<?php
/**
 * Database clean-up: expired WooCommerce sessions.
 *
 * @package AdminPowerups
 */

namespace SmartWP\AdminPowerups\Modules\DatabaseCleanup\Checks;

use SmartWP\AdminPowerups\Modules\DatabaseCleanup\BaseCheck;

defined( 'ABSPATH' ) || exit;

/**
 * Shopper sessions (carts) past their expiry. Deleted with WooCommerce's own statement
 * (`session_expiry < now ORDER BY session_expiry LIMIT n`), in a loop bounded by the budget:
 * WC_Session_Handler::cleanup_sessions() loops until everything is gone and needs WC()->session,
 * which REST requests don't load. Samples never include the session key or value.
 *
 * @since 1.0.0
 */
class ExpiredSessions extends BaseCheck {

	/**
	 * Sessions table.
	 *
	 * @since 1.0.0
	 * @return string
	 */
	public static function table(): string {
		global $wpdb;
		return $wpdb->prefix . 'woocommerce_sessions';
	}

	/**
	 * {@inheritDoc} Also when another plugin stores sessions.
	 */
	public function unavailable(): string {
		$reason = parent::unavailable();
		if ( '' !== $reason ) {
			return $reason;
		}
		$handler = apply_filters( 'woocommerce_session_handler', 'WC_Session_Handler' ); // phpcs:ignore WooCommerce.Commenting.CommentHooks.MissingHookComment, WordPress.NamingConventions.PrefixAllGlobals.NonPrefixedHooknameFound -- WooCommerce's own filter, read the way WooCommerce picks its session class.
		if ( ! is_string( $handler ) || ! class_exists( $handler ) || ! is_a( $handler, 'WC_Session_Handler', true ) ) {
			return __( 'Another plugin stores shopper sessions on this site, so they aren’t in WooCommerce’s table.', 'admin-powerups-for-woocommerce' );
		}
		return '';
	}

	/**
	 * {@inheritDoc}
	 *
	 * @param array<string, mixed> $state  State from the last call.
	 * @param float                $budget Seconds to spend.
	 * @return array{count: int, done: bool, state: array<string, mixed>}
	 */
	public function count( array $state, float $budget ): array {
		global $wpdb;
		// phpcs:ignore WordPress.DB.DirectDatabaseQuery -- live count on the session_expiry index.
		$count = (int) $wpdb->get_var( $wpdb->prepare( 'SELECT COUNT(*) FROM %i WHERE session_expiry < %d', self::table(), time() ) );
		return array(
			'count' => $count,
			'done'  => true,
			'state' => array(),
		);
	}

	/**
	 * {@inheritDoc}
	 *
	 * @param array<string, mixed> $state  State from the last call.
	 * @param int                  $batch  Rows per statement.
	 * @param float                $budget Seconds to spend.
	 * @return array{deleted: int, skipped: int, notes: array<string, int>, done: bool, state: array<string, mixed>}
	 */
	public function clean( array $state, int $batch, float $budget ): array {
		global $wpdb;
		$out   = self::cleaned( $state, false );
		$start = microtime( true );
		$now   = time();
		do {
			// phpcs:ignore WordPress.DB.DirectDatabaseQuery -- WooCommerce's own clean-up statement, bounded; the cache group is invalidated below.
			$gone            = (int) $wpdb->query( $wpdb->prepare( 'DELETE FROM %i WHERE session_expiry < %d ORDER BY session_expiry LIMIT %d', self::table(), $now, $batch ) );
			$out['deleted'] += max( 0, $gone );
			if ( $gone < $batch || '' !== $wpdb->last_error ) {
				$out['done'] = '' === $wpdb->last_error;
				break;
			}
		} while ( self::time_left( $start, $budget ) );
		if ( $out['deleted'] && class_exists( '\WC_Cache_Helper' ) && defined( 'WC_SESSION_CACHE_GROUP' ) ) {
			\WC_Cache_Helper::invalidate_cache_group( WC_SESSION_CACHE_GROUP );
		}
		return $out;
	}

	/**
	 * {@inheritDoc} ID, expiry and size only.
	 *
	 * @param int $limit Rows (at most 10).
	 * @return array{columns: array<string, string>, rows: array<int, array<string, string>>}
	 */
	public function sample( int $limit = 10 ): array {
		global $wpdb;
		// phpcs:ignore WordPress.DB.DirectDatabaseQuery -- a few rows for the sample; never the key or value.
		$rows = (array) $wpdb->get_results( $wpdb->prepare( 'SELECT session_id, session_expiry, LENGTH(session_value) AS size FROM %i WHERE session_expiry < %d ORDER BY session_expiry LIMIT %d', self::table(), time(), max( 1, min( 10, $limit ) ) ) );
		$out  = array();
		foreach ( $rows as $row ) {
			$out[] = array(
				'id'      => self::cell( $row->session_id ),
				'expired' => self::date_cell( (int) $row->session_expiry ),
				'size'    => (string) size_format( (int) $row->size ),
			);
		}
		return array(
			'columns' => array(
				'id'      => __( 'Session ID', 'admin-powerups-for-woocommerce' ),
				'expired' => __( 'Expired', 'admin-powerups-for-woocommerce' ),
				'size'    => __( 'Size', 'admin-powerups-for-woocommerce' ),
			),
			'rows'    => $out,
		);
	}
}