<?php

namespace NoccyLabs\Mercureact\Http\Middleware;

use NoccyLabs\Mercureact\Broker\TopicManager;
use NoccyLabs\Mercureact\Broker\Subscriber\WsSubscriber;
use NoccyLabs\Mercureact\Configuration;
use NoccyLabs\React\WebSocket\WebSocketConnection;
use NoccyLabs\React\WebSocket\WebSocketMiddleware;
use Psr\Http\Message\ServerRequestInterface;
use React\EventLoop\Loop;
use React\EventLoop\LoopInterface;
use React\Promise\Promise;
use React\Promise\PromiseInterface;
use SplObjectStorage;

class WebSocketHandler
{
    private LoopInterface $loop;

    private WebSocketMiddleware $webSocket;

    public function __construct(
        private Configuration $config,
        private SplObjectStorage $webSocketClients,
        private TopicManager $topicManager,
        ?LoopInterface $loop=null
    )
    {
        $this->loop = $loop ?? Loop::get();

        $this->webSocket = new WebSocketMiddleware();
        $this->webSocket->on(WebSocketMiddleware::EVENT_CONNECTION, $this->onWebSocketConnection(...));
    }

    /**
     * 
     * 
     * @param ServerRequestInterface $request
     * @param callable $next
     * @return PromiseInterface
     */
    public function __invoke(ServerRequestInterface $request, callable $next): PromiseInterface
    {
        return new Promise(
            function (callable $resolve, callable $reject) use ($next, $request) {
                if ($request->getUri()->getPath() == "/.well-known/mercure")
                    $resolve(call_user_func($this->webSocket, $request, $next));
                else 
                    $resolve($next($request));
            }
        );
    }

    /**
     * 
     * 
     */
    private function onWebSocketConnection(WebSocketConnection $connection)
    {
        $this->webSocketClients->attach($connection);

        $request = $connection->getServerRequest();
        $subscriber = new WsSubscriber($connection, $request, $this->topicManager);

        $connection->on('close', function () use ($connection, $subscriber) {
            $this->webSocketClients->detach($connection);
            $this->topicManager->unsubscribe($subscriber);
        });

        $this->topicManager->subscribe($subscriber, []);
        
    }

}