WP_Error object that extensions may add errors to.
			 * @param string   $field_key   Key of the field being sanitized.
			 * @param mixed    $field_value The value of the field being validated.
			 *
			 * @since 8.7.0
			 */
			do_action( 'woocommerce_validate_additional_field', $errors, $field_key, $field_value );

		} catch ( \Throwable $e ) {

			// One of the filters errored so skip them and validate the field. This allows the checkout process to continue.
			// phpcs:ignore WordPress.PHP.DevelopmentFunctions.error_log_trigger_error
			trigger_error(
				sprintf(
					'Field validation for %s encountered an error. %s',
					esc_html( $field_key ),
					esc_html( $e->getMessage() )
				),
				E_USER_WARNING
			);
		}

		return $errors;
	}

	/**
	 * Update the default locale with additional fields without country limitations.
	 *
	 * @param array $locale The locale to update.
	 * @return mixed
	 */
	public function update_default_locale_with_fields( $locale ) {
		foreach ( $this->fields_locations['address'] as $field_id => $additional_field ) {
			if ( empty( $locale[ $field_id ] ) ) {
				$locale[ $field_id ] = $additional_field;
			}
		}
		return $locale;
	}

	/**
	 * Returns an array of fields keys for the address location.
	 *
	 * @return array An array of fields keys.
	 */
	public function get_address_fields_keys() {
		return $this->fields_locations['address'];
	}

	/**
	 * Returns an array of fields keys for the contact location.
	 *
	 * @return array An array of fields keys.
	 */
	public function get_contact_fields_keys() {
		return $this->fields_locations['contact'];
	}

	/**
	 * Returns an array of fields keys for the additional area location.
	 *
	 * @return array An array of fields keys.
	 * @deprecated 8.9.0 Use get_order_fields_keys instead.
	 */
	public function get_additional_fields_keys() {
		wc_deprecated_function( __METHOD__, '8.9.0', 'get_order_fields_keys' );
		return $this->get_order_fields_keys();
	}

	/**
	 * Returns an array of fields keys for the additional area group.
	 *
	 * @return array An array of fields keys.
	 */
	public function get_order_fields_keys() {
		return $this->fields_locations['order'];
	}

	/**
	 * Returns an array of fields for a given location.
	 *
	 * @param string $location The location to get fields for (address|contact|order).
	 * @return array An array of fields definitions.
	 */
	public function get_fields_for_location( $location ) {
		if ( 'additional' === $location ) {
			wc_deprecated_argument( 'location', '8.9.0', 'The "additional" location is deprecated. Use "order" instead.' );
			$location = 'order';
		}

		if ( in_array( $location, array_keys( $this->fields_locations ), true ) ) {
			$order_fields_keys = $this->fields_locations[ $location ];

			return array_filter(
				$this->get_additional_fields(),
				function ( $key ) use ( $order_fields_keys ) {
					return in_array( $key, $order_fields_keys, true );
				},
				ARRAY_FILTER_USE_KEY
			);
		}
		return [];
	}

	/**
	 * Validates a set of fields for a given location against custom validation rules.
	 *
	 * @param array  $fields Array of key value pairs of field values to validate.
	 * @param string $location The location being validated (address|contact|order).
	 * @param string $group The group to get the field value for (shipping|billing|other).
	 * @return WP_Error
	 */
	public function validate_fields_for_location( $fields, $location, $group = 'other' ) {
		$errors = new WP_Error();

		if ( 'additional' === $location ) {
			wc_deprecated_argument( 'location', '8.9.0', 'The "additional" location is deprecated. Use "order" instead.' );
			$location = 'order';
		}

		if ( 'additional' === $group ) {
			wc_deprecated_argument( 'group', '8.9.0', 'The "additional" group is deprecated. Use "other" instead.' );
			$group = 'other';
		}

		try {
			/**
			 * Pass an error object to allow validation of an additional field.
			 *
			 * @param WP_Error $errors  A WP_Error object that extensions may add errors to.
			 * @param mixed    $fields  List of fields (key value pairs) in this location.
			 * @param string   $group   The group of this location (shipping|billing|other).
			 *
			 * @since 8.6.0
			 * @deprecated 8.9.0 Use woocommerce_blocks_validate_location_order_fields instead.
			 */
			wc_do_deprecated_action( 'woocommerce_blocks_validate_location_additional_fields', array( $errors, $fields, $group ), '8.9.0', 'woocommerce_blocks_validate_location_additional_fields', 'This action has been graduated, use woocommerce_blocks_validate_location_additional_fields instead.' );
			/**
			 * Pass an error object to allow validation of an additional field.
			 *
			 * @param WP_Error $errors  A WP_Error object that extensions may add errors to.
			 * @param mixed    $fields  List of fields (key value pairs) in this location.
			 * @param string   $group   The group of this location (shipping|billing|other).
			 *
			 * @since 8.6.0
			 * @deprecated 8.9.0 Use woocommerce_blocks_validate_location_{location}_fields instead.
			 */
			wc_do_deprecated_action( '__experimental_woocommerce_blocks_validate_location_' . $location . '_fields', array( $errors, $fields, $group ), '8.9.0', 'woocommerce_blocks_validate_location_' . $location . '_fields', 'This action has been graduated, use woocommerce_blocks_validate_location_' . $location . '_fields instead.' );

			/**
			 * Pass an error object to allow validation of an additional field.
			 *
			 * @param WP_Error $errors  A WP_Error object that extensions may add errors to.
			 * @param mixed    $fields  List of fields (key value pairs) in this location.
			 * @param string   $group   The group of this location (shipping|billing|other).
			 *
			 * @since 8.7.0
			 */
			do_action( 'woocommerce_blocks_validate_location_' . $location . '_fields', $errors, $fields, $group );

		} catch ( \Throwable $e ) {

			// One of the filters errored so skip them. This allows the checkout process to continue.
			// phpcs:ignore WordPress.PHP.DevelopmentFunctions.error_log_trigger_error
			trigger_error(
				sprintf(
					'The action %s encountered an error. The field location %s may not have any custom validation applied to it. %s',
					esc_html( 'woocommerce_blocks_validate_' . $location . '_fields' ),
					esc_html( $location ),
					esc_html( $e->getMessage() )
				),
				E_USER_WARNING
			);
		}

		return $errors;
	}

	/**
	 * Validates a field to check it belongs to the given location and is valid according to its registration.
	 *
	 * This does not apply any custom validation rules on the value.
	 *
	 * @param string $key The field key.
	 * @param mixed  $value The field value.
	 * @param string $location The location to validate the field for (address|contact|order).
	 *
	 * @return true|WP_Error True if the field is valid, a WP_Error otherwise.
	 */
	public function validate_field_for_location( $key, $value, $location ) {
		if ( 'additional' === $location ) {
			wc_deprecated_argument( 'location', '8.9.0', 'The "additional" location is deprecated. Use "order" instead.' );
			$location = 'order';
		}

		if ( ! $this->is_field( $key ) ) {
			return new WP_Error(
				'woocommerce_invalid_checkout_field',
				\sprintf(
				// translators: % is field key.
					__( 'The field %s is invalid.', 'woocommerce' ),
					$key
				)
			);
		}

		if ( ! in_array( $key, $this->fields_locations[ $location ], true ) ) {
			return new WP_Error(
				'woocommerce_invalid_checkout_field_location',
				\sprintf(
				// translators: %1$s is field key, %2$s location.
					__( 'The field %1$s is invalid for the location %2$s.', 'woocommerce' ),
					$key,
					$location
				)
			);
		}

		$field = $this->additional_fields[ $key ];
		if ( ! empty( $field['required'] ) && empty( $value ) ) {
			return new WP_Error(
				'woocommerce_required_checkout_field',
				\sprintf(
				// translators: %s is field key.
					__( 'The field %s is required.', 'woocommerce' ),
					$key
				)
			);
		}

		return true;
	}

	/**
	 * Returns all fields key for a given group.
	 *
	 * @param string $group The group to get the key for (shipping|billing|other).
	 *
	 * @return string[] Field keys.
	 */
	public function get_fields_for_group( $group = 'other' ) {
		if ( 'shipping' === $group ) {
			return $this->get_fields_for_location( 'address' );
		}

		if ( 'billing' === $group ) {
			return $this->get_fields_for_location( 'address' );
		}

		return \array_merge(
			$this->get_fields_for_location( 'contact' ),
			$this->get_fields_for_location( 'order' )
		);
	}

	/**
	 * Returns true if the given key is a valid field.
	 *
	 * @param string $key The field key.
	 *
	 * @return bool True if the field is valid, false otherwise.
	 */
	public function is_field( $key ) {
		return array_key_exists( $key, $this->additional_fields );
	}

	/**
	 * Returns true if the given key is a valid customer field.
	 *
	 * Customer fields are fields saved to the customer data, like address and contact fields.
	 *
	 * @param string $key The field key.
	 *
	 * @return bool True if the field is valid, false otherwise.
	 */
	public function is_customer_field( $key ) {
		return in_array( $key, array_intersect( array_merge( $this->get_address_fields_keys(), $this->get_contact_fields_keys() ), array_keys( $this->additional_fields ) ), true );
	}

	/**
	 * Persists a field value for a given order. This would also optionally set the field value on the customer object if the order is linked to a registered customer.
	 *
	 * @param string   $key The field key.
	 * @param mixed    $value The field value.
	 * @param WC_Order $order The order to persist the field for.
	 * @param string   $group The group to persist the field for (shipping|billing|other).
	 * @param bool     $set_customer Whether to set the field value on the customer or not.
	 *
	 * @return void
	 */
	public function persist_field_for_order( string $key, $value, WC_Order $order, string $group = 'other', bool $set_customer = true ) {
		if ( 'additional' === $group ) {
			wc_deprecated_argument( 'group', '8.9.0', 'The "additional" group is deprecated. Use "other" instead.' );
			$group = 'other';
		}

		$this->set_array_meta( $key, $value, $order, $group );
		if ( $set_customer && $order->get_customer_id() ) {
			$customer = new WC_Customer( $order->get_customer_id() );
			$this->persist_field_for_customer( $key, $value, $customer, $group );
		}
	}

	/**
	 * Persists a field value for a given customer.
	 *
	 * @param string      $key The field key.
	 * @param mixed       $value The field value.
	 * @param WC_Customer $customer The customer to persist the field for.
	 * @param string      $group The group to persist the field for (shipping|billing|other).
	 *
	 * @return void
	 */
	public function persist_field_for_customer( string $key, $value, WC_Customer $customer, string $group = 'other' ) {
		if ( 'additional' === $group ) {
			wc_deprecated_argument( 'group', '8.9.0', 'The "additional" group is deprecated. Use "other" instead.' );
			$group = 'other';
		}

		$this->set_array_meta( $key, $value, $customer, $group );
	}

	/**
	 * Sets a field value in an array meta, supporting routing things to billing, shipping, or additional fields, based on a prefix for the key.
	 *
	 * @param string               $key The field key.
	 * @param mixed                $value The field value.
	 * @param WC_Customer|WC_Order $wc_object The object to set the field value for.
	 * @param string               $group The group to set the field value for (shipping|billing|other).
	 *
	 * @return void
	 */
	private function set_array_meta( string $key, $value, WC_Data $wc_object, string $group ) {
		$meta_key = self::get_group_key( $group ) . $key;

		/**
		 * Allow reacting for saving an additional field value.
		 *
		 * @param string               $key The key of the field being saved.
		 * @param mixed                $value The value of the field being saved.
		 * @param string               $group The group of this location (shipping|billing|other).
		 * @param WC_Customer|WC_Order $wc_object The object to set the field value for.
		 *
		 * @since 8.9.0
		 */
		do_action( 'woocommerce_set_additional_field_value', $key, $value, $group, $wc_object );
		// Convert boolean values to strings because Data Stores will skip false values.
		if ( is_bool( $value ) ) {
			$value = $value ? '1' : '0';
		}
		// Replacing all meta using `add_meta_data`. For some reason `update_meta_data` causes duplicate keys.
		$wc_object->add_meta_data( $meta_key, $value, true );
	}

	/**
	 * Returns a field value for a given object.
	 *
	 * @param string               $key The field key.
	 * @param WC_Customer|WC_Order $wc_object The customer or order to get the field value for.
	 * @param string               $group The group to get the field value for (shipping|billing|other).
	 *
	 * @return mixed The field value.
	 */
	public function get_field_from_object( string $key, WC_Data $wc_object, string $group = 'other' ) {
		if ( 'additional' === $group ) {
			wc_deprecated_argument( 'group', '8.9.0', 'The "additional" group is deprecated. Use "other" instead.' );
			$group = 'other';
		}

		$meta_key = self::get_group_key( $group ) . $key;

		$value = $wc_object->get_meta( $meta_key, true );

		if ( ! $value ) {
			/**
			 * Allow providing a default value for additional fields if no value is already set.
			 *
			 * @param null $value The default value for the filter, always null.
			 * @param string $group The group of this key (shipping|billing|other).
			 * @param WC_Data $wc_object The object to get the field value for.
			 *
			 * @since 8.9.0
			 */
			$value = apply_filters( "woocommerce_get_default_value_for_{$key}", null, $group, $wc_object );
		}

		// We cast the value to a boolean if the field is a checkbox.
		if ( $this->is_field( $key ) && 'checkbox' === $this->additional_fields[ $key ]['type'] ) {
			return '1' === $value;
		}

		if ( null === $value ) {
			return '';
		}

		return $value;
	}

	/**
	 * Returns an array of all fields values for a given object in a group.
	 *
	 * @param WC_Data $wc_object The object or order to get the fields for.
	 * @param string  $group The group to get the fields for (shipping|billing|other).
	 * @param bool    $all Whether to return all fields or only the ones that are still registered. Default false.
	 *
	 * @return array An array of fields.
	 */
	public function get_all_fields_from_object( WC_Data $wc_object, string $group = 'other', bool $all = false ) {
		if ( 'additional' === $group ) {
			wc_deprecated_argument( 'group', '8.9.0', 'The "additional" group is deprecated. Use "other" instead.' );
			$group = 'other';
		}

		$meta_data = [];

		$prefix = self::get_group_key( $group );

		if ( $wc_object instanceof WC_Data ) {
			$meta = $wc_object->get_meta_data();
			foreach ( $meta as $meta_data_object ) {
				if ( 0 === \strpos( $meta_data_object->key, $prefix ) ) {
					$key = \str_replace( $prefix, '', $meta_data_object->key );
					if ( $all || $this->is_field( $key ) ) {
						$meta_data[ $key ] = $meta_data_object->value;
					}
				}
			}
		}

		$missing_fields = array_diff( array_keys( $this->get_fields_for_group( $group ) ), array_keys( $meta_data ) );

		foreach ( $missing_fields as $missing_field ) {
				/**
				 * Allow providing a default value for additional fields if no value is already set.
				 *
				 * @param null $value The default value for the filter, always null.
				 * @param string $group The group of this key (shipping|billing|other).
				 * @param WC_Data $wc_object The object to get the field value for.
				 *
				 * @since 8.9.0
				 */
				$value = apply_filters( "woocommerce_get_default_value_for_{$missing_field}", null, $group, $wc_object );

			if ( $value ) {
				$meta_data[ $missing_field ] = $value;
			}
		}

		return $meta_data;
	}

	/**
	 * Copies additional fields from an order to a customer.
	 *
	 * @param WC_Order    $order The order to sync the fields for.
	 * @param WC_Customer $customer The customer to sync the fields for.
	 */
	public function sync_customer_additional_fields_with_order( WC_Order $order, WC_Customer $customer ) {
		foreach ( $this->groups as $group ) {
			$order_additional_fields = $this->get_all_fields_from_object( $order, $group, true );

			// Sync customer additional fields with order additional fields.
			foreach ( $order_additional_fields as $key => $value ) {
				if ( $this->is_customer_field( $key ) ) {
					$this->persist_field_for_customer( $key, $value, $customer, $group );
				}
			}
		}
	}

	/**
	 * Copies additional fields from a customer to an order.
	 *
	 * @param WC_Order    $order The order to sync the fields for.
	 * @param WC_Customer $customer The customer to sync the fields for.
	 */
	public function sync_order_additional_fields_with_customer( WC_Order $order, WC_Customer $customer ) {
		foreach ( $this->groups as $group ) {
			$customer_additional_fields = $this->get_all_fields_from_object( $customer, $group, true );

			// Sync order additional fields with customer additional fields.
			foreach ( $customer_additional_fields as $key => $value ) {
				if ( $this->is_field( $key ) ) {
					$this->persist_field_for_order( $key, $value, $order, $group, false );
				}
			}
		}
	}
	/**
	 * From a set of fields, returns only the ones for a given location.
	 *
	 * @param array  $fields The fields to filter.
	 * @param string $location The location to validate the field for (address|contact|order).
	 * @return array The filtered fields.
	 */
	public function filter_fields_for_location( array $fields, string $location ) {
		if ( 'additional' === $location ) {
			wc_deprecated_argument( 'location', '8.9.0', 'The "additional" location is deprecated. Use "order" instead.' );
			$location = 'order';
		}

		return array_filter(
			$fields,
			function ( $key ) use ( $location ) {
				return $this->is_field( $key ) && $this->get_field_location( $key ) === $location;
			},
			ARRAY_FILTER_USE_KEY
		);
	}

	/**
	 * Filter fields for order confirmation.
	 *
	 * @param array $fields The fields to filter.
	 * @return array The filtered fields.
	 */
	public function filter_fields_for_order_confirmation( $fields ) {
		return array_filter(
			$fields,
			function ( $field ) {
				return ! empty( $field['show_in_order_confirmation'] );
			}
		);
	}

	/**
	 * Get additional fields for an order.
	 *
	 * @param WC_Order $order Order object.
	 * @param string   $location The location to get fields for (address|contact|order).
	 * @param string   $group The group to get the field value for (shipping|billing|other).
	 * @param string   $context The context to get the field value for (edit|view).
	 * @return array An array of fields definitions as well as their values formatted for display.
	 */
	public function get_order_additional_fields_with_values( WC_Order $order, string $location, string $group = 'other', string $context = 'edit' ) {

		// Because the Additional Checkout Fields API only applies to orders created with Store API, we should not
		// return any values unless it was created using Store API. This is mainly to prevent "empty" checkbox values
		// from being shown on the order confirmation page for orders placed using the shortcode. It's rare that this
		// will happen but not impossible.
		if ( 'store-api' !== $order->get_created_via() ) {
			return [];
		}

		if ( 'additional' === $location ) {
			wc_deprecated_argument( 'location', '8.9.0', 'The "additional" location is deprecated. Use "order" instead.' );
			$location = 'order';
		}

		if ( 'additional' === $group ) {
			wc_deprecated_argument( 'group', '8.9.0', 'The "additional" group is deprecated. Use "other" instead.' );
			$group = 'other';
		}

		$fields             = $this->get_fields_for_location( $location );
		$fields_with_values = [];

		foreach ( $fields as $field_key => $field ) {
			$value = $this->get_field_from_object( $field_key, $order, $group );

			if ( '' === $value || null === $value ) {
				continue;
			}

			if ( 'view' === $context ) {
				$value = $this->format_additional_field_value( $value, $field );
			}

			$field['value']                   = $value;
			$fields_with_values[ $field_key ] = $field;
		}

		return $fields_with_values;
	}

	/**
	 * Formats a raw field value for display based on its type definition.
	 *
	 * @param string $value Value to format.
	 * @param array  $field Additional field definition.
	 * @return string
	 */
	public function format_additional_field_value( $value, $field ) {
		if ( 'checkbox' === $field['type'] ) {
			$value = $value ? __( 'Yes', 'woocommerce' ) : __( 'No', 'woocommerce' );
		}

		if ( 'select' === $field['type'] ) {
			$options = array_column( $field['options'], 'label', 'value' );
			$value   = isset( $options[ $value ] ) ? $options[ $value ] : $value;
		}

		return $value;
	}

	/**
	 * Returns a group meta prefix based on its name.
	 *
	 * @param string $group_name The group name (billing|shipping|other).
	 * @return string The group meta prefix.
	 */
	public static function get_group_key( $group_name ) {
		if ( 'additional' === $group_name ) {
			wc_deprecated_argument( 'group_name', '8.9.0', 'The "additional" group is deprecated. Use "other" instead.' );
			$group_name = 'other';
		}

		if ( 'billing' === $group_name ) {
			return self::BILLING_FIELDS_PREFIX;
		}
		if ( 'shipping' === $group_name ) {
			return self::SHIPPING_FIELDS_PREFIX;
		}
		return self::OTHER_FIELDS_PREFIX;
	}

	/**
	 * Returns a group name based on passed group key.
	 *
	 * @param string $group_key The group name (_wc_billing|_wc_shipping|_wc_other).
	 * @return string The group meta prefix.
	 */
	public static function get_group_name( $group_key ) {
		if ( '_wc_additional' === $group_key ) {
			wc_deprecated_argument( 'group_key', '8.9.0', 'The "_wc_additional" group key is deprecated. Use "_wc_other" instead.' );
			$group_key = '_wc_other';
		}

		if ( 0 === \strpos( self::BILLING_FIELDS_PREFIX, $group_key ) ) {
			return 'billing';
		}
		if ( 0 === \strpos( self::SHIPPING_FIELDS_PREFIX, $group_key ) ) {
			return 'shipping';
		}
		return 'other';
	}
}