static function add_tables( $wc_tables ) {
		return array_merge(
			$wc_tables,
			self::get_tables()
		);
	}

	/**
	 * Uninstall tables when MU blog is deleted.
	 *
	 * @param array $tables List of tables that will be deleted by WP.
	 *
	 * @return string[]
	 */
	public static function wpmu_drop_tables( $tables ) {
		return array_merge( $tables, self::get_tables() );
	}

	/**
	 * Get list of DB update callbacks.
	 *
	 * @return array
	 */
	public static function get_db_update_callbacks() {
		return self::$db_updates;
	}

	/**
	 * Is a DB update needed?
	 *
	 * @return boolean
	 */
	public static function needs_db_update() {
		$current_db_version = get_option( self::VERSION_OPTION, null );
		$updates            = self::get_db_update_callbacks();
		$update_versions    = array_keys( $updates );
		usort( $update_versions, 'version_compare' );

		return ! is_null( $current_db_version ) && version_compare( $current_db_version, end( $update_versions ), '<' );
	}

	/**
	 * See if we need to show or run database updates during install.
	 */
	private static function maybe_update_db_version() {
		if ( self::needs_db_update() ) {
			self::update();
		} else {
			self::update_db_version();
		}
	}

	/**
	 * Push all needed DB updates to the queue for processing.
	 */
	private static function update() {
		$current_db_version = get_option( self::VERSION_OPTION );
		$loop               = 0;

		foreach ( self::get_db_update_callbacks() as $version => $update_callbacks ) {
			if ( version_compare( $current_db_version, $version, '<' ) ) {
				$completed_version_updates = 0;

				foreach ( $update_callbacks as $update_callback ) {
					$pending_jobs = WC()->queue()->search(
						array(
							'per_page' => 1,
							'hook'     => 'woocommerce_run_update_callback',
							'search'   => wp_json_encode( array( $update_callback ) ),
							'group'    => 'woocommerce-db-updates',
							'status'   => 'pending',
						)
					);

					$complete_jobs = WC()->queue()->search(
						array(
							'per_page' => 1,
							'hook'     => 'woocommerce_run_update_callback',
							'search'   => wp_json_encode( array( $update_callback ) ),
							'group'    => 'woocommerce-db-updates',
							'status'   => 'complete',
						)
					);

					$completed_version_updates += count( $complete_jobs );

					if ( empty( $pending_jobs ) && empty( $complete_jobs ) ) {
						WC()->queue()->schedule_single(
							time() + $loop,
							'woocommerce_run_update_callback',
							array( $update_callback ),
							'woocommerce-db-updates'
						);
						Cache::invalidate();
					}

					$loop++;

				}

				// Users have experienced concurrency issues where all update callbacks
				// have run but the version option hasn't been updated. If all the updates
				// for a version are complete, update the version option to reflect that.
				// See: https:// github.com/woocommerce/woocommerce-admin/issues/5058.
				if ( count( $update_callbacks ) === $completed_version_updates ) {
					self::update_db_version( $version );
				}
			}
		}
	}

	/**
	 * Update WC Admin version to current.
	 *
	 * @param string|null $version New WooCommerce Admin DB version or null.
	 */
	public static function update_db_version( $version = null ) {
		delete_option( self::VERSION_OPTION );
		add_option( self::VERSION_OPTION, is_null( $version ) ? WC_ADMIN_VERSION_NUMBER : $version );
	}

	/**
	 * Schedule cron events.
	 */
	public static function create_events() {
		if ( ! wp_next_scheduled( 'wc_admin_daily' ) ) {
			wp_schedule_event( time(), 'daily', 'wc_admin_daily' );
		}
		// Note: this is potentially redundant when the core package exists.
		wp_schedule_single_event( time() + 10, 'generate_category_lookup_table' );
	}

	/**
	 * Delete obsolete notes.
	 */
	protected static function delete_obsolete_notes() {
		$obsolete_notes_names = array(
			'wc-admin-welcome-note',
			'wc-admin-store-notice-setting-moved',
			'wc-admin-store-notice-giving-feedback',
			'wc-admin-learn-more-about-product-settings',
			'wc-admin-onboarding-profiler-reminder',
			'wc-admin-historical-data',
			'wc-admin-review-shipping-settings',
			'wc-admin-home-screen-feedback',
			'wc-admin-effortless-payments-by-mollie',
			'wc-admin-google-ads-and-marketing',
		);

		$additional_obsolete_notes_names = apply_filters(
			'woocommerce_admin_obsolete_notes_names',
			array()
		);

		if ( is_array( $additional_obsolete_notes_names ) ) {
			$obsolete_notes_names = array_merge(
				$obsolete_notes_names,
				$additional_obsolete_notes_names
			);
		}

		Notes::delete_notes_with_name( $obsolete_notes_names );
	}

	/**
	 * Drop WooCommerce Admin tables.
	 *
	 * @return void
	 */
	public static function drop_tables() {
		global $wpdb;

		$tables = self::get_tables();

		foreach ( $tables as $table ) {
			/* phpcs:ignore WordPress.DB.PreparedSQL.InterpolatedNotPrepared */
			$wpdb->query( "DROP TABLE IF EXISTS {$table}" );
			/* phpcs:enable */
		}
	}
}