<?php

namespace App\Services;

use App\Facade\UserConfig;
use App\QueueItem;
use PhpAmqpLib\Channel\AMQPChannel;
use PhpAmqpLib\Connection\AMQPStreamConnection;
use PhpAmqpLib\Message\AMQPMessage;

class RabbitMQService
{
    protected $password;

    protected $port;

    protected $queue;

    protected $server;

    protected $username;
    
    protected $vhost;

    /**
     * @var AMQPChannel
     */
    private $channel;

    /**
     * @var AMQPStreamConnection
     */
    private $connection;

    public function __construct()
    {
        $this->server = UserConfig::get('rabbitmq_server');
        $this->port = intval(UserConfig::get('rabbitmq_port'));
        $this->username = UserConfig::get('rabbitmq_username');
        $this->password = decrypt(UserConfig::get('rabbitmq_password'));
        $this->queue = UserConfig::get('rabbitmq_queue');

        $vhost = UserConfig::get('rabbitmq_vhost');
        $this->vhost = empty($vhost) ? '/' : $vhost;
    }

    public function queueItem(QueueItem $queueItem)
    {
        $this->connectAndInit();

        try
        {
            $message = new AMQPMessage(
                $queueItem->id,
                array('delivery_mode' => AMQPMessage::DELIVERY_MODE_PERSISTENT)
            );
            $this->channel->basic_publish($message, '', $this->queue);
        }
        finally
        {
            $this->disconnectAndCleanUp();
        }
    }

    public function waitOnQueue($callback)
    {
        $this->connectAndInit();

        try
        {
            $this->channel->basic_consume($this->queue, '', false, false, false, false, $callback);

            while (count($this->channel->callbacks))
            {
                $this->channel->wait();
            }
        }
        finally
        {
            $this->disconnectAndCleanUp();
        }
    }

    private function connectAndInit()
    {
        $this->connection = new AMQPStreamConnection($this->server, $this->port, $this->username, $this->password, $this->vhost);
        $this->channel = $this->connection->channel();

        $this->channel->queue_declare($this->queue, false, true, false, false);
    }

    private function disconnectAndCleanUp()
    {
        $this->channel->close();
        $this->connection->close();

        $this->channel = null;
        $this->connection = null;
    }
}