<?php
/**
 * Debounced WordPress Cron scheduling.
 *
 * @package TwoUA_SEO_Release_Guard
 */

declare(strict_types=1);

namespace TwoUA\SeoReleaseGuard;

if ( ! defined( 'ABSPATH' ) ) {
	exit;
}

final class ReleaseScheduler {
	public const CRON_HOOK         = 'two_ua_release_guard_dispatch';
	private const DEBOUNCE_SECONDS = 300;
	private const RETRY_SECONDS    = 60;

	private RunDispatcher $dispatcher;
	private RunPoller $poller;
	private RunResultStore $results;

	public function __construct( RunDispatcher $dispatcher, RunPoller $poller, RunResultStore $results ) {
		$this->dispatcher = $dispatcher;
		$this->poller     = $poller;
		$this->results    = $results;
	}

	public function register_hooks(): void {
		add_action( self::CRON_HOOK, array( $this, 'dispatch' ), 10, 2 );
	}

	public function schedule( ReleaseEvent $event ): void {
		$key = $event->debounce_key();
		if ( $event->is_automatic() && false !== get_transient( $key ) ) {
			return;
		}

		$scheduled = wp_schedule_single_event( time() + 5, self::CRON_HOOK, array( $event->to_payload(), 0 ) );
		if ( true === $scheduled && $event->is_automatic() ) {
			set_transient( $key, '1', self::DEBOUNCE_SECONDS );
		}
	}

	/** @param array<string, mixed> $payload WordPress Cron boundary payload. */
	public function dispatch( array $payload, int $attempt = 0 ): void {
		$event = ReleaseEvent::from_payload( $payload );
		if ( ! $event instanceof ReleaseEvent ) {
			return;
		}

		try {
			$summary = $this->dispatcher->dispatch( $event );
			if ( $summary instanceof RunSummary ) {
				$this->poller->start( $summary );
			}
		} catch ( ApiException $exception ) {
			$this->results->mark_error( $exception->error_code() );
			if ( 0 === $attempt && $this->retryable( $exception ) ) {
				wp_schedule_single_event( time() + self::RETRY_SECONDS, self::CRON_HOOK, array( $payload, 1 ) );
			}
		}
	}

	private function retryable( ApiException $exception ): bool {
		return in_array( $exception->error_code(), array( ApiException::QUEUE, ApiException::REMOTE_FETCH ), true );
	}
}