<?php
/**
 * Queue worker HTTP endpoint.
 *
 * @package Rahkar\WP
 */

declare( strict_types = 1 );

namespace Rahkar\WP\Queue;

use Rahkar\WP\Lifecycle;
use Rahkar\WP\Support\Context;

defined( 'ABSPATH' ) || exit;

/**
 * The URL a real server cron hits to drain the queue.
 *
 * Answers on `plugins_loaded` at priority 1 and exits, so a worker request never
 * pays for module registration, theme setup, or a query it will not use. That
 * keeps a once-a-minute cron line genuinely cheap even on a large store.
 *
 * Authentication is a shared secret compared in constant time. It is not a
 * capability check — the endpoint takes no user input beyond the key and can
 * only cause already-queued work to run sooner.
 */
final class WorkerEndpoint {

	public const PARAM = 'rahkar_worker';

	/**
	 * Handle the request when this is a worker call.
	 *
	 * @internal Hooked callback.
	 */
	public static function maybeHandle(): void {
		if ( ! Context::is( Context::WORKER ) ) {
			return;
		}

		// phpcs:ignore WordPress.Security.NonceVerification.Recommended
		$key = isset( $_GET['key'] ) ? sanitize_text_field( wp_unslash( $_GET['key'] ) ) : '';

		if ( ! hash_equals( Lifecycle::workerKey(), $key ) ) {
			status_header( 403 );
			nocache_headers();

			echo 'forbidden';
			exit;
		}

		// A worker must never be cached, and must never be interrupted halfway
		// through a batch by a client that hung up.
		nocache_headers();
		ignore_user_abort( true );

		if ( function_exists( 'set_time_limit' ) ) {
			// phpcs:ignore WordPress.PHP.NoSilencedErrors.Discouraged, Squiz.PHP.DiscouragedFunctions.Discouraged -- Only on this endpoint, which exists to work the queue; a batch cut off by the default limit would leave jobs reserved and unfinished. Hosts that forbid it are handled by the guard above and the silence here.
			@set_time_limit( 120 );
		}

		$result = Dispatcher::instance()->run();

		status_header( 200 );
		header( 'Content-Type: application/json; charset=utf-8' );

		echo wp_json_encode(
			[
				'ok'        => true,
				'processed' => $result['processed'],
				'failed'    => $result['failed'],
			]
		);

		exit;
	}

	/**
	 * Full worker URL, including the secret.
	 */
	public static function url(): string {
		return add_query_arg(
			[
				self::PARAM => 1,
				'key'       => Lifecycle::workerKey(),
			],
			home_url( '/' )
		);
	}

	/**
	 * The crontab line to paste on the server.
	 *
	 * Shown verbatim on the health screen — the whole point of the second trigger
	 * is that setting it up takes one copy-paste.
	 */
	public static function cronLine(): string {
		return sprintf( '* * * * * curl -s %s >/dev/null 2>&1', escapeshellarg( self::url() ) );
	}
}