<?php

/**
 * The form displayed on admin/structure/crumbs(/weights)
 *
 * @param array $form
 * @param array $form_state
 * @param string $type
 *   E.g. 'tabledrag' or 'textual' or 'expansible'.
 *
 * @return array
 */
function crumbs_admin_weights_form($form, $form_state, $type = 'tabledrag') {

  $form = array();

  $info = crumbs()->pluginInfo;

  // Re-discover plugins, when the admin visits the weights configuration form.
  $info->flushCaches();

  $form['crumbs_weights'] = array(
    '#title' => t('Weights'),
    // Fetching the default value is not automated by system_settings_form().
    '#default_value' => $info->userWeights,
    '#crumbs_plugin_info' => $info,
  );

  switch ($type) {
    case 'textual':
      // You need to enable crumbs_labs to get this.
      $form['crumbs_weights']['#type'] = 'crumbs_weights_textual';
      break;
    case 'expansible':
      // You need to enable crumbs_labs to get this.
      $form['crumbs_weights']['#type'] = 'crumbs_weights_expansible';
      break;
    case 'tabledrag':
    default:
      $form['crumbs_weights']['#type'] = 'crumbs_weights_tabledrag';
  }

  $form = system_settings_form($form);
  $form['#submit'][] = '_crumbs_admin_flush_cache';
  return $form;
}

/**
 * The form displayed on admin/structure/crumbs/display
 */
function crumbs_admin_display_form() {
  $form = array();

  // Home link settings
  $form['home_link_settings'] = array(
    '#type' => 'fieldset',
    '#title' => t('Home link settings'),
  );
  $form['home_link_settings']['crumbs_show_front_page'] = array(
    '#type' => 'checkbox',
    '#title' => t('Show the home page link (recommended).'),
    '#default_value' => variable_get('crumbs_show_front_page', TRUE),
  );
  $form['home_link_settings']['crumbs_home_link_title'] = array(
    '#type' => 'textfield',
    '#title' => t('Home link title'),
    '#default_value' => variable_get('crumbs_home_link_title', 'Home'),
    '#description' => t('Title of the link that points to the front page.'),
    '#size' => 30,
  );

  // Current page settings
  $form['current_page_settings'] = array(
    '#type' => 'fieldset',
    '#title' => t('Current page settings'),
  );
  $form['current_page_settings']['crumbs_show_current_page'] = array(
    '#type' => 'radios',
    '#title' => t('Show the current page at the end of the breadcrumb trail?'),
    '#options' => array(
      // @todo Smarter option values
      FALSE => t('Hide.'),
      CRUMBS_TRAILING_SEPARATOR => t('Hide, but end the trail with a separator.'),
      CRUMBS_SHOW_CURRENT_PAGE => t('Show, as plain text.'),
      CRUMBS_SHOW_CURRENT_PAGE_SPAN => t('Show, wrapped in !tags tags.', array(
        '!tags' =>  '<code>&lt;span class="crumbs-current-page"&gt;</code>',
      )),
      CRUMBS_SHOW_CURRENT_PAGE_LINK => t('Show, as a link.'),
    ),
    '#default_value' => variable_get('crumbs_show_current_page', FALSE),
  );

  // Visibility settings
  $form['visibility_settings'] = array(
    '#type' => 'fieldset',
    '#title' => t('Breadcrumb visibility settings'),
  );
  $home = t('Home');
  $current = t('Current page');
  $intermediate = t('Intermediate page');
  $form['visibility_settings']['crumbs_minimum_trail_items'] = array(
    '#type' => 'radios',
    '#title' => t('Shortest visible breadcrumb'),
    '#description' => t('If the trail has fewer items than specified here, the breadcrumb will be hidden.'),
    '#default_value' => variable_get('crumbs_minimum_trail_items', 2),
    '#options' => array(
      1 => "($home)",
      2 => "(<a href='#'>$home</a>) &raquo; ($current)",
      3 => "(<a href='#'>$home</a>) &raquo; <a href='#'>$intermediate</a> &raquo; ($current)",
    ),
  );

  // Separator settings
  $form['separator_settings'] = array(
    '#type' => 'fieldset',
    '#title' => t('Separator settings'),
  );
  $form['separator_settings']['crumbs_separator_span'] = array(
    '#type' => 'checkbox',
    '#title' => t('Wrap the separator in !tags tags:', array(
        '!tags' => '<code>&lt;span class="crumbs-separator"&gt;</code>',
      )),
    '#default_value' => variable_get('crumbs_separator_span', FALSE),
  );
  $separator_notes = '';
  foreach (array(
    'A subset of HTML is accepted.',
    'Special characters should be specified as htmlentities, e.g. "&amp;raquo;".',
    'Spaces should be added around the separator symbol.',
    'The setting will only work in themes where the Crumbs implementation of theme_breadcrumb() is used.',
  ) as $note) {
    $separator_notes .= '<li>' . str_replace("\n", '<br/>', t($note)) . '</li>';
  }
  $separator_notes = '<ul>' . $separator_notes . '</ul>';
  $separator_desc = '<p>' . t('A custom separator symbol, such as " &amp;raquo; " ( &raquo; ) or " &amp;gt; " (&gt).') . '</p>';
  $form['separator_settings']['crumbs_separator'] = array(
    '#type' => 'textfield',
    '#title' => t('Custom separator HTML'),
    '#description' => $separator_desc,
    '#default_value' => variable_get('crumbs_separator', ' &raquo; '),
    '#element_validate' => array('_crumbs_validate_separator_xss'),
  );
  $form['separator_settings']['notes'] = array(
    '#type' => 'markup',
    '#markup' => '<p>' . t('Notes:') . '</p>' . $separator_notes,
  );

  // Theme override settings
  $theme_override_options = array('theme_breadcrumb' => array());
  $themes_need_flush = FALSE;
  $originals = variable_get('crumbs_original_theme_breadcrumb', array());
  foreach (list_themes() as $theme_name => $theme_obj) {
    if ('1' !== '' . $theme_obj->status) {
      // Theme is disabled.
      continue;
    }
    $path = 'admin/appearance/settings/' . $theme_name;
    $link = l($theme_obj->info['name'], $path);
    if (!isset($originals[$theme_name])) {
      $f = 'theme_breadcrumb';
      $link .= '?';
      $themes_need_flush = TRUE;
    }
    else {
      $f = $originals[$theme_name];
    }
    $theme_override_options[$f][$theme_name] = $link;
  }

  foreach ($theme_override_options as $f => $theme_links) {
    $option_text = t('Override !theme_breadcrumb', array(
      '!theme_breadcrumb' => $f . '()',
    ));
    if (!empty($theme_links)) {
      $option_text .= ': ' . implode(', ', $theme_links);
    }
    $theme_override_options[$f] = $option_text;
  }

  if ($themes_need_flush) {
    $theme_override_options['theme_breadcrumb'] .= '<br/>' .
      t('The "?" indicates that the theme registry has not been rebuilt for the respective theme yet, so we do not know if it has its own implementation of theme_breadcrumb().');
  }

  if (!empty($theme_override_options)) {
    $form['theme_override_settings']['crumbs_override_theme_breadcrumb'] = array(
      '#type' => 'checkboxes',
      '#options' => $theme_override_options,
      '#html' => TRUE,
      '#default_value' => variable_get('crumbs_override_theme_breadcrumb', array('theme_breadcrumb')),
      '#title' => t('Override theme implementations'),
    );
    $form['theme_override_settings']['notes'] = array(
      '#type' => 'markup',
      '#markup' =>
        '<p>' . t('Use !crumbs_module_implementation instead of the respective theme implementation.', array(
            '!crumbs_module_implementation' => '<code>crumbs_theme_breadcrumb()</code>',
          )) . '<br/>' .
        t('This may conflict with some themes.') . '</p>',
    );
  }
  if (!empty($form['theme_override_settings'])) {
    $form['theme_override_settings'] += array(
      '#type' => 'fieldset',
      '#title' => t('Theme override settings'),
    );
  }

  $form = system_settings_form($form);
  $form['#submit'][] = '_crumbs_admin_display_submit_flush_cache';
  return $form;
}

/**
 * Element validate callback for separator string.
 *
 * @param array $element
 * @param array $form_state
 */
function _crumbs_validate_separator_xss($element, $form_state) {
  $string = $element['#value'];
  $filtered = filter_xss_admin($string);
  if ($string !== $filtered) {
    form_error($element, t('%name contains unsafe HTML. Maybe you meant %safe instead.', array(
      '%name' => $element['#title'],
      '!safe' => '"<code>' . check_plain($filtered) . '</code>"',
    )));
  }
}

/**
 * Additional submit handler for crumbs_admin_display_form, that will flush the
 * crumbs-related caches.
 *
 * @param array $form
 */
function _crumbs_admin_display_submit_flush_cache($form) {
  _crumbs_admin_flush_cache();

  // Check if the theme registry needs rebuild.
  if (_crumbs_admin_display_submit_checkboxes_changed($form['theme_override_settings']['crumbs_override_theme_breadcrumb'])) {
    // Flush theme registry.
    // See _admin_menu_flush_cache() in admin_menu module.
    system_rebuild_theme_data();
    drupal_theme_rebuild();
  }
}

/**
 * Determine if a submitted checkboxes element value has changed.
 *
 * @param array $element
 *   Form element with "#type" = "checkboxes".
 *
 * @return bool
 *   TRUE, if the value has changed. That is, if some checkboxes have been
 *   checked or unchecked.
 */
function _crumbs_admin_display_submit_checkboxes_changed($element) {
  $before = $element['#default_value'];
  $after = $element['#value'];
  foreach ($before as $key => $value) {
    if ($key === $value) {
      if (!isset($after[$key])) {
        // Found a difference.
        return TRUE;
      }
      unset($after[$key]);
    }
  }
  return !empty($after);
}
