function wc_trigger_stock_change_notifications( $order, $changes ) {
	if ( empty( $changes ) ) {
		return;
	}

	$order_notes     = array();
	$no_stock_amount = absint( get_option( 'woocommerce_notify_no_stock_amount', 0 ) );

	foreach ( $changes as $change ) {
		$order_notes[]    = $change['product']->get_formatted_name() . ' ' . $change['from'] . '→' . $change['to'];
		$low_stock_amount = absint( wc_get_low_stock_amount( wc_get_product( $change['product']->get_id() ) ) );
		if ( $change['to'] <= $no_stock_amount ) {
			do_action( 'woocommerce_no_stock', wc_get_product( $change['product']->get_id() ) );
		} elseif ( $change['to'] <= $low_stock_amount ) {
			do_action( 'woocommerce_low_stock', wc_get_product( $change['product']->get_id() ) );
		}

		if ( $change['to'] < 0 ) {
			do_action(
				'woocommerce_product_on_backorder',
				array(
					'product'  => wc_get_product( $change['product']->get_id() ),
					'order_id' => $order->get_id(),
					'quantity' => abs( $change['from'] - $change['to'] ),
				)
			);
		}
	}

	$order->add_order_note( __( 'Stock levels reduced:', 'woocommerce' ) . ' ' . implode( ', ', $order_notes ) );
}