<?php
ob_start();
require_once 'php/utils.php';

if (!fs_is_authenticated())
{
	error(403, "Authentication failed");
	return;
}


if (!isset($_GET['file_id']))
{
	error(404, "file_id not specified");	
}

global $conn;
global $tables;
$id = $conn->escape($_GET['file_id']);
$uid = $conn->escape(fs_current_user_id());

$res = $conn->get_var("SELECT file_name FROM $tables->files WHERE id=$id");
if ($res === false) error(500,db_error());
if ($res == null) error(404, "file_id $id not found in database");

$file_path = FILES_ROOT."/$res";
if (!file_exists($file_path)) 
{
	sendmail(ADMIN_EMAIL, "Download file not found","The file $file_path is missing (download_id = $id)");
	error(404, "File not found, the site administrator have been notified. please try again later.");
}
$res = $conn->get_var("SELECT num_downloads FROM $tables->downloads WHERE file_id=$id and user_id=$uid");
if ($res === false) error(500,db_error());
if ($res == null)
{
	$res = $conn->query("INSERT INTO $tables->downloads (user_id,file_id) VALUES ($uid,$id)");
	if ($res === false)  error(500,db_error());
}

$res = $conn->get_var("SELECT num_downloads FROM $tables->downloads WHERE user_id = $uid AND file_id= $id");
if ($res === false) error(500,db_error());
if ((int)$res > MAX_DOWNLOADS_PER_FILE) 
{
	error(403, sprintf("Download limit exceeded for this file, please contact %s", fs_link("mailto:".ADMIN_EMAIL, "support")));
}

header('Cache-control: private');
header('Content-Type: application/octet-stream');
header('Content-Length: '.filesize($file_path));
header('Content-Disposition: filename='.basename($file_path));

flush();
$file = fopen($file_path, "r");
while(!feof($file))
{
	// send the current file part to the browser
	print fread($file, 8192);
	// flush the content to the browser
	flush();
}
fclose($file);

if (connection_aborted ()) return; // not really working with fcgi (?), but I can hope.

$res = $conn->query("UPDATE downloads set num_downloads = num_downloads + 1 WHERE user_id = $uid AND file_id= $id");
if ($res === false) error(500,db_error());
?>