<?php

declare(strict_types=1);

namespace Evomedien\Vitec\Service;

use TYPO3\CMS\Core\Utility\GeneralUtility;
use TYPO3\CMS\Frontend\ContentObject\ContentObjectRenderer;

/**
 * Resolves a page uid to its frontend URL.
 *
 * A headless renderer cannot hand a raw page uid to the frontend — React has no
 * way to turn `12` into a path. Every field that carries a link (`detailUrl`,
 * `headerLink`, the usecase list's item links) is therefore resolved server side.
 *
 * The resolution goes through `typoLink_URL`, so route enhancers and the slug of
 * the target page are honoured; building the path by hand would bypass both.
 *
 * This lived as a private copy in four renderers (Market list/show, Usecase
 * list/show). The copies had drifted in their failure handling — two returned
 * null, two an empty string — which is why the contract is spelled out here:
 * **null means "no link"**, and callers that need a string coalesce it.
 */
final class LinkResolver
{
    /**
     * Returns null when no page is set or the link cannot be resolved.
     *
     * Never throws: a broken link must not take down the whole JSON response,
     * so a failure downgrades to "no link" like an empty field would.
     */
    public static function pageUrl(int $pageUid): ?string
    {
        if ($pageUid <= 0) {
            return null;
        }

        try {
            $cObj = GeneralUtility::makeInstance(ContentObjectRenderer::class);
            $url = $cObj->typoLink_URL(['parameter' => (string)$pageUid]);

            return $url !== '' ? $url : null;
        } catch (\Throwable $e) {
            return null;
        }
    }
}