<?php

namespace EP\EpTheme\Form;

use TYPO3\CMS\Core\Site\SiteFinder;
use TYPO3\CMS\Core\Utility\GeneralUtility;
use TYPO3\CMS\Form\Domain\Finishers\AbstractFinisher;

class AddReferrerFinisher extends AbstractFinisher
{
    protected function executeInternal()
    {
        $this->addCurrentUrlField();
        $this->addReferrerField();
    }

    private function addReferrerField(): void
    {
        // Look for key 'referrer' in frontend session
        $referrer = $GLOBALS['TSFE']->fe_user->getKey('ses', 'referrer');

        if (null === $referrer) {
            return;
        }

        // Add textfield to form containing referrer value
        $field = $this->finisherContext
            ->getFormRuntime()
            ->getFormDefinition()
            ->getPageByIndex(0)
            ->createElement('referrer', 'Text');

        $field->setDefaultValue($referrer);
        $field->setDataType('string');
        $field->setLabel('Referrer');

        // Add finisher variable for potential later use
        $this->finisherContext->getFinisherVariableProvider()->add(
            $this->shortFinisherIdentifier,
            'referrer',
            $referrer
        );

        // Remove session key
        $GLOBALS['TSFE']->fe_user->setKey('ses', 'referrer', null);
        $GLOBALS['TSFE']->fe_user->storeSessionData();
    }

    private function addCurrentUrlField(): void
    {
        // Get URL of current page
        $pageId = $GLOBALS['TSFE']->id;
        $site = GeneralUtility::makeInstance(SiteFinder::class)->getSiteByPageId($pageId);
        $url = $site->getRouter()->generateUri($pageId);

        // Add textfield to form containing url value
        $field = $this->finisherContext
            ->getFormRuntime()
            ->getFormDefinition()
            ->getPageByIndex(0)
            ->createElement('pageurl', 'Text');

        $field->setDefaultValue($url);
        $field->setDataType('string');
        $field->setLabel('URL');

        // Add finisher variable for potential later use
        $this->finisherContext->getFinisherVariableProvider()->add(
            $this->shortFinisherIdentifier,
            'pageurl',
            $url
        );
    }
}