<?php

/**
 * @file
 * Provides an API for adding jump menus based on configured
 * menus, vocabularies, or custom php code.
 */

/**
 * Implement hook_menu().
 *
 * @return array
 */
function jump_menu() {
  $items = array();
  $items['admin/config/system/jump'] = array(
    'title' => 'Jump Settings',
    'description' => 'Configure Jump module settings.',
    'page callback' => 'drupal_get_form',
    'page arguments' => array('jump_settings'),
    'access callback' => 'user_access',
    'access arguments' => array('administer menu'),
  );
  return $items;
}

/**
 * Menu callback for 'admin/settings/jump'.
 *
 * @return string
 */
function jump_settings() {
  $form['jump_activepageinmenu'] = array(
    '#type' => 'checkbox',
    '#title' => t('Show active page in menu.'),
    '#default_value' => variable_get('jump_activepageinmenu', 1),
    '#description' => t('This setting will force the jump menu to show the current page as the default selection in the jump menu when checked.  If you have a menu option that you would always like displayed at the top of the menu, like <em>Select a menu item</em>, you will want to uncheck this. This setting controls this behavior for all jump menus sitewide.  You can override this setting on a block-by-block basis.'),
  );
  return system_settings_form($form);
}

/**
 * Implement hook_block_info().
 * @return array
 */
function jump_block_info() {
  $blocks = array();
  if (function_exists('menu_get_menus')) {
    foreach (menu_get_menus() as $name => $title) {
      $blocks['menu-' . $name] = array(
        'info' => t('Jump menu: !menu', array('!menu' => $name))
      );
    }
  }

  if (function_exists('taxonomy_get_vocabularies')) {
    $vocs = taxonomy_get_vocabularies();
    foreach ($vocs as $vid => $vocabulary) {
      $blocks['taxo-' . $vid] = array(
        'info' => t('Jump menu: !voc', array('!voc' => $vocabulary->name))
      );
    }
  }
  return $blocks;
}

/**
 * Implement hook_block_view().
 * @param string $delta
 * @return array
 */
function jump_block_view($delta = '') {
  // The first 5 characters of $delta should be one of:
  //    menu-
  //    taxo-
  $subject = '';
  // don't use drupal_substr() since we know the specific indices and php substr is faster.
  $jumpmenu_type = substr($delta, 0, 4);
  $jumpmenu_name = substr($delta, 5);
  $active = jump_get_active_setting($delta);
  if ($jumpmenu_type == 'menu') {
    $form = jump_quickly($jumpmenu_name, 'menu', $active);

    // Use the menu label as the default block subject
    $menus = menu_get_menus();
    $subject = $menus[$jumpmenu_name];
  }
  elseif ($jumpmenu_type == 'taxo') {
    $form = jump_quickly($jumpmenu_name, 'taxo', $active);

    // Use the vocabulary name as the default block subject
    $vocab = taxonomy_vocabulary_load($jumpmenu_name);
    $subject = $vocab->name;
  }

  return array('subject' => $subject, 'content' => $form);
}

/**
 * Implement hook_block_configure().
 * @param string $delta
 * @return array
 */
function jump_block_configure($delta = '') {
  $form = array();
  $form['jump_activepageinmenu_' . $delta] = array(
    '#type' => 'checkbox',
    '#title' => t('Show active page in jump menu.'),
    '#default_value' => variable_get('jump_activepageinmenu_' . $delta, 1),
    '#description' => t('This setting will force the jump menu to show the current page as the default selection in this block\'s jump menu.'),
  );
  return $form;
}

/**
 *
 * @param string $delta
 * @param array $edit
 * @return nothing
 */
function jump_block_save($delta = '', $edit = array()) {
  variable_set('jump_activepageinmenu_' . $delta, $edit['jump_activepageinmenu_' . $delta]);
  return;
}

/**
 * Get a quick-jump menu form that contains a dropdown and a go button.
 *
 * @staticvar integer $num_jump_forms
 * @param string $name
 *   If it's an array, then these are the options for the select box.  If it's
 *   a scalar, then check the type to see what it means.
 * @param string $type
 *   If 'menu' then $name is the menu name from which the options will be
 *   derived.  If 'taxo' then $name is the vocabulary id from which the terms
 *   will be derived.  If 'custom' then $name should be an array that contains
 *   the options.
 * @param integer $active
 * @return array
 */
function jump_quickly($name = 'navigation', $type = 'menu', $active = -1) {
  if ($active === -1) {
    $active = variable_get('jump_activepageinmenu', 1);
  }

  if (is_array($name)) {
    $options = $name;
  }
  else {
    $options = array();
    if ($type == 'menu') {
      jump_menu_get_menu_options($options, $name);
    }
    elseif ($type == 'taxo') {
      jump_menu_get_taxo_options($options, $name);
    }
  }

  // Give each form on the page a unique id so we can handle multiple
  // jump forms...
  static $num_jump_forms = 0;
  $num_jump_forms++;

  $form_id = 'jump_quickly_form_' . $num_jump_forms;

  return drupal_get_form($form_id, $options, $active);
}

/**
 * Form constructor for the jump form.
 *
 * @param array $form_state
 * @param array $options
 * @param integer $active
 * @return array
 */
function jump_quickly_form($form, &$form_state, $options, $active) {
  $default = '';
  if ($active) {
    if (isset($options[$_GET['q']])) {
      $default = $_GET['q'];
    }
  }

  $form = array();
  $form['#submit'][] = 'jump_quickly_form_submit';
  $form['#theme'] = 'jump_quickly_form';
  $form['#attributes']['class'] = 'jump-quickly';
  $form['jump_goto'] = array(
    '#type' => 'select',
    '#default_value' => $default,
    '#options' => $options,
  );
  $form['submit'] = array(
    '#type' => 'submit',
    '#value' => t('Go')
  );

  return $form;
}

/**
 * Form submit callback for the jump form.
 *
 * @param array $form
 * @param array $form_state
 */
function jump_quickly_form_submit($form, &$form_state) {
  if (!empty($form_state['values']['jump_goto'])) {
    $fragment = explode('#', $form_state['values']['jump_goto']);
    if (isset($fragment[1])) {
      drupal_goto($fragment[0], NULL, $fragment[1]);
    }
    else {
      drupal_goto($form_state['values']['jump_goto']);
    }
  }
}

/**
 * Theme function for jump form.
 *
 * @param array $form
 * @return string
 */
function theme_jump_quickly_form($variables) {
  $form = $variables['form'];
  $output = '<div class="container-inline">';
  $output .= drupal_render($form['jump_goto']);
  $output .= drupal_render($form['submit']);
  $output .= '</div>';
  $output .= drupal_render_children($form);
  return $output;
}

/**
 * Utility function to retrieve an array of menu items for the jump menu.
 *
 * @param array $options
 * @param string $name
 */
function jump_menu_get_menu_options(&$options, $name) {
  $tree = menu_tree_page_data($name);
  $front = variable_get('site_frontpage', 'node');
  foreach ($tree as $data) {
    if (!$data['link']['hidden']) {
      $href = ($data['link']['href'] == '<front>') ? $front : $data['link']['href'];
      $href = (isset($data['link']['options']['fragment'])) ? $href . '#' . $data['link']['options']['fragment'] : $href;
      $options[$href] = $data['link']['title'];
    }
  }
}

/**
 * Utility function to retrieve an array of taxonomy terms for the jump menu.
 *
 * @param array $options
 * @param integer $vid
 */
function jump_menu_get_taxo_options(&$options, $vid) {
  $tree = taxonomy_get_tree($vid, 0, NULL, TRUE);
  foreach ($tree as $term) {
    $uri = entity_uri('taxonomy_term', $term);
    $options[$uri['path']] = $term->name;
  }
}

/**
 * Implement hook_forms().
 *   Allows us to use the same callbacks for forms with different ids.
 *
 * @param string $form_id
 * @return array
 */
function jump_forms($form_id, $args) {
  // Ensure we map a callback for our form and not something else
  $forms = array();
  if (strpos($form_id, 'jump_quickly_form') === 0) {
    // Let the forms API know where to get the form data corresponding
    // to this form id.
    $forms[$form_id] = array(
      'callback' => 'jump_quickly_form',
      'callback arguments' => $args,
    );
  }

  return $forms;
}

/**
 * Implement hook_theme().
 *
 * @return array
 */
function jump_theme() {
  return array(
    'jump_quickly_form' => array(
      'render element' => 'form',
    )
  );
}

/**
 * Utility function to retrieve the 'active' setting for a give block.
 *
 * @param string $delta
 * @return integer
 */
function jump_get_active_setting($delta) {
  $active_site_default = variable_get('jump_activepageinmenu', 1);
  $active = variable_get('jump_activepageinmenu_' . $delta, $active_site_default);
  return $active;
}