class-wc-subscriptions-upgrader.php

<?php
/**
 * A timeout resistant, single-serve upgrader for WC Subscriptions.
 *
 * This class is used to make all reasonable attempts to neatly upgrade data between versions of Subscriptions.
 *
 * For example, the way subscription data is stored changed significantly between v1.n and v2.0. It was imperative
 * the data be upgraded to the new schema without hassle. A hassle could easily occur if 100,000 orders were being
 * modified - memory exhaustion, script time out etc.
 *
 * @author      Prospress
 * @category    Admin
 * @package     WooCommerce Subscriptions/Admin/Upgrades
 * @version     1.0.0 - Migrated from WooCommerce Subscriptions v2.0.0
 * @since       1.0.0 - Migrated from WooCommerce Subscriptions v1.2
 */
class WC_Subscriptions_Upgrader {

	/**
	 * @var string The database version of Subscriptions.
	 */
	private static $active_version;

	/**
	 * @var string The minimum supported version that this class can upgrade from.
	 */
	private static $minimum_supported_version = '3.0';

	/**
	 * @var array An array of WCS_Background_Updater objects used to run upgrade scripts in the background.
	 */
	protected static $background_updaters = array();

	/**
	 * Deprecated variables.
	 *
	 * @deprecated subscriptions-core 7.7.0
	 */
	public static $is_wc_version_2 = false;
	public static $updated_to_wc_2_0;
	private static $upgrade_limit_subscriptions;
	private static $about_page_url;
	private static $old_subscription_count = null;
	private static $upgrade_limit_hooks;

	/**
	 * Hooks upgrade function to init.
	 *
	 * @since 1.0.0 - Migrated from WooCommerce Subscriptions v1.2
	 */
	public static function init() {
		self::$active_version = get_option( WC_Subscriptions_Admin::$option_prefix . '_active_version', '0' );
		self::$about_page_url = admin_url( 'admin.php?page=wc-admin' );
		$version_out_of_date  = version_compare( self::$active_version, WC_Subscriptions_Core_Plugin::instance()->get_library_version(), '<' );

		// Show warning that upgrades are no longer supported.
		if ( '0' !== self::$active_version && version_compare( self::$active_version, self::$minimum_supported_version, '<=' ) ) {
			add_action(
				'admin_notices',
				function () {
					self::show_unsupported_upgrade_path_notice();
				}
			);
			return;
		}

		if ( @current_user_can( 'activate_plugins' ) && $version_out_of_date ) { // phpcs:ignore WordPress.PHP.NoSilencedErrors
			// Run upgrades as soon as admin hits site
			add_action( 'wp_loaded', [ __CLASS__, 'upgrade' ], 11 );
		}

		add_action( 'init', [ __CLASS__, 'initialise_background_updaters' ], 0 );
	}

	/**
	 * Checks which upgrades need to run and calls the necessary functions for that upgrade.
	 *
	 * @since 1.0.0 - Migrated from WooCommerce Subscriptions v1.2
	 */
	public static function upgrade() {
		global $wpdb;

		update_option( WC_Subscriptions_Admin::$option_prefix . '_previous_version', self::$active_version );

		/**
		 * before upgrade hook.
		 */
		do_action( 'woocommerce_subscriptions_before_upgrade', WC_Subscriptions_Core_Plugin::instance()->get_library_version(), self::$active_version );

		if ( '0' === self::$active_version ) {
			// Update the hold stock notification to be one week (if it's still at the default 60 minutes) to prevent cancelling subscriptions using manual renewals and payment methods that can take more than 1 hour (i.e. PayPal eCheck)
			$hold_stock_duration = get_option( 'woocommerce_hold_stock_minutes' );

			if ( 60 == $hold_stock_duration ) {
				update_option( 'woocommerce_hold_stock_minutes', 60 * 24 * 7 );
			}

			// Allow products & subscriptions to be purchased in the same transaction
			update_option( 'woocommerce_subscriptions_multiple_purchase', 'yes' );

			// Keep track of site url to prevent duplicate payments from staging sites, first added in 1.3.8 & updated with 1.4.2 to work with WP Engine staging sites
			WCS_Staging::set_duplicate_site_url_lock();

			// Upon installing for the first time, enable or disable PayPal Standard for Subscriptions.
			WCS_PayPal::set_enabled_for_subscriptions_default();
		}

		// Delete old subscription period string ranges transients.
		if ( version_compare( self::$active_version, '3.0.10', '<' ) ) {
			$deleted_rows = $wpdb->query( "DELETE FROM {$wpdb->options} WHERE `option_name` LIKE '_transient_timeout_wcs-sub-ranges-%' OR `option_name` LIKE '_transient_wcs-sub-ranges-%'" );
		}

		// When upgrading from version 3.0.12, delete `switch_totals_calc_base_length` meta from product post meta as it was saved rather than set in memory.
		if ( version_compare( self::$active_version, '3.0.12', '==' ) ) {
			$deleted_rows = $wpdb->query( "DELETE FROM {$wpdb->postmeta} WHERE `meta_key` = '_switch_totals_calc_base_length'" );
		}

		if ( version_compare( self::$active_version, '3.1.0', '<' ) ) {
			// Upon upgrading to 3.1.0 from a version after 3.0.10, repair subscriptions _subtracted_base_location_tax line item meta.
			if ( version_compare( self::$active_version, '3.0.10', '>=' ) ) {
				self::$background_updaters['3.1']['subtracted_base_tax_repair']->schedule_repair();
			}

			WCS_Upgrade_3_1_0::migrate_subscription_webhooks_using_api_version_3();
		}

		if ( version_compare( self::$active_version, '6.8.0', '<' ) ) {
			// Upon upgrading to 6.8.0 delete the 'wcs_cleanup_big_logs' WP Cron job that is no longer used.
			wp_unschedule_hook( 'wcs_cleanup_big_logs' );
		}

		if ( version_compare( self::$active_version, '8.0.0', '<' ) ) {
			// As of Subscriptions 7.2.0 (Core 8.0.0), admin notices are stored one transient per-user.
			delete_transient( '_wcs_admin_notices' );
		}

		self::upgrade_complete();
	}

	/**
	 * When an upgrade is complete, set the active version and fire a hook.
	 *
	 * @since 1.0.0 - Migrated from WooCommerce Subscriptions v1.2
	 */
	public static function upgrade_complete() {
		update_option( WC_Subscriptions_Admin::$option_prefix . '_active_version', WC_Subscriptions_Core_Plugin::instance()->get_library_version() );
		do_action( 'woocommerce_subscriptions_upgraded', WC_Subscriptions_Core_Plugin::instance()->get_library_version(), self::$active_version );
	}

	/**
	 * Load and initialise the background updaters.
	 *
	 * @since 1.0.0 - Migrated from WooCommerce Subscriptions v2.4.0
	 */
	public static function initialise_background_updaters() {
		$logger = new WC_logger();
		self::$background_updaters['3.1']['subtracted_base_tax_repair'] = new WCS_Repair_Subtracted_Base_Tax_Line_Item_Meta( $logger );

		// Init the updaters
		foreach ( self::$background_updaters as $version => $updaters ) {
			foreach ( $updaters as $updater ) {
				$updater->init();
			}
		}
	}

	/**
	 * Repair a single item's subtracted base tax meta.
	 *
	 * @since 3.1.0
	 * @param int $item_id The ID of the item which needs repairing.
	 */
	public static function repair_subtracted_base_taxes( $item_id ) {
		if ( ! isset( self::$background_updaters['3.1']['subtracted_base_tax_repair'] ) ) {
			return;
		}

		self::$background_updaters['3.1']['subtracted_base_tax_repair']->repair_item( $item_id );
	}

	/**
	 * Show an admin notice if the store is upgrading from a Subscriptions version that's no longer supported.
	 *
	 * @since 7.7.0
	 */
	private static function show_unsupported_upgrade_path_notice() {
		echo '<div class="notice notice-error"><p>' .
			esc_html(
				__(
					'A database upgrade is required to use Subscriptions. Upgrades from the previously installed version is no longer supported. You will need to install an older version of WooCommerce Subscriptions or WooCommerce Payments to proceed with the upgrade before you can use a newer version.',
					'woocommerce-subscriptions'
				)
			) .
		'</p></div>';
	}

	/* Deprecated Functions */

	/**
	 * Handles the WC 3.5.0 upgrade routine that moves customer IDs from post metadata to the 'post_author' column.
	 *
	 * @since 1.0.0 - Migrated from WooCommerce Subscriptions v2.4.0
	 * @deprecated 1.0.0 - Migrated from WooCommerce Subscriptions v2.5.0
	 */
	public static function maybe_update_subscription_post_author() {
		wcs_deprecated_function( __METHOD__, '2.5.0' );

		if ( version_compare( WC()->version, '3.5.0', '<' ) ) {
			return;
		}

		// If WC hasn't run the update routine yet we can hook into theirs to update subscriptions, otherwise we'll need to schedule our own update.
		if ( version_compare( get_option( 'woocommerce_db_version' ), '3.5.0', '<' ) ) {
			self::$background_updaters['2.4']['subscription_post_author']->hook_into_wc_350_update();
		} elseif ( version_compare( self::$active_version, '2.4.0', '<' ) ) {
			self::$background_updaters['2.4']['subscription_post_author']->schedule_repair();
		}
	}

	/**
	 * Used to check if a user ID is greater than the last user upgraded to version 1.4.
	 *
	 * Needs to be a separate function so that it can use a static variable (and therefore avoid calling get_option() thousands
	 * of times when iterating over thousands of users).
	 *
	 * @since 1.0.0 - Migrated from WooCommerce Subscriptions v1.4
	 */
	public static function is_user_upgraded_to_1_4( $user_id ) {
		_deprecated_function( __METHOD__, '2.0', 'WCS_Upgrade_1_4::is_user_upgraded( $user_id )' );
		return WCS_Upgrade_1_4::is_user_upgraded( $user_id );
	}

	/**
	 * Display an admin notice if the database version is greater than the active version of the plugin by at least one minor release (eg 1.1 and 1.0).
	 *
	 * @since 2.3.0
	 * @deprecated 1.2.0
	 */
	public static function maybe_add_downgrade_notice() {
		wcs_deprecated_function( __METHOD__, '1.2.0' );

		// If there's no downgrade, exit early. self::$active_version is a bit of a misnomer here but in an upgrade context it refers to the database version of the plugin.
		if ( ! version_compare( wcs_get_minor_version_string( self::$active_version ), wcs_get_minor_version_string( WC_Subscriptions_Core_Plugin::instance()->get_library_version() ), '>' ) ) {
			return;
		}

		$admin_notice = new WCS_Admin_Notice( 'error' );
		$admin_notice->set_simple_content(
			sprintf(
				// translators: 1-2: opening/closing <strong> tags, 3: active version of Subscriptions, 4: current version of Subscriptions, 5-6: opening/closing tags linked to ticket form, 7-8: opening/closing tags linked to documentation.
				esc_html__( '%1$sWarning!%2$s It appears that you have downgraded %1$sWooCommerce Subscriptions%2$s from %3$s to %4$s. Downgrading the plugin in this way may cause issues. Please update to %3$s or higher, or %5$sopen a new support ticket%6$s for further assistance. %7$sLearn more &raquo;%8$s', 'woocommerce-subscriptions' ),
				'<strong>',
				'</strong>',
				'<code>' . self::$active_version . '</code>',
				'<code>' . WC_Subscriptions_Core_Plugin::instance()->get_library_version() . '</code>',
				'<a href="https://woocommerce.com/my-account/marketplace-ticket-form/" target="_blank">',
				'</a>',
				'<a href="https://woocommerce.com/document/subscriptions/upgrade-instructions/#section-12" target="_blank">',
				'</a>'
			)
		);

		$admin_notice->display();
	}

	/**
	 * Deprecated functions.
	 */

	/**
	 * Set limits on the number of items to upgrade at any one time based on the size of the site.
	 *
	 * The size of subscription at the time the upgrade is started is used to determine the batch size.
	 *
	 * @deprecated subscriptions-core 7.7.0 - Upgrade limits were used when the upgrade process used AJAX.
	 *
	 * @since 1.0.0 - Migrated from WooCommerce Subscriptions v2.0
	 */
	protected static function set_upgrade_limits() {
		wcs_deprecated_function( __METHOD__, 'subscriptions-core 7.7.0' );

		$total_initial_subscription_count = self::get_total_subscription_count( true );

		if ( $total_initial_subscription_count > 5000 ) {
			$base_upgrade_limit = 20;
		} elseif ( $total_initial_subscription_count > 1500 ) {
			$base_upgrade_limit = 30;
		} else {
			$base_upgrade_limit = 50;
		}

		self::$upgrade_limit_hooks         = apply_filters( 'woocommerce_subscriptions_hooks_to_upgrade', $base_upgrade_limit * 5 );
		self::$upgrade_limit_subscriptions = apply_filters( 'woocommerce_subscriptions_to_upgrade', $base_upgrade_limit );
	}

	/**
	 * Try to block WP-Cron until upgrading finishes. spawn_cron() will only let us steal the lock for 10 minutes into the future, so
	 * we can actually only block it for 9 minutes confidently. But as long as the upgrade process continues, the lock will remain.
	 *
	 * @deprecated subscriptions-core 7.7.0 Cron lock was required for more intensive upgrades prior to v3.0
	 *
	 * @since 1.0.0 - Migrated from WooCommerce Subscriptions v2.0
	 */
	protected static function set_cron_lock() {
		wcs_deprecated_function( __METHOD__, 'subscriptions-core 7.7.0' );
		delete_transient( 'doing_cron' );
		set_transient( 'doing_cron', sprintf( '%.22F', 9 * MINUTE_IN_SECONDS + microtime( true ) ), 0 );
	}

	/**
	 * Redirect to the Subscriptions major version Welcome/About page for major version updates.
	 *
	 * @deprecated subscriptions-core 7.7.0
	 *
	 * @since 1.0.0 - Migrated from WooCommerce Subscriptions v2.1
	 */
	public static function maybe_redirect_after_upgrade_complete( $current_version, $previously_active_version ) {
		wcs_deprecated_function( __METHOD__, 'subscriptions-core 7.7.0' );

		if ( version_compare( $previously_active_version, '2.1.0', '<' ) && version_compare( $current_version, '2.1.0', '>=' ) && version_compare( $current_version, '2.2.0', '<' ) ) {
			wp_safe_redirect( self::$about_page_url );
			exit();
		}
	}

	/**
	 * Add support for quantities for subscriptions.
	 * Update all current subscription wp_cron tasks to the new action-scheduler system.
	 *
	 * @deprecated subscriptions-core 7.7.0
	 *
	 * @since 1.0.0 - Migrated from WooCommerce Subscriptions v2.0
	 */
	private static function ajax_upgrade_handler() {
		wcs_deprecated_function( __METHOD__, 'subscriptions-core 7.7.0' );

		$_GET['wcs_upgrade_step'] = ( ! isset( $_GET['wcs_upgrade_step'] ) ) ? 0 : $_GET['wcs_upgrade_step'];

		switch ( (int) $_GET['wcs_upgrade_step'] ) {
			case 1:
				self::display_database_upgrade_helper();
				break;
			case 3: // keep a way to circumvent the upgrade routine just in case
				self::upgrade_complete();
				wp_safe_redirect( self::$about_page_url );
				break;
			case 0:
			default:
				wp_safe_redirect( admin_url( 'admin.php?wcs_upgrade_step=1' ) );
				break;
		}

		exit();
	}

	/**
	 * Move scheduled subscription hooks out of wp-cron and into the new Action Scheduler.
	 *
	 * Also set all existing subscriptions to "sold individually" to maintain previous behavior
	 * for existing subscription products before the subscription quantities feature was enabled..
	 *
	 * @deprecated subscriptions-core 7.7.0 - This function is only used when upgrading from versions less than v3.0.
	 *
	 * @since 1.0.0 - Migrated from WooCommerce Subscriptions v1.5
	 */
	public static function ajax_upgrade() {
		global $wpdb;
		wcs_deprecated_function( __METHOD__, 'subscription-core 7.7.0' );

		check_admin_referer( 'wcs_upgrade_process', 'nonce' );

		self::set_upgrade_limits();

		WCS_Upgrade_Logger::add( sprintf( 'Starting upgrade step: %s', $_POST['upgrade_step'] ) );

		if ( ini_get( 'max_execution_time' ) < 600 ) {
			@set_time_limit( 600 );
		}

		@ini_set( 'memory_limit', apply_filters( 'admin_memory_limit', WP_MAX_MEMORY_LIMIT ) );

		update_option( 'wc_subscriptions_is_upgrading', gmdate( 'U' ) + 60 * 2 );

		switch ( $_POST['upgrade_step'] ) {

			case 'really_old_version':
				$upgraded_versions = self::upgrade_really_old_versions();
				$results = array(
					// translators: placeholder is a list of version numbers (e.g. "1.3 & 1.4 & 1.5")
					'message' => sprintf( __( 'Database updated to version %s', 'woocommerce-subscriptions' ), $upgraded_versions ),
				);
				break;

			case 'products':
				$upgraded_product_count = WCS_Upgrade_1_5::upgrade_products();
				$results = array(
					// translators: placeholder is number of upgraded subscriptions
					'message' => sprintf( _x( 'Marked %s subscription products as "sold individually".', 'used in the subscriptions upgrader', 'woocommerce-subscriptions' ), $upgraded_product_count ),
				);
				break;

			case 'hooks':
				$upgraded_hook_count = WCS_Upgrade_1_5::upgrade_hooks( self::$upgrade_limit_hooks );
				$results = array(
					'upgraded_count' => $upgraded_hook_count,
					// translators: 1$: number of action scheduler hooks upgraded, 2$: "{execution_time}", will be replaced on front end with actual time
					'message'        => sprintf( __( 'Migrated %1$s subscription related hooks to the new scheduler (in %2$s seconds).', 'woocommerce-subscriptions' ), $upgraded_hook_count, '{execution_time}' ),
				);
				break;

			case 'subscriptions':
				try {

					$upgraded_subscriptions = WCS_Upgrade_2_0::upgrade_subscriptions( self::$upgrade_limit_subscriptions );

					$results = array(
						'upgraded_count' => $upgraded_subscriptions,
						// translators: 1$: number of subscriptions upgraded, 2$: "{execution_time}", will be replaced on front end with actual time it took
						'message'        => sprintf( __( 'Migrated %1$s subscriptions to the new structure (in %2$s seconds).', 'woocommerce-subscriptions' ), $upgraded_subscriptions, '{execution_time}' ),
						'status'         => 'success',
						// translators: placeholder is "{time_left}", will be replaced on front end with actual time
						'time_message'   => sprintf( _x( 'Estimated time left (minutes:seconds): %s', 'Message that gets sent to front end.', 'woocommerce-subscriptions' ), '{time_left}' ),
					);

				} catch ( Exception $e ) {

					WCS_Upgrade_Logger::add( sprintf( 'Error on upgrade step: %s. Error: %s', $_POST['upgrade_step'], $e->getMessage() ) );

					$results = array(
						'upgraded_count' => 0,
						// translators: 1$: error message, 2$: opening link tag, 3$: closing link tag, 4$: break tag
						'message'        => sprintf( __( 'Unable to upgrade subscriptions.%4$sError: %1$s%4$sPlease refresh the page and try again. If problem persists, %2$scontact support%3$s.', 'woocommerce-subscriptions' ), '<code>' . $e->getMessage() . '</code>', '<a href="' . esc_url( 'https://woocommerce.com/my-account/create-a-ticket/' ) . '">', '</a>', '<br />' ),
						'status'         => 'error',
					);
				}

				break;

			case 'subscription_dates_repair':
				$subscription_ids_to_repair = WCS_Repair_2_0_2::get_subscriptions_to_repair( self::$upgrade_limit_subscriptions );

				try {

					$subscription_counts = WCS_Repair_2_0_2::maybe_repair_subscriptions( $subscription_ids_to_repair );

					// translators: placeholder is the number of subscriptions repaired
					$repair_incorrect = sprintf( _x( 'Repaired %d subscriptions with incorrect dates, line tax data or missing customer notes.', 'Repair message that gets sent to front end.', 'woocommerce-subscriptions' ), $subscription_counts['repaired_count'] );

					$repair_not_needed = '';

					if ( $subscription_counts['unrepaired_count'] > 0 ) {
						// translators: placeholder is number of subscriptions that were checked and did not need repairs. There's a space at the beginning!
						$repair_not_needed = sprintf( _nx( ' %d other subscription was checked and did not need any repairs.', '%d other subscriptions were checked and did not need any repairs.', $subscription_counts['unrepaired_count'], 'Repair message that gets sent to front end.', 'woocommerce-subscriptions' ), $subscription_counts['unrepaired_count'] );
					}

					// translators: placeholder is "{execution_time}", which will be replaced on front end with actual time
					$repair_time = sprintf( _x( '(in %s seconds)', 'Repair message that gets sent to front end.', 'woocommerce-subscriptions' ), '{execution_time}' );

					// translators: $1: "Repaired x subs with incorrect dates...", $2: "X others were checked and no repair needed", $3: "(in X seconds)". Ordering for RTL languages.
					$repair_message = sprintf( _x( '%1$s%2$s %3$s', 'The assembled repair message that gets sent to front end.', 'woocommerce-subscriptions' ), $repair_incorrect, $repair_not_needed, $repair_time );

					$results = array(
						'repaired_count'   => $subscription_counts['repaired_count'],
						'unrepaired_count' => $subscription_counts['unrepaired_count'],
						'message'          => $repair_message,
						'status'           => 'success',
						// translators: placeholder is "{time_left}", will be replaced on front end with actual time
						'time_message'     => sprintf( _x( 'Estimated time left (minutes:seconds): %s', 'Message that gets sent to front end.', 'woocommerce-subscriptions' ), '{time_left}' ),
					);

				} catch ( Exception $e ) {

					WCS_Upgrade_Logger::add( sprintf( 'Error on upgrade step: %s. Error: %s', $_POST['upgrade_step'], $e->getMessage() ) );

					$results = array(
						'repaired_count'   => 0,
						'unrepaired_count' => 0,
						// translators: 1$: error message, 2$: opening link tag, 3$: closing link tag, 4$: break tag
						'message'          => sprintf( _x( 'Unable to repair subscriptions.%4$sError: %1$s%4$sPlease refresh the page and try again. If problem persists, %2$scontact support%3$s.', 'Error message that gets sent to front end when upgrading Subscriptions', 'woocommerce-subscriptions' ), '<code>' . $e->getMessage() . '</code>', '<a href="' . esc_url( 'https://woocommerce.com/my-account/create-a-ticket/' ) . '">', '</a>', '<br />' ),
						'status'           => 'error',
					);
				}

				break;
		}

		if ( 'subscriptions' == $_POST['upgrade_step'] && 0 === self::get_total_subscription_count_query() ) {

			self::upgrade_complete();

		} elseif ( 'subscription_dates_repair' == $_POST['upgrade_step'] ) {

			$subscriptions_to_repair = WCS_Repair_2_0_2::get_subscriptions_to_repair( self::$upgrade_limit_subscriptions );

			if ( empty( $subscriptions_to_repair ) ) {
				self::upgrade_complete();
			}
		}

		WCS_Upgrade_Logger::add( sprintf( 'Completed upgrade step: %s', $_POST['upgrade_step'] ) );

		header( 'Content-Type: application/json; charset=utf-8' );
		echo wcs_json_encode( $results );
		exit();
	}

	/**
	 * Handle upgrades for really old versions.
	 *
	 * @deprecated subscriptions-core 7.7.0
	 * @since 1.0.0 - Migrated from WooCommerce Subscriptions v2.0
	 */
	private static function upgrade_really_old_versions() {
		wcs_deprecated_function( __METHOD__, 'subscriptions-core 7.7.0' );

		if ( '0' != self::$active_version && version_compare( self::$active_version, '1.2', '<' ) ) {
			WCS_Upgrade_1_2::init();
			self::generate_renewal_orders();
			update_option( WC_Subscriptions_Admin::$option_prefix . '_active_version', '1.2' );
			$upgraded_versions = '1.2, ';
		}

		// Add Variable Subscription product type term
		if ( '0' != self::$active_version && version_compare( self::$active_version, '1.3', '<' ) ) {
			WCS_Upgrade_1_3::init();
			update_option( WC_Subscriptions_Admin::$option_prefix . '_active_version', '1.3' );
			$upgraded_versions .= '1.3 & ';
		}

		// Moving subscription meta out of user meta and into item meta
		if ( '0' != self::$active_version && version_compare( self::$active_version, '1.4', '<' ) ) {
			WCS_Upgrade_1_4::init();
			update_option( WC_Subscriptions_Admin::$option_prefix . '_active_version', '1.4' );
			$upgraded_versions .= '1.4.';
		}

		return $upgraded_versions;
	}

	/**
	 * Version 1.2 introduced child renewal orders to keep a record of each completed subscription
	 * payment. Before 1.2, these orders did not exist, so this function creates them.
	 *
	 * @deprecated subscriptions-core 7.7.0
	 *
	 * @since 1.0.0 - Migrated from WooCommerce Subscriptions v1.2
	 */
	private static function generate_renewal_orders() {
		global $wpdb;
		wcs_deprecated_function( __METHOD__, 'subscriptions-core 7.7.0' );

		$woocommerce = WC();

		$subscriptions_grouped_by_user = WC_Subscriptions_Manager::get_all_users_subscriptions();

		// Don't send any order emails
		$email_actions = array( 'woocommerce_low_stock', 'woocommerce_no_stock', 'woocommerce_product_on_backorder', 'woocommerce_order_status_pending_to_processing', 'woocommerce_order_status_pending_to_completed', 'woocommerce_order_status_pending_to_on-hold', 'woocommerce_order_status_failed_to_processing', 'woocommerce_order_status_failed_to_completed', 'woocommerce_order_status_pending_to_processing', 'woocommerce_order_status_pending_to_on-hold', 'woocommerce_order_status_completed', 'woocommerce_new_customer_note' );
		foreach ( $email_actions as $action ) {
			remove_action( $action, array( &$woocommerce, 'send_transactional_email' ) );
		}

		remove_action( 'woocommerce_payment_complete', 'WC_Subscriptions_Renewal_Order::maybe_record_renewal_order_payment', 10, 1 );

		foreach ( $subscriptions_grouped_by_user as $user_id => $users_subscriptions ) {
			foreach ( $users_subscriptions as $subscription_key => $subscription ) {
				$order_post = get_post( $subscription['order_id'] );

				if ( isset( $subscription['completed_payments'] ) && count( $subscription['completed_payments'] ) > 0 && null != $order_post ) {
					foreach ( $subscription['completed_payments'] as $payment_date ) {

						$existing_renewal_order = $wpdb->get_var( $wpdb->prepare( "SELECT ID FROM {$wpdb->posts} WHERE post_date_gmt = %s AND post_parent = %d AND post_type = 'shop_order'", $payment_date, $subscription['order_id'] ) );

						// If a renewal order exists on this date, don't generate another one
						if ( null !== $existing_renewal_order ) {
							continue;
						}

						$renewal_order_id = WC_Subscriptions_Renewal_Order::generate_renewal_order( $subscription['order_id'], $subscription['product_id'], array( 'new_order_role' => 'child' ) );

						if ( $renewal_order_id ) {

							// Mark the order as paid
							$renewal_order = wc_get_order( $renewal_order_id );

							$renewal_order->payment_complete();

							// Avoid creating 100s "processing" orders
							$renewal_order->update_status( 'completed' );

							// Set correct dates on the order
							$renewal_order = array(
								'ID'            => $renewal_order_id,
								'post_date'     => $payment_date,
								'post_date_gmt' => $payment_date,
							);
							wp_update_post( $renewal_order );

							update_post_meta( $renewal_order_id, '_paid_date', $payment_date );
							update_post_meta( $renewal_order_id, '_completed_date', $payment_date );

						}
					}
				}
			}
		}
	}

	/**
	 * Let the site administrator know we are upgrading the database and provide a confirmation is complete.
	 *
	 * This is important to avoid the possibility of a database not upgrading correctly, but the site continuing
	 * to function without any remedy.
	 *
	 * @since 1.0.0 - Migrated from WooCommerce Subscriptions v1.2
	 */
	public static function display_database_upgrade_helper() {
		wcs_deprecated_function( __METHOD__, 'subscriptions-core 7.7.0' );

		wp_register_style( 'wcs-upgrade', WC_Subscriptions_Core_Plugin::instance()->get_subscriptions_core_directory_url( 'assets/css/wcs-upgrade.css' ) );
		wp_register_script( 'wcs-upgrade', WC_Subscriptions_Core_Plugin::instance()->get_subscriptions_core_directory_url( 'assets/js/wcs-upgrade.js' ), 'jquery' );

		$subscription_count = 0;

		$script_data = array(
			'really_old_version' => 'false',
			'upgrade_to_1_5'     => false,
			'upgrade_to_2_0'     => false,
			'repair_2_0'         => false,
			'hooks_per_request'  => self::$upgrade_limit_hooks,
			'ajax_url'           => admin_url( 'admin-ajax.php' ),
			'upgrade_nonce'      => wp_create_nonce( 'wcs_upgrade_process' ),
			'subscription_count' => $subscription_count,
		);

		wp_localize_script( 'wcs-upgrade', 'wcs_update_script_data', $script_data );

		// Can't get subscription count with database structure < 1.4
		if ( 'false' == $script_data['really_old_version'] ) {

			// The base duration is 50 subscriptions per minute (i.e. approximately 60 seconds per batch of 50)
			$estimated_duration = ceil( $subscription_count / 50 );

			// Large sites take about 2-3x as long (i.e. approximately 80 seconds per batch of 35)
			if ( $subscription_count > 5000 ) {
				$estimated_duration *= 3;
			}

			// And really large sites take around 5-6x as long (i.e. approximately 100 seconds per batch of 25)
			if ( $subscription_count > 10000 ) {
				$estimated_duration *= 2;
			}
		}

		$about_page_url = self::$about_page_url;

		@header( 'Content-Type: ' . get_option( 'html_type' ) . '; charset=' . get_option( 'blog_charset' ) );
		include_once( dirname( __FILE__ ) . '/templates/wcs-upgrade.php' );
		WCS_Upgrade_Logger::add( 'Loaded database upgrade helper' );
	}

	/**
	 * Let the site administrator know we are upgrading the database already to prevent duplicate processes running the
	 * upgrade. Also provides some useful diagnostic information, like how long before the site admin can restart the
	 * upgrade process, and how many subscriptions per request can typically be updated given the amount of memory
	 * allocated to PHP.
	 *
	 * @deprecated subscriptions-core 7.7.0 - We know longer use a notice or pages to display upgrade progress.
	 *
	 * @since 1.0.0 - Migrated from WooCommerce Subscriptions v1.4
	 */
	public static function upgrade_in_progress_notice() {
		wcs_deprecated_function( __METHOD__, 'subscriptions-core 7.7.0' );

		include_once( dirname( __FILE__ ) . '/templates/wcs-upgrade-in-progress.php' );
		WCS_Upgrade_Logger::add( 'Loaded database upgrade in progress notice...' );
	}

	/**
	 * Display the Subscriptions welcome/about page after successfully upgrading to the latest version.
	 *
	 * @since 1.0.0 - Migrated from WooCommerce Subscriptions v1.4
	 */
	public static function updated_welcome_page() {
		wcs_deprecated_function( __METHOD__, 'subscriptions-core 7.7.0' );

		$about_page = add_dashboard_page( __( 'Welcome to WooCommerce Subscriptions 2.1', 'woocommerce-subscriptions' ), __( 'About WooCommerce Subscriptions', 'woocommerce-subscriptions' ), 'manage_options', 'wcs-about', __CLASS__ . '::about_screen' );
		add_action( 'admin_print_styles-' . $about_page, __CLASS__ . '::admin_css' );
		add_action( 'admin_head', __CLASS__ . '::admin_head' );
	}

	/**
	 * admin_css function.
	 *
	 * @return void
	 */
	public static function admin_css() {
		wcs_deprecated_function( __METHOD__, 'subscriptions-core 7.7.0' );

		wp_enqueue_style( 'woocommerce-subscriptions-about', WC_Subscriptions_Core_Plugin::instance()->get_subscriptions_core_directory_url( 'assets/css/about.css' ), array(), self::$active_version );
	}

	/**
	 * Add styles just for this page, and remove dashboard page links.
	 *
	 * @return void
	 */
	public static function admin_head() {
		wcs_deprecated_function( __METHOD__, 'subscriptions-core 7.7.0' );
		remove_submenu_page( 'index.php', 'wcs-about' );
	}

	/**
	 * Output the about screen.
	 */
	public static function about_screen() {
		wcs_deprecated_function( __METHOD__, 'subscriptions-core 7.7.0' );

		$active_version = self::$active_version;
		$settings_page  = admin_url( 'admin.php?page=wc-settings&tab=subscriptions' );

		include_once( dirname( __FILE__ ) . '/templates/wcs-about.php' );
	}

	/**
	 * In v2.0 and newer, it's possible to simply use wp_count_posts( 'shop_subscription' ) to count subscriptions,
	 * but not in v1.5, because a subscription data is still stored in order item meta. This function queries the
	 * v1.5 database structure.
	 *
	 * @since 1.0.0 - Migrated from WooCommerce Subscriptions v2.0
	 */
	private static function get_total_subscription_count( $initial = false ) {
		wcs_deprecated_function( __METHOD__, 'subscriptions-core 7.7.0' );

		if ( $initial ) {

			$subscription_count = get_option( 'wcs_upgrade_initial_total_subscription_count', false );

			if ( false === $subscription_count ) {
				$subscription_count = self::get_total_subscription_count();
				update_option( 'wcs_upgrade_initial_total_subscription_count', $subscription_count );
			}
		} else {

			if ( null === self::$old_subscription_count ) {
				self::$old_subscription_count = self::get_total_subscription_count_query();
			}

			$subscription_count = self::$old_subscription_count;
		}

		return $subscription_count;
	}

	/**
	 * Returns the number of subscriptions left in the 1.5 structure
	 * @return integer number of 1.5 subscriptions left
	 */
	private static function get_total_subscription_count_query() {
		global $wpdb;
		wcs_deprecated_function( __METHOD__, 'subscriptions-core 7.7.0' );

		$query = self::get_subscription_query();

		$wpdb->get_results( $query );

		return $wpdb->num_rows;
	}


	/**
	 * Single source of truth for the query
	 * @param  integer $limit the number of subscriptions to get
	 * @return string        SQL query of what we need
	 */
	public static function get_subscription_query( $batch_size = null ) {
		global $wpdb;
		wcs_deprecated_function( __METHOD__, 'subscriptions-core 7.7.0' );

		if ( null === $batch_size ) {
			$select = 'SELECT DISTINCT items.order_item_id';
			$limit = '';
		} else {
			$select = 'SELECT meta.*, items.*';
			$limit = sprintf( ' LIMIT 0, %d', $batch_size );
		}

		$query = sprintf( "%s FROM `{$wpdb->prefix}woocommerce_order_itemmeta` AS meta
			LEFT JOIN `{$wpdb->prefix}woocommerce_order_items` AS items USING (order_item_id)
			LEFT JOIN (
				SELECT a.order_item_id FROM `{$wpdb->prefix}woocommerce_order_itemmeta` AS a
				LEFT JOIN (
					SELECT `{$wpdb->prefix}woocommerce_order_itemmeta`.order_item_id FROM `{$wpdb->prefix}woocommerce_order_itemmeta`
					WHERE `{$wpdb->prefix}woocommerce_order_itemmeta`.meta_key = '_subscription_status'
				) AS s
				USING (order_item_id)
				WHERE 1=1
				AND a.order_item_id = s.order_item_id
				AND a.meta_key = '_subscription_start_date'
				ORDER BY CASE WHEN CAST(a.meta_value AS DATETIME) IS NULL THEN 1 ELSE 0 END, CAST(a.meta_value AS DATETIME) ASC
				%s
			) AS a3 USING (order_item_id)
			WHERE meta.meta_key REGEXP '_subscription_(.*)|_product_id|_variation_id'
			AND meta.order_item_id = a3.order_item_id
			AND items.order_item_id IS NOT NULL", $select, $limit );

		return $query;
	}

	/**
	 * Check if the database has some data that was migrated from 1.5 to 2.0
	 *
	 * @return bool True if it detects some v1.5 migrated data, otherwise false
	 */
	protected static function migrated_subscription_count() {
		global $wpdb;
		wcs_deprecated_function( __METHOD__, 'subscriptions-core 7.7.0' );

		$migrated_subscription_count = $wpdb->get_var(
			"SELECT COUNT(DISTINCT `post_id`) FROM $wpdb->postmeta
			 WHERE `meta_key` LIKE '%wcs\_migrated%'"
		);

		return $migrated_subscription_count;
	}


	/**
	 * While the upgrade is in progress, we need to block IPN messages to avoid renewals failing to process correctly.
	 *
	 * PayPal will retry the IPNs for up to a day or two until it has a successful request, so the store will continue to receive
	 * IPN messages during the upgrade process, then once it is completed, the IPN will be successfully processed.
	 *
	 * The method returns a 409 Conflict HTTP response code to indicate that the IPN is conflicting with the upgrader.
	 *
	 * @deprecated subscriptions-core 7.7.0 - We no lock down the store during subscription upgrades so we don't need to block IPNs.
	 *
	 * @since 1.0.0 - Migrated from WooCommerce Subscriptions v2.0
	 */
	public static function maybe_block_paypal_ipn() {
		wcs_deprecated_function( __METHOD__, 'subscriptions-core 7.7.0' );

		if ( false !== get_option( 'wc_subscriptions_is_upgrading', false ) ) {
			WCS_Upgrade_Logger::add( '*** PayPal IPN Request blocked: ' . print_r( wp_unslash( $_POST ), true ) ); // No CSRF needed as it's from outside
			wp_die( 'PayPal IPN Request Failure', 'PayPal IPN', array( 'response' => 409 ) );
		}
	}

	/**
	 * Run the end of prepaid term repair script.
	 * @deprecated subscriptions-core 7.7.0
	 * @since 1.0.0 - Migrated from WooCommerce Subscriptions v2.2.7
	 */
	public static function repair_end_of_prepaid_term_actions() {
		wcs_deprecated_function( __METHOD__, 'subscriptions-core 7.7.0' );
		WCS_Upgrade_2_2_7::repair_pending_cancelled_subscriptions();
	}

	/**
	 * Repair subscriptions with missing contains_synced_subscription post meta.
	 * @deprecated subscriptions-core 7.7.0
	 * @since 1.0.0 - Migrated from WooCommerce Subscriptions v2.2.9
	 */
	public static function repair_subscription_contains_sync_meta() {
		wcs_deprecated_function( __METHOD__, 'subscriptions-core 7.7.0' );
		WCS_Upgrade_2_2_9::repair_subscriptions_containing_synced_variations();
	}

	/**
	 * When updating WC to a version after 3.0 from a version prior to 3.0, schedule the repair script to add address indexes.
	 *
	 * @deprecated subscriptions-core 7.7.0 - Upgrading from before WC 3.0 is not supported.
	 *
	 * @since 1.0.0 - Migrated from WooCommerce Subscriptions v2.3.0
	 */
	public static function maybe_add_subscription_address_indexes() {
		wcs_deprecated_function( __METHOD__, 'subscriptions-core 7.7.0' );

		$woocommerce_active_version   = WC()->version;
		$woocommerce_database_version = get_option( 'woocommerce_version' );

		if ( $woocommerce_active_version !== $woocommerce_database_version && version_compare( $woocommerce_active_version, '3.0', '>=' ) && version_compare( $woocommerce_database_version, '3.0', '<' ) ) {
			$logger             = new WC_logger();
			$background_updater = new WCS_Repair_Subscription_Address_Indexes( $logger );
			$background_updater->init();
			$background_updater->schedule_repair();
		}
	}

	/**
	 * Display an admin notice if the site had customer subscription and/or subscription renewal order cached data stored in the options table
	 * and was using an external object cache at the time of updating to 2.3.3.
	 *
	 * Under these circumstances, there is a chance that the persistent caches introduced in 2.3 could contain invalid data.
	 *
	 * @see https://github.com/Prospress/woocommerce-subscriptions/issues/2822 for more details.
	 * @since 1.0.0 - Migrated from WooCommerce Subscriptions v2.3.3
	 * @deprecated subscriptions-core 7.7.0
	 */
	public static function maybe_display_external_object_cache_warning() {
		wcs_deprecated_function( __METHOD__, 'subscriptions-core 7.7.0' );

		$option_name = 'wcs_display_2_3_3_warning';
		$nonce       = '_wcsnonce';
		$action      = 'wcs_external_cache_warning';

		// First, check if the notice is being dismissed.
		if ( isset( $_GET[ $action ], $_GET[ $nonce ] ) && wp_verify_nonce( $_GET[ $nonce ], $action ) ) {
			delete_option( $option_name );
			return;
		}

		if ( 'yes' !== get_option( $option_name ) ) {
			return;
		}

		$admin_notice = new WCS_Admin_Notice( 'error' );
		$admin_notice->set_simple_content(
			sprintf(
				// translators: 1-2: opening/closing <strong> tags, 3-4: opening/closing tags linked to ticket form.
				esc_html__( '%1$sWarning!%2$s We discovered an issue in %1$sWooCommerce Subscriptions 2.3.0 - 2.3.2%2$s that may cause your subscription renewal order and customer subscription caches to contain invalid data. For information about how to update the cached data, please %3$sopen a new support ticket%4$s.', 'woocommerce-subscriptions' ),
				'<strong>', '</strong>',
				'<a href="https://woocommerce.com/my-account/marketplace-ticket-form/" target="_blank">', '</a>'
			)
		);
		$admin_notice->set_actions( array(
			array(
				'name' => 'Dismiss',
				'url'  => wp_nonce_url( add_query_arg( $action, 'dismiss' ), $action, $nonce ),
			),
		) );

		$admin_notice->display();
	}
}