/**
 * Unhides the tickets button for past events.
 *
 * @param	string		$html
 * @param	WPT_Event	$event
 * @return	string
 */
function unhide_old_tickets_url( $html, $event ) {

	ob_start();
	?><div class="<?php echo WPT_event::post_type_name; ?>_tickets"><?php

		if ( WPT_Event::tickets_status_onsale == $event->tickets_status() ) {
			echo $event->tickets_url_html();
			echo $event->prices_html();
		} else {
			echo $event->tickets_status_html();
		}
	?></div><?php

	return ob_get_clean();
}
add_filter( 'wpt/event/tickets/html', 'unhide_old_tickets_url', 10, 2);