<?php
/**
 * Action Scheduler failures (WooCommerce background jobs).
 *
 * @package Keepwatch
 */

namespace Keepwatch\WooCommerce;

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

defined( 'ABSPATH' ) || exit;

/**
 * Failed jobs often mean stuck order e-mails, webhooks or subscription renewals.
 * Reads a single COUNT from the Action Scheduler table; read-only.
 */
final class FailedActionsCheck implements Check {

	public const CRITICAL_COUNT = 20;

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

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

	/**
	 * Pure evaluation.
	 *
	 * @param int|null $failed Failed actions in the last 7 days, null if Action Scheduler tables are missing.
	 * @return Result[]
	 */
	public static function evaluate( ?int $failed ): array {
		if ( null === $failed ) {
			return array();
		}

		if ( 0 === $failed ) {
			return array( new Result( 'woocommerce.actions', Result::GOOD, __( 'No failed background jobs in the last 7 days', 'keepwatch' ) ) );
		}

		return array(
			new Result(
				'woocommerce.actions',
				$failed >= self::CRITICAL_COUNT ? Result::CRITICAL : Result::RECOMMENDED,
				/* translators: %d: number of failed jobs */
				sprintf( _n( '%d background job failed in the last 7 days', '%d background jobs failed in the last 7 days', $failed, 'keepwatch' ), $failed ),
				__( 'WooCommerce uses Action Scheduler for e-mails, webhooks and renewals. Failed jobs can mean customers did not receive something.', 'keepwatch' ),
				admin_url( 'admin.php?page=wc-status&tab=action-scheduler&status=failed' ),
				__( 'View failed jobs', 'keepwatch' )
			),
		);
	}

	/**
	 * Count failed actions from the last 7 days.
	 */
	private function failed_last_week(): ?int {
		global $wpdb;

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

		// 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 last_attempt_gmt >= %s',
				$table,
				'failed',
				gmdate( 'Y-m-d H:i:s', time() - WEEK_IN_SECONDS )
			)
		);

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