<?php

// This file is part of Moodle - http://moodle.org/
//
// Moodle is free software: you can redistribute it and/or modify
// it under the terms of the GNU General Public License as published by
// the Free Software Foundation, either version 3 of the License, or
// (at your option) any later version.
//
// Moodle is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
// GNU General Public License for more details.
//
// You should have received a copy of the GNU General Public License
// along with Moodle.  If not, see <http://www.gnu.org/licenses/>.

/**
 * This script serves draft files of current user
 *
 * @package    core
 * @subpackage file
 * @copyright  2008 Petr Skoda (http://skodak.org)
 * @license    http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
 */

// disable moodle specific debug messages and any errors in output
define('NO_DEBUG_DISPLAY', true);

require_once('config.php');
require_once('lib/filelib.php');

require_login();
if (isguestuser()) {
    throw new \moodle_exception('noguest');
}

$relativepath = get_file_argument();
$preview = optional_param('preview', null, PARAM_ALPHANUM);

// relative path must start with '/'
if (!$relativepath) {
    throw new \moodle_exception('invalidargorconf');
} else if ($relativepath[0] != '/') {
    throw new \moodle_exception('pathdoesnotstartslash');
}

// extract relative path components
$args = explode('/', ltrim($relativepath, '/'));

if (count($args) == 0) { // always at least user id
    throw new \moodle_exception('invalidarguments');
}

$contextid = (int)array_shift($args);
$component = array_shift($args);
$filearea  = array_shift($args);
$draftid   = (int)array_shift($args);

if ($component !== 'user' or $filearea !== 'draft') {
    send_file_not_found();
}

$context = context::instance_by_id($contextid);
if ($context->contextlevel != CONTEXT_USER) {
    send_file_not_found();
}

$userid = $context->instanceid;
if ($USER->id != $userid) {
    throw new \moodle_exception('invaliduserid');
}


$fs = get_file_storage();

$relativepath = implode('/', $args);
$fullpath = "/$context->id/user/draft/$draftid/$relativepath";

if (!$file = $fs->get_file_by_hash(sha1($fullpath)) or $file->get_filename() == '.') {
    send_file_not_found();
}

// ========================================
// finally send the file
// ========================================
\core\session\manager::write_close(); // Unlock session during file serving.
send_stored_file($file, 0, false, true, array('preview' => $preview)); // force download - security first!