ap_append_qameta( object $post )

function ap_append_qameta( $post ) {
	// Convert object as array to prevent using __isset of WP_Post.
	$post_arr = (array) $post;
	if ( ! in_array( $post_arr['post_type'], array( 'question', 'answer' ), true ) || isset( $post_arr['ap_qameta_wrapped'] ) ) {
		return $post;
	}

	$exist = true;
	foreach ( ap_qameta_fields() as $fields_name => $val ) {
		if ( ! isset( $post_arr[ $fields_name ] ) ) {
			$exist = false;
			break;
		}
	}

	if ( ! $exist ) {
		$defaults = ap_get_qameta( $post->ID );
		if ( ! empty( $defaults ) ) {
			foreach ( $defaults as $pkey => $value ) {
				if ( ! isset( $post_arr[ $pkey ] ) || empty( $post_arr[ $pkey ] ) ) {
					$post->$pkey = $value;
				}
			}
		}

		$post->terms      = maybe_unserialize( $post->terms );
		$post->activities = maybe_unserialize( $post->activities );

		$post->votes_net = $post->votes_up - $post->votes_down;
	}

	return $post;
}