<?php
declare(strict_types=1);

namespace HttpServer\Events;


use Annotation\Route\Socket;
use Exception;
use HttpServer\Abstracts\Callback;
use HttpServer\Http\HttpHeaders;
use HttpServer\Http\HttpParams;
use HttpServer\Http\Request;
use HttpServer\Http\Response;
use ReflectionException;
use Snowflake\Core\ArrayAccess;
use Snowflake\Event;
use Snowflake\Exception\NotFindClassException;
use Snowflake\Snowflake;
use Swoole\Http\Request as SRequest;
use Swoole\Http\Response as SResponse;
use Swoole\WebSocket\Server;


/**
 * Class OnHandshake
 * @package HttpServer\Events
 */
class OnHandshake extends Callback
{


    /**
     * @param $request
     * @param $response
     * @throws Exception
     */
    private function resolveParse($request, $response)
    {
        /** @var Server $server */
        $secWebSocketKey = $request->header['sec-websocket-key'];
        $patten = '#^[+/0-9A-Za-z]{21}[AQgw]==$#';
        if (0 === preg_match($patten, $secWebSocketKey) || 16 !== strlen(base64_decode($secWebSocketKey))) {
            throw new Exception('protocol error.', 500);
        }
        $key = base64_encode(sha1($request->header['sec-websocket-key'] . '258EAFA5-E914-47DA-95CA-C5AB0DC85B11', TRUE));
        $headers = [
            'Upgrade'               => 'websocket',
            'Connection'            => 'Upgrade',
            'Sec-websocket-Accept'  => $key,
            'Sec-websocket-Version' => '13',
        ];
        if (isset($request->header['sec-websocket-protocol'])) {
            $headers['Sec-websocket-Protocol'] = $request->header['sec-websocket-protocol'];
        }
        foreach ($headers as $key => $val) {
            $response->header($key, $val);
        }
    }


    /**
     * @param SResponse $response
     * @param int $code
     * @return false
     */
    private function disconnect(SResponse $response, $code = 500): bool
    {
        $server = Snowflake::getWebSocket();
        if (!$server->exist($response->fd)) {
            return false;
        }
        $response->status($code);
        $response->end();
        return false;
    }


    /**
     * @param $response
     * @param int $code
     * @return false
     */
    private function connect($response, $code = 101): bool
    {
        $response->status($code);
        $response->end();
        return false;
    }


    /**
     * @param SRequest $request
     * @param SResponse $response
     * @return void
     * @throws Exception
     */
    public function onHandler(SRequest $request, SResponse $response): void
    {
        try {
            defer(fn() => fire(Event::SYSTEM_RESOURCE_RELEASES));

            $this->execute($request, $response);
        } catch (\Throwable $exception) {
            $this->addError($exception, 'throwable');
            $response->status(500);
            $response->end($exception->getMessage());
        }
    }


    /**
     * @param SRequest $request
     * @param SResponse $response
     * @return mixed
     * @throws Exception
     */
    private function execute(SRequest $request, SResponse $response): mixed
    {
        $this->resolveParse($request, $response);

        $router = Snowflake::app()->getRouter();

        [$sRequest, $sResponse] = $this->sRequest($request, $response);

        if (($node = $router->find_path($sRequest)) !== null) {
            return $node->dispatch($sRequest, $sResponse);
        }
        return $this->disconnect($response, 404);
    }


    /**
     * @param $request
     * @param SResponse $response
     * @return array
     * @throws NotFindClassException
     * @throws ReflectionException
     */
    private function sRequest($request, SResponse $response): array
    {
        /** @var Request $sRequest */
        $sRequest = Request::create($request);
        $sRequest->uri = '/' . Socket::HANDSHAKE . '::event';

        $sRequest->headers = new HttpHeaders(ArrayAccess::merge($request->server, $request->header));

        $sRequest->headers->replace('request_method', 'sw::socket');
        $sRequest->headers->replace('request_uri', $sRequest->uri);

        $sRequest->params = new HttpParams([], $request->get, []);

        $sRequest->parseUri();

        return [$sRequest, Response::create($response)];
    }


}