Laravel job example

<?php

namespace App\Jobs\EmlCampaign;

use App\Entities\CampaignState;
use App\Entities\RecipientState;
use App\Exceptions\CampaignIsNotRunningException;
use App\Models\EmlCampaign;
use App\Utils\Campaign\Manager;
use Illuminate\Bus\Queueable;
use Illuminate\Contracts\Queue\ShouldQueue;
use Illuminate\Database\QueryException;
use Illuminate\Queue\InteractsWithQueue;
use Illuminate\Queue\SerializesModels;
use Illuminate\Support\Facades\DB;
use Illuminate\Support\Facades\Log;

class Enqueue extends \App\Jobs\Job implements ShouldQueue
{
    use InteractsWithQueue, Queueable, SerializesModels;

    /**
     * @var EmlCampaign
     */
    private $campaign = null;

    public function __construct(EmlCampaign $campaign)
    {
        $this->campaign = $campaign;
    }


    public function handle()
    {

        try {

            $this->refreshCampaign();

            throw_unless($this->campaign->exists(), new \Exception('Campaign does not exist'));

            throw_if(CampaignState::RUNNING != $this->campaign->getState(), new CampaignIsNotRunningException('Campaign is not running'));

            $this->campaign->setState(CampaignState::RUNNING, 'Enqueuing');

            $this->delete();//Remove job from queue, because worker may run longer than RMQ heartbeat

            $processingQueues = config('queue.names.campaigns');
            DB::table($this->campaign->recipientsList->getDataTableName())->orderBy('email')->chunk(config('triton.campaign_enqueue_chunk_size', 5000), function($recipients) use ($processingQueues) {

                foreach ($processingQueues as $mtaId => $queueName) {
                    foreach ($recipients->where('mta_id', $mtaId)->chunk(config('triton.campaign_enqueue_batch_size', 100)) as $batch) {
                        Log::debug('Enqueuer: going to dispatch a batch of recipients', ['mta' => $mtaId, 'batch size' => count($batch)]);
                        dispatch((new Process($this->campaign, $batch))->onQueue($queueName));
                        Manager::incrementCampaignCounter($this->campaign, RecipientState::ENQUEUED, count($batch));
                    }
                }
            });

            Log::info('Campaign enqueuing finished', ['campaign' => $this->campaign->id]);
            $this->campaign->setState(CampaignState::RUNNING, 'Processing');
        } catch (QueryException $qe) {
            Log::warning('Failed to enqueue campaign. Query exception', [
                'errorInfo' => $qe->errorInfo,
                'reason' => $qe->getMessage(),
                'previous' => optional($qe->getPrevious())->getMessage(),
                'trace' => $qe->getTrace(),
                'traceAsString' => $qe->getTraceAsString(),
                'campaign' => $this->campaign->id
            ]);
        } catch (CampaignIsNotRunningException $e) {
            Log::warning('Campaign enqueuing terminated', ['reason' => $e->getMessage(), 'campaign' => $this->campaign->id]);
        } catch (\Exception $e) {
            Log::warning('Failed to enqueue campaign', ['reason' => $e->getMessage(), 'campaign' => $this->campaign->id]);
        }
    }


    /**
     * Sync model with db
     */
    private function refreshCampaign()
    {
        $this->campaign = $this->campaign->fresh();
    }
}