<?php
/**
 * Overdue / stuck Action Scheduler jobs.
 *
 * @package Keepwatch
 */

namespace Keepwatch\WooCommerce;

use Keepwatch\Checks\Check;
use Keepwatch\Checks\Result;

defined( 'ABSPATH' ) || exit;

/**
 * Pending jobs past their schedule and long-running in-progress claims.
 */
final class StuckActionsCheck implements Check {

	public const OVERDUE_SECONDS = HOUR_IN_SECONDS;
	public const WARN_COUNT      = 5;
	public const CRITICAL_COUNT  = 25;

	/**
	 * {@inheritDoc}
	 */
	public function group(): string {
		return 'woocommerce';
	}

	/**
	 * {@inheritDoc}
	 */
	public function run(): array {
		return self::evaluate( $this->stuck_count() );
	}

	/**
	 * Pure evaluation.
	 *
	 * @param int|null $stuck Stuck job count, null if tables are missing.
	 * @return Result[]
	 */
	public static function evaluate( ?int $stuck ): array {
		if ( null === $stuck ) {
			return array();
		}

		if ( 0 === $stuck ) {
			return array( new Result( 'woocommerce.stuck', Result::GOOD, __( 'No overdue or stuck background jobs', 'keepwatch' ) ) );
		}

		$status = ( $stuck >= self::CRITICAL_COUNT ) ? Result::CRITICAL : Result::RECOMMENDED;

		return array(
			new Result(
				'woocommerce.stuck',
				$status,
				/* translators: %d: number of stuck jobs */
				sprintf( _n( '%d background job is overdue or stuck', '%d background jobs are overdue or stuck', $stuck, 'keepwatch' ), $stuck ),
				__( 'Pending jobs past their run time or long in-progress claims usually mean WP-Cron or Action Scheduler runners are not keeping up.', 'keepwatch' ),
				admin_url( 'admin.php?page=wc-status&tab=action-scheduler&status=pending' ),
				__( 'View scheduled actions', 'keepwatch' )
			),
		);
	}

	/**
	 * Count overdue pending and aged in-progress actions.
	 */
	private function stuck_count(): ?int {
		global $wpdb;

		$table = $wpdb->prefix . 'actionscheduler_actions';
		// phpcs:ignore WordPress.DB.DirectDatabaseQuery.DirectQuery, WordPress.DB.DirectDatabaseQuery.NoCaching -- single read-only COUNT.
		if ( $table !== $wpdb->get_var( $wpdb->prepare( 'SHOW TABLES LIKE %s', $wpdb->esc_like( $table ) ) ) ) {
			return null;
		}

		$cutoff = gmdate( 'Y-m-d H:i:s', time() - self::OVERDUE_SECONDS );

		// phpcs:ignore WordPress.DB.DirectDatabaseQuery.DirectQuery, WordPress.DB.DirectDatabaseQuery.NoCaching -- see above.
		$count = $wpdb->get_var(
			$wpdb->prepare(
				'SELECT COUNT(*) FROM %i WHERE ( status = %s AND scheduled_date_gmt < %s ) OR ( status = %s AND last_attempt_gmt < %s )',
				$table,
				'pending',
				$cutoff,
				'in-progress',
				$cutoff
			)
		);

		return null === $count ? null : (int) $count;
	}
}