<?php

declare(strict_types=1);

namespace LinkCheckup\Features\Scanning;

use LinkCheckup\Shared\Jobs\SchedulerLog;
use LinkCheckup\Shared\Time\IsoTime;

final class SchedulerHealth {

	public const TOLERANCE_SECONDS = 10 * MINUTE_IN_SECONDS;

	public function __construct(
		private SchedulerLog $scheduler_log,
		private IsoTime $iso_time
	) {
	}

	/** @return array{healthy: bool, last_run_at: string|null} */
	public function describe( int $now ): array {
		$last_run_at = $this->scheduler_log->last_run_at();

		$is_healthy = null === $last_run_at
			? ! $this->is_job_overdue( $now )
			: $now - $last_run_at <= self::TOLERANCE_SECONDS;

		return array(
			'healthy'     => $is_healthy,
			'last_run_at' => $this->iso_time->from_timestamp( $last_run_at ),
		);
	}

	private function is_job_overdue( int $now ): bool {
		$earliest_due_at = $this->scheduler_log->earliest_due_at();

		return null !== $earliest_due_at
			&& $now - $earliest_due_at > self::TOLERANCE_SECONDS;
	}
}