<?php

namespace NoccyLabs\UPnP\SSDP;

use IteratorAggregate;
use ArrayIterator;
use JsonSerializable;
use NoccyLabs\UPnP\HTTPU\Endpoint;
use NoccyLabs\UPnP\HTTPU\EndpointException;
use NoccyLabs\UPnP\HTTPU\MSearchRequest;
use NoccyLabs\UPnP\HTTPU\MSearchResponse;

/**
 * Basic implementation of the SSDP protocol.
 *
 *
 */
class Discovery implements IteratorAggregate, JsonSerializable
{

    protected $devices = [];

    /**
     *
     *
     * @param string $search_type The device type or schema to search for
     * @return int The number of devices found
     */
    public function discover($search_type, $timeout=1)
    {
        // Set up the endpoint
        try {
            $endpoint = new Endpoint();
        } catch (EndpointException $e) {
            throw new DiscoveryException("Discovery failed", 0, $e);
        }

        // Clean up previous state
        $this->devices = [];

        // Create the request
        $request = new MSearchRequest();
        $request->setSearchType($search_type);
        $request->setMaxWait($timeout-1);

        // Send the request and wait for responses
        $responses = $endpoint->send($request, $timeout);
        foreach ($responses as $response) {
            // Add the relevant responses to the list
            if ($response instanceof MSearchResponse) {
                $loc = $response->getLocation();
                if (array_key_exists($loc, $this->devices)) {
                    continue;
                }
                $device = Device::createFromSchema($response->getLocation(), $response->getIp());
                if ($device) {
                    $this->devices[$loc] = $device;
                }
            }
        }

        $this->devices = array_values($this->devices);

        return count($this->devices);

    }

    public function getIterator()
    {
        return new ArrayIterator($this->devices);
    }

    public function jsonSerialize()
    {
        return $this->devices;
    }

}