<?php

declare(strict_types=1);

/**
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License
 * as published by the Free Software Foundation; under version 2
 * of the License (non-upgradable).
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
 *
 * Copyright (c) 2013 (original work) Open Assessment Technologies S.A.
 *
 * @author "Patrick Plichart, <patrick@taotesting.com>"
 *
 * An Assessment Result is used to report the results of a candidate's interaction
 * with a test and/or one or more items attempted.
 * Information about the test is optional,
 * in some systems it may be possible to interact with items that are not organized into a test at all. For example,
 * items that are organized with learning resources and presented individually in a formative context.
 */
class taoResultServer_models_classes_TraceVariable extends taoResultServer_models_classes_Variable
{
    public const TYPE = 'traceVariable';

    /**
     * When a response variable is bound to an interaction that supports the shuffling of choices, the sequence of
     * choices experienced by the candidate will vary between test instances. When shuffling is in effect, the sequence
     * of choices should be reported as a sequence of choice identifiers using this attribute.
     *
     * @var string|null
     */
    protected $trace;

    public function setTrace(string $trace): self
    {
        $this->trace = $trace;

        return $this;
    }

    public function getTrace(): ?string
    {
        return $this->trace;
    }

    public function getValue()
    {
        return $this->getTrace();
    }

    public function setValue($value): self
    {
        $this->setTrace($value);

        return $this;
    }

    /**
     * {@inheritdoc}
     */
    public function jsonSerialize()
    {
        return parent::jsonSerialize() +
            [
                'trace' => $this->trace,
            ];
    }

    protected function getType(): string
    {
        return self::TYPE;
    }
}