diff --git a/.gitignore b/.gitignore
index c105493..7a1e76a 100644
--- a/.gitignore
+++ b/.gitignore
@@ -1,3 +1,5 @@
 vendor/*
 composer.lock
-.idea
\ No newline at end of file
+.idea
+.phpunit.cache/*
+.phpunit.*.cache
\ No newline at end of file
diff --git a/composer.json b/composer.json
index db97502..b67d234 100644
--- a/composer.json
+++ b/composer.json
@@ -8,12 +8,12 @@
     }
   ],
   "require": {
-    "php": ">=5.3.0",
+    "php": ">=8.1.0",
     "cakephp/filesystem": "^3.0",
-    "monolog/monolog": "^1.17"
+    "monolog/monolog": "^2.0"
   },
   "require-dev": {
-    "phpunit/phpunit": "~4.0"
+    "phpunit/phpunit": "~10.0"
   },
   "license": "MIT",
   "autoload": {
diff --git a/phpunit.xml b/phpunit.xml
index 9447c87..851d307 100644
--- a/phpunit.xml
+++ b/phpunit.xml
@@ -1,18 +1,8 @@
 <?xml version="1.0" encoding="UTF-8"?>
-<phpunit backupGlobals="false"
-         backupStaticAttributes="false"
-         bootstrap="./vendor/autoload.php"
-         colors="true"
-         convertErrorsToExceptions="true"
-         convertNoticesToExceptions="true"
-         convertWarningsToExceptions="true"
-         processIsolation="false"
-         stopOnFailure="true"
-         syntaxCheck="false"
-        >
-    <testsuites>
-        <testsuite name="Package Test Suite">
-            <directory suffix=".php">./test/</directory>
-        </testsuite>
-    </testsuites>
-</phpunit>
\ No newline at end of file
+<phpunit xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" backupGlobals="false" bootstrap="./vendor/autoload.php" colors="true" processIsolation="false" stopOnFailure="true" xsi:noNamespaceSchemaLocation="https://schema.phpunit.de/10.5/phpunit.xsd" cacheDirectory=".phpunit.cache" backupStaticProperties="false">
+  <testsuites>
+    <testsuite name="Package Test Suite">
+      <directory suffix=".php">./test/</directory>
+    </testsuite>
+  </testsuites>
+</phpunit>
diff --git a/readme.md b/readme.md
index d3e3462..ce08d66 100644
--- a/readme.md
+++ b/readme.md
@@ -1,6 +1,5 @@
 # PHP backend for resumable.js
 
-
 ## Installation
 
 To install, use composer:
@@ -21,11 +20,23 @@ use Dilab\Resumable;
 
 $request = new SimpleRequest();
 $response = new SimpleResponse();
+// optional instanceId to seperate uploads from diffrent users like if two users want to upload untitled.jpg there would be no conflict anymore
+$instanceId = session_id();
 
-$resumable = new Resumable($request, $response);
+$resumable = new Resumable($request, $response, $instanceId);
 $resumable->tempFolder = 'tmps';
 $resumable->uploadFolder = 'uploads';
-$resumable->process();
+$status = $resumable->process();
+
+return match ($status){
+            200 => ['message' => 'OK'], // Uploading of chunk is complete.
+            201 => [
+                'message' => 'File uploaded',
+                'file' => $_REQUEST['resumableFilename']
+            ],// Uploading of whole file is complete.
+            204 => ['message' => 'Chunk not found'],
+            default => ['message' => 'An error occurred'] //status => 404
+        };
 
 ```
 
diff --git a/src/Network/SimpleResponse.php b/src/Network/SimpleResponse.php
index 715d8a2..5d37b96 100644
--- a/src/Network/SimpleResponse.php
+++ b/src/Network/SimpleResponse.php
@@ -11,12 +11,14 @@ class SimpleResponse implements Response
      */
     public function header($statusCode)
     {
-        if (200==$statusCode) {
-            return header($_SERVER["SERVER_PROTOCOL"]." 200 Ok");
-        } else if (404==$statusCode) {
-            return header($_SERVER["SERVER_PROTOCOL"]." 404 Not Found");
+        if($statusCode >= 500) {
+            $statusCode = 204;
         }
-        return header($_SERVER["SERVER_PROTOCOL"]." 204 No Content");
+        if (!in_array($statusCode, [200,201,204,404])) {
+            $statusCode = 404;
+        }
+        http_response_code($statusCode);
+        return $statusCode;
     }
 
 }
diff --git a/src/Resumable.php b/src/Resumable.php
index f2ae54c..a487237 100644
--- a/src/Resumable.php
+++ b/src/Resumable.php
@@ -24,6 +24,8 @@ class Resumable
 
     protected $response;
 
+    protected $instanceId;
+
     protected $params;
 
     protected $chunkFile;
@@ -45,15 +47,17 @@ class Resumable
         'filename' => 'filename',
         'chunkNumber' => 'chunkNumber',
         'chunkSize' => 'chunkSize',
-        'totalSize' => 'totalSize'
+        'totalSize' => 'totalSize',
+        'totalChunks' => 'totalChunks'
     ];
 
     const WITHOUT_EXTENSION = true;
 
-    public function __construct(Request $request, Response $response)
+    public function __construct(Request $request, Response $response, string|null $instanceId = null)
     {
         $this->request = $request;
         $this->response = $response;
+        $this->instanceId = $instanceId;
 
         $this->log = new Logger('debug');
         $this->log->pushHandler(new StreamHandler('debug.log', Logger::DEBUG));
@@ -81,9 +85,9 @@ public function process()
     {
         if (!empty($this->resumableParams())) {
             if (!empty($this->request->file())) {
-                $this->handleChunk();
+                return $this->handleChunk();
             } else {
-                $this->handleTestChunk();
+                return $this->handleTestChunk();
             }
         }
     }
@@ -174,10 +178,17 @@ public function handleTestChunk()
         $identifier = $this->resumableParam($this->resumableOption['identifier']);
         $filename = $this->resumableParam($this->resumableOption['filename']);
         $chunkNumber = $this->resumableParam($this->resumableOption['chunkNumber']);
+        $chunkSize = $this->resumableParam($this->resumableOption['chunkSize']);
+        $totalChunks = $this->resumableParam($this->resumableOption['totalChunks']);
 
         if (!$this->isChunkUploaded($identifier, $filename, $chunkNumber)) {
             return $this->response->header(204);
         } else {
+            if ($this->isFileUploadComplete($filename, $identifier, $totalChunks)) {
+                $this->isUploadComplete = true;
+                $this->createFileAndDeleteTmp($identifier, $filename);
+                return $this->response->header(201);
+            }
             return $this->response->header(200);
         }
 
@@ -190,16 +201,17 @@ public function handleChunk()
         $filename = $this->resumableParam($this->resumableOption['filename']);
         $chunkNumber = $this->resumableParam($this->resumableOption['chunkNumber']);
         $chunkSize = $this->resumableParam($this->resumableOption['chunkSize']);
-        $totalSize = $this->resumableParam($this->resumableOption['totalSize']);
+        $totalChunks = $this->resumableParam($this->resumableOption['totalChunks']);
 
         if (!$this->isChunkUploaded($identifier, $filename, $chunkNumber)) {
             $chunkFile = $this->tmpChunkDir($identifier) . DIRECTORY_SEPARATOR . $this->tmpChunkFilename($filename, $chunkNumber);
             $this->moveUploadedFile($file['tmp_name'], $chunkFile);
         }
 
-        if ($this->isFileUploadComplete($filename, $identifier, $chunkSize, $totalSize)) {
+        if ($this->isFileUploadComplete($filename, $identifier, $totalChunks)) {
             $this->isUploadComplete = true;
             $this->createFileAndDeleteTmp($identifier, $filename);
+            return $this->response->header(201);
         }
 
         return $this->response->header(200);
@@ -221,7 +233,12 @@ private function createFileAndDeleteTmp($identifier, $filename)
         }
 
         // replace filename reference by the final file
-        $this->filepath = $this->uploadFolder . DIRECTORY_SEPARATOR . $finalFilename;
+        $this->filepath = $this->uploadFolder . DIRECTORY_SEPARATOR;
+        if (!empty($this->instanceId)) {
+            $this->filepath .= $this->instanceId . DIRECTORY_SEPARATOR;
+        }
+        $this->filepath .= $finalFilename;
+
         $this->extension = $this->findExtension($this->filepath);
 
         if ($this->createFileFromChunks($chunkFiles, $this->filepath) && $this->deleteTmpFolder) {
@@ -249,13 +266,9 @@ public function resumableParams()
         }
     }
 
-    public function isFileUploadComplete($filename, $identifier, $chunkSize, $totalSize)
+    public function isFileUploadComplete($filename, $identifier, $totalChunks)
     {
-        if ($chunkSize <= 0) {
-            return false;
-        }
-        $numOfChunks = intval($totalSize / $chunkSize) + ($totalSize % $chunkSize == 0 ? 0 : 1);
-        for ($i = 1; $i < $numOfChunks; $i++) {
+        for ($i = 1; $i <= $totalChunks; $i++) {
             if (!$this->isChunkUploaded($identifier, $filename, $i)) {
                 return false;
             }
@@ -271,13 +284,38 @@ public function isChunkUploaded($identifier, $filename, $chunkNumber)
 
     public function tmpChunkDir($identifier)
     {
-        $tmpChunkDir = $this->tempFolder . DIRECTORY_SEPARATOR . $identifier;
-        if (!file_exists($tmpChunkDir)) {
-            mkdir($tmpChunkDir);
+        $tmpChunkDir = $this->tempFolder. DIRECTORY_SEPARATOR;
+        if (!empty($this->instanceId)){
+            $tmpChunkDir .= $this->instanceId . DIRECTORY_SEPARATOR;
         }
+        $tmpChunkDir .= $identifier;
+        $this->ensureDirExists($tmpChunkDir);
         return $tmpChunkDir;
     }
 
+    /**
+     * make directory if it doesn't exists (Immune against the race condition)
+     * 
+     * 
+     * since the resuamble is usually used with simultaneously uploads,
+     * this sometimes resulted in directory creation btween the *is_dir* check
+     * and *mkdir* then following race condition.
+     * in this setup it will shut down the mkdir error
+     * then try to check if directory is created after that
+     * 
+     * @param string $path the directoryPath to ensure
+     * @return void
+     * @throws \Exception
+     */
+    private function ensureDirExists($path)
+    {
+        umask(0);
+        if ( is_dir($path) || @mkdir($path, 0775, true) || is_dir($path)) {
+            return;
+        }
+        throw new \Exception("could not mkdir $path");
+    }
+
     public function tmpChunkFilename($filename, $chunkNumber)
     {
         return $filename . '.' . str_pad($chunkNumber, 4, 0, STR_PAD_LEFT);
@@ -299,6 +337,10 @@ public function createFileFromChunks($chunkFiles, $destFile)
 
         natsort($chunkFiles);
 
+        if (!empty($this->instanceId)) {
+            $this->ensureDirExists(dirname($destFile));
+        }
+
         $handle = $this->getExclusiveFileHandle($destFile);
         if (!$handle) {
             return false;
@@ -319,6 +361,9 @@ public function createFileFromChunks($chunkFiles, $destFile)
 
     public function moveUploadedFile($file, $destFile)
     {
+        //workaround cakephp error regarding: TMP not defined 
+        define("TMP",sys_get_temp_dir());
+
         $file = new File($file);
         if ($file->exists()) {
             return $file->copy($destFile);
diff --git a/test/src/Network/SimpleRequestTest.php b/test/src/Network/SimpleRequestTest.php
index 9fa3301..e6d8843 100644
--- a/test/src/Network/SimpleRequestTest.php
+++ b/test/src/Network/SimpleRequestTest.php
@@ -8,14 +8,14 @@
  * @package Dilab\Network
  * @property $request Request
  */
-class SimpleRequestTest extends \PHPUnit_Framework_TestCase
+class SimpleRequestTest extends \PHPUnit\Framework\TestCase
 {
-    protected function setUp()
+    protected function setUp() : void
     {
         $this->request = new SimpleRequest();
     }
 
-    public function tearDown()
+    public function tearDown() : void
     {
         unset($this->request);
         parent::tearDown();
diff --git a/test/src/Network/SimpleResponseTest.php b/test/src/Network/SimpleResponseTest.php
index 8772214..d567c4d 100644
--- a/test/src/Network/SimpleResponseTest.php
+++ b/test/src/Network/SimpleResponseTest.php
@@ -8,28 +8,28 @@
  * @package Dilab\Network
  * @property $response Response
  */
-class SimpleResponseTest extends \PHPUnit_Framework_TestCase
+class SimpleResponseTest extends \PHPUnit\Framework\TestCase
 {
-    protected function setUp()
+    protected function setUp() : void
     {
         $this->response = new SimpleResponse();
     }
 
-    public function tearDown()
+    public function tearDown() : void
     {
         unset($this->response);
         parent::tearDown();
     }
 
 
-    public function headerProvider()
+    public static function headerProvider()
     {
-        return array(
-            array(404,404),
-            array(204,204),
-            array(200,200),
-            array(500,204),
-        );
+        return [
+            [404,404],
+            [204,204],
+            [200,200],
+            [500,204],
+        ];
     }
 
     /**
diff --git a/test/src/ResumableTest.php b/test/src/ResumableTest.php
index 635dedc..4afe706 100644
--- a/test/src/ResumableTest.php
+++ b/test/src/ResumableTest.php
@@ -12,13 +12,13 @@
  * @property $request Request
  * @property $response Response
  */
-class ResumbableTest extends \PHPUnit_Framework_TestCase
+class ResumableTest extends \PHPUnit\Framework\TestCase
 {
     public $resumbable;
 
     protected $provider;
 
-    protected function setUp()
+    protected function setUp() : void
     {
         $this->request = $this->getMockBuilder('Dilab\Network\SimpleRequest')
                         ->getMock();
@@ -27,7 +27,7 @@ protected function setUp()
                         ->getMock();
     }
 
-    public function tearDown()
+    public function tearDown() : void
     {
         unset($this->request);
         unset($this->response);
@@ -45,21 +45,21 @@ public function testProcessHandleChunk()
             'resumableRelativePath'=> 'upload',
         );
 
-        $this->request->method('is')->will($this->returnValue(true));
+        $this->request->method('is')->willReturn(true);
 
         $this->request->method('file')
-                    ->will($this->returnValue(array(
+                    ->willReturn([
                             'name'=> 'mock.png',
-                            'tmp_name'=>  'test/files/mock.png.003',
+                            'tmp_name'=>  'test/files/mock.png.0003',
                             'error'=> 0,
                             'size'=> 27000,
-                        )));
+                        ]);
 
         $this->request->method('data')->willReturn($resumableParams);
 
         $this->resumbable = $this->getMockBuilder('Dilab\Resumable')
                                 ->setConstructorArgs(array($this->request,$this->response))
-                                ->setMethods(array('handleChunk'))
+                                ->onlyMethods(array('handleChunk'))
                                 ->getMock();
 
         $this->resumbable->expects($this->once())
@@ -80,15 +80,15 @@ public function testProcessHandleTestChunk()
             'resumableRelativePath'=> 'upload',
         );
 
-        $this->request->method('is')->will($this->returnValue(true));
+        $this->request->method('is')->willReturn(true);
 
-        $this->request->method('file')->will($this->returnValue(array()));
+        $this->request->method('file')->willReturn([]);
 
         $this->request->method('data')->willReturn($resumableParams);
 
         $this->resumbable = $this->getMockBuilder('Dilab\Resumable')
                                 ->setConstructorArgs(array($this->request,$this->response))
-                                ->setMethods(array('handleTestChunk'))
+                                ->onlyMethods(array('handleTestChunk'))
                                 ->getMock();
 
         $this->resumbable->expects($this->once())
@@ -101,12 +101,12 @@ public function testProcessHandleTestChunk()
     public function testHandleTestChunk()
     {
         $this->request->method('is')
-                      ->will($this->returnValue(true));
+                      ->willReturn(true);
 
         $this->request->method('data')
                       ->willReturn(array(
                            'resumableChunkNumber'=> 1,
-                           'resumableTotalChunks'=> 600,
+                           'resumableTotalSize'=> 600,
                            'resumableChunkSize'=>  200,
                            'resumableIdentifier'=> 'identifier',
                            'resumableFilename'=> 'mock.png',
@@ -125,7 +125,8 @@ public function testHandleTestChunk()
     public function testHandleChunk() {
         $resumableParams = array(
             'resumableChunkNumber'=> 3,
-            'resumableTotalChunks'=> 600,
+            // 'resumableTotalChunks'=> 600,
+            'resumableTotalSize'=> 600,
             'resumableChunkSize'=>  200,
             'resumableIdentifier'=> 'identifier',
             'resumableFilename'=> 'mock.png',
@@ -134,7 +135,7 @@ public function testHandleChunk() {
 
 
         $this->request->method('is')
-            ->will($this->returnValue(true));
+            ->willReturn(true);
 
         $this->request->method('data')
                 ->willReturn($resumableParams);
@@ -142,7 +143,7 @@ public function testHandleChunk() {
         $this->request->method('file')
                 ->willReturn(array(
                     'name'=> 'mock.png',
-                    'tmp_name'=>  'test/files/mock.png.003',
+                    'tmp_name'=>  'test/files/mock.png.0003',
                     'error'=> 0,
                     'size'=> 27000,
                 ));
@@ -154,7 +155,7 @@ public function testHandleChunk() {
         $this->resumbable->handleChunk();
 
         $this->assertFileExists('test/uploads/mock.png');
-        file_exists('test/tmp/identifier/mock.png.003') && unlink('test/tmp/identifier/mock.png.003');
+        file_exists('test/tmp/identifier/mock.png.0003') && unlink('test/tmp/identifier/mock.png.0003');
         unlink('test/uploads/mock.png');
     }
 
@@ -173,7 +174,7 @@ public function testResumableParamsGetRequest()
             ->getMock();
 
         $this->request->method('is')
-            ->will($this->returnValue(true));
+            ->willReturn(true);
 
         $this->request->method('data')->willReturn($resumableParams);
 
@@ -181,7 +182,7 @@ public function testResumableParamsGetRequest()
         $this->assertEquals($resumableParams, $this->resumbable->resumableParams());
     }
 
-    public function isFileUploadCompleteProvider()
+    public static function isFileUploadCompleteProvider()
     {
         return array(
             array('mock.png', 'files', 20, 60, true),