koel/app/Http/Controllers/Download/FavoritesController.php

<?php

namespace App\Http\Controllers\Download;

use App\Http\Requests\Download\Request;
use App\Repositories\InteractionRepository;
use App\Services\DownloadService;

/**
 * @group 6. Download
 */
class FavoritesController extends Controller
{
    private $interactionRepository;

    public function __construct(DownloadService $downloadService, InteractionRepository $interactionRepository)
    {
        parent::__construct($downloadService);
        $this->interactionRepository = $interactionRepository;
    }

    /**
     * Download all songs favorite'd by the current user
     *
     * @response []
     */
    public function show(Request $request)
    {
        $songs = $this->interactionRepository->getUserFavorites($request->user());

        return response()->download($this->downloadService->from($songs));
    }
}