<?php

declare(strict_types=1);

namespace LinkCheckup\Features\Checking;

use LinkCheckup\Shared\Database\DatabaseHealth;
use LinkCheckup\Shared\Jobs\JobTask;
use LinkCheckup\Shared\Scan\ScanRunState;
use LinkCheckup\Shared\Scan\ScanStateStore;
use LinkCheckup\Shared\Settings\Settings;
use LinkCheckup\Shared\Settings\SettingsStore;
use LinkCheckup\Shared\Time\Clock;

final class CheckTask implements JobTask {

	private const TIME_BUDGET_SECONDS = 20;

	public function __construct(
		private ScanStateStore $scan_state_store,
		private DatabaseHealth $database_health,
		private SettingsStore $settings_store,
		private DueLinks $due_links,
		private LinkChecker $link_checker,
		private Clock $clock
	) {
	}

	public function run(): int {
		$settings = $this->settings_store->load();

		if ( $this->should_wait( $settings ) ) {
			return 0;
		}

		$started_at    = $this->clock->now();
		$due_links     = $this->due_links->one_per_host(
			$started_at,
			$settings->batch_size,
			$settings->skip_hosts
		);
		$checked_count = 0;

		foreach ( $due_links as $link ) {
			$spent_seconds = $this->clock->now() - $started_at;

			if ( $spent_seconds >= self::TIME_BUDGET_SECONDS ) {
				break;
			}

			$this->link_checker->check( $link );
			++$checked_count;
		}

		return $checked_count;
	}

	private function should_wait( Settings $settings ): bool {
		$is_paused = ScanRunState::Paused
			=== $this->scan_state_store->load()->run_state;

		return $is_paused
			|| $this->database_health->response_ms() > $settings->pause_at_ms;
	}
}