<?php

declare(strict_types=1);

namespace LinkCheckup\Features\Scanning;

use LinkCheckup\Shared\Jobs\JobTask;
use LinkCheckup\Shared\Scan\ScanPhase;
use LinkCheckup\Shared\Scan\ScanRunState;
use LinkCheckup\Shared\Scan\ScanStateStore;

final class ScanTick implements JobTask {

	private const NO_POSTS_READ = 0;

	public function __construct(
		private ScanStateStore $scan_state_store,
		private PostReader $post_reader,
		private ScanFinisher $scan_finisher
	) {
	}

	public function run(): int {
		$state = $this->scan_state_store->load();

		if ( ScanRunState::Running !== $state->run_state ) {
			return self::NO_POSTS_READ;
		}

		if ( ScanPhase::Reading === $state->phase ) {
			return $this->post_reader->read_next_posts( $state );
		}

		$this->scan_finisher->finish_when_checked( $state );

		return self::NO_POSTS_READ;
	}
}