jndrm/mqtt-packet

<?php

namespace Drmer\Mqtt\Packet;

use Drmer\Mqtt\Packet\Protocol\Version;
use Drmer\Mqtt\Packet\Protocol\Version4;

/**
 * After a Network Connection is established by a Client to a Server, the
 * first Packet sent from the Client to the Server MUST be a CONNECT Packet.
 */
class Connect extends ControlPacket
{

    /** @var null|string */
    protected $clientId = null;

    /** @var null|string  */
    protected $username = null;

    /** @var null|string  */
    protected $password = null;

    /** @var bool  */
    protected $cleanSession = true;

    /** @var string|null  */
    protected $willTopic;

    /** @var string|null  */
    protected $willMessage;

    /** @var int  */
    protected $willQos;

    /** @var null */
    protected $willRetain;

    /** @var int */
    private $keepAlive;

    /**
     * @param Version $version
     * @param ConnectionOptions|Array|null $opts
     */
    public function __construct($opts=null)
    {
        parent::__construct();
        $options = $opts;
        if (is_array($opts)) {
            $options = new ConnectionOptions($opts);
        }
        if ($options) {
            $this->clientId = $options->clientId;
            $this->username = $options->username;
            $this->password = $options->password;
            $this->cleanSession = boolval($options->cleanSession);
            $this->willTopic = $options->willTopic;
            $this->willMessage = $options->willMessage;
            $this->willQos = $options->willQos;
            $this->willRetain = $options->willRetain;
            $this->keepAlive = $options->keepAlive;
        }
    }

    public function getPayload()
    {
        if ($this->payload) {
            // payload is alread built
            return $this->payload;
        }
        $this->addLengthPrefixedField($this->getClientId());
        if (!is_null($this->willTopic)) {
            $this->addLengthPrefixedField($this->willTopic);
            $this->addLengthPrefixedField($this->willMessage);
        }
        if (!empty($this->username)) {
            $this->addLengthPrefixedField($this->username);
        }
        if (!empty($this->password)) {
            $this->addLengthPrefixedField($this->password);
        }
        return $this->payload;
    }

    public function parse($rawInput)
    {
        parent::parse($rawInput);

        // 2: fixed header
        // 2: MQTT length field chr(0), chr(4)
        // 4: MQTT
        $body = substr($rawInput, 2 + 2 + 4);

        $this->cleanSession = ord($body[1]) >> 1 & 0x1;
        $hasWill = ord($body[1]) >> 2 & 0x1;
        $this->willQos = ord($body[1]) >> 3 & 0x3;
        $this->willRetain = ord($body[1]) >> 5 & 0x1;
        $hasPassword  = ord($body[1]) >> 6 & 0x1;
        $hasUsername  = ord($body[1]) >> 7 & 0x1;

        $body = substr($body, 2);
        $this->keepAlive = static::readShortInt($body);

        $this->addLengthPrefixedField($this->clientId = static::readString($body));
        if ($hasWill) {
            $this->addLengthPrefixedField($this->willTopic = static::readString($body));
            $this->addLengthPrefixedField($this->willMessage = static::readString($body));
        }
        if ($hasUsername) {
            $this->addLengthPrefixedField($this->username = static::readString($body));
        }
        if ($hasPassword) {
            $this->addLengthPrefixedField($this->password = static::readString($body));
        }
    }

    /**
     * @return int
     */
    public static function getControlPacketType()
    {
        return ControlPacketType::CONNECT;
    }

    /**
     * @return string
     */
    protected function getVariableHeader()
    {
        return chr(ControlPacketType::MOST_SIGNIFICANT_BYTE)              // byte 1
             . chr(strlen($this->version->getProtocolIdentifierString())) // byte 2
             . $this->version->getProtocolIdentifierString()              // byte 3,4,5,6
             . chr($this->version->getProtocolVersion())                  // byte 7
             . chr($this->getConnectFlags())                              // byte 8
             . $this->getKeepAlive();                                     // byte 9,10
    }

    /**
     * @return string
     */
    private function getKeepAlive()
    {
        $msb = $this->keepAlive >> 8;
        $lsb = $this->keepAlive % 256;

        return chr($msb)
             . chr($lsb);
    }

    /**
     * @return int
     */
    protected function getConnectFlags()
    {
        $connectByte = 0;
        if ($this->cleanSession) {
            $connectByte += 1 << 1;
        }
        if (!is_null($this->willTopic) && !is_null($this->willMessage)) {
            $connectByte += 1 << 2;
        }

        if ($this->willQos) {
            $connectByte += $this->willQos << 3;
        }

        if ($this->willRetain) {
            $connectByte += 1 << 5;
        }

        if (!empty($this->password)) {
            $connectByte += 1 << 6;
        }

        if (!empty($this->username)) {
            $connectByte += 1 << 7;
        }
        return $connectByte;
    }

    /**
     * @return string
     */
    public function getClientId()
    {
        return $this->clientId;
    }

    public function getWillTopic()
    {
        return $this->willTopic;
    }

    public function getWillQos()
    {
        return $this->willQos;
    }
}