addThis Pinterest WordPress filter

add_filter( 'the_content', 'sharingButtons_addThis', 100 );
// Put AddThis buttons at the bottom of every post.
function sharingButtons_addThis( $content ) {
  global $post;
  if(isset($post)) {
    //Set Pinterest image using "Get The Image" plugin by Justin Tadlock
    if ( function_exists( 'get_the_image' ) ) {
      $getTheImageOptions = array(
        'meta_key' => array( 'Thumbnail', 'thumbnail' ),
        'post_id' => $post->ID,
        'attachment' => true,
        'the_post_thumbnail' => true,
        'size' => 'large',
        'default_image' => false,
        'order_of_image' => 1,
        'link_to_post' => true,
        'image_class' => false,
        'image_scan' => false,
        'width' => false,
        'height' => false,
        'format' => 'array',
        'meta_key_save' => false,
        'callback' => null,
        'cache' => true,
        'echo' => false
      );
      $pinterest = get_the_image($getTheImageOptions);
      $pinterestURL = $pinterest['url'];
    } else {
      $pinterestURL = wp_get_attachment_url( get_post_thumbnail_id($post->ID) );
    }
  } else {
    $pinterestURL = "";
  }

  $currentURL = 'http://'.$_SERVER['HTTP_HOST'] . $_SERVER['REQUEST_URI'];

  $content .= '     <!-- AddThis Button BEGIN -->';
  $content .= '    <div class="addthis_toolbox addthis_default_style ">';
  $content .= '    <a class="addthis_button_facebook_like" fb:like:layout="button_count"></a>';
  if(!empty($pinterestURL)) {
    $content .= '    <a class="addthis_button_pinterest" pi:pinit:url="'. $currentURL .'" pi:pinit:media="'. $pinterestURL .'" pi:pinit:layout="horizontal"></a>';
  }
  $content .= '    <a class="addthis_button_tweet"></a>';
  $content .= '    <a class="addthis_button_google_plusone" g:plusone:size="medium"></a>';
  $content .= '    <a class="addthis_counter addthis_pill_style"></a> ';
  $content .= '    </div>';
  $content .= '    <script type="text/javascript" src="http://s7.addthis.com/js/250/addthis_widget.js#pubid=btrivers"></script>';
  $content .= '    <!-- AddThis Button END -->    ';

  // Returns the content.
  return $content;
}