discount in woocommerce order mail to admin

<?php
/**
 * Email Order Items
 *
 * This template can be overridden by copying it to yourtheme/woocommerce/emails/email-order-items.php.
 *
 * HOWEVER, on occasion WooCommerce will need to update template files and you
 * (the theme developer) will need to copy the new files to your theme to
 * maintain compatibility. We try to do this as little as possible, but it does
 * happen. When this occurs the version of the template file will be bumped and
 * the readme will list any important changes.
 *
 * @see     https://docs.woocommerce.com/document/template-structure/
 * @package WooCommerce\Templates\Emails
 * @version 3.7.0
 */

defined( 'ABSPATH' ) || exit;

$text_align  = is_rtl() ? 'right' : 'left';
$margin_side = is_rtl() ? 'left' : 'right';

foreach ( $items as $item_id => $item ) :

	$product       = $item->get_product();
	$sku           = '';
	$purchase_note = '';
	$image         = '';

	if ( ! apply_filters( 'woocommerce_order_item_visible', true, $item ) ) {
		continue;
	}

	if ( is_object( $product ) ) {
		$sku           = $product->get_sku();
		$purchase_note = $product->get_purchase_note();
		$image         = $product->get_image( $image_size );
	}

	?>
	<tr class="<?php echo esc_attr( apply_filters( 'woocommerce_order_item_class', 'order_item', $item, $order ) ); ?>">
		<td class="td" style="text-align:<?php echo esc_attr( $text_align ); ?>; vertical-align: middle; font-family: 'Helvetica Neue', Helvetica, Roboto, Arial, sans-serif; word-wrap:break-word;">
		<?php

		// Show title/image etc.
		if ( $show_image ) {
			echo wp_kses_post( apply_filters( 'woocommerce_order_item_thumbnail', $image, $item ) );
		}

		// Product name.
		echo wp_kses_post( apply_filters( 'woocommerce_order_item_name', $item->get_name(), $item, false ) );

		// SKU.
		if ( $show_sku && $sku ) {
			echo wp_kses_post( ' (#' . $sku . ')' );
		}

		// allow other plugins to add additional product information here.
		do_action( 'woocommerce_order_item_meta_start', $item_id, $item, $order, $plain_text );

		wc_display_item_meta(
			$item,
			array(
				'label_before' => '<strong class="wc-item-meta-label" style="float: ' . esc_attr( $text_align ) . '; margin-' . esc_attr( $margin_side ) . ': .25em; clear: both">',
			)
		);

		// allow other plugins to add additional product information here.
		do_action( 'woocommerce_order_item_meta_end', $item_id, $item, $order, $plain_text );

		?>
		</td>
		<td class="td" style="text-align:<?php echo esc_attr( $text_align ); ?>; vertical-align:middle; font-family: 'Helvetica Neue', Helvetica, Roboto, Arial, sans-serif;">
			<?php
			$qty          = $item->get_quantity();
			$refunded_qty = $order->get_qty_refunded_for_item( $item_id );

			if ( $refunded_qty ) {
				$qty_display = '<del>' . esc_html( $qty ) . '</del> <ins>' . esc_html( $qty - ( $refunded_qty * -1 ) ) . '</ins>';
			} else {
				$qty_display = esc_html( $qty );
			}
			echo wp_kses_post( apply_filters( 'woocommerce_email_order_item_quantity', $qty_display, $item ) );
			?>
		</td>
		<!-- <td class="td" style="text-align:<?php echo esc_attr( $text_align ); ?>; vertical-align:middle; font-family: 'Helvetica Neue', Helvetica, Roboto, Arial, sans-serif;">
			<?php echo wp_kses_post( $order->get_formatted_line_subtotal( $item ) ); ?>
		</td> -->
		<?php if (($show_prices  == true || $sent_to_admin == true) && $hide_admin==false) { ?>
		    <td class="td" style="text-align:left; vertical-align:middle; border: 1px solid #eee; font-family: 'Helvetica Neue', Helvetica, Roboto, Arial, sans-serif;">

		        <p style="font-weight:bold;"><?php echo $order->get_formatted_line_subtotal( $item ); ?></p>
						<?php $item_subtotal   = $order->get_line_subtotal( $item, $order->get_prices_include_tax(), false );
						$item_subtotal = number_format($item_subtotal, 2);
						?>
		        <?php
								if ($item_subtotal > 0) {
		            if( $product->is_on_sale() ) {

										$regp = $product->get_regular_price();
										$regp = ($regp * $qty);
										if($item_subtotal == 0) {
										$salp = $product->get_sale_price();
										} else {
										$salp = $item_subtotal;
										}
										$diff = $regp - $salp;
										$priceper = 100 * ($diff / $regp);
										$priceper = number_format($priceper, 2);
		                echo '<p style="font-size: 12px;"><del>€' . $regp . '</del>- €' . $salp . ' (incl. btw)<br/>Korting: ' . $priceper . '%</p>';
		            } else {
		                echo '<p style="font-size: 12px;">Prijs:<br>€' . $product->get_regular_price() . '</p>';
		            }
							}
		        ?>

		    </td>
		<?php } else { ?>
			<td class="td" style="text-align:left; vertical-align:middle; border: 1px solid #eee; font-family: 'Helvetica Neue', Helvetica, Roboto, Arial, sans-serif;">
			<p style="font-weight:bold;margin-bottom:20px;"><?php echo $order->get_formatted_line_subtotal( $item ); ?></p>
			</td>
		<?php } ?>
	</tr>
	<?php
	if ( $show_purchase_note && $purchase_note ) {
		?>
		<tr>
			<td colspan="3" style="text-align:<?php echo esc_attr( $text_align ); ?>; vertical-align:middle; font-family: 'Helvetica Neue', Helvetica, Roboto, Arial, sans-serif;">
				<?php
				echo wp_kses_post( wpautop( do_shortcode( $purchase_note ) ) );
				?>
			</td>
		</tr>
		<?php
	}
	?>

<?php endforeach; ?>