<?php
/**
 * @file
 *   Defines a custom node type that stores a facebook application configuration.
 */

define('FB_APP_REQ_API_KEY', 'fb_sig_api_key');

// Events that a facebook app might need to know about:
define('FB_APP_EVENT_POST_AUTHORIZE', 'post_authorize');
define('FB_APP_EVENT_POST_REMOVE', 'post_remove');
define('FB_APP_PATH_EVENT', 'fb_app/event');
define('FB_APP_OP_EVENT', 'fb_app_event');

/**
 * hook_fb
 */
function fb_app_fb($fb, $fb_app, $op, &$return, $data) {
  
  //drupal_set_message("fb_app_fb($fb_app->label, $op)" . dpr($fb_app, 1));
  
  if ($op == FB_OP_GET_APP) {
    // This operation determines which app the request is for.  Theoretically,
    // the allows fb_app and other app-defining modules to co-exist.  We need
    // to determine if the app is one of ours and if so, return the app
    // details.
    
    // If apikey or nid was passed to us, use that
    if ($data['nid'])
      $fb_app = db_fetch_object(db_query("SELECT * FROM {fb_app} fb INNER JOIN {node} n ON n.nid=fb.nid WHERE fb.nid=%d and status=1",
                                         $data['nid']));
    else if ($data['apikey']) {
      $fb_app = db_fetch_object(db_query("SELECT * FROM {fb_app} fb INNER JOIN {node} n ON n.nid=fb.nid WHERE apikey='%s' and status=1",
                                         $data['apikey']));
    }
    else if ($apikey = $_REQUEST[FB_APP_REQ_API_KEY]) {
      // If facebook has passed the app key, let's use that.
      $fb_app = db_fetch_object(db_query("SELECT * FROM {fb_app} fb INNER JOIN {node} n ON n.nid=fb.nid WHERE apikey='%s' and status=1",
                                         $apikey));
    } 
    else {
      if (function_exists('fb_settings')) {
        // See fb_settings.inc
        if ($nid = fb_settings(FB_SETTINGS_APP_NID)) {
          // Here if we're in iframe, using our /fb_canvas/nid/ path convention.
          $fb_app = db_fetch_object(db_query("SELECT * FROM {fb_app} fb INNER JOIN {node} n ON n.nid=fb.nid WHERE fb.nid=%d and status=1",
                                             $nid));
          
        }
      }
    }
    if ($fb_app)
      $return = $fb_app;
    // If we didn't find the app, maybe someone else has written a module that
    // stores app info in a different way.
  }
  else if ($op == FB_OP_GET_ALL_APPS) {
    // Return all known applications
    $result = _fb_app_query_all();
    while ($app = db_fetch_object($result)) {
      $return[] = $app;
    }
  }
  else if ($op == FB_OP_INITIALIZE) {
    // User init has been moved to fb_user.module.
    // For now, nothing to do here.
  }
  else if ($op == FB_OP_POST_INIT) {
    /* TODO: move this feature to an explicit setting.  For now, we just use site homepage
    // Here we override the front_page settings
    if ($_REQUEST['q'] == '' && $fb_app->nid) {
      menu_set_active_item('node/'.$fb_app->nid);
      // Note, menu_set_active_item only works as intended if fb.module
      // is weighted lighter than node.module!
    }
      */
  }
}

function fb_app_menu($may_cache) {
  $items = array();
  if ($may_cache) {
    // Allow facebook to notify on various events, like adding or removing an app.
    $items[] = array('path' => FB_APP_PATH_EVENT,
                     'access' => TRUE,
                     'callback' => 'fb_app_event_cb',
                     'type' => MENU_CALLBACK,                     
    );
  }
  return $items;
}

/**
 * Callback for FB_APP_PATH_EVENT.
 * 
 * We don't act on the events directly.  We pass the information along via
 * hook_fb.  Other modules are thus notified of the event and can take action.
 */
function fb_app_event_cb($event_type) {
  global $fb_app;
  fb_invoke($fb_app, FB_APP_OP_EVENT, NULL, array('event_type' => $event_type));
  // This page is called by facebook, not a user's browser.
  print('Thanks Facebook, for your fancy API!');
  exit();
}

/**
 * hook_node_info.
 */
function fb_app_node_info() {
  return array('fb_app' =>
               array('name' => t('Facebook Application'),
                     'module' => 'fb_app',
                     'description' => t('Information such as apikey and secret for a facebook.com application.'),
                     'help' => t('Configure the behavior of your Facebook Application.'),
               ),
  );
}

function fb_app_access($op, $node) {
  if (user_access('administer fb apps'))
    return TRUE;
  if ($op == 'create' && user_access('create fb apps'))
    return TRUE;
  else if ($op == 'update' || $op == 'delete') {
    if ($node->uid == $user->uid && 
        user_access('edit own fb apps'))
      return TRUE;
  }
}

function fb_app_perm() {
  return array('administer fb apps', 'create fb apps', 'edit own fb apps');
}

function fb_app_form(&$node, &$param) {
  // Helpful link
  if (!$node->nid) {
    drupal_set_message(t("Before completing this form, <a href=!url>create your application</a> on Facebook.",
                         array('!url' => 'http://www.facebook.com/developers/editapp.php?new')));
  }
  $form = array();
  $type = node_get_types('type', $node);
  // We need to define form elements for the node's title and body. 
  $form['title'] = array('#type' => 'textfield', 
                         '#title' => check_plain($type->title_label), 
                         '#required' => TRUE, 
                         '#default_value' => $node->title, 
                         '#weight' => -5,
                         '#description' => t('Identifies the application to site administrators.'),
  );
  // We want the body and filter elements to be adjacent. We could try doing 
  // this by setting their weights, but another module might add elements to the 
  // form with the same weights and end up between ours. By putting them into a 
  // sub-array together, we're able force them to be rendered together. 
  $form['body_filter']['body'] = 
    array('#type' => 'textarea', 
          '#title' => check_plain($type->body_label), 
          '#default_value' => $node->body, 
          '#required' => FALSE,
          '#description' => 'A brief description of the application.',
    ); 
  $form['body_filter']['filter'] = filter_form($node->format); 
  
  // Now we define the form elements specific to our node type. 
  
  $form['fb_app'] = array('#tree' => TRUE,
                          '#weight' => -4,
  );
  $form['fb_app']['label'] = array('#type' => 'textfield',
                                   '#title' => t('Label'),
                                   '#required' => TRUE,
                                   '#default_value' => $node->fb_app->label,
                                   '#description' => t('Used behind the scenes, for naming roles, styles, etc.  Use no spaces or weird characters.'),
  );
  $form['fb_app']['apikey'] = array('#type' => 'textfield',
                                    '#title' => t('API Key'),
                                    '#required' => TRUE,
                                    '#default_value' => $node->fb_app->apikey,
                                    '#description' => t('Facebook will generate this value when you create the application.'),
  );
  $form['fb_app']['secret'] = array('#type' => 'textfield',
                                    '#title' => t('Secret'),
                                    '#required' => TRUE,
                                    '#default_value' => $node->fb_app->secret,
                                    '#description' => t('Facebook will generate this value when you create the application.'),
  );

  // Arguably, this belongs in fb_canvas.  It's here for historical reasons.
  $form['fb_app']['canvas'] = array('#type' => 'textfield',
                                    '#title' => t('Canvas Page Url Suffix'),
                                    '#required' => FALSE,
                                    '#default_value' => $node->fb_app->canvas,
                                    '#description' => t('Type only the part that comes after "http://apps.facebook.com/"'),
  );

  $form['fb_app']['id'] = array('#type' => 'textfield',
                                '#title' => t('Facebook App ID'),
                                '#required' => FALSE,
                                '#default_value' => $node->fb_app->id,
                                '#description' => t('To learn this number, visit your app\'s About Page (or other links from Facebook\'s Developer App).  The URL will end in ?id=1234...  Enter the number that follows "?id=" here.'),
  );

  // fb_app_data is a placeholder to make it easier for other module to attach
  // various settings to the node.
  $form['fb_app_data'] = array('#tree' => TRUE);  

  return $form;
}

function fb_app_validate($node) {
  // TODO: check label is unique, and role name will be unique.
  // check apikey is unique, canvas page is unique
  // check no menu items start with $fb_app->canvas, because we will rewrite those URLs
}

function fb_app_load($node) {
  $fb_app = db_fetch_object(db_query('SELECT * FROM {fb_app} WHERE nid=%d',
                                   $node->nid));
  $fb_app_data = fb_app_get_data($fb_app);
  return array('fb_app' => $fb_app,
               'fb_app_data' => $fb_app_data,
  );
}

function fb_app_view($node, $teaser=FALSE, $page=FALSE) {
  $node = node_prepare($node, $teaser);
  // Perhaps this info should be hidden, unless user can edit node.
  if (user_access('administer fb apps')) {
    $node->content['fb_app'] = 
      array('#value' => theme('fb_app', $node->fb_app),
            '#weight' => 1);
    
  }
  return $node;
}

function fb_app_get_about_url($fb_app) {
  if ($fb_app->id)
    return url("http://www.facebook.com/apps/application.php", "id=$fb_app->id");
}

function theme_fb_app($data) {
  $about_url = fb_app_get_about_url($data);
  $output .= theme('dl', array(t('Label') => $data->label,
                               t('API Key') => $data->apikey,
                               t('Secret') => $data->secret,
                               t('About page') => $about_url ? $about_url : t('N/A'),
                               
                               // TODO: edit and logout URLs
                   ));
  $url = url(FB_SETTINGS_APP_NID . '/' . $data->nid . '/' . FB_APP_PATH_EVENT, NULL, NULL, TRUE) . '/';
  $output .= theme('dl', array(t('Post-Remove URL') => $url . FB_APP_EVENT_POST_REMOVE,
                               t('Post-Authorize URL') => $url . FB_APP_EVENT_POST_AUTHORIZE,
                   ));
  return $output;
}

// this belongs elsewhere
function theme_dl($items) {
  if (count($items)) {
    $output = "<dl>\n";
    foreach ($items as $term => $data) {
      $output .= "  <dt>$term</dt><dd>$data</dd>\n";
    }
    $output .= "</dl>\n";
    return $output;
  }
}

function fb_app_insert($node) {
  //drupal_set_message("fb_app_insert" . dpr($node,1));
  $fb_app = (object) $node->fb_app;

  $data = serialize($node->fb_app_data);
  
  db_query("INSERT INTO {fb_app} (nid, label, apikey, secret, id, canvas, require_login, create_account, unique_account, data) VALUES (%d, '%s', '%s', '%s', '%s', '%s', %d, %d, %d, '%s')",
           $node->nid, $fb_app->label, $fb_app->apikey, $fb_app->secret,
           $fb_app->id,
           $fb_app->canvas, $fb_app->require_login, $fb_app->create_account, 
           $fb_app->unique_account, $data
  );

  watchdog('fb_app', t('Created Facebook Application %label.',
                       array('%label' => $fb_app->label,
                       )),
           WATCHDOG_NOTICE,
           l($node->title, 'node/'.$node->nid));
  
}

function fb_app_update($node) {
  $fb_app = (object) $node->fb_app;
  $data = serialize($node->fb_app_data);

  db_query("UPDATE {fb_app} SET label='%s', apikey='%s', secret='%s', id='%s', canvas='%s', require_login=%d, create_account=%d, unique_account=%d, data='%s' WHERE nid=%d",
           $fb_app->label, $fb_app->apikey, $fb_app->secret,
           $fb_app->id,
           $fb_app->canvas, $fb_app->require_login, $fb_app->create_account,
           $fb_app->unique_account, $data,
           $node->nid);
}

function fb_app_delete($node) {
  db_query('DELETE FROM {fb_app} WHERE nid=%d',
           $node->nid);
}


/**
 * Convenience method for other modules to attach data to the fb_app object.
 */
function fb_app_get_data(&$fb_app) {
  if (!$fb_app->fb_app_data) {
    $fb_app->fb_app_data = unserialize($fb_app->data);
  }
  return $fb_app->fb_app_data;
}

/**
 * Helper function returns a database query for all apps.
 */
function _fb_app_query_all() {
  $result = db_query("SELECT fb.*, n.title FROM {fb_app} fb INNER JOIN {node} n ON n.nid=fb.nid WHERE status=1");
  return $result;
}
function _fb_app_query_by_label($label) {
  $result = db_query("SELECT fb.*, n.title FROM {fb_app} fb INNER JOIN {node} n ON n.nid=fb.nid WHERE n.status=1 AND fb.label = '%s'", 
                     $label);
  return $result;
}

/**
 * Implementation of hook_user.
 */
function fb_app_user($op, &$edit, &$account, $category = NULL) {
  $items = array();
  if ($op == 'view') {
    $result = _fb_app_query_all();
    while ($fb_app = db_fetch_object($result)) {
      // Learn this user's FB id
      $fbu = fb_get_fbu($account->uid, $fb_app);
      if ($fbu) {
        // The drupal user is a facebook user.  Now, learn more from facebook.
        $fb = fb_api_init($fb_app, FB_FBU_ANY);
        if (fb_facebook_user($fb)) {
          $info = $fb->api_client->users_getInfo(array($fbu), 
                                                 array('about_me',
                                                       'affiliations',
                                                       'name',
                                                       'is_app_user',
                                                       'pic_big',
                                                       'profile_update_time',
                                                       'status',
                                                       ));
        }
        if (count($info)) {
          $output = theme('fb_app_user_info', $fb_app, $info[0]);
          
          $items[$fb_app->label] = array('title' => $fb_app->title,
                                         'value' => $output,
                                         'class' => 'fb_app');
        }
        else
          fb_report_errors($fb);
      }
    }
    if (count($items))
      return array(t('Facebook') => $items);
  }
}

function theme_fb_app_user_info($fb_app, $info) {
  if ($info['pic_big'])
    $output .= '<p><img src="'.$info['pic_big'].'" /></p>';
  $fb_link = l($info['name'], 'http://www.facebook.com/profile.php', NULL, 'id='.$info['uid']);
  if ($info['is_app_user'])
    $output .= '<p>' . t('!fb_link uses %title',
                         array('!fb_link' => $fb_link,
                               '%title' => $fb_app->title)) . '</p>';
  else
    $output .= '<p>'. t('!fb_link does not use %title',
                        array('!fb_link' => $fb_link,
                              '%title' => $fb_app->title)) . '</p>';

  return $output;
}

function fb_app_token_list($type = 'all') {
  if ($type == 'all' || $type == 'fb' || $type == 'fb_app') {
    $tokens['fb_app']['fb-app-nid'] = t('Facebook application ID');
    $tokens['fb_app']['fb-app-title'] = t('Facebook application title');
    $tokens['fb_app']['fb-app-url'] = t('Facebook application URL (base path)');
  }
  return $tokens;
}

function fb_app_token_values($type = 'all', $object = NULL) {
  if ($type == 'fb_app' && $object) {
    $fb_app = $object;
    $values['fb-app-title'] = $fb_app->title;
    $values['fb-app-nid'] = $fb_app->nid;
    $values['fb-app-url'] = 'http://apps.facebook.com/'.$fb_app->canvas;
  }
  return $values;
}

?>