<?php

declare(strict_types=1);

namespace LinkCheckup\Features\Maintenance;

use LinkCheckup\Shared\Database\QueryRunner;
use LinkCheckup\Shared\Database\Tables;
use LinkCheckup\Shared\DataVersion;
use LinkCheckup\Shared\Jobs\JobTask;
use LinkCheckup\Shared\Links\Outcome;
use LinkCheckup\Shared\Time\Clock;

final class TidyTask implements JobTask {

	private const RETENTION_SECONDS = 90 * DAY_IN_SECONDS;
	private const FIX_DONE          = 'done';
	private const FIX_UNDONE        = 'undone';

	public function __construct(
		private QueryRunner $query_runner,
		private Tables $tables,
		private DataVersion $data_version,
		private Clock $clock
	) {
	}

	public function run(): int {
		$oldest_kept_time = $this->clock->now() - self::RETENTION_SECONDS;
		$removed_links    = $this->delete_old_links( $oldest_kept_time );
		$removed_fixes    = $this->delete_old_fixes( $oldest_kept_time );
		$removed_rows     = $removed_links + $removed_fixes;

		if ( 0 < $removed_rows ) {
			$this->data_version->bump();
		}

		return $removed_rows;
	}

	private function delete_old_links( int $oldest_kept_time ): int {
		$links = $this->tables->links();

		return $this->query_runner->execute(
			$this->query_runner->prepare(
				'DELETE FROM ' . $links . ' WHERE outcome IN (%s, %s)'
					. ' AND NOT EXISTS (SELECT 1 FROM '
					. $this->tables->uses() . ' uses'
					. ' WHERE uses.link_id = ' . $links . '.id)'
					. ' AND fixed_by IN (SELECT fixes.id FROM '
					. $this->tables->fixes() . ' fixes'
					. ' WHERE fixes.created_at < %d)',
				Outcome::Resolved->value,
				Outcome::Removed->value,
				$oldest_kept_time
			)
		);
	}

	private function delete_old_fixes( int $oldest_kept_time ): int {
		return $this->query_runner->execute(
			$this->query_runner->prepare(
				'DELETE FROM ' . $this->tables->fixes()
					. ' WHERE state IN (%s, %s) AND created_at < %d',
				self::FIX_DONE,
				self::FIX_UNDONE,
				$oldest_kept_time
			)
		);
	}
}