$order );

		$this->persist_order_to_db( $order, $force_all_fields );

		$order->save_meta_data();
		$order->apply_changes();

		if ( $backfill ) {
			$this->maybe_backfill_post_record( $order );
		}
		$this->clear_caches( $order );
	}

	/**
	 * Method to update an order in the database.
	 *
	 * @param \WC_Order $order
	 */
	public function update( &$order ) {
		// Before updating, ensure date paid is set if missing.
		if (
			! $order->get_date_paid( 'edit' )
			&& version_compare( $order->get_version( 'edit' ), '3.0', '<' )
			&& $order->has_status( apply_filters( 'woocommerce_payment_complete_order_status', $order->needs_processing() ? 'processing' : 'completed', $order->get_id(), $order ) ) // phpcs:ignore WooCommerce.Commenting.CommentHooks.MissingHookComment
		) {
			$order->set_date_paid( $order->get_date_created( 'edit' ) );
		}

		if ( null === $order->get_date_created( 'edit' ) ) {
			$order->set_date_created( time() );
		}

		$order->set_version( Constants::get_constant( 'WC_VERSION' ) );

		// Fetch changes.
		$changes = $order->get_changes();
		$this->persist_updates( $order );

		// Update download permissions if necessary.
		if ( array_key_exists( 'billing_email', $changes ) || array_key_exists( 'customer_id', $changes ) ) {
			$data_store = \WC_Data_Store::load( 'customer-download' );
			$data_store->update_user_by_order_id( $order->get_id(), $order->get_customer_id(), $order->get_billing_email() );
		}

		// Mark user account as active.
		if ( array_key_exists( 'customer_id', $changes ) ) {
			wc_update_user_last_active( $order->get_customer_id() );
		}

		$order->apply_changes();
		$this->clear_caches( $order );

		do_action( 'woocommerce_update_order', $order->get_id(), $order ); // phpcs:ignore WooCommerce.Commenting.CommentHooks.MissingHookComment
	}

	/**
	 * Proxy to udpating order meta. Here for backward compatibility reasons.
	 *
	 * @param \WC_Order $order Order object.
	 *
	 * @return void
	 */
	protected function update_post_meta( &$order ) {
		$this->update_order_meta( $order );
	}

	/**
	 * Helper method that is responsible for persisting order updates to the database.
	 *
	 * This is expected to be reused by other order types, and should not contain any specific metadata updates or actions.
	 *
	 * @param \WC_Order $order Order object.
	 *
	 * @return array $changes Array of changes.
	 *
	 * @throws \Exception When unable to persist order.
	 */
	protected function persist_updates( &$order, $backfill = true ) {
		// Fetch changes.
		$changes = $order->get_changes();

		if ( ! isset( $changes['date_modified'] ) ) {
			$order->set_date_modified( time() );
		}

		if ( $backfill ) {
			$this->maybe_backfill_post_record( $order );
		}

		$this->persist_order_to_db( $order );
		$order->save_meta_data();

		return $changes;
	}

	/**
	 * Helper function to decide whether to backfill post record.
	 *
	 * @param \WC_Abstract_Order $order Order object.
	 *
	 * @return void
	 */
	private function maybe_backfill_post_record( $order ) {
		$data_sync = wc_get_container()->get( DataSynchronizer::class );
		if ( $data_sync->data_sync_is_enabled() ) {
			$this->backfill_post_record( $order );
		}
	}

	/**
	 * Helper method that updates post meta based on an order object.
	 * Mostly used for backwards compatibility purposes in this datastore.
	 *
	 * @param \WC_Order $order Order object.
	 *
	 * @since 7.0.0
	 */
	public function update_order_meta( &$order ) {
		$changes = $order->get_changes();
		$this->update_address_index_meta( $order, $changes );
	}

	/**
	 * Helper function to update billing and shipping address metadata.
	 * @param \WC_Abstract_Order $order Order Object
	 * @param array              $changes Array of changes.
	 *
	 * @return void
	 */
	private function update_address_index_meta( $order, $changes ) {
		// If address changed, store concatenated version to make searches faster.
		foreach ( array( 'billing', 'shipping' ) as $address_type ) {
			if ( isset( $changes[ $address_type ] ) ) {
				$order->update_meta_data( "_{$address_type}_address_index", implode( ' ', $order->get_address( $address_type ) ) );
			}
		}
	}

	/**
	 * Return array of coupon_code => meta_key for coupon which have usage limit and have tentative keys.
	 * Pass $coupon_id if key for only one of the coupon is needed.
	 *
	 * @param WC_Order $order     Order object.
	 * @param int      $coupon_id If passed, will return held key for that coupon.
	 *
	 * @return array|string Key value pair for coupon code and meta key name. If $coupon_id is passed, returns meta_key for only that coupon.
	 */
	public function get_coupon_held_keys( $order, $coupon_id = null ) {
		$held_keys = $order->get_meta( '_coupon_held_keys' );
		if ( $coupon_id ) {
			return isset( $held_keys[ $coupon_id ] ) ? $held_keys[ $coupon_id ] : null;
		}
		return $held_keys;
	}

	/**
	 * Return array of coupon_code => meta_key for coupon which have usage limit per customer and have tentative keys.
	 *
	 * @param WC_Order $order Order object.
	 * @param int      $coupon_id If passed, will return held key for that coupon.
	 *
	 * @return mixed
	 */
	public function get_coupon_held_keys_for_users( $order, $coupon_id = null ) {
		$held_keys_for_user = $order->get_meta( '_coupon_held_keys_for_users' );
		if ( $coupon_id ) {
			return isset( $held_keys_for_user[ $coupon_id ] ) ? $held_keys_for_user[ $coupon_id ] : null;
		}
		return $held_keys_for_user;
	}

	/**
	 * Add/Update list of meta keys that are currently being used by this order to hold a coupon.
	 * This is used to figure out what all meta entries we should delete when order is cancelled/completed.
	 *
	 * @param WC_Order $order              Order object.
	 * @param array    $held_keys          Array of coupon_code => meta_key.
	 * @param array    $held_keys_for_user Array of coupon_code => meta_key for held coupon for user.
	 *
	 * @return mixed
	 */
	public function set_coupon_held_keys( $order, $held_keys, $held_keys_for_user ) {
		if ( is_array( $held_keys ) && 0 < count( $held_keys ) ) {
			$order->update_meta_data( '_coupon_held_keys', $held_keys );
		}
		if ( is_array( $held_keys_for_user ) && 0 < count( $held_keys_for_user ) ) {
			$order->update_meta_data( '_coupon_held_keys_for_users', $held_keys_for_user );
		}
	}

	/**
	 * Release all coupons held by this order.
	 *
	 * @param WC_Order $order Current order object.
	 * @param bool     $save  Whether to delete keys from DB right away. Could be useful to pass `false` if you are building a bulk request.
	 */
	public function release_held_coupons( $order, $save = true ) {
		$coupon_held_keys = $this->get_coupon_held_keys( $order );
		if ( is_array( $coupon_held_keys ) ) {
			foreach ( $coupon_held_keys as $coupon_id => $meta_key ) {
				$coupon = new \WC_Coupon( $coupon_id );
				$coupon->delete_meta_data( $meta_key );
				$coupon->save_meta_data();
			}
		}
		$order->delete_meta_data( '_coupon_held_keys' );

		$coupon_held_keys_for_users = $this->get_coupon_held_keys_for_users( $order );
		if ( is_array( $coupon_held_keys_for_users ) ) {
			foreach ( $coupon_held_keys_for_users as $coupon_id => $meta_key ) {
				$coupon = new \WC_Coupon( $coupon_id );
				$coupon->delete_meta_data( $meta_key );
				$coupon->save_meta_data();
			}
		}
		$order->delete_meta_data( '_coupon_held_keys_for_users' );

		if ( $save ) {
			$order->save_meta_data();
		}

	}

	public function query( $query_vars ) {
		if ( ! isset( $query_vars['paginate'] ) || ! $query_vars['paginate'] ) {
			$query_vars['no_found_rows'] = true;
		}

		if ( isset( $query_vars['anonymized'] ) ) {
			$query_vars['meta_query'] = $query_vars['meta_query'] ?? array(); // phpcs:ignore WordPress.DB.SlowDBQuery.slow_db_query_meta_query

			if ( $query_vars['anonymized'] ) {
				$query_vars['meta_query'][] = array(
					'key'   => '_anonymized',
					'value' => 'yes',
				);
			} else {
				$query_vars['meta_query'][] = array(
					'key'     => '_anonymized',
					'compare' => 'NOT EXISTS',
				);
			}
		}

		try {
			$query = new OrdersTableQuery( $query_vars );
		} catch ( \Exception $e ) {
			$query = (object) array(
				'orders'        => array(),
				'found_orders'  => 0,
				'max_num_pages' => 0,
			);
		}

		if ( isset( $query_vars['return'] ) && 'ids' === $query_vars['return'] ) {
			$orders = $query->orders;
		} else {
			$orders = WC()->order_factory->get_orders( $query->orders );
		}

		if ( isset( $query_vars['paginate'] ) && $query_vars['paginate'] ) {
			return (object) array(
				'orders'        => $orders,
				'total'         => $query->found_orders,
				'max_num_pages' => $query->max_num_pages,
			);
		}

		return $orders;
	}

	public function get_order_item_type( $order, $order_item_id ) {
		return 'line_item';
	}

	//phpcs:enable Squiz.Commenting, Generic.Commenting

	/**
	 * Get the SQL needed to create all the tables needed for the custom orders table feature.
	 *
	 * @return string
	 */
	public function get_database_schema() {
		global $wpdb;

		$collate = $wpdb->has_cap( 'collation' ) ? $wpdb->get_charset_collate() : '';

		$orders_table_name           = $this->get_orders_table_name();
		$addresses_table_name        = $this->get_addresses_table_name();
		$operational_data_table_name = $this->get_operational_data_table_name();
		$meta_table                  = $this->get_meta_table_name();

		$sql = "
CREATE TABLE $orders_table_name (
	id bigint(20) unsigned,
	status varchar(20) null,
	currency varchar(10) null,
	type varchar(20) null,
	tax_amount decimal(26,8) null,
	total_amount decimal(26,8) null,
	customer_id bigint(20) unsigned null,
	billing_email varchar(320) null,
	date_created_gmt datetime null,
	date_updated_gmt datetime null,
	parent_order_id bigint(20) unsigned null,
	payment_method varchar(100) null,
	payment_method_title text null,
	transaction_id varchar(100) null,
	ip_address varchar(100) null,
	user_agent text null,
	customer_note text null,
	PRIMARY KEY (id),
	KEY status (status),
	KEY date_created (date_created_gmt),
	KEY customer_id_billing_email (customer_id, billing_email),
	KEY billing_email (billing_email),
	KEY type_status (type, status),
	KEY parent_order_id (parent_order_id),
	KEY date_updated (date_updated_gmt)
) $collate;
CREATE TABLE $addresses_table_name (
	id bigint(20) unsigned auto_increment primary key,
	order_id bigint(20) unsigned NOT NULL,
	address_type varchar(20) null,
	first_name text null,
	last_name text null,
	company text null,
	address_1 text null,
	address_2 text null,
	city text null,
	state text null,
	postcode text null,
	country text null,
	email varchar(320) null,
	phone varchar(100) null,
	KEY order_id (order_id),
	UNIQUE KEY address_type_order_id (address_type, order_id),
	KEY email (email),
	KEY phone (phone)
) $collate;
CREATE TABLE $operational_data_table_name (
	id bigint(20) unsigned auto_increment primary key,
	order_id bigint(20) unsigned NULL,
	created_via varchar(100) NULL,
	woocommerce_version varchar(20) NULL,
	prices_include_tax tinyint(1) NULL,
	coupon_usages_are_counted tinyint(1) NULL,
	download_permission_granted tinyint(1) NULL,
	cart_hash varchar(100) NULL,
	new_order_email_sent tinyint(1) NULL,
	order_key varchar(100) NULL,
	order_stock_reduced tinyint(1) NULL,
	date_paid_gmt datetime NULL,
	date_completed_gmt datetime NULL,
	shipping_tax_amount decimal(26, 8) NULL,
	shipping_total_amount decimal(26, 8) NULL,
	discount_tax_amount decimal(26, 8) NULL,
	discount_total_amount decimal(26, 8) NULL,
	recorded_sales tinyint(1) NULL,
	UNIQUE KEY order_id (order_id),
	UNIQUE KEY order_key (order_key)
) $collate;
CREATE TABLE $meta_table (
	id bigint(20) unsigned auto_increment primary key,
	order_id bigint(20) unsigned null,
	meta_key varchar(255),
	meta_value text null,
	KEY meta_key_value (meta_key, meta_value(100)),
	KEY order_id_meta_key_meta_value (order_id, meta_key, meta_value(100))
) $collate;
";

		return $sql;
	}

	/**
	 * Returns an array of meta for an object.
	 *
	 * @param  WC_Data $object WC_Data object.
	 * @return array
	 */
	public function read_meta( &$object ) {
		$raw_meta_data = $this->data_store_meta->read_meta( $object );
		return $this->filter_raw_meta_data( $object, $raw_meta_data );
	}

	/**
	 * Deletes meta based on meta ID.
	 *
	 * @param  WC_Data  $object WC_Data object.
	 * @param  stdClass $meta (containing at least ->id).
	 */
	public function delete_meta( &$object, $meta ) {
		return $this->data_store_meta->delete_meta( $object, $meta );
	}

	/**
	 * Add new piece of meta.
	 *
	 * @param  WC_Data  $object WC_Data object.
	 * @param  stdClass $meta (containing ->key and ->value).
	 * @return int meta ID
	 */
	public function add_meta( &$object, $meta ) {
		return $this->data_store_meta->add_meta( $object, $meta );
	}

	/**
	 * Update meta.
	 *
	 * @param  WC_Data  $object WC_Data object.
	 * @param  stdClass $meta (containing ->id, ->key and ->value).
	 */
	public function update_meta( &$object, $meta ) {
		return $this->data_store_meta->update_meta( $object, $meta );
	}
}