<?php
function savePhoto($remoteImage, $isbn) {
    $ch = curl_init();
    curl_setopt ($ch, CURLOPT_URL, $remoteImage);
    curl_setopt ($ch, CURLOPT_RETURNTRANSFER, 1);
    curl_setopt ($ch, CURLOPT_CONNECTTIMEOUT, 0);
    $fileContents = curl_exec($ch);
    curl_close($ch);
    $newImg = imagecreatefromstring($fileContents);
    return imagejpeg($newImg, "./photos/{$isbn}.jpg",100);
}
function rand_str($length = 32, $chars = 'ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz1234567890')
{
    $chars_length = (strlen($chars) - 1);
    $string = $chars{rand(0, $chars_length)};
    for ($i = 1; $i < $length; $i = strlen($string))
    {
        $r = $chars{rand(0, $chars_length)};
        if ($r != $string{$i - 1}) $string .=  $r;
    }
    return $string;
}
$fileURL = $_POST['filadress'];
savePhoto($fileURL, rand_str());