unreal4u\MQTT\Protocol\Unsubscribe

Complexity

Total Complexity

6

Size/Duplication

Total Lines	69
Duplicated Lines	0 %

Test Coverage

Coverage

100%

Importance

Changes

0

4 Methods

Rating	Name	Duplication	Size	Complexity
A	createVariableHeader()	0	10	2
A	createPayload()	0	8	2
A	addTopics()	0	6	1
A	shouldExpectAnswer()	0	3	1

<?php

declare(strict_types=1);

namespace unreal4u\MQTT\Protocol;

use unreal4u\MQTT\DataTypes\Topic;
use unreal4u\MQTT\Exceptions\MustContainTopic;
use unreal4u\MQTT\Internals\PacketIdentifierFunctionality;
use unreal4u\MQTT\Internals\ProtocolBase;
use unreal4u\MQTT\Internals\WritableContent;
use unreal4u\MQTT\Internals\WritableContentInterface;

/**
 * An UNSUBSCRIBE Packet is sent by the Client to the Server, to unsubscribe from topics.
 */
final class Unsubscribe extends ProtocolBase implements WritableContentInterface
{
    use WritableContent, PacketIdentifierFunctionality;

    const CONTROL_PACKET_VALUE = 10;

    /**
     * An array of topics on which unsubscribe to
     * @var Topic[]
     */
    private $topics = [];

    /**
     * @return string
     * @throws \unreal4u\MQTT\Exceptions\MustContainTopic
     * @throws \OutOfRangeException
     */
    public function createVariableHeader(): string
    {
        if (count($this->topics) === 0) {
            throw new MustContainTopic('An unsubscribe command must contain at least one topic');
        }

        // Unsubscribe must always send a 2 flag
        $this->specialFlags = 2;

        return $this->getPacketIdentifierBinaryRepresentation();
    }

    /**
     * @return string
     * @throws \OutOfRangeException
     */
    public function createPayload(): string
    {
        $output = '';
        foreach ($this->topics as $topic) {
            // chr on QoS level is safe because it will create an 8-bit flag where the first 6 are only 0's
            $output .= $this->createUTF8String($topic->getTopicName());
        }
        return $output;
    }

    /**
     * When the Server receives a SUBSCRIBE Packet from a Client, the Server MUST respond with a SUBACK Packet
     *
     * This can however not be in the same order, as we may be able to receive PUBLISH packets before getting a SUBACK
     * back
     *
     * @see http://docs.oasis-open.org/mqtt/mqtt/v3.1.1/os/mqtt-v3.1.1-os.html#_Toc398718134 (MQTT-3.8.4-1)
     * @return bool
     */
    public function shouldExpectAnswer(): bool
    {
        return true;
    }

    /**
     * A subscription is based on filters, this function allows us to pass on filters
     *
     * @param Topic[] $topics
     * @return Unsubscribe
     */
    public function addTopics(Topic ...$topics): self
    {
        $this->topics = array_merge($this->topics, $topics);
        $this->logger->debug('Topics added', ['totalTopics', count($this->topics)]);

        return $this;
    }
}