<?php


/**
 *
 * @file
 * Taxonomy Manager
 *
 * Administration interface for managing taxonomy vocabularies
 *
 */

// Default value for the tree pager. Value can be overridden with the variable
// taxonomy_manager_pager_tree_page_size.
define('TAXONOMY_MANAGER_PAGER_TREE_PAGE_SIZE_DEFAULT', 100);

/**
 * Implements hook_menu().
 */
function taxonomy_manager_menu() {

  $items['admin/structure/taxonomy_manager/voc'] = array(
    'title' => 'Taxonomy Manager',
    'description' => 'Administer vocabularies with the Taxonomy Manager',
    'page callback' => 'taxonomy_manager_voc_list',
    'access arguments' => array('administer taxonomy'),
    'file' => 'taxonomy_manager.admin.inc',
  );

  $items['admin/structure/taxonomy_manager/voc/%taxonomy_vocabulary_machine_name'] = array(
    'title callback' => 'taxonomy_admin_vocabulary_title_callback',
    'title arguments' => array(4),
    'page callback' => 'drupal_get_form',
    'page arguments' => array('taxonomy_manager_form', 4),
    'access arguments' => array('administer taxonomy'),
    'file' => 'taxonomy_manager.admin.inc',
  );

  $items['admin/structure/taxonomy_manager/childform'] = array(
    'page callback' => 'taxonomy_manager_tree_build_child_form',
    'access arguments' => array('administer taxonomy'),
    'type' => MENU_CALLBACK,
  );

  $items['admin/structure/taxonomy_manager/weight'] = array(
    'page callback' => 'taxonomy_manager_update_weights',
    'access arguments' => array('administer taxonomy'),
    'type' => MENU_CALLBACK,
    'file' => 'taxonomy_manager.admin.inc',
  );

  $items['admin/structure/taxonomy_manager/siblingsform'] = array(
    'page callback' => 'taxonomy_manager_tree_build_siblings_form',
    'access arguments' => array('administer taxonomy'),
    'type' => MENU_CALLBACK,
  );

  $items['admin/structure/taxonomy_manager/export'] = array(
    'page callback' => 'taxonomy_manager_export',
    'access arguments' => array('administer taxonomy'),
    'type' => MENU_CALLBACK,
    'file' => 'taxonomy_manager.admin.inc',
  );

  $items['admin/structure/taxonomy_manager/double-tree/%taxonomy_vocabulary_machine_name/%taxonomy_vocabulary_machine_name'] = array(
    'title' => 'Taxonomy Manager',
    'page callback' => 'drupal_get_form',
    'page arguments' => array('taxonomy_manager_double_tree_form', 4, 5),
    'access arguments' => array('administer taxonomy'),
    'file' => 'taxonomy_manager.admin.inc',
  );

  $items['admin/config/user-interface/taxonomy-manager-settings'] = array(
    'title' => 'Taxonomy Manager',
    'description' => 'Advanced settings for the Taxonomy Manager',
    'page callback' => 'drupal_get_form',
    'page arguments' => array('taxonomy_manager_settings'),
    'access arguments' => array('administer site configuration'),
    'type' => MENU_NORMAL_ITEM,
    'file' => 'taxonomy_manager.admin.inc',
  );

  $items['taxonomy_manager/autocomplete'] = array(
    'title' => 'Taxonomy Manager Autocomplete',
    'page callback' => 'taxonomy_manager_autocomplete_load',
    'access arguments' => array('administer taxonomy'),
    'type' => MENU_CALLBACK,
    'file' => 'taxonomy_manager.admin.inc',
  );
  return $items;
}

/**
 * Implements hook_admin_menu_map().
 */
function taxonomy_manager_admin_menu_map() {
  if (!user_access('administer taxonomy')) {
    return;
  }
  $map['admin/structure/taxonomy_manager/voc/%taxonomy_vocabulary_machine_name'] = array(
    'parent' => 'admin/structure/taxonomy_manager/voc',
    'arguments' => array(
      array('%taxonomy_vocabulary_machine_name' => array_keys(taxonomy_vocabulary_get_names())),
    ),
  );
  return $map;
}


/**
 * Implements hook_theme().
 */
function taxonomy_manager_theme() {
  return array(
    'taxonomy_manager_form' => array(
      'render element' => 'form',
    ),
    'taxonomy_manager_double_tree_form' => array(
      'render element' => 'form',
    ),
    'no_submit_button' => array(
      'render element' => 'element',
    ),
    'taxonomy_manager_image_button' => array(
      'render element' => 'element',
    ),
    'taxonomy_manager_tree' => array(
      'render element' => 'element',
    ),
    'taxonomy_manager_tree_elements' => array(
      'render element' => 'element',
    ),
    'taxonomy_manager_tree_checkbox' => array(
      'render element' => 'element',
    ),
    'taxonomy_manager_tree_radio' => array(
      'render element' => 'element',
    ),
    'taxonomy_manager_term_data_extra' => array(
      'render element' => 'element',
    ),
  );
}

/**
 * Implements hook_help().
 */
function taxonomy_manager_help($path, $arg) {
  switch ($path) {
    case 'admin/help#taxonomy_manager':
      $output = t('The Taxonomy Manager provides an additional interface for managing vocabularies of the taxonomy module. It\'s especially very useful for long sets of terms.
                   The vocabulary is represented in a dynamic tree view.
                   It supports operation like mass adding and deleting of terms, fast weight editing, moving of terms in hierarchies, merging of terms and fast term data editing.
                   For more information on how to use please read the readme file included in the taxonomy_manager directory.');
      return $output;
  }
}


/**
 * function gets called by the taxonomy_manager_tree form type ('taxonomy_manager_'. form_id .'_operations')
 * return an form array with values to show next to every term value
 */
function taxonomy_manager_taxonomy_manager_tree_operations($term) {
  $form = array();
  if (!variable_get('taxonomy_manager_disable_mouseover', 0)) {
    $module_path = drupal_get_path('module', 'taxonomy_manager') . '/';
    if (_taxonomy_manager_tree_term_children_count($term->tid) > 0) {
      $form['select_all'] = array('#weight' => -1, '#markup' => '<span class="select-all-children" title="' . t("Select all children") . '">&nbsp;&nbsp;&nbsp;&nbsp;</span>');
    }
    $form['up'] = array('#markup' => theme("image", array('path' => $module_path . "images/go-up-small.png", 'alt' => "go up", 'title' => t("Move up"), 'attributes' => array('class' => 'term-up'))));
    $form['down'] = array('#markup' => theme("image", array('path' => $module_path . "images/go-down-small.png", 'alt' => "go down", 'title' => t("Move down"), 'attributes' => array('class' => 'term-down'))));
    $link_img = theme("image", array('path' => $module_path . "images/link-small.png", 'alt' => "link to term page"));
    $link = l('&nbsp;' . $link_img, 'taxonomy/term/' . $term->tid, array('attributes' => array('rel' => 'tag', 'title' => t("Go to term page"), 'target' => '_blank'), 'html' => TRUE));
    $form['link'] = array('#markup' => $link, '#weight' => 10);
  }
  return $form;
}

/**
 * function gets called by taxonomy_manager_tree form type ('taxonomy_manager_'. form_id .'_link')
 * and returns an link, where to go, when a term gets clicked
 *
 * @param $vid vocabulary id
 */
function taxonomy_manager_taxonomy_manager_tree_link($term) {
  return "admin/structure/taxonomy_manager/termdata/" . $term->tid;
}

function taxonomy_manager_taxonomy2_manager_tree_operations($term) {
  return taxonomy_manager_taxonomy_manager_tree_operations($term);
}
function taxonomy_manager_taxonomy2_manager_tree_link($term) {
  return taxonomy_manager_taxonomy_manager_tree_link($term);
}


/******************************************
 * TAXONOMY TREE FORM ELEMENT DEFINITION
 *
 * how to use:
 * $form['name'] = array(
 *   '#type' => 'taxonomy_manager_tree',
 *   '#vid' => $vid,
 * );
 *
 * additional parameter:
 *   #pager: TRUE / FALSE,
 *     whether to use pagers (drupal pager, load of nested children, load of siblings)
 *     or to load the whole tree on page generation
 *   #parent: only children on this parent will be loaded
 *   #terms_to_expand: loads and opens the first path of given term ids
 *   #siblings_page: current page for loading pf next siblings, internal use
 *   #default_value: an array of term ids, which get selected by default
 *   #render_whole_tree: set this option to TRUE, if you have defined a parent for the tree and you want
 *      the the tree is fully rendered
 *   #add_term_info: if TRUE, hidden form values with the term id and weight are going to be added
 *   #expand_all: if TRUE, all elements are going to be expanded by default
 *   #multiple: if TRUE the tree will contain checkboxes, otherwise radio buttons
 *   #tree_is_required: use #tree_is_required instead of #required if you are using the tree within an other
 *                      element and don't want that both are internally required, because it might cause that
 *                      error messages are shown twice (see content_taxonomy_tree)
 *   #language lang code if i18n is enabled and multilingual vocabulary
 *
 * defining term operations:
 *   to add values (operations,..) to each term, add a function, which return a form array
 *   'taxonomy_manager_'. $tree_form_id .'_operations'
 *
 * how to retrieve selected values:
 *   selected terms ids are available in validate / submit function in
 *   $form_values['name']['selected_terms'];
 *
 ******************************************/

/**
 * Implements hook_elements().
 */
function taxonomy_manager_element_info() {
  $type['taxonomy_manager_tree'] = array(
    '#input' => TRUE,
    '#process' => array('taxonomy_manager_tree_process_elements'),
    '#tree' => TRUE,
    '#element_validate' => array('taxonomy_manager_tree_validate'),
    '#theme' => 'taxonomy_manager_tree',
    '#parent' => 0,
    '#siblings_page' => 0,
    '#operations' => "",
    '#default_value' => array(),
    '#multiple' => TRUE,
    '#add_term_info' => TRUE,
    '#required' => FALSE,
    '#expand_all' => FALSE,
    '#render_whole_tree' => FALSE,
    '#search_string' => '',
    '#terms_to_expand' => array(),
    '#terms_to_highlight' => array(),
    '#language' => NULL,
    '#pager' => FALSE,
  );

  return $type;
}

/**
 * Processes the tree form element
 *
 * @param $element
 * @return the tree element
 */
function taxonomy_manager_tree_process_elements($element) {
  global $_taxonomy_manager_existing_ids; //TEMP: seems like this functions gets called twice in preview and cause problem because of adding the settings to js twice
  $_taxonomy_manager_existing_ids = is_array($_taxonomy_manager_existing_ids) ? $_taxonomy_manager_existing_ids : array();

  $module_path = drupal_get_path('module', 'taxonomy_manager') . '/';
  $id = drupal_clean_css_identifier(implode('-', $element['#parents']));
  $element['#id'] = $id;
  $vid = $element['#vid'];

  if (!$element['#siblings_page'] && !in_array($id, $_taxonomy_manager_existing_ids)) {
    $_taxonomy_manager_existing_ids[$id] = $id;
    drupal_add_css($module_path . 'css/taxonomy_manager.css');
    drupal_add_js($module_path . 'js/tree.js');

    drupal_add_js(array('siblingsForm' => array('url' => url('admin/structure/taxonomy_manager/siblingsform'), 'modulePath' => $module_path)), 'setting');
    drupal_add_js(array('childForm' => array('url' => url('admin/structure/taxonomy_manager/childform'), 'modulePath' => $module_path)), 'setting');
    drupal_add_js(array('taxonomytree' => array(array('id' => $id, 'vid' => $vid, 'parents' => $element['#parents']))), 'setting');
  }

  if (empty($element['#operations'])) {
    $opertions_callback = 'taxonomy_manager_' . implode('_', $element['#parents']) . '_operations';
    if (function_exists($opertions_callback)) {
      $element['#operations_callback'] = $opertions_callback;
    }
  }
  if (!isset($element['#link'])) {
    $link_callback = 'taxonomy_manager_' . implode('_', $element['#parents']) . '_link';
    if (function_exists($link_callback)) {
      $element['#link_callback'] = $link_callback;
    }
  }

  $element['#elements'] = array();
  $tree = _taxonomy_manager_tree_get_item($element['#vid'], $element['#parent'], $element['#pager'], $element['#siblings_page'], $element['#search_string'], $element['#language']);
  if (count($tree)) {
    if ($element['#pager'] && !($element['#parent'] || $element['#siblings_page'])) {
      $element['pager'] = array('#value' => theme('pager'));
    }

    $terms_to_expand = array();
    if (isset($element['#terms_to_expand'])) {
      // allow multiple terms to be expanded
      $requested_terms_to_expand = is_array($element['#terms_to_expand']) ? $element['#terms_to_expand'] : array($element['#terms_to_expand']);
      foreach ($requested_terms_to_expand as $term_to_expand) {
        // Multiple term version
        _taxonomy_manager_tree_get_first_path($term_to_expand, $tree, $terms_to_expand);
      }
      $terms_to_expand = taxonomy_manager_tree_get_terms_to_expand($tree, $requested_terms_to_expand, TRUE);
    }

    if (count($element['#default_value']) && !$element['#expand_all']) {
      $terms_to_expand = taxonomy_manager_tree_get_terms_to_expand($tree, $element['#default_value'], $element['#multiple']);
    }

    if (!empty($element['#language'])) {
      $element['#elements']['language'] = array('#type' => 'hidden', '#value' => $element['#language'], '#attributes' => array('class' => 'tree-lang'));
      _taxonomy_manager_tree_element_set_params($element['#parents'], $element['#elements']);
    }

    if (!is_array($element['#terms_to_highlight'])) {
      $element['#terms_to_highlight'] = array($element['#terms_to_highlight']);
    }

    $index = 0;
    taxonomy_manager_tree_build_form($index, $tree, $element['#elements'], $element, $element['#parents'], $element['#siblings_page'], $element['#default_value'], $element['#multiple'], $terms_to_expand, $element['#terms_to_highlight']);
  }

  return $element;
}

/**
 * loads tree with terms (depending on various settings)
 *
 * @param $vid
 * @param $parent
 * @param $pager
 * @param $siblings_page
 * @return array with term elements
 */
function _taxonomy_manager_tree_get_item($vid, $parent = 0, $pager = FALSE, $siblings_page = 0, $search_string = NULL, $language_code = NULL) {
  $tree = array();
  if (module_exists('i18n_taxonomy') && $language_code != "") {
    return _taxonomy_manager_tree_get_translated_item($vid, $parent, $pager, $siblings_page, $search_string, $language_code);
  }
  if ($pager) {
    if ($parent || $siblings_page) {
      $start = ($siblings_page-1) * variable_get('taxonomy_manager_pager_tree_page_size', TAXONOMY_MANAGER_PAGER_TREE_PAGE_SIZE_DEFAULT);
      $result = db_query_range("SELECT t.* FROM {taxonomy_term_data} t INNER JOIN {taxonomy_term_hierarchy} h ON t.tid = h.tid WHERE vid = :vid AND h.parent = :parent ORDER BY t.weight, t.name", $start, variable_get('taxonomy_manager_pager_tree_page_size', 100), array(':vid' => $vid, ':parent' => $parent));
    }
    else {
      $query = db_select('taxonomy_term_data', 't')->extend('PagerDefault');
      $query->fields('t');
      $table_alias = $query->join('taxonomy_term_hierarchy', 'h', 't.tid = h.tid AND h.parent = 0');
      $query->condition('t.vid', $vid)
        ->orderBy('t.weight', 'ASC')
        ->orderBy('t.name', 'ASC')
        ->limit(variable_get('taxonomy_manager_pager_tree_page_size', TAXONOMY_MANAGER_PAGER_TREE_PAGE_SIZE_DEFAULT));

      if ($search_string) {
        $query->condition('name', '%' . db_like($search_string) . '%', 'LIKE');
      }
      $result = $query->execute();
    }
    foreach ($result as $term) {
      $term->depth = 0;
      $tree[] = $term;
    }
  }
  else {
    $tree = taxonomy_get_tree($vid, $parent);
  }
  return $tree;
}

/**
 * loads translated tree with terms (depending on various settings)
 *
 * @param $vid
 * @param $parent
 * @param $pager
 * @param $siblings_page
 * @return array with term elements
 */
function _taxonomy_manager_tree_get_translated_item($vid, $parent = 0, $pager = FALSE, $siblings_page = 0, $search_string = NULL, $language_code = NULL) {
  //TODO merge with function above

  $tree = array();
  if ($language_code == "no language") {
    $language_code = ""; //get terms where no language is specified
  }
  if ($pager) {
    if ($parent || $siblings_page) {
      $start = ($siblings_page-1) * variable_get('taxonomy_manager_pager_tree_page_size', TAXONOMY_MANAGER_PAGER_TREE_PAGE_SIZE_DEFAULT);
      $result = db_query_range("SELECT t.* FROM {taxonomy_term_data} t INNER JOIN {taxonomy_term_hierarchy} h ON t.tid = h.tid WHERE vid = :vid AND h.parent = :parent AND t.language = :language ORDER BY t.weight, t.name", $start, variable_get('taxonomy_manager_pager_tree_page_size', 50), array(':vid' => $vid, ':parent' => $parent, ':language' => $language_code));
    }
    else {
      $query = db_select('taxonomy_term_data', 't')->extend('PagerDefault');
      $query->fields('t');
      $table_alias = $query->join('taxonomy_term_hierarchy', 'h', 't.tid = h.tid AND h.parent = 0');
      $query->condition('t.vid', $vid)
        ->condition('t.language', $language_code)
        ->orderBy('t.weight', 'ASC')
        ->orderBy('t.name', 'ASC')
        ->limit(variable_get('taxonomy_manager_pager_tree_page_size', TAXONOMY_MANAGER_PAGER_TREE_PAGE_SIZE_DEFAULT));

      if ($search_string) {
        $query->condition('name', '%' . db_like($search_string) . '%', 'LIKE');
      }
      $result = $query->execute();

    }
    foreach ($result as $term) {
      $term->depth = 0;
      $tree[] = $term;
    }
  }
  else {
    $tree = i18n_taxonomy_get_tree($vid, $language_code, $parent);
  }
  return $tree;
}

/**
 * marks parent terms to expand if a child terms is selected by default
 */
function taxonomy_manager_tree_get_terms_to_expand($tree, $default_values, $multiple) {
  $terms = array();
  foreach (array_reverse($tree) as $term) {
    if (in_array($term->tid, array_values($default_values)) || in_array($term->tid, $terms)) {
      if (isset($term->parents) && is_array($term->parents)) {
        foreach ($term->parents as $parent) {
          if ($parent) {
            $terms[$parent] = $parent;
          }
          if (!$multiple) {
            break;
          }
        }
      }
    }
  }
  return $terms;
}

/**
 * calculates a path to a certain term and merges it into the tree
 */
function _taxonomy_manager_tree_get_first_path($tid, &$tree, &$terms_to_expand) {
  $path = array();
  $next_tid = $tid;

  $i = 0;
  while ($i < 100) { //prevent infinite loop if inconsistent hierarchy
    $parents = taxonomy_get_parents($next_tid);
    if (count($parents)) {
      // Takes first parent.
      $parent = array_shift($parents);
      $path[] = $parent;
      $next_tid = $parent->tid;
      if (taxonomy_manager_term_is_root($next_tid)) {
        break;
      }
    }
    else {
      break;
    }
    $i++;
  }
  $path = array_reverse($path);
  $path[] = taxonomy_term_load($tid);

  $root_term = $path[0];
  $root_term_index;

  // build a map of the path keyed on tid - helps in avoiding duplicates when merging multiple paths to the tree
  $term_map = array();
  if (count($path) > 1) {
    foreach ($tree as $index => $term) {
      $term_map[$term->tid] = $index;
      if ($term->tid == $root_term->tid) {
        $root_term_index = $index;
      }
    }
    reset($tree);
  }

  if (isset($root_term_index)) {
    $path_tree = taxonomy_manager_get_partial_tree($path);

    // build map of path tree keyed on tids
    $path_term_map = array();
    foreach ($path_tree as $index => $term) {
      $path_term_map[$term->tid] = $index;
    }

    reset($path_tree);

    // first find the set of new terms that we need to add - new terms should be contiguous within $path_tree
    $new_path_terms_map = array_diff_key($path_term_map, $term_map);

    if (!empty($new_path_terms_map)) {
      // something to add
      $insert_term_index = reset($new_path_terms_map);
      if ($insert_term_index > 0) {
        // use previous term as insertion point
        $previous_tid = $path_tree[$insert_term_index-1]->tid;
        $insertion_index = $term_map[$previous_tid];
      }
      else {
        // use root index as insertion point
        $insertion_index = $root_term_index;
      }

      // get the new terms to add from the path tree
      $new_path_tree = array_slice($path_tree, $insert_term_index, count($new_path_terms_map));

      // stick the new terms into the tree at the insertion point
      array_splice($tree, $insertion_index+1, 0, $new_path_tree);
    }
  }
}

/**
 * helper function to check whether a given term is a root term
 */
function taxonomy_manager_term_is_root($tid) {
  $is_root = (bool) db_query_range("SELECT 1 FROM {taxonomy_term_hierarchy} h WHERE h.tid = :tid AND h.parent = 0", 0, 1, array(':tid' => $tid))->fetchField();
  if ($is_root) {
    return TRUE;
  }
  return FALSE;
}

/**
 * returns partial tree for a given path
 */
function taxonomy_manager_get_partial_tree($path, $depth = 0) {
  $tree = array();
  $root_term = $path[$depth];
  $children = taxonomy_get_children($root_term->tid);
  if (isset($path[++$depth])) {
    $next_term = $path[$depth];
  }
  foreach ($children as $key => $child) {
    $child->depth = $depth;
    $child->parents = array(0 => $root_term->tid);
    $tree[] = $child;
    if (isset($next_term) && $child->tid == $next_term->tid) {
      $tree = array_merge($tree, taxonomy_manager_get_partial_tree($path, $depth));
    }
  }
  return $tree;
}

/**
 * recursive function for building nested form array
 * with checkboxes and weight forms for each term
 *
 * nested form array are allways appended to parent-form['children']
 *
 * @param $index current index in tree, start with 0
 * @param $tree of terms (generated by taxonomy_get_tree)
 * @return a form array
 */
function taxonomy_manager_tree_build_form(&$index, $tree, &$form, $root_form, $parents = array(), $page = 0, $default_value = array(), $multiple = TRUE, $terms_to_expand = array(), $terms_to_highlight = array()) {
  $current_depth = $tree[$index]->depth;
  while ($index < count($tree) && $tree[$index]->depth >= $current_depth) {
    $term = $tree[$index];
    $attributes = array();

    $this_parents = $parents;
    $this_parents[] = $term->tid;

    $value = in_array($term->tid, $default_value) ? 1 : 0;
    if ($value && !$multiple) {
      // Find our direct parent
      $newindex = $index;
      while ($newindex >= 0 && $tree[$newindex]->depth >= $current_depth) {
        $newindex--;
      }
      if ($newindex >= 0) {
        $value = in_array($tree[$newindex]->tid, $terms_to_expand) ? 1 : 0;
      }
    }
    $form[$term->tid]['checkbox'] = array(
      '#type' => ($multiple) ? 'checkbox' : 'radio',
      '#title' => $term->name, // Escaping is done in theme wrappers.
      '#value' => $value,
      '#return_value' => $term->tid,
      '#required' => FALSE,
      '#theme_wrappers' => ($multiple) ? array('taxonomy_manager_tree_checkbox') : array('taxonomy_manager_tree_radio'),
      '#highlight' => in_array($term->tid, $terms_to_highlight) ? TRUE : FALSE,
    );
    $form[$term->tid]['#attributes'] = array();

    if (!empty($root_form['#link_callback'])) {
      $link_callback = $root_form['#link_callback'];
      if (function_exists($link_callback)) {
        $form[$term->tid]['checkbox']['#link'] = $link_callback($term);
      }
    }

    if ($root_form['#add_term_info']) {
      $form[$term->tid]['weight'] = array('#type' => 'hidden', '#value' => $term->weight, '#attributes' => array('class' => array('weight-form')));
      $form[$term->tid]['tid'] = array('#type' => 'hidden', '#value' => $term->tid, '#attributes' => array('class' => array('term-id')));
      $form[$term->tid]['checkbox']['#extra_info'] = taxonomy_manager_tree_term_extra_info($term);
    }

    if (!empty($root_form['#operations_callback'])) {
      $opertions_callback = $root_form['#operations_callback'];
      if (function_exists($opertions_callback)) {
        $form[$term->tid]['operations'] = $opertions_callback($term);
      }
    }

    if ($page) {
      if ($index == (variable_get('taxonomy_manager_pager_tree_page_size', TAXONOMY_MANAGER_PAGER_TREE_PAGE_SIZE_DEFAULT) - 1) && !isset($tree[$index+1])) {
        $form[$term->tid]['page'] = array(
          '#type' => 'hidden',
          '#value' => $page,
          '#attributes' => array('class' => 'page'),
        );
        $next_count = _taxonomy_manager_tree_get_next_siblings_count($term->vid, $page, $root_form['#parent']);
        $form[$term->tid]['next_count'] = array('#markup' => $next_count);
        $form[$term->tid]['#attributes']['class'][] = 'has-more-siblings';
      }
    }

    _taxonomy_manager_tree_element_set_params($this_parents, $form[$term->tid]);

    _taxonomy_manager_tree_term_set_class($form[$term->tid]['#attributes']['class'], $index, $tree, ($root_form['#expand_all'] || in_array($term->tid, $terms_to_expand)));

    $index++;

    if (isset($tree[$index]) && $tree[$index]->depth > $current_depth) {
      taxonomy_manager_tree_build_form($index, $tree, $form[$term->tid]['children'], $root_form, array_merge($this_parents, array('children')), $page, $default_value, $multiple, $terms_to_expand, $terms_to_highlight);
    }
  }
}

/**
 * adds #id and #name to all form elements
 *
 * @param $parents
 * @param $form
 */
function _taxonomy_manager_tree_element_set_params($parents, &$form) {
  foreach (element_children($form) as $field_name) {
    $field_parents = array_merge($parents, array($field_name));
    $form[$field_name]['#tree'] = TRUE;
    $form[$field_name]['#post'] = array();
    $form[$field_name]['#parents'] = $field_parents;
    $form[$field_name]['#id'] = drupal_clean_css_identifier('edit- ' . implode('-', $field_parents));
    $form[$field_name]['#name'] = array_shift($field_parents) . '[' . implode('][', $field_parents) . ']';
  }
}

/**
 * calculates class type (expandable, lastExpandable) for current element
 *
 * @param $current_index in tree array
 * @param $tree array with terms
 */
function _taxonomy_manager_tree_term_set_class(&$class, $current_index, $tree, $expand) {
  $term = $tree[$current_index];

  $next_index = ++$current_index;
  $next = isset($tree[$next_index]) ? $tree[$next_index] : NULL;

  $children = FALSE;
  if (!empty($next) && $next->depth > $term->depth) {
    $children = TRUE;
  }

  if ($children) {
    if (!empty($next->depth) && $next->depth == $term->depth) {
      $class[] = ($expand) ? 'collapsable' : 'expandable';
    }
    else {
      $class[] = ($expand) ? 'lastCollapsable' : 'lastExpandable';
    }
  }
  elseif (_taxonomy_manager_tree_term_children_count($term->tid) > 0) {
    $class[] = 'has-children';
    if ($current_index == count($tree)) {
      $class[] = 'lastExpandable';
    }
    else {
      $class[] = 'expandable';
    }
  }
  elseif ((count($tree) == $current_index) || (!empty($next) && $term->depth > $next->depth)) {
    $class[] = 'last';
  }

  return $class;
}

/**
 * @param $tid
 * @return children count
 */
function _taxonomy_manager_tree_term_children_count($tid) {
  static $tids = array();

  if (!isset($tids[$tid])) {
    $query = db_select('taxonomy_term_hierarchy', 'h');
    $query->condition('h.parent', $tid);
    $tids[$tid] = $query->countQuery()->execute()->fetchField();
  }

  return $tids[$tid];
}

/**
* returns some additional information about the term which gets added to the link title
*/
function taxonomy_manager_tree_term_extra_info($term) {
  $extra_info = "";
  $term_children_count = _taxonomy_manager_tree_term_children_count($term->tid);
  $term_parents = taxonomy_get_parents($term->tid);

  if ($term_children_count > 0) {
    $extra_info = t('Children Count:') . ' ' . $term_children_count;
  }

  if (count($term_parents) >= 1) {
    $extra_info .= !empty($extra_info) ? ' | ' : '';
    $extra_info .= t('Direct Parents:') . ' ';
    $p_names = array();
    foreach ($term_parents as $p) {
      if ($p->tid != $term->tid) {
        $p_names[] = $p->name;
      }
    }
    $extra_info .= implode(', ', $p_names);
  }
  return $extra_info;
}

/**
 * calculates number of next siblings if using paging
 *
 * @param $vid
 * @param $page
 * @param $parent
 * @return next page size
 */
function _taxonomy_manager_tree_get_next_siblings_count($vid, $page, $parent = 0) {
  $query = db_select('taxonomy_term_data', 't');
  $query->join('taxonomy_term_hierarchy', 'h', 't.tid = h.tid');
  $query->condition('t.vid', $vid);
  $query->condition('h.parent', $parent);
  $count = $query->countQuery()->execute()->fetchField();

  $current_count = variable_get('taxonomy_manager_pager_tree_page_size', TAXONOMY_MANAGER_PAGER_TREE_PAGE_SIZE_DEFAULT) * $page;
  $diff = $count - $current_count;

  if ($diff > variable_get('taxonomy_manager_pager_tree_page_size', TAXONOMY_MANAGER_PAGER_TREE_PAGE_SIZE_DEFAULT)) {
    $diff = variable_get('taxonomy_manager_pager_tree_page_size', TAXONOMY_MANAGER_PAGER_TREE_PAGE_SIZE_DEFAULT);
  }

  return $diff;
}

/**
 * callback for generating and rendering nested child forms (AHAH)
 *
 * @param $tree_id
 * @param $parent term id of parent, that is expanded and of which children have to be loaded
 */
function taxonomy_manager_tree_build_child_form($tree_id, $vid, $parent) {
  $params = $_GET;
  $form_state = form_state_defaults();
  $form_state['method'] = 'get';
  $form_state['values'] = array();
  $form_state['process_input'] = TRUE;
  $form_state['input'] = array();
  $form_state['complete form'] = array();

  $tids = array();
  if (isset($params['#terms_to_expand']) && $params['#terms_to_expand'] != 0) {
    // convert to array
    $tids = explode(',', $params['#terms_to_expand']);
  }

  if (count($tids) == 1) {
    $language = _taxonomy_manager_term_get_lang($tids[0]);
  }
  else {
    $language = $params['language'];
  }

  $child_form = array(
    '#type' => 'taxonomy_manager_tree',
    '#vid' => $vid,
    '#parent' => $parent,
    '#pager' => TRUE,
    '#language' => $language,
    '#terms_to_expand' => $tids,
    '#siblings_page' => 1,
  );

  $opertions_callback = 'taxonomy_manager_' . str_replace('-', '_', $tree_id) . '_operations';
  if (function_exists($opertions_callback)) {
    $child_form['#operations_callback'] = $opertions_callback;
  }

  $link_callback = 'taxonomy_manager_' . str_replace('-', '_', $tree_id) . '_link';
  if (function_exists($link_callback)) {
    $child_form['#link_callback'] = $link_callback;
  }

  _taxonomy_manager_tree_sub_forms_set_parents($params['form_parents'], $parent, $child_form);

  $child_form = form_builder('taxonomy_manager_form', $child_form, $form_state);

  print drupal_json_output(array('data' => drupal_render($child_form)));
  ajax_footer();
}

/**
 * callback for generating and rendering next siblings terms form (AHAH)
 *
 * @param $tree_id
 * @param $page current page
 * @param $prev_tid last sibling, that appears
 * @param $parent if in hierarchies, parent id
 */
function taxonomy_manager_tree_build_siblings_form($tree_id, $page, $prev_tid, $parent = 0) {
  $params = $_GET;
  $form_state = form_state_defaults();
  $form_state['method'] = 'get';
  $form_state['values'] = array();
  $form_state['process_input'] = TRUE;
  $form_state['input'] = array();
  $form_state['complete form'] = array();

  $vid = db_query("SELECT vid FROM {taxonomy_term_data} WHERE tid = :tid", array(':tid' => $prev_tid))->fetchField();

  $siblings_form = array(
    '#type' => 'taxonomy_manager_tree',
    '#vid' => $vid,
    '#parent' => $parent,
    '#pager' => TRUE,
    '#siblings_page' => $page+1,
    '#language' => $params['language'],
  );

  $opertions_callback = 'taxonomy_manager_' . str_replace('-', '_', $tree_id) . '_operations';
  if (function_exists($opertions_callback)) {
    $siblings_form['#operations_callback'] = $opertions_callback;
  }

  $link_callback = 'taxonomy_manager_' . str_replace('-', '_', $tree_id) . '_link';
  if (function_exists($link_callback)) {
    $siblings_form['#link_callback'] = $link_callback;
  }

  _taxonomy_manager_tree_sub_forms_set_parents($params['form_parents'], $parent, $siblings_form);

  $siblings_form = form_builder('taxonomy_manager_form', $siblings_form, $form_state);

  $output = drupal_render($siblings_form);

  //cutting of <ul> and ending </ul> ... can this be done cleaner?
  $output = drupal_substr($output, 21, -5);

  print drupal_json_output(array('data' => $output));
  ajax_footer();

}

/**
 * sets parents depending on form_id and hierarchical parents
 *
 * @param $tree_id
 * @param $parent term id
 * @param $form
 */
function _taxonomy_manager_tree_sub_forms_set_parents($form_parents, $parent, &$form) {
  $tree_ids = $form_parents;
  foreach ($tree_ids as $key => $id) {
    $form['#parents'][] = $id;
  }
  if ($parent) {
    $form['#parents'][] = $parent;
    $form['#parents'][] = 'children';
    /*$all_parents = taxonomy_get_parents_all($parent);
    for ($i=count($all_parents)-1; $i >= 0; $i--) {
      $form['#parents'][] = $all_parents[$i]->tid;
      $form['#parents'][] = 'children';
    }*/
  }
}

/**
 * validates submitted form values
 * checks if selected terms really belong to initial voc, if not --> form_set_error
 *
 * if all is valid, selected values get added to 'selected_terms' for easy use in submit
 *
 * @param $form
 */
function taxonomy_manager_tree_validate($form, &$form_state) {
  $selected = array();

  //this can be useful for more complex processing, where the parent of the selecte term in the tree view is need (releveant if multi parent)
  //used in double tree
  $direct_parents = array();
  $selected = _taxonomy_manager_tree_get_selected_terms($form['#value'], $direct_parents);
  if (!$form['#multiple'] && count($selected) > 1) {
    // There should only be one selected term here. Make sure this is the case.
    $selected = array(key($selected) => key($selected));
  }
  $vid = $form['#vid'];
  foreach ($selected as $tid) {
    if (!_taxonomy_manager_tree_term_valid($tid, $vid)) {
      form_set_error('', t('An illegal choice has been detected. Please contact the site administrator.'));
    }
  }
  form_set_value($form, array('selected_terms' => $selected, 'selected_terms_direct_parents' => $direct_parents), $form_state);
}

/**
 * checks if term id belongs to vocabulary
 *
 * @param $tid term id
 * @param $vid voc id
 * @return true, if term belongs to voc, else false
 */
function _taxonomy_manager_tree_term_valid($tid, $vid) {
  $term = taxonomy_term_load($tid);
  if ($term->vid != $vid) return FALSE;
  return TRUE;
}

/**
 * returns term ids of selected checkboxes
 *
 * goes through nested form array recursivly
 *
 * @param $form_values
 * @return an array with ids of selected terms
 */
function _taxonomy_manager_tree_get_selected_terms($form_values, &$direct_parents = array(), $direct_parent = 0) {
  $tids = array();
  if (is_array($form_values)) {
    foreach ($form_values as $tid => $form_value) {
      if (isset($form_value['checkbox']) && $tid && ($tid == $form_value['checkbox'])) {
        $tids[$tid] = $tid;
        if ($direct_parent) {
          $direct_parents[$tid] = $direct_parent;
        }
      }
      if (isset($form_value['children']) && is_array($form_value['children'])) {
        $tids += _taxonomy_manager_tree_get_selected_terms($form_value['children'], $direct_parents, $tid);
      }
    }
  }
  return $tids;
}

/**
 * returns language of a term (multilingual voc), if i18ntaxonomy enabled
 */
function _taxonomy_manager_term_get_lang($tid) {
  if (module_exists('i18n_taxonomy')) {
    $term = taxonomy_term_load($tid);
    if ($term && isset($term->language)) {
      return $term->language;
    }
  }
  return "";
}

/**
 * theme function for root element
 *
 * @param $element
 * @return html output
 */
function theme_taxonomy_manager_tree($variables) {
  $element = $variables['element'];
  $tree = theme('taxonomy_manager_tree_elements', array('element' => $element['#elements']));
  if ((!$element['#parent'] && !$element['#siblings_page']) || $element['#render_whole_tree']) {
    $element['#children'] = '<div id="' . $element['#id'] . '">';
    $element['#children'] .= $tree;
    $element['#children'] .= '</div>';
    $element['#title_display'] = 'none';
    return theme('form_element', array('element' => $element));
  }

  return $tree;
}

/**
 * recursive theme function for term elements
 *
 * @param $element
 * @return html lists
 */
function theme_taxonomy_manager_tree_elements($variables) {
  $element = $variables['element'];
  $output = '<ul class="treeview">';

  if (is_array($element)) {
    foreach (element_children($element) as $tid) {
      if (is_numeric($tid)) {
        $output .= '<li' . drupal_attributes($element[$tid]['#attributes']) . '>';
        if ((is_array($element[$tid]['#attributes']['class']) && in_array('has-children', $element[$tid]['#attributes']['class'])) || (isset($element[$tid]['children']) && is_array($element[$tid]['children']))) {
          $output .= '<div class="hitArea"></div>';
        }
        $output .= '<div class="term-line' . (($element[$tid]['checkbox']['#highlight']) ? ' highlightActiveTerm' : '') . '">';
        $output .= drupal_render($element[$tid]['checkbox']);

        $output .= '<div class="term-operations" style="display: none;">';
        $output .= drupal_render($element[$tid]['operations']);
        $output .= '</div>';

        if (is_array($element[$tid]['weight']) && is_array($element[$tid]['tid'])) {
          $output .= drupal_render($element[$tid]['weight']);
          $output .= drupal_render($element[$tid]['tid']);
        }

        $output .= '</div>';

        // Siblings Pager.
        if (isset($element[$tid]['next_count'])) {
          $output .= '<div class="term-has-more-siblings">';
          $output .= '<div class="term-next-count">' . t('next') . " " . drupal_render($element[$tid]['next_count']) . '</div>';
          $output .= drupal_render($element[$tid]['page']);
          $output .= '</div>';
        }

        if (isset($element[$tid]['children']) && is_array($element[$tid]['children'])) {
          $output .= theme('taxonomy_manager_tree_elements', array('element' => $element[$tid]['children']));
        }

        $output .='</li>';
      }
    }
  }

  $output .= "</ul>";
  if (isset($element['language'])) {
    $output .= drupal_render($element['language']);
  }
  return $output;
}

/**
 * themes a checkbox, where a label can optional contain a link
 */
function theme_taxonomy_manager_tree_checkbox($variables) {
  $element = $variables['element'];
  $element['#attributes']['type'] = 'checkbox';
  element_set_attributes($element, array('id', 'name', '#return_value' => 'value'));

  // Unchecked checkbox has #value of integer 0.
  if (!empty($element['#checked'])) {
    $element['#attributes']['checked'] = 'checked';
  }
  _form_set_class($element, array('form-checkbox'));
  $output = '<input' . drupal_attributes($element['#attributes']) . ' />';

  $title = $element['#title'];
  if (isset($element['#link'])) {
    $attr = array();
    $attr["class"][] = "term-data-link";
    $attr["class"][] = "term-data-link-id-" . $element['#return_value'];
    if (isset($element['#extra_info'])) {
      $attr["title"] = $element['#extra_info'];
    }
    $title = l($title, $element['#link'], array('attributes' => $attr));
  }
  else {
    $title = check_plain($title);
  }
  $element['#children'] = '<label class="option">' . $output . ' ' . $title . '</label>';
  $element['#title_display'] = 'none';

  return theme('form_element', array('element' => $element));
}

/**
 * themes a radio, where a label can optional contain a link
 */
function theme_taxonomy_manager_tree_radio($variables) {
  $element = $variables['element'];
  $element['#attributes']['type'] = 'radio';
  element_set_attributes($element, array('id', 'name', '#return_value' => 'value'));
  if (isset($element['#return_value']) && $element['#value'] !== FALSE && $element['#value'] == $element['#return_value']) {
    $element['#attributes']['checked'] = 'checked';
  }
  _form_set_class($element, array('form-radio'));

  $output = '<input' . drupal_attributes($element['#attributes']) . ' />';

  $title = $element['#title'];
  if (isset($element['#link'])) {
    $title = l($title, $element['#link'], array('attributes' => array("class" => "term-data-link term-data-link-id-" . $element['#return_value'])));
  }
  else {
    $title = check_plain($title);
  }
  $element['#children'] = '<label class="option">' . $output . ' ' . $title . '</label>';
  $element['#title_display'] = 'none';

  return theme('form_element', array('element' => $element));
}