<?php

namespace App\Console\Commands;

use App\Facade\UserConfig;
use App\Photo;
use App\QueueItem;
use App\Services\PhotoService;
use App\Services\RabbitMQService;
use App\UserActivity;
use Illuminate\Console\Command;

class ProcessQueueCommand extends Command
{
    /**
     * The name and signature of the console command.
     *
     * @var string
     */
    protected $signature = 'queue:process';

    /**
     * The console command description.
     *
     * @var string
     */
    protected $description = 'Processes items in the processing queue.';

    /**
     * Create a new command instance.
     *
     * @return void
     */
    public function __construct()
    {
        parent::__construct();
    }

    /**
     * Execute the console command.
     *
     * @return mixed
     */
    public function handle()
    {
        if (!UserConfig::isImageProcessingQueueEnabled())
        {
            $this->output->error('The image processing queue is not enabled');
        }

        $rabbitmq = new RabbitMQService();

        $this->output->writeln('Monitoring queue');

        $rabbitmq->waitOnQueue([$this, 'processQueueItem']);
    }

    /**
     * Processes a single item from the queue.
     *
     * @param $msg
     * @return void
     */
    public function processQueueItem($msg)
    {
        $queueItemID = intval($msg->body);

        $this->output->writeln(sprintf('Processing queue item %d', $queueItemID));

        /** @var QueueItem $queueItem */
        $queueItem = QueueItem::where('id', $queueItemID)->first();
        if (is_null($queueItem))
        {
            $this->output->writeln('Queue item does not exist; skipping');
            $msg->delivery_info['channel']->basic_ack($msg->delivery_info['delivery_tag']);
            return;
        }

        try
        {
            switch (strtolower($queueItem->action_type))
            {
                case 'photo.analyse':
                    $this->processPhotoAnalyseMessage($queueItem);
                    break;

                default:
                    $this->output->writeln(sprintf('Action %s is not recognised, skipping', $queueItem->action_type));
                    return;
            }

            $queueItem->completed_at = new \DateTime();
            $queueItem->save();
        }
        catch (\Exception $ex)
        {
            $this->output->error($ex->getMessage());
        }
        finally
        {
            $msg->delivery_info['channel']->basic_ack($msg->delivery_info['delivery_tag']);
        }
    }

    private function createActivityRecord(Photo $photo, $type, $activityDateTime = null)
    {
        if (is_null($activityDateTime))
        {
            $activityDateTime = new \DateTime();
        }

        $userActivity = new UserActivity();
        $userActivity->user_id = $photo->user_id;
        $userActivity->activity_at = $activityDateTime;
        $userActivity->type = $type;
        $userActivity->photo_id = $photo->id;
        $userActivity->save();
    }

    private function processPhotoAnalyseMessage(QueueItem $queueItem)
    {
        $this->output->writeln(sprintf('Analysing photo ID %l (batch: %s)', $queueItem->photo_id, $queueItem->batch_reference));

        $photo = Photo::where('id', $queueItem->photo_id)->first();

        if (is_null($photo))
        {
            $this->output->writeln('Photo does not exist; skipping');
        }

        /* IF CHANGING THIS LOGIC, ALSO CHECK PhotoController::analyse */
        $photoService = new PhotoService($photo);
        $photoService->analyse($queueItem->batch_reference);

        // Log an activity record for the user's feed (remove an existing one as the date may have changed)
        $this->removeExistingActivityRecords($photo, 'photo.taken');

        if (!is_null($photo->taken_at))
        {
            // Log an activity record for the user's feed
            $this->createActivityRecord($photo, 'photo.taken', $photo->taken_at);
        }
    }

    private function removeExistingActivityRecords(Photo $photo, $type)
    {
        $existingFeedRecords = UserActivity::where([
            'user_id' => $photo->user_id,
            'photo_id' => $photo->id,
            'type' => $type
        ])->get();

        foreach ($existingFeedRecords as $existingFeedRecord)
        {
            $existingFeedRecord->delete();
        }
    }
}