],
  )));

  // Set custom submit callback.
  array_unshift($form['#submit'], 'hs_menu_menu_edit_item_form_submit');
}


//----------------------------------------------------------------------------
// Form API callbacks.

/**
 * Submit callback; menu edit item form.
 */
function hs_menu_menu_edit_item_form_submit(&$form, &$form_state) {
  // Don't return an array, but a single item.
  $form_state['values']['parent'] = $form_state['values']['parent'][0];
}

/**
 * Submit callback; node edit form.
 */
function hs_menu_node_form_submit(&$form, &$form_state) {
  // Don't return an array, but a single item.
  $form_state['values']['menu']['parent'] = $form_state['values']['menu']['parent'][0];
}

//----------------------------------------------------------------------------
// Menu callbacks.

/**
 * Form definition; admin settings.
 */
function hs_menu_admin_settings() {
  $form['hs_menu_resizable'] = array(
    '#type' => 'radios',
    '#title' => t('Resizable'),
    '#description' => t(
      "When enabled, a handle appears below the Hierarchical Select to allow
      the user to dynamically resize it. Double clicking will toggle between
      the smallest and a sane 'big size'."
    ),
    '#options' => array(
      0 => t('Disabled'),
      1 => t('Enabled'),
    ),
    '#default_value' => variable_get('hs_menu_resizable', 1),
  );

  return system_settings_form($form);
}


//----------------------------------------------------------------------------
// Hierarchical Select hooks.

/**
 * Implements hook_hierarchical_select_params().
 */
function hs_menu_hierarchical_select_params() {
  $params = array(
    'exclude', // The menu_name and mlid (in an array) of a menu link that should be excluded from the hierarchy.
  );
  return $params;
}

/**
 * Implements hook_hierarchical_select_root_level().
 */
function hs_menu_hierarchical_select_root_level($params) {
  $menus = array();

  $result = db_query("SELECT menu_name, title FROM {menu_custom} ORDER BY title");
  // If the type is set, respect the core menu options setting.
  if (isset($params['type'])) {
    $type_menus = variable_get('menu_options_' . $params['type'], array('main-menu' => 'main-menu'));
    while ($menu = $result->fetchObject()) {
      if (in_array($menu->menu_name, $type_menus)) {
        $menus[$menu->menu_name . ':0'] = $menu->title;
      }
    }
  }
  // Fall back to the legacy approach, show all menu's.
  else {
    while ($menu = $result->fetchObject()) {
      $menus[$menu->menu_name . ':0'] = $menu->title;
    }
  }

  return $menus;
}

/**
 * Implements hook_hierarchical_select_children().
 */
function hs_menu_hierarchical_select_children($parent, $params) {
  $children = array();
  list($menu_name, $plid) = explode(':', $parent);
  $tree = menu_tree_all_data($menu_name, NULL);
  return _hs_menu_children($tree, $menu_name, $plid, $params['exclude']);
}

/**
 * Implements hook_hierarchical_select_lineage().
 */
function hs_menu_hierarchical_select_lineage($item, $params) {
  $lineage = array($item);

  list($menu_name, $mlid) = explode(':', $item);

  // If the initial mlid is zero, then this is the root level, so we don't
  // have to get the lineage.
  if ($mlid > 0) {
    // Prepend each parent mlid (i.e. plid) to the lineage.
    do {
      $plid = db_query("SELECT plid FROM {menu_links} WHERE mlid = :mlid", array(':mlid' => $mlid))->fetchField();
      array_unshift($lineage, "$menu_name:$plid");
      $mlid = $plid;
    } while ($plid > 0);
  }

  return $lineage;
}

/**
 * Implements hook_hierarchical_select_valid_item().
 */
function hs_menu_hierarchical_select_valid_item($item, $params) {
  $parts = explode(':', $item);

  $valid = TRUE;

  // Validate menu name.
  $valid = (array_key_exists($parts[0], menu_get_menus()));

  // Validate hierarchy of mlids.
  for ($i = 1; $valid && $i < count($parts); $i++) {
    $valid = $valid && is_numeric($parts[$i]);
  }

  // Ensure that this isn't the excluded menu link.
  $valid = $valid && $item != $params['exclude'][0] . $params['exclude'][1];

  return $valid;
}

/**
 * Implements hook_hierarchical_select_item_get_label().
 */
function hs_menu_hierarchical_select_item_get_label($item, $params) {
  static $labels = array();

  $parts = explode(':', $item);
  if (count($parts) == 1) { // Get the menu name.
    $menu_name = $parts[0];
    $labels[$item] = db_query("SELECT title FROM {menu_custom} WHERE menu_name = :menu_name", array(':menu_name' => $menu_name))->fetchField();
  }
  else { // Get the menu link title.
    $mlid = end($parts);
    $menu_link = menu_link_load($mlid);
    $labels[$item] = $menu_link['title'];
  }

  return $labels[$item];
}

/**
 * Implements hook_hierarchical_select_implementation_info().
 */
function hs_menu_hierarchical_select_implementation_info() {
  return array(
    'hierarchy type' => t('Menu'),
    'entity type'    => t('N/A'),
  );
}


//----------------------------------------------------------------------------
// Private functions.

/**
 * Recursive helper function for hs_menu_hierarchical_select_children().
 */
function _hs_menu_children($tree, $menu_name, $plid = 0, $exclude = FALSE) {
  $children = array();

  foreach ($tree as $data) {
    if ($data['link']['plid'] == $plid && $data['link']['hidden'] >= 0) {
      if ($exclude && $data['link']['menu_name'] === $exclude[0] && $data['link']['mlid'] == $exclude[1]) {
        continue;
      }

      $title = truncate_utf8($data['link']['title'], 30, TRUE, FALSE);
      if ($data['link']['hidden']) {
        $title .= ' (' . t('disabled') . ')';
      }
      $children[$menu_name . ':' . $data['link']['mlid']] = $title;
      if ($data['below']) {
        $children += _hs_menu_children($data['below'], $menu_name, $plid, $exclude);
      }
    }
    elseif ($data['below']) {
      $children += _hs_menu_children($data['below'], $menu_name, $plid, $exclude);
    }
  }

  return $children;
}

/**
 * Helper function to apply the HS config to a form item.
 */
function _hs_menu_apply_config(&$form, $params) {
  $form['#config'] = array(
    'module' => 'hs_menu',
    'params' => array(
      'exclude' => isset($params['exclude']) ? $params['exclude'] : NULL,
      'type' => isset($params['type']) ? $params['type'] : NULL,
    ),
    'save_lineage'    => 0,
    'enforce_deepest' => 0,
    'entity_count'    => 0,
    'require_entity'  => 0,
    'resizable'       => variable_get('hs_menu_resizable', 1),
    'level_labels' => array(
      'status' => 0,
    ),
    'dropbox' => array(
      'status' => 0,
    ),
    'editability' => array(
      'status' => 0,
    ),
    'render_flat_select' => 0,
  );
}