<?php
namespace XaiCorp\AbcParser\Domain\Core;

class TuneCollection extends Collection
{
    /**
     * Get the value of the first element in this collection.
     *
     * @throws \Enzyme\Collection\CollectionException If the collection is empty.
     *
     * @return \XaiCorp\AbcParser\Domain\Core\Tune
     */
    public function first()
    {
        return parent::first();
    }

    public function unique()
    {
        $result = [];
        /**
         * @var int $key
         * @var Tune $tune
         */
        foreach ($this->items as $key => $tune) {
            $tuneId = $tune->getETag();
            $result[$tuneId] = $tune;
        }

        return new TuneCollection(array_values($result));
    }
}