bp_blogs_comments_open( object $activity )

function bp_blogs_comments_open( $activity ) {
	$open = true;

	$blog_id = $activity->item_id;

	// See if we've mirrored the close comments option before.
	$days_old = bp_blogs_get_blogmeta( $blog_id, 'close_comments_days_old' );

	// We've never cached these items before, so do it now.
	if ( '' === $days_old ) {
		switch_to_blog( $blog_id );

		// Use comments_open().
		remove_filter( 'comments_open', 'bp_comments_open', 10 );
		$open = comments_open( $activity->secondary_item_id );
		add_filter( 'comments_open', 'bp_comments_open', 10, 2 );

		// Might as well mirror values to blogmeta since we're here!
		$thread_depth = get_option( 'thread_comments' );
		if ( ! empty( $thread_depth ) ) {
			$thread_depth = get_option( 'thread_comments_depth' );
		} else {
			// Perhaps filter this?
			$thread_depth = 1;
		}

		bp_blogs_update_blogmeta( $blog_id, 'close_comments_for_old_posts', get_option( 'close_comments_for_old_posts' ) );
		bp_blogs_update_blogmeta( $blog_id, 'close_comments_days_old',      get_option( 'close_comments_days_old' ) );
		bp_blogs_update_blogmeta( $blog_id, 'thread_comments_depth',        $thread_depth );

		restore_current_blog();

	// Check blogmeta and manually check activity item.
	// Basically a copy of _close_comments_for_old_post().
	} else {

		// Comments are closed.
		if ( 'closed' == bp_activity_get_meta( $activity->id, 'post_comment_status' ) ) {
			return false;
		}

		if ( ! bp_blogs_get_blogmeta( $blog_id, 'close_comments_for_old_posts' ) ) {
			return $open;
		}

		$days_old = (int) $days_old;
		if ( ! $days_old ) {
			return $open;
		}

		/*
		   Commenting out for now - needs some more thought...
		   should we add the post type to activity meta?

		$post = get_post($post_id);

		// This filter is documented in wp-includes/comment.php
		$post_types = apply_filters( 'close_comments_for_post_types', array( 'post' ) );
		if ( ! in_array( $post->post_type, $post_types ) )
			return $open;
		*/

		if ( time() - strtotime( $activity->date_recorded ) > ( $days_old * DAY_IN_SECONDS ) ) {
			return false;
		}

		return $open;
	}

	return $open;
}