<?php
/**
 * @file
 * Code pertaining to Facebook's extended permissions.  
 * see http://wiki.developers.facebook.com/index.php/Extended_permissions
 */

function fb_permission_perm() {
  return array('edit own extended permissions');
}

/**
 * Helper function for menu item access check.
 */
function fb_permission_access_own($account, $perm) {
  if (fb_facebook_user())
    return ($GLOBALS['user']->uid == $account->uid && user_access($perm));
}

function fb_permission_map() {
  static $perms;
  if (!isset($perms)) {
    // http://developers.facebook.com/docs/authentication/permissions
    $perms = array(
      'email' => 'Allow %application to send you email', 
      'offline_access' => 'Grant %application access to your Facebook profile.',
      'status_update' => 'Allow %application to set your status.', 
      'photo_upload' => 'Allow %application to upload photos.', 
      'create_listing' => 'Allow %application to create marketplace listings on your behalf.',
      'create_event' => 'Allow %application to create events on your behalf.',
      'rsvp_event' => 'Allow %application to RSVP to events on your behalf',
      'sms' => 'Allow %application to send you SMS text messages.',
      'read_stream' => 'Allow %application to display your stream.',
      'publish_stream' => 'Allow %application to publish to your stream.',
    );
  }
  return $perms;
}


/**
 * Implementation of hook_user.
 */
function fb_permission_user($op, &$edit, &$account, $category = NULL) {
  global $user;

  if ($op == 'categories') {
    $items = array();
    // A tab for each application
    foreach (fb_get_all_apps() as $fb_app) {
      // TODO: limit only to apps which can be added to a user's account.
      $items[] = array(
        'name' => $fb_app->label,
        'title' => $fb_app->label, // TODO: human-readable title.
        'access callback' => 'fb_permission_access_own',
        'access arguments' => array(1, 'edit own extended permissions'),
        'weight' => 2);
    }
    return $items;
  }
  elseif ($op == 'form') {
    // See if the category corresponds to a facebook app.
    $fb_app = fb_get_app(array('label' => $category));
    
    if ($fb_app) {
      $map = fb_permission_map(); // All known permissions.
      // Show only permissions we've configured for this app.
      $fb_app_data = fb_get_app_data($fb_app);
      $fb_permission_data = $fb_app_data['fb_permission'];
      if (is_array($fb_permission_data['map'])) {
        foreach ($fb_permission_data['map'] as $key => $value) {
          if (!$value)
            unset($map[$key]);
        }
      }

      //TODO: support for non-fbml pages
      $form = fb_permission_form_fbml($fb_app, $map);
      
      $form['description'] =
        array('#type' => 'markup',
              '#value' => l(t('All settings for %application (and other Facebook Applications).', array('%application' => $fb_app->title)),
                            'http://www.facebook.com/editapps.php',
                            array('html' => TRUE)),
              '#prefix' => '<p>',
              '#suffix' => "</p>\n",
        );
      // A value for hook_form_alter to find.
      $form['_fb_permission'] = array('#type' => 'value',
                                      '#value' => TRUE);
      return $form;      
    }
    
  }
  
}

/**
 * for canvas pages and connect pages.
 */
function fb_permission_form_fbml($fb_app, $map) {
  foreach ($map as $key => $t) {
    $form[$key] = array(
      '#type' => 'markup',
      '#value' => '<fb:prompt-permission perms="'. $key .'">'.
      t($t, array('%application' => $fb_app->title)) .
      '<br /></fb:prompt-permission>',
    );
  }

  // Add buttons for boxes and info
  $sections = array('profile', 'info');
  foreach ($sections as $section) {
    if (fb_is_fbml_canvas()) {
      $form[$section] = array(
        '#type' => 'markup',
        '#value' => '<fb:add-section-button section="'. $section . '" />',
      );
    }
  }
  

  return $form;
}

function fb_permission_form_html($fb_app, $map) {
  // Non-fbml page
  // TODO: use API to hide permissions we already have
  $url = url($_GET['q'], array('absolute' => TRUE));
  foreach ($map as $key => $t) {
    $form[$key] =
      array('#type' => 'markup',
            '#value' => l(t($t, array('%application' => $fb_app->title)),
                          "http://www.facebook.com/authorize.php",
                          array('html' => TRUE),
                          "api_key={$fb_app->api_key}&v=1.0&ext_perm={$key}&next={$url}&next_cancel={$url}"),
            '#prefix' => '<p>',
            '#suffix' => '</p>',
      );
  }

  // TODO: add section buttons with http://wiki.developers.facebook.com/index.php/Fb:add-section-button

  return $form;
}

function fb_permission_form_alter(&$form, $state, $id) {
  //dpm(func_get_args(), 'fb_permission_form_alter');
  if ($id == 'user_profile_form' && isset($form['_fb_permission'])) {
    unset($form['submit']);
    unset($form['delete']);
  }
  
  // Add settings to fb_app form
  if (isset($form['fb_app_data'])) {
    $fb_app = $form['#fb_app'];
    $fb_app_data = fb_get_app_data($fb_app);
    $fb_permission_data = $fb_app_data['fb_permission'];
    $form['fb_app_data']['fb_permission'] = array(
      '#type' => 'fieldset',
      '#title' => t('Facebook Extended Permissions'),
      '#tree' => TRUE,
      '#collapsible' => TRUE,
      '#collapsed' => TRUE,
    );

    foreach (fb_permission_map() as $key => $desc) {
      $options[$key] = $key;
    }

    // defaults
    if (!isset($fb_permission_data['map'])) {
      $fb_permission_data['map'] = array();
    }

    $form['fb_app_data']['fb_permission']['map'] = array(
      '#type' => 'checkboxes',
      '#title' => t('Extended Permissions'),
      '#options' => $options,
      '#default_value' => $fb_permission_data['map'],
      '#description' => t('Which extended permissions does this application use?  Users will be able to grant these permissions on their user edit pages.'),
    );

    if (!isset($fb_permission_data['prompt'])) {
      $fb_permission_data['prompt'] = array();
    }
    $form['fb_app_data']['fb_permission']['prompt'] = array(
      '#type' => 'checkboxes',
      '#title' => t('Prompt New Users for Permission'),
      '#options' => $options,
      '#default_value' => $fb_permission_data['prompt'],
      '#description' => t('Prompt users when they first authorize the application.  Select only the most important features.'),
    );
    
  }
}

/**
 * Implementation of hook_fb().  Here we customize the behavior of
 * Drupal for Facebook.
 *
 * Prompts user for extended permission when they have authorized the
 * application.
 *
 * Currently supporting only connect pages, not canvas pages.
 */
function fb_permission_fb($op, $data, &$return) {
  if ($op == FB_APP_OP_EVENT) {
    if ($data['event_type'] == FB_APP_EVENT_POST_AUTHORIZE) {
      // User has authorized the application.
      $fb_app = isset($data['fb_app']) ? $data['fb_app'] : NULL;
      $fb_app_data = fb_get_app_data($fb_app);
      $fb_permission_data = $fb_app_data['fb_permission'];
      
      if (is_array($fb_permission_data['prompt'])) {
        $perms = array();
        foreach ($fb_permission_data['prompt'] as $key => $value) {
          if ($value) {
            $perms[] = $key;
          }
        }
        if (count($perms)) {
          // http://wiki.developers.facebook.com/index.php/JS_API_M_FB.Connect.ShowPermissionDialog
          $js = "FB.Connect.showPermissionDialog('" . implode(',', $perms) . "')";
          fb_connect_init_js($js); // Add javascript to the next page.
        }
      }
    }
  }
}