<?php
header('Access-Control-Allow-Origin: *');
header('Access-Control-Allow-Methods: PUT, GET, POST, DELETE, OPTIONS');

if (array_key_exists('HTTP_ACCESS_CONTROL_REQUEST_HEADERS', $_SERVER))
{
    header('Access-Control-Allow-Headers: ' . $_SERVER['HTTP_ACCESS_CONTROL_REQUEST_HEADERS']);
}
else
{
    header('Access-Control-Allow-Headers: origin, x-requested-with, content-type, cache-control');
}

if ($_SERVER['REQUEST_METHOD'] == 'OPTIONS') die();

/**
 * @author Gregory Chris (http://online-php.com)
 * @email www.online.php@gmail.com
 * @editor Bivek Joshi (http://www.bivekjoshi.com.np)
 * @email meetbivek@gmail.com
 * HEAVILY MODIFIED by Veny T
 * This is a plain PHP version for dropzone
 * Chunks collected in uploads/tmp/
 * Whole files placed in uploads/whole_from_chunks/
 * Name of the final file returned upon finished process
 */

function returnJson($arr)
{
    header('Content-type: application/json');
    print json_encode($arr);
    exit;
}

if (!empty($_FILES))
{
    foreach ($_FILES as $file)
    {
        if ($file['error'] != 0)
        {
            $errors[] = array(
                'text' => 'File error',
                'error' => $file['error'],
                'name' => $file['name']
            );
            continue;
        }
        if (!$file['tmp_name'])
        {
            $errors[] = array(
                'text' => 'Tmp file not found',
                'name' => $file['name']
            );
            continue;
        }

        $tmp_file_path = $file['tmp_name'];
	
       	$filename = (isset($file['filename'])) ? $file['filename'] : $file['name'];
	
	if (isset($_POST['filename'])) {
	 $info = pathinfo($filename);
         $extension = isset($info['extension']) ? '.' . strtolower($info['extension']) : '';
	$filename = $_POST['filename'] .  $extension;
	}
        if (isset($_POST['dzuuid']))
        {
            $chunks_res = resumableUpload($tmp_file_path, $filename);
            if (!$chunks_res['final'])
            {
                returnJson($chunks_res);
            }
            else
            {
                returnJson($chunks_res);
            }
            $tmp_file_path = $chunks_res['path'];
        } else {
            $rel_path = $_REQUEST['dir'];
            $filename = str_replace(array(
                ' ',
                '(',
                ')'
            ) , '_', $filename); # remove problematic symbols
            $info = pathinfo($filename);
            $extension = isset($info['extension']) ? '.' . strtolower($info['extension']) : '';
            $saveName = isset($_POST['filename']) ? $_POST['filename'] :  $info['filename'];

            $new_path = "$rel_path$saveName$extension";

            move_uploaded_file($tmp_file_path, $new_path);

            returnJson(array(
                'final' => true,
                'path' => $new_path,
                'successes' => array('Successfully uploaded'),
                'errors' => array(),
                'warnings' => array()
            ));
        }
    }
}

/**
 *
 * Delete a directory RECURSIVELY
 * @param string $dir - directory path
 * @link http://php.net/manual/en/function.rmdir.php
 */
function rrmdir($dir)
{
    if (is_dir($dir))
    {
        $objects = scandir($dir);
        foreach ($objects as $object)
        {
            if ($object != "." && $object != "..")
            {
                if (filetype("$dir/$object") == "dir")
                {
                    rrmdir("$dir/$object");
                }
                else
                {
                    unlink("$dir/$object");
                }
            }
        }
        reset($objects);
        rmdir($dir);
    }
}

function cleanUp($file_chunks_folder)
{
    // rename the temporary directory (to avoid access from other concurrent chunks uploads) and than delete it
    if (rename($file_chunks_folder, $file_chunks_folder . '_UNUSED'))
    {
        rrmdir($file_chunks_folder . '_UNUSED');
    }
    else
    {
        rrmdir($file_chunks_folder);
    }
}

function resumableUpload($tmp_file_path, $filename)
{
    $successes = array();
    $errors = array();
    $warnings = array();
    $dir = "/tmp_upload/";

    $identifier = (isset($_POST['dzuuid'])) ? trim($_POST['dzuuid']) : '';

    $file_chunks_folder = "$dir$identifier";
    if (!is_dir($file_chunks_folder))
    {
        mkdir($file_chunks_folder, 0777, true);
    }

    $filename = str_replace(array(
        ' ',
        '(',
        ')'
    ) , '_', $filename); # remove problematic symbols
    $info = pathinfo($filename);
    $extension = isset($info['extension']) ? '.' . strtolower($info['extension']) : '';
    $filename = $info['filename'];

    $totalSize = (isset($_POST['dztotalfilesize'])) ? (int)$_POST['dztotalfilesize'] : 0;
    $totalChunks = (isset($_POST['dztotalchunkcount'])) ? (int)$_POST['dztotalchunkcount'] : 0;
    $chunkInd = (isset($_POST['dzchunkindex'])) ? (int)$_POST['dzchunkindex'] : 0;
    $chunkSize = (isset($_POST['dzchunksize'])) ? (int)$_POST['dzchunksize'] : 0;
    $startByte = (isset($_POST['dzchunkbyteoffset'])) ? (int)$_POST['dzchunkbyteoffset'] : 0;

    $chunk_file = "$file_chunks_folder/{$filename}.part{$chunkInd}";

    if (!move_uploaded_file($tmp_file_path, $chunk_file))
    {
        $errors[] = array(
            'text' => 'Move error',
            'name' => $filename,
            'index' => $chunkInd
        );
    }
    //$filename = time();
    if (count($errors) == 0 and $new_path = checkAllParts($file_chunks_folder, $filename, $extension, $totalSize, $totalChunks, $successes, $errors, $warnings) and count($errors) == 0)
    {
        return array(
            'final' => true,
            'path' => $new_path,
            'successes' => $successes,
            'errors' => $errors,
            'warnings' => $warnings
        );
    }
    return array(
        'final' => false,
        'successes' => $successes,
        'errors' => $errors,
        'warnings' => $warnings
    );
}

function checkAllParts($file_chunks_folder, $filename, $extension, $totalSize, $totalChunks, &$successes, &$errors, &$warnings)
{

    // reality: count all the parts of this file
    $parts = glob("$file_chunks_folder/*");
    $successes[] = count($parts) . " of $totalChunks parts done so far in $file_chunks_folder";

    // check if all the parts present, and create the final destination file
    if (count($parts) == $totalChunks)
    {
        $loaded_size = 0;
        foreach ($parts as $file)
        {
            $loaded_size += filesize($file);
        }
        if ($loaded_size >= $totalSize and $new_path = createFileFromChunks($file_chunks_folder, $filename, $extension, $totalSize, $totalChunks, $successes, $errors, $warnings) and count($errors) == 0)
        {
            cleanUp($file_chunks_folder);
            return $new_path;
        }
    }
    return false;
}

/**
 * Check if all the parts exist, and
 * gather all the parts of the file together
 * @param string $file_chunks_folder - the temporary directory holding all the parts of the file
 * @param string $fileName - the original file name
 * @param string $totalSize - original file size (in bytes)
 */
function createFileFromChunks($file_chunks_folder, $fileName, $extension, $total_size, $total_chunks, &$successes, &$errors, &$warnings)
{

    $rel_path = $_REQUEST['dir'];
    //$rel_path = "functions/uploads/whole_from_chunks/";
    $saveName = getNextAvailableFilename($rel_path, $fileName, $extension, $errors);

    if (!$saveName)
    {
        return false;
    }

    $fp = fopen("$rel_path$saveName$extension", 'w');
    if ($fp === false)
    {
        $errors[] = 'cannot create the destination file ' . $rel_path . $saveName . $extension;
        return false;
    }
    for ($i = 0;$i < $total_chunks;$i++)
    {
        fwrite($fp, file_get_contents($file_chunks_folder . '/' . $fileName . '.part' . $i));
    }
    fclose($fp);

    return "$rel_path$saveName$extension";
}

function getNextAvailableFilename($rel_path, $orig_file_name, $extension, &$errors)
{
    if (file_exists("$rel_path$orig_file_name$extension"))
    {
        $i = 0;
        while (file_exists("$rel_path{$orig_file_name}_" . (++$i) . $extension) and $i < 10000)
        {
        }
        if ($i >= 10000)
        {
            $errors[] = "Can not create unique name for saving file $orig_file_name$extension";
            return false;
        }
        return $orig_file_name . "_" . $i;
    }
    return $orig_file_name;
}