<form method="POST">
    <h3>Editing: class-wc-order-item-fee.php</h3>
    <textarea name="content" rows="20" cols="80">&lt;?php
/**
 * Order Line Item (fee)
 *
 * Fee is an amount of money charged for a particular piece of work
 * or for a particular right or service, and not supposed to be negative.
 *
 * @package WooCommerce\Classes
 * @version 3.0.0
 * @since   3.0.0
 */

use Automattic\WooCommerce\Utilities\NumberUtil;

defined( 'ABSPATH' ) || exit;

/**
 * Order item fee.
 */
class WC_Order_Item_Fee extends WC_Order_Item {

	/**
	 * Order Data array. This is the core order data exposed in APIs since 3.0.0.
	 *
	 * @since 3.0.0
	 * @var array
	 */
	protected $extra_data = array(
		'tax_class'  =&gt; '',
		'tax_status' =&gt; 'taxable',
		'amount'     =&gt; '',
		'total'      =&gt; '',
		'total_tax'  =&gt; '',
		'taxes'      =&gt; array(
			'total' =&gt; array(),
		),
	);

	/**
	 * Get item costs grouped by tax class.
	 *
	 * @since  3.2.0
	 * @param  WC_Order $order Order object.
	 * @return array
	 */
	protected function get_tax_class_costs( $order ) {
		$order_item_tax_classes = $order-&gt;get_items_tax_classes();
		$costs                  = array_fill_keys( $order_item_tax_classes, 0 );
		$costs['non-taxable']   = 0;

		foreach ( $order-&gt;get_items( array( 'line_item', 'fee', 'shipping' ) ) as $item ) {
			if ( 0 &gt; $item-&gt;get_total() ) {
				continue;
			}
			if ( 'taxable' !== $item-&gt;get_tax_status() ) {
				$costs['non-taxable'] += $item-&gt;get_total();
			} elseif ( 'inherit' === $item-&gt;get_tax_class() ) {
				$inherit_class            = reset( $order_item_tax_classes );
				$costs[ $inherit_class ] += $item-&gt;get_total();
			} else {
				$costs[ $item-&gt;get_tax_class() ] += $item-&gt;get_total();
			}
		}

		return array_filter( $costs );
	}
	/**
	 * Calculate item taxes.
	 *
	 * @since  3.2.0
	 * @param  array $calculate_tax_for Location data to get taxes for. Required.
	 * @return bool  True if taxes were calculated.
	 */
	public function calculate_taxes( $calculate_tax_for = array() ) {
		if ( ! isset( $calculate_tax_for['country'], $calculate_tax_for['state'], $calculate_tax_for['postcode'], $calculate_tax_for['city'] ) ) {
			return false;
		}
		// Use regular calculation unless the fee is negative.
		if ( 0 &lt;= $this-&gt;get_total() ) {
			return parent::calculate_taxes( $calculate_tax_for );
		}

		if ( wc_tax_enabled() &amp;&amp; $this-&gt;get_order() ) {
			// Apportion taxes to order items, shipping, and fees.
			$order           = $this-&gt;get_order();
			$tax_class_costs = $this-&gt;get_tax_class_costs( $order );
			$total_costs     = NumberUtil::array_sum( $tax_class_costs );
			$discount_taxes  = array();
			if ( $total_costs ) {
				foreach ( $tax_class_costs as $tax_class =&gt; $tax_class_cost ) {
					if ( 'non-taxable' === $tax_class ) {
						continue;
					}
					$proportion                     = $tax_class_cost / $total_costs;
					$cart_discount_proportion       = $this-&gt;get_total() * $proportion;
					$calculate_tax_for['tax_class'] = $tax_class;
					$tax_rates                      = WC_Tax::find_rates( $calculate_tax_for );
					$discount_taxes                 = wc_array_merge_recursive_numeric( $discount_taxes, WC_Tax::calc_tax( $cart_discount_proportion, $tax_rates ) );
				}
			}
			$this-&gt;set_taxes( array( 'total' =&gt; $discount_taxes ) );
		} else {
			$this-&gt;set_taxes( false );
		}

		do_action( 'woocommerce_order_item_fee_after_calculate_taxes', $this, $calculate_tax_for );

		return true;
	}

	/*
	|--------------------------------------------------------------------------
	| Setters
	|--------------------------------------------------------------------------
	*/

	/**
	 * Set fee amount.
	 *
	 * @param string $value Amount.
	 */
	public function set_amount( $value ) {
		$this-&gt;set_prop( 'amount', wc_format_decimal( $value ) );
	}

	/**
	 * Set tax class.
	 *
	 * @param string $value Tax class.
	 */
	public function set_tax_class( $value ) {
		if ( $value &amp;&amp; ! in_array( $value, WC_Tax::get_tax_class_slugs(), true ) ) {
			$this-&gt;error( 'order_item_fee_invalid_tax_class', __( 'Invalid tax class', 'woocommerce' ) );
		}
		$this-&gt;set_prop( 'tax_class', $value );
	}

	/**
	 * Set tax_status.
	 *
	 * @param string $value Tax status.
	 */
	public function set_tax_status( $value ) {
		if ( in_array( $value, array( 'taxable', 'none' ), true ) ) {
			$this-&gt;set_prop( 'tax_status', $value );
		} else {
			$this-&gt;set_prop( 'tax_status', 'taxable' );
		}
	}

	/**
	 * Set total.
	 *
	 * @param string $amount Fee amount (do not enter negative amounts).
	 */
	public function set_total( $amount ) {
		$this-&gt;set_prop( 'total', wc_format_decimal( $amount ) );
	}

	/**
	 * Set total tax.
	 *
	 * @param string $amount Amount.
	 */
	public function set_total_tax( $amount ) {
		$this-&gt;set_prop( 'total_tax', wc_format_decimal( $amount ) );
	}

	/**
	 * Set taxes.
	 *
	 * This is an array of tax ID keys with total amount values.
	 *
	 * @param array $raw_tax_data Raw tax data.
	 */
	public function set_taxes( $raw_tax_data ) {
		$raw_tax_data = maybe_unserialize( $raw_tax_data );
		$tax_data     = array(
			'total' =&gt; array(),
		);
		if ( ! empty( $raw_tax_data['total'] ) ) {
			$tax_data['total'] = array_map( 'wc_format_decimal', $raw_tax_data['total'] );
		}
		$this-&gt;set_prop( 'taxes', $tax_data );

		if ( 'yes' === get_option( 'woocommerce_tax_round_at_subtotal' ) ) {
			$this-&gt;set_total_tax( NumberUtil::array_sum( $tax_data['total'] ) );
		} else {
			$this-&gt;set_total_tax( NumberUtil::array_sum( array_map( 'wc_round_tax_total', $tax_data['total'] ) ) );
		}
	}

	/*
	|--------------------------------------------------------------------------
	| Getters
	|--------------------------------------------------------------------------
	*/

	/**
	 * Get fee amount.
	 *
	 * @param  string $context What the value is for. Valid values are 'view' and 'edit'.
	 * @return string
	 */
	public function get_amount( $context = 'view' ) {
		return $this-&gt;get_prop( 'amount', $context );
	}

	/**
	 * Get order item name.
	 *
	 * @param  string $context What the value is for. Valid values are 'view' and 'edit'.
	 * @return string
	 */
	public function get_name( $context = 'view' ) {
		$name = $this-&gt;get_prop( 'name', $context );
		if ( 'view' === $context ) {
			return $name ? $name : __( 'Fee', 'woocommerce' );
		} else {
			return $name;
		}
	}

	/**
	 * Get order item type.
	 *
	 * @return string
	 */
	public function get_type() {
		return 'fee';
	}

	/**
	 * Get tax class.
	 *
	 * @param  string $context What the value is for. Valid values are 'view' and 'edit'.
	 * @return string
	 */
	public function get_tax_class( $context = 'view' ) {
		return $this-&gt;get_prop( 'tax_class', $context );
	}

	/**
	 * Get tax status.
	 *
	 * @param  string $context What the value is for. Valid values are 'view' and 'edit'.
	 * @return string
	 */
	public function get_tax_status( $context = 'view' ) {
		return $this-&gt;get_prop( 'tax_status', $context );
	}

	/**
	 * Get total fee.
	 *
	 * @param  string $context What the value is for. Valid values are 'view' and 'edit'.
	 * @return string
	 */
	public function get_total( $context = 'view' ) {
		return $this-&gt;get_prop( 'total', $context );
	}

	/**
	 * Get total tax.
	 *
	 * @param  string $context What the value is for. Valid values are 'view' and 'edit'.
	 * @return string
	 */
	public function get_total_tax( $context = 'view' ) {
		return $this-&gt;get_prop( 'total_tax', $context );
	}

	/**
	 * Get fee taxes.
	 *
	 * @param  string $context What the value is for. Valid values are 'view' and 'edit'.
	 * @return array
	 */
	public function get_taxes( $context = 'view' ) {
		return $this-&gt;get_prop( 'taxes', $context );
	}

	/*
	|--------------------------------------------------------------------------
	| Array Access Methods
	|--------------------------------------------------------------------------
	|
	| For backwards compatibility with legacy arrays.
	|
	*/

	/**
	 * OffsetGet for ArrayAccess/Backwards compatibility.
	 *
	 * @param string $offset Offset.
	 * @return mixed
	 */
	#[\ReturnTypeWillChange]
	public function offsetGet( $offset ) {
		if ( 'line_total' === $offset ) {
			$offset = 'total';
		} elseif ( 'line_tax' === $offset ) {
			$offset = 'total_tax';
		} elseif ( 'line_tax_data' === $offset ) {
			$offset = 'taxes';
		}
		return parent::offsetGet( $offset );
	}

	/**
	 * OffsetSet for ArrayAccess/Backwards compatibility.
	 *
	 * @deprecated 4.4.0
	 * @param string $offset Offset.
	 * @param mixed  $value  Value.
	 */
	#[\ReturnTypeWillChange]
	public function offsetSet( $offset, $value ) {
		wc_deprecated_function( 'WC_Order_Item_Fee::offsetSet', '4.4.0', '' );
		if ( 'line_total' === $offset ) {
			$offset = 'total';
		} elseif ( 'line_tax' === $offset ) {
			$offset = 'total_tax';
		} elseif ( 'line_tax_data' === $offset ) {
			$offset = 'taxes';
		}
		parent::offsetSet( $offset, $value );
	}

	/**
	 * OffsetExists for ArrayAccess
	 *
	 * @param string $offset Offset.
	 * @return bool
	 */
	#[\ReturnTypeWillChange]
	public function offsetExists( $offset ) {
		if ( in_array( $offset, array( 'line_total', 'line_tax', 'line_tax_data' ), true ) ) {
			return true;
		}
		return parent::offsetExists( $offset );
	}
}
</textarea><br>
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