Steam Workshop downloader

steamworkshop.php

<?php
/*
 * Usage Multiples:
 *      http://localhost/steamworkshop.php?ids[]=779297608&ids[]=468207596&ids[]=568872931&ids[]=898613611
 * Usage Single:
 *      http://localhost/steamworkshop.php?id=779297608
*/
set_time_limit(0);

define("API_URL", "http://api.steampowered.com/ISteamRemoteStorage/GetPublishedFileDetails/v0001/");
function getWorkshopFileUrl($id)
{
    $ch = curl_init(API_URL);
    curl_setopt($ch, CURLOPT_HEADER, 0);
    curl_setopt($ch, CURLOPT_POST, 1);
    curl_setopt($ch, CURLOPT_POSTFIELDS, "itemcount=1&publishedfileids[0]=" . $id . "&format=json");
    curl_setopt($ch, CURLOPT_RETURNTRANSFER, 1);
    $output = curl_exec($ch);
    $sharedfile = json_decode($output);
    curl_close($ch);
    
    if(!isset($sharedfile->response))
        return null;
    if(!isset($sharedfile->response->publishedfiledetails) || sizeof($sharedfile->response->publishedfiledetails) == 0)
        return null;

    return array(
        "url"  => $sharedfile->response->publishedfiledetails[0]->file_url,
        "name" => $sharedfile->response->publishedfiledetails[0]->filename
    );
}

function getWorkshopFileDetails($num, $ids)
{
    $ch = curl_init(API_URL);
    curl_setopt($ch, CURLOPT_HEADER, 0);
    curl_setopt($ch, CURLOPT_POST, 1);
    curl_setopt($ch, CURLOPT_POSTFIELDS, "itemcount=" . $num . "&" . $ids . "&format=json");
    curl_setopt($ch, CURLOPT_RETURNTRANSFER, 1);
    $output = curl_exec($ch);
    $sharedfile = json_decode($output);
    curl_close($ch);

    if(!isset($sharedfile->response))
        return null;
    if(!isset($sharedfile->response->publishedfiledetails) || sizeof($sharedfile->response->publishedfiledetails) == 0)
        return null;

    return $sharedfile->response->publishedfiledetails;
}

function convertIdsToParameter($ids)
{
    $res = array();
    for ($i = 0; $i < sizeof($ids); $i++)
        array_push($res, "publishedfileids[" . $i . "]=" . $ids[$i]);

    return join("&", $res);
}

function downloadFileTemp($fileUrl, $fileName, $method = 0)
{
    //$tempFileName = sys_get_temp_dir() . "/" . $fileName;
    $tempFileName = "temp/" . $fileName;
    if ($method == 0) {
        if (!file_put_contents($tempFileName, fopen($fileUrl, 'r')))
            throw new Exception("Downloading file failed.");
    } elseif ($method == 1) {
        $fp = fopen($tempFileName, "w");

        $ch = curl_init();
        $options = array(
            CURLOPT_FILE    => $fp,
            CURLOPT_TIMEOUT => 28800,
            CURLOPT_URL     => $fileUrl,
        );
        curl_setopt_array($ch, $options);
        curl_exec($ch);
        curl_close($ch);
        fclose($fp);
    }

    return $tempFileName;
}

if (isset($_GET['id'])) {
    $id = $_GET['id'];
    if (!is_numeric($id))
        exit("Unsupported ID.");
    $file = getWorkshopFileUrl($id);
    if($file == null)
        die("File not found.");
    
    $fileUrl = $file['url'];
    $fileName = $file['name'];
    
    header('Content-Type: application/octet-stream');
    header("Content-Transfer-Encoding: Binary");
    header("Content-disposition: attachment; filename=\"" . $fileName . "\"");

    if( ini_get('allow_url_fopen') ) {
        readfile($fileUrl);
        exit();
    }else{
        exit("Not supported.");
    }
} elseif (isset($_GET['ids'])) {
    $ids = $_GET['ids'];
    if (!is_array($ids))
        exit("Unsupported.");

    $files = getWorkshopFileDetails(sizeof($ids), convertIdsToParameter($ids));
    if($files == null)
      die("Not supported.");

    $fileNames = array();
    foreach ($files as $file) {
      $fileNames[] = downloadFileTemp($file->file_url, basename($file->filename));
    }

    $zipname = time() . "_" . $_SERVER['REMOTE_ADDR'] . ".zip";
    $zip = new ZipArchive;
    if(!$zip->open($zipname, ZipArchive::CREATE))
      die("Error creating zip..");
    foreach ($fileNames as $file) {
      $zip->addFile($file, basename($file));
    }
    $zip->close();

    foreach ($fileNames as $file) {
      @unlink($file);
    }
    header('Content-Type: application/zip');
    header('Content-disposition: attachment; filename=' . $zipname);
    header('Content-Length: ' . filesize($zipname));
    readfile($zipname);
    @unlink($zipname);
}