import_featured_image

function import_featured_image($image_url, $caption, $post_id) {
	$upload_dir = wp_upload_dir();
	$image_data = file_get_contents($image_url);
	$filename = basename($image_url);
	if(wp_mkdir_p($upload_dir['path']))     
		$file = $upload_dir['path'] . '/' . $filename;
	else                                    
		$file = $upload_dir['basedir'] . '/' . $filename;
	file_put_contents($file, $image_data);

	$wp_filetype = wp_check_filetype($filename, null );
	$attachment = array(
	    'post_mime_type' => $wp_filetype['type'],
	    'post_title' => $caption,
	    'post_content' => $caption,
	    'post_status' => 'inherit'
	);
	$attach_id = wp_insert_attachment( $attachment, $file, $post_id );
	require_once(ABSPATH . 'wp-admin/includes/image.php');
	$attach_data = wp_generate_attachment_metadata( $attach_id, $file );
	$res1= wp_update_attachment_metadata( $attach_id, $attach_data );
  $res2 = set_post_thumbnail( $post_id, $attach_id );
  return $attach_id;
}