<?php
// $Id$

/**
 * Implement hook_menu().
 */
function dashboard_menu() {
  $items['admin/dashboard'] = array(
    'title' => 'Dashboard',
    'page callback' => 'dashboard_admin',
    'access arguments' => array('access dashboard'),
    // Make this appear first, so for example, in admin menus, it shows up on
    // the top corner of the window as a convinient "home link".
    'weight' => -100,
  );
  $items['admin/dashboard/customize'] = array(
    'title' => 'Dashboard',
    'page callback' => 'dashboard_admin',
    'page arguments' => array(TRUE),
    'access arguments' => array('access dashboard'),
    'type' => MENU_CALLBACK,
  );
  $items['admin/dashboard/drawer'] = array(
    'page callback' => 'dashboard_show_disabled',
    'access arguments' => array('administer blocks'),
    'type' => MENU_CALLBACK,
  );
  $items['admin/dashboard/block-content/%/%'] = array(
    'page callback' => 'dashboard_show_block_content',
    'page arguments' => array(3, 4),
    'access arguments' => array('administer blocks'),
    'type' => MENU_CALLBACK,
  );
  $items['admin/dashboard/update'] = array(
    'page callback' => 'dashboard_update',
    'access arguments' => array('administer blocks'),
    'type' => MENU_CALLBACK,
  );
  return $items;
}

/**
 * Implement hook_block_info_alter().
 *
 * Skip rendering dashboard blocks when not on the dashboard page itself. This
 * prevents expensive dashboard blocks from causing performance issues on pages
 * where they will never be displayed.
 */
function dashboard_block_info_alter(&$blocks) {
  if (!dashboard_is_visible()) {
    foreach ($blocks as $key => $block) {
      if (in_array($block->region, dashboard_regions())) {
        unset($blocks[$key]);
      }
    }
  }
}

/**
 * Implement hook_page_build().
 *
 * Display dashboard blocks in the main content region.
 */
function dashboard_page_build(&$page) {
  global $theme_key;

  if (dashboard_is_visible()) {
    $block_info = array();

    // Create a wrapper for the dashboard itself, then insert each dashboard
    // region into it.
    $page['content']['dashboard'] = array('#theme_wrappers' => array('dashboard'));
    foreach (dashboard_regions() as $region) {
      // Insert regions even when they are empty, so that they will be
      // displayed when the dashboard is being configured.
      $page['content']['dashboard'][$region] = !empty($page[$region]) ? $page[$region] : array();
      $page['content']['dashboard'][$region]['#dashboard_region'] = $region;
      // Allow each dashboard region to be themed differently, or fall back on
      // the generic theme wrapper function for dashboard regions.
      $page['content']['dashboard'][$region]['#theme_wrappers'][] = array($region, 'dashboard_region');
      unset($page[$region]);
      $blocks_found = array();
      foreach ($page['content']['dashboard'][$region] as $item) {
        if (isset($item['#theme_wrappers']) && is_array($item['#theme_wrappers']) && in_array('block', $item['#theme_wrappers'])) {
          // If this item is a block, ensure it has a subject.
          if (empty($item['#block']->subject)) {
            // Locally cache info data for the object for all blocks, in case
            // we find a block similarly missing title from the same module.
            if (!isset($block_info[$item['#block']->module])) {
              $block_info[$item['#block']->module] = module_invoke($item['#block']->module, 'block_info');
            }
            $item['#block']->subject = $block_info[$item['#block']->module][$item['#block']->delta]['info'];
          }
          $blocks_found[$item['#block']->module . '_' . $item['#block']->delta] = TRUE;
        }
      }

      // Find blocks which were not yet displayed on the page (were empty), and
      // add placeholder items in their place for rendering.
      $block_list = db_select('block')
        ->condition('theme', $theme_key)
        ->condition('status', 1)
        ->condition('region', $region)
        ->fields('block')
        ->execute();
      foreach ($block_list as $block) {
        if (!isset($blocks_found[$block->module . '_' . $block->delta])) {
          $block->enabled = $block->page_match = TRUE;
          $block->content = array('#markup' => '<div class="dashboard-block-empty">(empty)</div>');
          if (!isset($block_info[$block->module])) {
            $block_info[$block->module] = module_invoke($block->module, 'block_info');
          }
          $block->subject = t('@title', array('@title' => $block_info[$block->module][$block->delta]['info']));
          $block_render = array($block->module . '_' . $block->delta => $block);
          $build = _block_get_renderable_array($block_render);
          $page['content']['dashboard'][$block->region][] = $build;
        }
      }
    }
  }
}

/**
 * Implement hook_permission().
 */
function dashboard_permission() {
  return array(
    'access dashboard' => array(
      'title' => t('View the administrative dashboard'),
      'description' => t('Access the site-wide dashboard. Modifying the dashboard requires the "Administer blocks" permission.'),
    ),
  );
}

/**
 * Implement hook_system_info_alter().
 *
 * Add regions to each theme to store the dashboard blocks.
 */
function dashboard_system_info_alter(&$info, $file, $type) {
  if ($type == 'theme') {
    $info['regions'] += dashboard_region_descriptions();
    if (module_exists('overlay')) {
      $info['overlay_regions'] = !empty($info['overlay_regions']) ? array_merge($info['overlay_regions'], dashboard_regions()) : dashboard_regions();
    }
  }
}

/**
 * Implement hook_theme().
 */
function dashboard_theme() {
  return array(
    'dashboard' => array(
      'render element' => 'element',
    ),
    'dashboard_admin' => array(
      'render element' => 'element',
    ),
    'dashboard_region' => array(
      'render element' => 'element',
    ),
    'dashboard_disabled_blocks' => array(
      'variables' => array('blocks' => NULL),
    ),
    'dashboard_disabled_block' => array(
      'variables' => array('block' => NULL),
    ),
  );
}

/**
 * Dashboard page callback.
 *
 * @param $launch_customize
 *   Whether to launch in customization mode right away. TRUE or FALSE.
 */
function dashboard_admin($launch_customize = FALSE) {
  $js_settings = array(
    'dashboard' => array(
      'drawer' => url('admin/dashboard/drawer'),
      'blockContent' => url('admin/dashboard/block-content'),
      'updatePath' => url('admin/dashboard/update'),
      'formToken' => drupal_get_token('dashboard-update'),
      'launchCustomize' => $launch_customize,
      'dashboard' => url('admin/dashboard'),
      'emptyBlockText' => _dashboard_get_default_string('dashboard_empty_block_text'),
      'emptyRegionTextInactive' => _dashboard_get_default_string('dashboard_empty_region_text_inactive'),
      'emptyRegionTextActive' => _dashboard_get_default_string('dashboard_empty_region_text_active'),
    ),
  );
  $build = array(
    '#theme' => 'dashboard_admin',
    '#message' => t('To customize the dashboard page, move blocks to the dashboard regions on !block-admin, or enable JavaScript on this page to use the drag-and-drop interface.', array('!block-admin' => l('the block administration page', 'admin/structure/block'))),
    '#access' => user_access('administer blocks'),
    '#attached' => array(
      'js' => array(
        drupal_get_path('module', 'dashboard') . '/dashboard.js',
        array('data' => $js_settings, 'type' => 'setting'),
      ),
      'library' => array(array('system', 'ui.sortable')),
    ),
  );
  return $build;
}

/**
 * Returns TRUE if the user is currently viewing the dashboard.
 */
function dashboard_is_visible() {
  $menu_item = menu_get_item();
  return isset($menu_item['page_callback']) && $menu_item['page_callback'] == 'dashboard_admin';
}

/**
 * Return an array of dashboard region descriptions, keyed by region name.
 */
function dashboard_region_descriptions() {
  $regions = module_invoke_all('dashboard_regions');
  drupal_alter('dashboard_regions', $regions);
  return $regions;
}

/**
 * Return an array of dashboard region names.
 */
function dashboard_regions() {
  return array_keys(dashboard_region_descriptions());
}

/**
 * Implement hook_dashboard_regions().
 */
function dashboard_dashboard_regions() {
  return array(
    'dashboard_main' =>  'Dashboard main',
    'dashboard_sidebar' => 'Dashboard sidebar',
  );
}

/**
 * AJAX callback to show disabled blocks in the dashboard customization mode.
 */
function dashboard_show_disabled() {
  global $theme_key;

  // Blocks are not necessarily initialized at this point.
  $blocks = _block_rehash();

  // Limit the list to disabled blocks for the current theme.
  foreach ($blocks as $key => $block) {
    if ($block['theme'] != $theme_key || (!empty($block['status']) && !empty($block['region']))) {
      unset($blocks[$key]);
    }
  }

  // Theme the output and end the page request.
  print theme('dashboard_disabled_blocks', array('blocks' => $blocks));
  drupal_exit();
}

/**
 * AJAX callback to display the rendered contents of a specific block.
 *
 * @param $module
 *   The block's module name.
 * @param $delta
 *   The block's delta.
 */
function dashboard_show_block_content($module, $delta) {
  drupal_theme_initialize();
  global $theme_key;

  $blocks = array();
  $block_object = db_query("SELECT * FROM {block} WHERE theme = :theme AND module = :module AND delta = :delta", array(
    ":theme" => $theme_key,
    ":module" => $module,
    ":delta" => $delta,
    ))
    ->fetchObject();
  $block_object->enabled = $block_object->page_match = TRUE;
  $blocks[$module . "_" . $delta] = $block_object;
  $block_content = _block_render_blocks($blocks);
  $build = _block_get_renderable_array($block_content);
  $rendered_block = drupal_render($build);
  print $rendered_block;
  drupal_exit();
}

/**
 * Set the new weight of each region according to the drag-and-drop order.
 */
function dashboard_update() {
  drupal_theme_initialize();
  global $theme_key;
  // Check the form token to make sure we have a valid request.
  if (!empty($_REQUEST['form_token']) && drupal_valid_token($_REQUEST['form_token'], 'dashboard-update')) {
    parse_str($_REQUEST['regions'], $regions);
    foreach ($regions as $region_name => $blocks) {
      if ($region_name == 'disabled_blocks') {
        $region_name = '';
      }
      foreach ($blocks as $weight => $block_string) {
        // Parse the query string to determine the block's module and delta.
        preg_match('/block-([^-]+)-(.+)/', $block_string, $matches);
        $block = new stdClass;
        $block->module = $matches[1];
        $block->delta = $matches[2];

        $block->region = $region_name;
        $block->weight = $weight;
        if (empty($region_name)) {
          $block->status = 0;
        }
        else {
          $block->status = 1;
        }

        db_merge('block')
          ->key(array(
            'module' => $block->module,
            'delta' => $block->delta,
            'theme' => $theme_key,
          ))
          ->fields(array(
            'status' => $block->status,
            'weight' => $block->weight,
            'region' => $block->region,
            'pages' => '',
          ))
          ->execute();
      }
    }
  }
  drupal_exit();
}

/**
 * Theme the entire dashboard.
 *
 * @param $variables
 *   - element: An associative array containing the properties of the dashboard region
 *              element. Properties used: #dashboard_region, #children
 * @return
 *   A string representing the themed dashboard.
 *
 * @ingroup themeable
 */
function theme_dashboard($variables) {
  extract($variables);
  drupal_add_css(drupal_get_path('module', 'dashboard') . '/dashboard.css');
  return '<div id="dashboard">' . $element['#children'] . '</div>';
}

/**
 * Theme the page containing the dashboard.
 *
 * @param $variables
 *   An associative array containing:
 *   - elements: An associative array containing the properties of the element.
 *     Properties used: #message
 * @return
 *   A themed HTML string representing the non-customizable part of the
 *   dashboard page.
 *
 * @ingroup themeable
 */
function theme_dashboard_admin($variables) {
  // We only return a simple help message, since the actual content of the page
  // will be populated via the dashboard regions in dashboard_page_build().
  return '<div class="customize-dashboard js-hide">' . $variables['element']['#message'] . '</div>';
}

/**
 * Theme a generic dashboard region.
 *
 * @param $variables
 *   - element: An associative array containing the properties of the dashboard region
 *              element. Properties used: #dashboard_region, #children
 * @return
 *   A string representing the themed dashboard region.
 *
 * @ingroup themeable
 */
function theme_dashboard_region($variables) {
  extract($variables);
  $output = '<div id="' . $element['#dashboard_region'] . '" class="dashboard-region">';
  $output .= '<div class="region clearfix">';
  $output .= $element['#children'];
  // Closing div.region
  $output .= '</div>';
  // Closing div.dashboard-region
  $output .= '</div>';
  return $output;
}

/**
 * Theme a set of disabled blocks, for display in dashboard customization mode.
 *
 * @param $variables
 *   - blocks: An array of block objects from _block_rehash().
 * @return
 *   A string representing the disabled blocks region of the dashboard
 *   customization page.
 *
 * @ingroup themeable
 */
function theme_dashboard_disabled_blocks($variables) {
  extract($variables);
  $output = '<div class="canvas-content"><p>' . t('Drag and drop dashboard blocks to their place. Changes are automatically saved. You can also <a href="@add-block">add a custom block</a>.', array('@add-block' => url('admin/structure/block/add', array('query' => array('destination' => 'admin/dashboard/customize'))))) . '</p>';
  $output .= '<div id="disabled-blocks"><div class="section region disabled-blocks clearfix">';
  foreach ($blocks as $block) {
    $output .= theme('dashboard_disabled_block', array('block' => $block));
  }
  $output .= '</div></div></div>';
  return $output;
}

/**
 * Theme a disabled block, for display in dashboard customization mode.
 *
 * @param $variables
 *   - block: A block object from _block_rehash().
 * @return
 *   A string representing the disabled block.
 *
 * @ingroup themeable
 */
function theme_dashboard_disabled_block($variables) {
  extract($variables);
  $output = "";
  if (isset($block)) {
    $output .= '<div id="block-' . $block['module'] . '-' . $block['delta']
    . '" class="disabled-block block block-' . $block['module'] . '-' . $block['delta']
    . ' module-'.$block['module'].' delta-'.$block['delta'].'">'
    . '<h2>'.(!empty($block['title']) ? $block['title'] : $block['info']).'</h2>'
    . '<div class="content"></div>'
    . '</div>';
  }
  return $output;
}

/**
 * Central storage for strings.
 *
 * @param <type> $key
 * @return string
 */
function _dashboard_get_default_string($key) {
  $defaults = array(
    'dashboard_empty_region_text_inactive' => 'This dashboard region is empty, click customize to add blocks to it.',
    'dashboard_empty_block_text' => '(empty)',
    'dashboard_empty_region_text_active' => 'DRAG HERE',
  );
  return t(variable_get($key, $defaults[$key]));

}