blue-twilight/app/Http/Controllers/Gallery/PhotoController.php

<?php

namespace App\Http\Controllers\Gallery;

use App\Album;
use app\Http\Controllers\Admin\AlbumController;
use App\Http\Controllers\Controller;
use App\Photo;
use Illuminate\Support\Facades\App;
use Symfony\Component\HttpFoundation\Request;

class PhotoController extends Controller
{
    public function download(Request $request, $albumUrlAlias, $photoFilename)
    {
        $album = PhotoController::loadAlbumByAlias($albumUrlAlias);
        $albumSource = $album->getAlbumSource();

        $thumbnail = $request->get('t', $albumSource->getOriginalsFolder());
        $photo = PhotoController::loadPhotoByAlbumAndFilename($album, $photoFilename);

        return response()->file($albumSource->getPathToPhoto($album, $photo, $thumbnail));
    }

    /**
     * @param $id
     * @return Album
     */
    public static function loadAlbumByAlias($alias)
    {
        $album = Album::where('url_alias', $alias)->first();
        if (is_null($album))
        {
            App::abort(404);
            return null;
        }

        return $album;
    }

    /**
     * @param $id
     * @return Photo
     */
    public static function loadPhotoByAlbumAndFilename(Album $album, $filename)
    {
        $photo = Photo::where([
            ['album_id', $album->id],
            ['file_name', $filename]
        ])->first();

        if (is_null($photo))
        {
            App::abort(404);
            return null;
        }

        return $photo;
    }
}