Erant-OldApp/api/routes/game/details.php

<?php

function remoteFileExists($url) {
    $curl = curl_init($url);

    //don't fetch the actual page, you only want to check the connection is ok
    curl_setopt($curl, CURLOPT_NOBODY, true);

    //do request
    $result = curl_exec($curl);

    $ret = false;

    //if request did not fail
    if ($result !== false) {
        //if request was ok, check response code
        $statusCode = curl_getinfo($curl, CURLINFO_HTTP_CODE);  

        if ($statusCode == 200) {
            $ret = true;   
        }
    }

    curl_close($curl);

    return $ret;
}

return [

	"post" => function($data, $headers, $db) {
		$imagesHostName = 'https://geohry.skolazdola.cz/';

		$gameUrl = $data['gameurl'];

		$gameDetails = $db->select('games4', '*', [
			'url' => $gameUrl
		])[0];

		$gameDetails["questions"] = $db->select('questions4', '*', [
			'url' => $gameUrl
		]);

		$thumbnailPath = "{$imagesHostName}/games/{$gameUrl}/intro.jpg";
		$gameDetails["thumbnail"] = remoteFileExists($thumbnailPath) ? $thumbnailPath : null;

		foreach($gameDetails["questions"] as &$question) {
			$questionThumbnailPath = "{$imagesHostName}/games/{$gameUrl}/" . $question["uniqid"] . ".jpg";
			$question["thumbnail"] = remoteFileExists($questionThumbnailPath) ? $questionThumbnailPath : null;
		}

		return $gameDetails;
	}

];