<?php
// $Id$

/**
 * @file
 * Allows users to manage customizable lists of shortcut links.
 */

/**
 * The name of the default shortcut set.
 *
 * This set will be displayed to any user that does not have another set
 * assigned.
 */
define('SHORTCUT_DEFAULT_SET_NAME', 'shortcut-set-1');

/**
 * Implement hook_permission().
 */
function shortcut_permission() {
  return array(
    'administer shortcuts' => array(
      'title' => t('Administer shortcuts'),
      'description' => t('Manage all shortcut and shortcut sets.'),
    ),
    'customize shortcut links' => array(
      'title' => t('Customize shortcut links'),
      'description' => t("Edit, add and delete the links in shortcut set the user is using."),
    ),
    'switch shortcut sets' => array(
      'title' => t('Choose a different shortcut set'),
      'description' => t('Choose which set of shortcuts are displayed for the user.')
    ),
  );
}

/**
 * Implement hook_menu().
 */
function shortcut_menu() {
  $items['admin/config/system/shortcut'] = array(
    'title' => 'Shortcuts',
    'description' => 'List the available shortcut sets and switch between them.',
    'page callback' => 'drupal_get_form',
    'page arguments' => array('shortcut_set_switch'),
    'access arguments' => array('administer shortcuts'),
    'file' => 'shortcut.admin.inc',
  );
  $items['admin/config/system/shortcut/%shortcut_set'] = array(
    'title' => 'Customize shortcuts',
    'page callback' => 'drupal_get_form',
    'page arguments' => array('shortcut_set_customize', 4),
    'access callback' => 'shortcut_set_edit_access',
    'access arguments' => array(4),
    'type' => MENU_CALLBACK,
    'file' => 'shortcut.admin.inc',
  );
  $items['admin/config/system/shortcut/%shortcut_set/add-link'] = array(
    'title' => 'Add shortcut',
    'page callback' => 'drupal_get_form',
    'page arguments' => array('shortcut_link_add', 4),
    'access callback' => 'shortcut_set_edit_access',
    'access arguments' => array(4),
    'type' => MENU_LOCAL_ACTION,
    'file' => 'shortcut.admin.inc',
  );
  $items['admin/config/system/shortcut/%shortcut_set/add-link-inline'] = array(
    'title' => 'Add shortcut',
    'page callback' => 'shortcut_link_add_inline',
    'page arguments' => array(4),
    'access callback' => 'shortcut_set_edit_access',
    'access arguments' => array(4),
    'type' => MENU_CALLBACK,
    'file' => 'shortcut.admin.inc',
  );
  $items['admin/config/system/shortcut/link/%menu_link'] = array(
    'title' => 'Edit shortcut',
    'page callback' => 'drupal_get_form',
    'page arguments' => array('shortcut_link_edit', 5),
    'access callback' => 'shortcut_link_access',
    'access arguments' => array(5),
    'type' => MENU_CALLBACK,
    'file' => 'shortcut.admin.inc',
  );
  $items['admin/config/system/shortcut/link/%menu_link/delete'] = array(
    'title' => 'Delete shortcut',
    'page callback' => 'drupal_get_form',
    'page arguments' => array('shortcut_link_delete', 5),
    'access callback' => 'shortcut_link_access',
    'access arguments' => array(5),
    'type' => MENU_CALLBACK,
    'file' => 'shortcut.admin.inc',
  );
  $items['user/%user/shortcuts'] = array(
    'title' => 'Shortcuts',
    'page callback' => 'drupal_get_form',
    'page arguments' => array('shortcut_set_switch', 1),
    'access callback' => 'shortcut_set_switch_access',
    'access arguments' => array(1),
    'type' => MENU_LOCAL_TASK,
    'file' => 'shortcut.admin.inc',
  );
  return $items;
}

/**
 * Implement hook_theme().
 */
function shortcut_theme() {
  return array(
    'shortcut_set_switch' => array(
      'render element' => 'form',
      'file' => 'shortcut.admin.inc',
    ),
    'shortcut_set_customize' => array(
      'render element' => 'form',
      'file' => 'shortcut.admin.inc',
    ),
  );
}

/**
 * Implement hook_block_info().
 */
function shortcut_block_info() {
  $blocks['shortcuts']['info'] = t('Shortcuts');
  // Shortcut blocks can't be cached because each menu item can have a custom
  // access callback. menu.inc manages its own caching.
  $blocks['shortcuts']['cache'] = DRUPAL_NO_CACHE;
  return $blocks;
}

/**
 * Implement hook_block_view().
 */
function shortcut_block_view($delta = '') {
  if ($delta == 'shortcuts') {
    $shortcut_set = shortcut_current_displayed_set();
    $data['subject'] = t('@shortcut_set shortcuts', array('@shortcut_set' => $shortcut_set->title));
    $data['content'] = shortcut_renderable_links($shortcut_set);
    return $data;
  }
}

/**
 * Access callback for editing a shortcut set.
 *
 * @param $shortcut_set
 *   (optional) The shortcut set to be edited. If not set, the current
 *   displayed shortcut set will be assumed.
 * @return
 *   TRUE if the current user has access to edit the shortcut set, FALSE
 *   otherwise.
 */
function shortcut_set_edit_access($shortcut_set = NULL) {
  // Sufficiently-privileged users can edit their currently displayed shortcut
  // set, but not other sets. Shortcut administrators can edit any set.
  if (user_access('administer shortcuts')) {
    return TRUE;
  }
  if (user_access('customize shortcut links')) {
    return !isset($shortcut_set) || $shortcut_set == shortcut_current_displayed_set();
  }
  return FALSE;
}

/**
 * Access callback for switching the shortcut set assigned to a user account.
 *
 * @param $account
 *   (optional) The user account whose shortcuts will be switched. If not set,
 *   the account of the current logged-in user will be assumed.
 * @return
 *   TRUE if the current user has access to switch the shortcut set of the
 *   provided account, FALSE otherwise.
 */
function shortcut_set_switch_access($account = NULL) {
  global $user;
  // Sufficiently-privileged users can switch their own shortcut sets, but not
  // those of other users. Shortcut administrators can switch any user's set.
  return user_access('administer shortcuts') || (user_access('switch shortcut sets') && (!isset($account) || $user->uid == $account->uid));
}

/**
 * Access callback for editing a link in a shortcut set.
 */
function shortcut_link_access($menu_link) {
  // The link must belong to a shortcut set that the current user has access
  // to edit.
  if ($shortcut_set = shortcut_set_load($menu_link['menu_name'])) {
    return shortcut_set_edit_access($shortcut_set);
  }
  return FALSE;
}

/**
 * Loads the data for a shortcut set.
 *
 * @param $set_name
 *   The name of the shortcut set to load.
 * @return
 *   If the shortcut set exists, an object of type stdClass containing the
 *   following properties:
 *   - 'set_name': The internal name of the shortcut set.
 *   - 'title': The title of the shortcut set.
 *   - 'links': An array of links associated with this shortcut set.
 *   If the shortcut set does not exist, the function returns FALSE.
 */
function shortcut_set_load($set_name) {
  $set = db_select('shortcut_set', 'ss')
  ->fields('ss')
  ->condition('set_name', $set_name)
  ->execute()
  ->fetchObject();
  if (!$set) {
    return FALSE;
  }
  $set->links = menu_load_links($set_name);
  return $set;
}

/**
 * Saves a shortcut set.
 *
 * @param $shortcut_set
 *   An object containing the following properties:
 *   - 'title': The title of the shortcut set.
 *   - 'set_name': (optional) The internal name of the shortcut set. If
 *     omitted, a new shortcut set will be created, and the 'set_name' property
 *     will be added to the passed-in array.
 *   - 'links': (optional) An array of menu links to save for the shortcut set.
 *     Each link is an array containing at least the following keys (which will
 *     be expanded to fill in other default values after the shortcut set is
 *     saved):
 *     - 'link_path': The Drupal path or external path that the link points to.
 *     - 'link_title': The title of the link.
 *     Any other keys accepted by menu_link_save() may also be provided.
 * @return
 *   A constant which is either SAVED_NEW or SAVED_UPDATED depending on whether
 *   a new set was created or an existing one was updated.
 *
 * @see menu_link_save()
 */
function shortcut_set_save(&$shortcut_set) {
  // First save the shortcut set itself.
  if (isset($shortcut_set->set_name)) {
    $return = drupal_write_record('shortcut_set', $shortcut_set, 'set_name');
  }
  else {
    $shortcut_set->set_name = shortcut_set_get_unique_name();
    $return = drupal_write_record('shortcut_set', $shortcut_set);
  }
  // If links were provided for the set, save them, replacing any that were
  // there before.
  if (isset($shortcut_set->links)) {
    menu_delete_links($shortcut_set->set_name);
    foreach ($shortcut_set->links as &$link) {
      // Do not specifically associate these links with the shortcut module,
      // since other modules may make them editable via the menu system.
      // However, we do need to specify the correct menu name.
      $link['menu_name'] = $shortcut_set->set_name;
      menu_link_save($link);
    }
    // Make sure that we have a return value, since if the links were updated
    // but the shortcut set was not, the call to drupal_write_record() above
    // would not return an indication that anything had changed.
    if (empty($return)) {
      $return = SAVED_UPDATED;
    }
  }
  return $return;
}

/**
 * Deletes a shortcut set.
 *
 * Note that the default set cannot be deleted.
 *
 * @param $shortcut_set
 *   An object representing the shortcut set to delete.
 * @return
 *   TRUE if the set was deleted, FALSE otherwise.
 */
function shortcut_set_delete($shortcut_set) {
  // Make sure not to delete the default set.
  $default_set = shortcut_default_set();
  if ($shortcut_set->set_name == $default_set->set_name) {
    return FALSE;
  }
  // First, delete any user assignments for this set, so that each of these
  // users will go back to using whatever default set applies.
  db_delete('shortcut_set_users')
    ->condition('set_name', $shortcut_set->set_name)
    ->execute();
  // Next, delete the menu links for this set.
  menu_delete_links($shortcut_set->set_name);
  // Finally, delete the set itself.
  $deleted = db_delete('shortcut_set')
    ->condition('set_name', $shortcut_set->set_name)
    ->execute();
  return (bool) $deleted;
}

/**
 * Reset the link weights in a shortcut set to match their current order.
 *
 * This function can be used, for example, when a new shortcut link is added to
 * the set. If the link is added to the end of the array and this function is
 * called, it will force that link to display at the end of the list.
 *
 * @param $shortcut_set
 *   An object representing a shortcut set. The link weights of the passed-in
 *   object will be reset as described above.
 */
function shortcut_set_reset_link_weights(&$shortcut_set) {
  $weight = -50;
  foreach ($shortcut_set->links as &$link) {
    $link['weight'] = $weight;
    $weight++;
  }
}

/**
 * Assign a user to a particular shortcut set.
 *
 * @param $shortcut_set
 *   An object representing the shortcut set.
 * @param $account
 *   A user account that will be assigned to use the set.
 */
function shortcut_set_assign_user($shortcut_set, $account) {
  db_merge('shortcut_set_users')
    ->key(array('uid' => $account->uid))
    ->fields(array('set_name' => $shortcut_set->set_name))
    ->execute();
}

/**
 * Unassign a user from any shortcut set they may have been assigned to.
 *
 * The user will go back to using whatever default set applies.
 *
 * @param $account
 *   A user account that will be removed from the shortcut set assignment.
 * @return
 *   TRUE if the user was previously assigned to a shortcut set and has been
 *   successfully removed from it. FALSE if the user was already not assigned
 *   to any set.
 */
function shortcut_set_unassign_user($account) {
  $deleted = db_delete('shortcut_set')
    ->condition('uid', $account->uid)
    ->execute();
  return (bool) $deleted;
}

/**
 * Returns the current displayed shortcut set for the provided user account.
 *
 * @param $account
 *   (optional) The user account whose shortcuts will be returned. Defaults to
 *   the current logged-in user.
 * @return
 *   An object representing the shortcut set that should be displayed to the
 *   current user. If the user does not have an explicit shortcut set defined,
 *   the default set is returned.
 */
function shortcut_current_displayed_set($account = NULL) {
  $shortcut_sets = &drupal_static(__FUNCTION__, array());
  global $user;
  if (!isset($account)) {
    $account = $user;
  }
  // Try to return a shortcut set from the static cache.
  if (isset($shortcut_sets[$account->uid])) {
    return $shortcut_sets[$account->uid];
  }
  // If none was found, try to find a shortcut set that is explicitly assigned
  // to this user.
  $query = db_select('shortcut_set', 's');
  $query->fields('s');
  $query->join('shortcut_set_users', 'u', 's.set_name = u.set_name');
  $query->condition('u.uid', $account->uid);
  $shortcut_set = $query->execute()->fetchObject();
  // Otherwise, use the default set.
  if (!$shortcut_set) {
    $shortcut_set = shortcut_default_set($account);
  }
  $shortcut_sets[$account->uid] = $shortcut_set;
  return $shortcut_set;
}

/**
 * Returns the default shortcut set for a given user account.
 *
 * @param $account
 *   (optional) The user account whose shortcuts will be returned. Defaults to
 *   the current logged-in user.
 * @return
 *   An object representing the default shortcut set.
 */
function shortcut_default_set($account = NULL) {
  global $user;
  if (!isset($account)) {
    $account = $user;
  }
  // Allow modules to return a default shortcut set name. Since we can only
  // have one, we allow the last module which returns a valid result to take
  // precedence. If no module returns a valid set, fall back on the site-wide
  // default.
  $shortcut_set_names = array_reverse(array_merge(array(SHORTCUT_DEFAULT_SET_NAME), module_invoke_all('shortcut_default_set', $account)));
  foreach ($shortcut_set_names as $name) {
    if ($shortcut_set = shortcut_set_load($name)) {
      break;
    }
  }
  return $shortcut_set;
}

/**
 * Returns a unique, machine-readable shortcut set name.
 */
function shortcut_set_get_unique_name() {
  // Shortcut sets are numbered sequentially, so we keep trying until we find
  // one that is available. For better performance, we start with a number
  // equal to one more than the current number of shortcut sets, so that if
  // no shortcut sets have been deleted from the database, this will
  // automatically give us the correct one.
  $number = db_query("SELECT COUNT(*) FROM {shortcut_set}")->fetchField() + 1;
  do {
    $name = shortcut_set_name($number);
    $number++;
  } while ($shortcut_set = shortcut_set_load($name));
  return $name;
}

/**
 * Returns the name of a shortcut set, based on a provided number.
 *
 * All shortcut sets have names like "shortcut-set-N" so that they can be
 * matched with a properly-namespaced entry in the {menu_links} table.
 *
 * @param $number
 *   A number representing the shortcut set whose name should be retrieved.
 * @return
 *   A string representing the expected shortcut name.
 */
function shortcut_set_name($number) {
  return "shortcut-set-$number";
}

/**
 * Returns an array of all shortcut sets, keyed by the set name.
 *
 * @return
 *   An array of shortcut sets. Note that only the basic shortcut set
 *   properties (name and title) are returned by this function, not the list
 *   of menu links that belong to the set.
 */
function shortcut_sets() {
  return db_select('shortcut_set', 'ss')
  ->fields('ss')
  ->execute()
  ->fetchAllAssoc('set_name');
}

/**
 * Determines if a path corresponds to a valid shortcut link.
 *
 * @param $path
 *   The path to the link.
 * @return
 *   TRUE if the shortcut link is valid, FALSE otherwise. Valid links are ones
 *   that correspond to actual paths on the site.
 *
 * @see menu_edit_item_validate()
 */
function shortcut_valid_link($path) {
  // Do not use URL aliases.
  $normal_path = drupal_get_normal_path($path);
  if ($path != $normal_path) {
    $path = $normal_path;
  }
  // Only accept links that correspond to valid paths on the site itself.
  return !url_is_external($path) && menu_get_item($path);
}

/**
 * Returns an array of shortcut links, suitable for rendering.
 *
 * @param $shortcut_set
 *   (optional) An object representing the set whose links will be displayed.
 *   If not provided, the user's current set will be displayed.
 * @return
 *   An array of shortcut links, in the format returned by the menu system.
 *
 * @see menu_tree()
 */
function shortcut_renderable_links($shortcut_set = NULL) {
  if (!isset($shortcut_set)) {
    $shortcut_set = shortcut_current_displayed_set();
  }
  return menu_tree($shortcut_set->set_name);
}

/**
 * Implement hook_page_build().
 */
function shortcut_page_build(&$page) {
  if (shortcut_set_edit_access()) {
    $link = $_GET['q'];
    $query_parameters = drupal_get_query_parameters();
    if (!empty($query_parameters)) {
     $link .= '?' . drupal_http_build_query($query_parameters);
    }
    $query = array(
     'link' => $link,
     'name' => drupal_get_title(),
     'token' => drupal_get_token('shortcut-add-link'),
    );
    $query += drupal_get_destination();

    $shortcut_set = shortcut_current_displayed_set();
    $link_text = shortcut_set_switch_access() ? t('Add to %shortcut_set shortcuts', array('%shortcut_set' => $shortcut_set->title)) : t('Add to shortcuts');
    $page['add_to_shortcuts'] = array(
     '#prefix' => '<div class="add-to-shortcuts">',
     '#markup' => l('<span class="icon"></span><span class="text">' . $link_text . '</span>', 'admin/config/system/shortcut/' . $shortcut_set->set_name . '/add-link-inline', array('query' => $query, 'html' => TRUE)),
     '#suffix' => '</div>',
    );
  }

  $links = shortcut_renderable_links();
  $links['#attached'] = array('css' => array(drupal_get_path('module', 'shortcut') . '/shortcut.css'));
  $links['#prefix'] = '<div class="toolbar-shortcuts">';
  $links['#suffix'] = '</div>';
  $shortcut_set = shortcut_current_displayed_set();
  $configure_link = NULL;
  if (shortcut_set_edit_access($shortcut_set)) {
    $configure_link = array('#markup' => l(t('edit shortcuts'), 'admin/config/system/shortcut/' . $shortcut_set->set_name, array('attributes' => array('id' => 'toolbar-customize'))));
  }

  $drawer = array(
    'shortcuts' => $links,
    'configure' => $configure_link,
  );

  $page['toolbar_drawer'] = $drawer;
}

/**
 * Implement hook_preprocess_page().
 */
function shortcut_preprocess_page(&$variables) {
  if (isset($variables['page']['add_to_shortcuts'])) {
    $variables['add_to_shortcuts'] = drupal_render($variables['page']['add_to_shortcuts']);
  }
}