diff --git a/.gitignore b/.gitignore
new file mode 100644
index 0000000000000000000000000000000000000000..f4da20891502a3992abf2981d8f6c46e33868ab6
--- /dev/null
+++ b/.gitignore
@@ -0,0 +1,4 @@
+tools/
+phpstan.neon
+.phpunit.result.cache
+phpunit.xml
\ No newline at end of file
diff --git a/.phive/phars.xml b/.phive/phars.xml
new file mode 100644
index 0000000000000000000000000000000000000000..a1315a09b4adad780a9c5e52f74835c708c5c7d5
--- /dev/null
+++ b/.phive/phars.xml
@@ -0,0 +1,4 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<phive xmlns="https://phar.io/phive">
+  <phar name="phpstan" version="^1.10.67" installed="1.10.67" location="./tools/phpstan" copy="false"/>
+</phive>
diff --git a/ajax/activate.php b/ajax/activate.php
index f0d9443ea69e53cae2a5c33bb276741eacb690e7..b84ce1082bdcad248149960b65389499ec6b56e0 100644
--- a/ajax/activate.php
+++ b/ajax/activate.php
@@ -9,13 +9,16 @@
  *
  * @param integer $discountId - Discount-ID
  */
+
+use QUI\ERP\Discount\Discount;
+
 QUI::$Ajax->registerFunction(
     'package_quiqqer_discount_ajax_activate',
     function ($discountId) {
-        $Handler  = new QUI\ERP\Discount\Handler();
+        $Handler = new QUI\ERP\Discount\Handler();
         $Discount = $Handler->getChild($discountId);
 
-        /* @var $Discount \QUI\ERP\Discount\Discount */
+        /* @var $Discount Discount */
         $Discount->setAttribute('active', 1);
         $Discount->update();
 
diff --git a/ajax/create.php b/ajax/create.php
index 44fb53279a924cdeab5896a339e4b35b309e97a1..d014dcbc4ea1842a8a20272edc55e5c15b644862 100644
--- a/ajax/create.php
+++ b/ajax/create.php
@@ -12,7 +12,7 @@
 QUI::$Ajax->registerFunction(
     'package_quiqqer_discount_ajax_create',
     function ($params) {
-        $params    = json_decode($params, true);
+        $params = json_decode($params, true);
         $Discounts = new QUI\ERP\Discount\Handler();
 
         if (!isset($params['active'])) {
diff --git a/ajax/deactivate.php b/ajax/deactivate.php
index dd763228ecbc5ffebc4a748674d7cf86c7324574..d82213b85cdb306278a4cba0f91fd7d5760cb585 100644
--- a/ajax/deactivate.php
+++ b/ajax/deactivate.php
@@ -9,13 +9,16 @@
  *
  * @param integer $discountId - Discount-ID
  */
+
+use QUI\ERP\Discount\Discount;
+
 QUI::$Ajax->registerFunction(
     'package_quiqqer_discount_ajax_deactivate',
     function ($discountId) {
-        $Handler  = new QUI\ERP\Discount\Handler();
+        $Handler = new QUI\ERP\Discount\Handler();
         $Discount = $Handler->getChild($discountId);
 
-        /* @var $Discount \QUI\ERP\Discount\Discount */
+        /* @var $Discount Discount */
         $Discount->setAttribute('active', 0);
         $Discount->update();
 
diff --git a/ajax/deleteChild.php b/ajax/deleteChild.php
index c95c99f64a87e6cef6a6a142b88c09af14e8ad6a..1ab42737aa058a82e124c091363611a94b05ab6f 100644
--- a/ajax/deleteChild.php
+++ b/ajax/deleteChild.php
@@ -15,7 +15,7 @@
     'package_quiqqer_discount_ajax_deleteChild',
     function ($discountId) {
         $Discounts = new QUI\ERP\Discount\Handler();
-        $Discount  = $Discounts->getChild($discountId);
+        $Discount = $Discounts->getChild($discountId);
         $Discount->delete();
     },
     ['discountId'],
diff --git a/ajax/deleteChildren.php b/ajax/deleteChildren.php
index 933bcbb89e1c04755945a8e19a2f2b97d6750af0..1b06068f259bae5d6f6ded74ace6e9f00ffd84dd 100644
--- a/ajax/deleteChildren.php
+++ b/ajax/deleteChildren.php
@@ -14,8 +14,8 @@
 QUI::$Ajax->registerFunction(
     'package_quiqqer_discount_ajax_deleteChildren',
     function ($discountIds) {
-        $discountIds    = json_decode($discountIds, true);
-        $Discounts      = new QUI\ERP\Discount\Handler();
+        $discountIds = json_decode($discountIds, true);
+        $Discounts = new QUI\ERP\Discount\Handler();
         $ExceptionStack = new QUI\ExceptionStack();
 
         foreach ($discountIds as $discountId) {
diff --git a/ajax/get.php b/ajax/get.php
index c6efba879f4379ba5eefd623da3483d423e66e3e..7a941df712e29a81218ee05b3f6379b480366092 100644
--- a/ajax/get.php
+++ b/ajax/get.php
@@ -11,14 +11,17 @@
  *
  * @return array
  */
+
+use QUI\ERP\Discount\Discount;
+
 QUI::$Ajax->registerFunction(
     'package_quiqqer_discount_ajax_get',
     function ($id) {
-        $Discounts  = new QUI\ERP\Discount\Handler();
-        $Discount   = $Discounts->getChild($id);
+        $Discounts = new QUI\ERP\Discount\Handler();
+        $Discount = $Discounts->getChild($id);
         $attributes = $Discount->getAttributes();
 
-        /* @var $Discount \QUI\ERP\Discount\Discount */
+        /* @var $Discount Discount */
         $attributes['title'] = $Discount->getTitle();
 
         return $attributes;
diff --git a/ajax/list.php b/ajax/list.php
index c01ebe6796519bebcf4692c1f426e3a4b3561e2a..6a0665c7a933e5e40f84b4650473fe38f444ab47 100644
--- a/ajax/list.php
+++ b/ajax/list.php
@@ -20,7 +20,7 @@ function ($params) {
         $Locale = QUI::getLocale();
 
         // search
-        $params = $Grid->parseDBParams(\json_decode($params, true));
+        $params = $Grid->parseDBParams(json_decode($params, true));
 
         $params['where'] = [
             'hidden' => 0
diff --git a/ajax/toggle.php b/ajax/toggle.php
index da595f9bada0f6e63ae5265e392e8951053c7bad..2ff6bc5c79523e9761dabcdca9a65cfdd62fbba0 100644
--- a/ajax/toggle.php
+++ b/ajax/toggle.php
@@ -9,13 +9,16 @@
  *
  * @param integer $discountId - Discount-ID
  */
+
+use QUI\ERP\Discount\Discount;
+
 QUI::$Ajax->registerFunction(
     'package_quiqqer_discount_ajax_toggle',
     function ($discountId) {
-        $Handler  = new QUI\ERP\Discount\Handler();
+        $Handler = new QUI\ERP\Discount\Handler();
         $Discount = $Handler->getChild($discountId);
 
-        /* @var $Discount \QUI\ERP\Discount\Discount */
+        /* @var $Discount Discount */
         if ($Discount->isActive()) {
             $Discount->setAttribute('active', 0);
         } else {
diff --git a/ajax/update.php b/ajax/update.php
index 790782af429c5fef61ca11ff961c8f7efc39f44c..d957092b5af2fa5df48157551c45ebe7aa58d482 100644
--- a/ajax/update.php
+++ b/ajax/update.php
@@ -16,8 +16,8 @@
     'package_quiqqer_discount_ajax_update',
     function ($discountId, $params) {
         $Discounts = new QUI\ERP\Discount\Handler();
-        $Discount  = $Discounts->getChild($discountId);
-        $params    = json_decode($params, true);
+        $Discount = $Discounts->getChild($discountId);
+        $params = json_decode($params, true);
 
         $Discount->setAttributes($params);
         $Discount->update();
diff --git a/composer.json b/composer.json
index d9f20c7b961b84641891186ac575d29f6264ab9d..fbc7f6afd4bca6a2b3be7f79a119f347566db92c 100644
--- a/composer.json
+++ b/composer.json
@@ -1,5 +1,5 @@
 {
-  "name": "quiqqer\/discount",
+  "name": "quiqqer/discount",
   "type": "quiqqer-plugin",
   "description": "Create discounts for user groups, specific users as well as time controlled.",
   "license": [
@@ -9,25 +9,25 @@
     {
       "name": "Henning Leutz",
       "email": "leutz@pcsg.de",
-      "homepage": "http:\/\/www.pcsg.de",
+      "homepage": "https://www.pcsg.de",
       "role": "Developer"
     }
   ],
   "support": {
     "email": "support@pcsg.de",
-    "url": "http:\/\/www.pcsg.de"
+    "url": "https://www.pcsg.de"
   },
   "require": {
-    "php": ">=5.3",
-    "quiqqer\/quiqqer": "*@dev",
-    "quiqqer\/areas": "*@dev",
-    "quiqqer\/products": "^1.6|*@dev",
-    "quiqqer\/tax": "*@dev"
+    "php": "^8.2",
+    "quiqqer/core": "^2",
+    "quiqqer/areas": "^2",
+    "quiqqer/products": "^2",
+    "quiqqer/tax": "^2"
   },
   "autoload": {
     "psr-4": {
-      "QUI\\ERP\\Discount\\": "src\/QUI\/ERP\/Discount",
-      "QUITests\\ERP\\Discount\\": "tests\/QUITests\/ERP\/Discount"
+      "QUI\\ERP\\Discount\\": "src/QUI/ERP/Discount",
+      "QUITests\\ERP\\Discount\\": "tests/QUITests/ERP/Discount"
     }
   }
 }
diff --git a/phpstan-baseline.neon b/phpstan-baseline.neon
new file mode 100644
index 0000000000000000000000000000000000000000..e69de29bb2d1d6434b8b29ae775ad8c2e48c5391
diff --git a/phpstan.dist.neon b/phpstan.dist.neon
new file mode 100644
index 0000000000000000000000000000000000000000..a545a041a3c5b0c758d99bf8c1c49b2a83252eaa
--- /dev/null
+++ b/phpstan.dist.neon
@@ -0,0 +1,10 @@
+includes:
+    - phpstan-baseline.neon
+
+parameters:
+    level: 1
+    paths:
+        - src
+        - ajax
+    bootstrapFiles:
+        - tests/phpstan-bootstrap.php
\ No newline at end of file
diff --git a/src/QUI/ERP/Discount/Discount.php b/src/QUI/ERP/Discount/Discount.php
index 2715d73681b662bdb25545db46ae9eaf77858022..b9b2171d23d138b1907afdf56fd898e95a564c1f 100644
--- a/src/QUI/ERP/Discount/Discount.php
+++ b/src/QUI/ERP/Discount/Discount.php
@@ -7,12 +7,25 @@
 namespace QUI\ERP\Discount;
 
 use QUI;
+use QUI\Database\Exception;
 use QUI\ERP\Order\OrderInterface;
+use QUI\ERP\Products\Interfaces\PriceFactorInterface;
+use QUI\ERP\Products\Interfaces\PriceFactorWithVatInterface;
+use QUI\ERP\Products\Utils\PriceFactor;
 use QUI\Users\User;
 use QUI\Permissions\Permission;
 use QUI\Utils\Security\Orthos;
 use QUI\ERP\Areas\Utils as AreaUtils;
 
+use function array_key_exists;
+use function explode;
+use function implode;
+use function is_array;
+use function is_numeric;
+use function is_string;
+use function strtotime;
+use function time;
+
 /**
  * Class Discount
  * @package QUI\ERP\Discount
@@ -24,6 +37,7 @@ class Discount extends QUI\CRUD\Child
      *
      * @param int $id
      * @param Handler $Factory
+     * @throws Exception
      */
     public function __construct($id, Handler $Factory)
     {
@@ -61,7 +75,7 @@ public function __construct($id, Handler $Factory)
 
         // cleanup user group save
         $cleanup = QUI\Utils\ArrayHelper::cleanup($this->getAttribute('user_groups'));
-        $cleanup = \implode(',', $cleanup);
+        $cleanup = implode(',', $cleanup);
 
         if (!empty($cleanup)) {
             $cleanup = ',' . $cleanup . ',';
@@ -72,7 +86,7 @@ public function __construct($id, Handler $Factory)
 
         // cleanup product(s)
         $cleanup = QUI\Utils\ArrayHelper::cleanup($this->getAttribute('articles'));
-        $cleanup = \implode(',', $cleanup);
+        $cleanup = implode(',', $cleanup);
 
         if (!empty($cleanup)) {
             $cleanup = ',' . $cleanup . ',';
@@ -83,7 +97,7 @@ public function __construct($id, Handler $Factory)
 
         // cleanup user group save
         $cleanup = QUI\Utils\ArrayHelper::cleanup($this->getAttribute('user_groups'));
-        $cleanup = \implode(',', $cleanup);
+        $cleanup = implode(',', $cleanup);
 
         if (!empty($cleanup)) {
             $cleanup = ',' . $cleanup . ',';
@@ -94,7 +108,7 @@ public function __construct($id, Handler $Factory)
 
         // cleanup product(s)
         $cleanup = QUI\Utils\ArrayHelper::cleanup($this->getAttribute('articles'));
-        $cleanup = \implode(',', $cleanup);
+        $cleanup = implode(',', $cleanup);
 
         if (!empty($cleanup)) {
             $cleanup = ',' . $cleanup . ',';
@@ -203,29 +217,29 @@ public function __construct($id, Handler $Factory)
     }
 
     /**
-     * @param string $key
-     * @param array|bool|object|string $value
-     * @return QUI\QDOM|void
+     * @param string $name
+     * @param mixed $value
+     * @return void
      */
-    public function setAttribute($key, $value)
+    public function setAttribute(string $name, mixed $value): void
     {
-        if ($key === 'lastSumDiscount' && empty($value)) {
+        if ($name === 'lastSumDiscount' && empty($value)) {
             $value = null;
         }
 
-        if ($key === 'lastProductDiscount' && empty($value)) {
+        if ($name === 'lastProductDiscount' && empty($value)) {
             $value = null;
         }
 
         if (
-            $key === 'scope' ||
-            $key === 'discount_type' ||
-            $key === 'usage_type'
+            $name === 'scope' ||
+            $name === 'discount_type' ||
+            $name === 'usage_type'
         ) {
             $value = (int)$value;
         }
 
-        parent::setAttribute($key, $value);
+        parent::setAttribute($name, $value);
     }
 
     /**
@@ -234,7 +248,7 @@ public function setAttribute($key, $value)
      * @param null|QUI\Locale $Locale - optional, locale object
      * @return string
      */
-    public function getTitle($Locale = null)
+    public function getTitle(QUI\Locale $Locale = null): string
     {
         if (!$Locale) {
             $Locale = QUI::getLocale();
@@ -251,9 +265,9 @@ public function getTitle($Locale = null)
      *
      * @return boolean
      */
-    public function isActive()
+    public function isActive(): bool
     {
-        return $this->getAttribute('active') ? true : false;
+        return (bool)$this->getAttribute('active');
     }
 
     /**
@@ -262,7 +276,7 @@ public function isActive()
      * @param Discount $Discount
      * @return bool
      */
-    public function canCombinedWith(Discount $Discount)
+    public function canCombinedWith(Discount $Discount): bool
     {
         $combine = $this->getAttribute('combine');
 
@@ -270,16 +284,10 @@ public function canCombinedWith(Discount $Discount)
             return false;
         }
 
-        $combine = \implode($combine, ',');
+        $combine = implode($combine, ',');
 
-        if (!\is_array($combine)) {
-            return false;
-        }
-
-        foreach ($combine as $combineId) {
-            if ($Discount->getId() == $combineId) {
-                return true;
-            }
+        if (in_array($Discount->getId(), (array)$combine)) {
+            return true;
         }
 
         return false;
@@ -291,7 +299,7 @@ public function canCombinedWith(Discount $Discount)
      * @param QUI\Interfaces\Users\User $User
      * @return boolean
      */
-    public function canUsedBy(QUI\Interfaces\Users\User $User)
+    public function canUsedBy(QUI\Interfaces\Users\User $User): bool
     {
         if ($this->isActive() === false) {
             return false;
@@ -300,13 +308,13 @@ public function canUsedBy(QUI\Interfaces\Users\User $User)
         // usage definitions / limits
         $dateFrom = $this->getAttribute('date_from');
         $dateUntil = $this->getAttribute('date_until');
-        $now = \time();
+        $now = time();
 
-        if ($dateFrom && \strtotime($dateFrom) > $now) {
+        if ($dateFrom && strtotime($dateFrom) > $now) {
             return false;
         }
 
-        if ($dateUntil && \strtotime($dateUntil) < $now) {
+        if ($dateUntil && strtotime($dateUntil) < $now) {
             return false;
         }
 
@@ -314,7 +322,7 @@ public function canUsedBy(QUI\Interfaces\Users\User $User)
         $userGroupValue = $this->getAttribute('user_groups');
         $areasValue = $this->getAttribute('areas');
 
-        // if groups and areas are empty, everbody is allowed
+        // if groups and areas are empty, everybody is allowed
         if (empty($userGroupValue) && empty($areasValue)) {
             return true;
         }
@@ -336,6 +344,10 @@ public function canUsedBy(QUI\Interfaces\Users\User $User)
             if ($User->getId() == $uid) {
                 return true;
             }
+
+            if ($User->getUUID() == $uid) {
+                return true;
+            }
         }
 
         // group checking
@@ -344,7 +356,11 @@ public function canUsedBy(QUI\Interfaces\Users\User $User)
         /* @var $Group QUI\Groups\Group */
         foreach ($discountGroups as $gid) {
             foreach ($groupsOfUser as $Group) {
-                if ($Group->getId() == $gid) {
+                if ($Group->getUsers() == $gid) {
+                    return true;
+                }
+
+                if ($Group->getUUID() == $gid) {
                     return true;
                 }
             }
@@ -359,26 +375,26 @@ public function canUsedBy(QUI\Interfaces\Users\User $User)
      * @param QUI\ERP\Products\Interfaces\ProductInterface $Product
      * @return boolean
      */
-    public function canUsedWith(QUI\ERP\Products\Interfaces\ProductInterface $Product)
+    public function canUsedWith(QUI\ERP\Products\Interfaces\ProductInterface $Product): bool
     {
         if ($this->isActive() === false) {
             return false;
         }
 
         // coupon
-        if ($Product->getId() === '-') {
+        if ($Product->getId() === -1) {
             return false;
         }
 
         $articles = $this->getAttribute('articles');
         $categories = $this->getAttribute('categories');
 
-        if (\is_string($articles)) {
-            $articles = \explode(',', $articles);
+        if (is_string($articles)) {
+            $articles = explode(',', $articles);
         }
 
-        if (\is_string($categories)) {
-            $categories = \explode(',', $categories);
+        if (is_string($categories)) {
+            $categories = explode(',', $categories);
         }
 
 
@@ -388,9 +404,9 @@ public function canUsedWith(QUI\ERP\Products\Interfaces\ProductInterface $Produc
         }
 
         // article / product check
-        if (\is_array($articles)) {
+        if (is_array($articles)) {
             foreach ($articles as $articleId) {
-                if ((int)$Product->getId() === (int)$articleId) {
+                if ($Product->getId() === (int)$articleId) {
                     return true;
                 }
             }
@@ -401,7 +417,7 @@ public function canUsedWith(QUI\ERP\Products\Interfaces\ProductInterface $Produc
             return true;
         }
 
-        if (!\is_array($categories)) {
+        if (!is_array($categories)) {
             return false;
         }
 
@@ -410,7 +426,7 @@ public function canUsedWith(QUI\ERP\Products\Interfaces\ProductInterface $Produc
 
             foreach ($productCategories as $Category) {
                 /* @var $Category QUI\ERP\Products\Category\Category */
-                if ((int)$Category->getId() === (int)$category) {
+                if ($Category->getId() === (int)$category) {
                     return true;
                 }
             }
@@ -424,7 +440,7 @@ public function canUsedWith(QUI\ERP\Products\Interfaces\ProductInterface $Produc
      * @param OrderInterface $Order
      * @return bool
      */
-    public function canUsedInOrder(OrderInterface $Order)
+    public function canUsedInOrder(OrderInterface $Order): bool
     {
         if ($this->isActive() === false) {
             return false;
@@ -436,7 +452,7 @@ public function canUsedInOrder(OrderInterface $Order)
             /* @var $Article QUI\ERP\Accounting\Article */
             $id = $Article->getId();
 
-            if (!\is_numeric($id)) {
+            if (!is_numeric($id)) {
                 continue;
             }
 
@@ -446,7 +462,7 @@ public function canUsedInOrder(OrderInterface $Order)
                 if ($this->canUsedWith($Product)) {
                     return true;
                 }
-            } catch (QUI\Exception $Exception) {
+            } catch (QUI\Exception) {
                 continue;
             }
         }
@@ -460,7 +476,7 @@ public function canUsedInOrder(OrderInterface $Order)
      * @param Discount $Discount
      * @throws QUI\ERP\Discount\Exception
      */
-    public function verifyCombinationWith(Discount $Discount)
+    public function verifyCombinationWith(Discount $Discount): void
     {
         if ($this->canCombinedWith($Discount) === false) {
             throw new QUI\ERP\Discount\Exception([
@@ -480,7 +496,7 @@ public function verifyCombinationWith(Discount $Discount)
      * @param User $User
      * @throws QUI\ERP\Discount\Exception
      */
-    public function verifyUser(User $User)
+    public function verifyUser(User $User): void
     {
         if ($this->canUsedBy($User) === false) {
             throw new QUI\ERP\Discount\Exception([
@@ -488,7 +504,7 @@ public function verifyUser(User $User)
                 'exception.discount.user.cant.use.discount',
                 [
                     'id' => $this->getId(),
-                    'userId' => $User->getId()
+                    'userId' => $User->getUUID()
                 ]
             ]);
         }
@@ -497,13 +513,15 @@ public function verifyUser(User $User)
     /**
      * Parse the discount to a price factor
      *
-     * @param null|QUI\Locale $Locale - optional, locale object
-     * @param null|QUI\Interfaces\Users\User $Customer - optional,
+     * @param null $Locale - optional, locale object
+     * @param null $Customer - optional,
      *
-     * @return QUI\ERP\Products\Interfaces\PriceFactorWithVatInterface|QUI\ERP\Products\Interfaces\PriceFactorInterface
+     * @return PriceFactorInterface|PriceFactorWithVatInterface|PriceFactor
      */
-    public function toPriceFactor($Locale = null, $Customer = null)
-    {
+    public function toPriceFactor(
+        $Locale = null,
+        $Customer = null
+    ): QUI\ERP\Products\Interfaces\PriceFactorInterface|QUI\ERP\Products\Interfaces\PriceFactorWithVatInterface|QUI\ERP\Products\Utils\PriceFactor {
         switch ($this->getAttribute('discount_type')) {
             case QUI\ERP\Accounting\Calc::CALCULATION_PERCENTAGE:
                 $calculation = QUI\ERP\Accounting\Calc::CALCULATION_PERCENTAGE;
@@ -515,14 +533,10 @@ public function toPriceFactor($Locale = null, $Customer = null)
                 break;
         }
 
-        switch ($this->getAttribute('price_calculation_basis')) {
-            case QUI\ERP\Accounting\Calc::CALCULATION_BASIS_NETTO:
-                $basis = QUI\ERP\Accounting\Calc::CALCULATION_BASIS_NETTO;
-                break;
-
-            default:
-                $basis = QUI\ERP\Accounting\Calc::CALCULATION_BASIS_CURRENTPRICE;
-        }
+        $basis = match ($this->getAttribute('price_calculation_basis')) {
+            QUI\ERP\Accounting\Calc::CALCULATION_BASIS_NETTO => QUI\ERP\Accounting\Calc::CALCULATION_BASIS_NETTO,
+            default => QUI\ERP\Accounting\Calc::CALCULATION_BASIS_CURRENTPRICE,
+        };
 
         // check calculation basis VAT
         $useAuto = $this->getAttribute('consider_vat') === 'auto'
@@ -542,7 +556,7 @@ public function toPriceFactor($Locale = null, $Customer = null)
             $Config = $Plugin->getConfig();
 
             $hideDiscounts = (int)$Config->getValue('products', 'hideDiscounts');
-        } catch (QUI\Exception $Exception) {
+        } catch (QUI\Exception) {
             $hideDiscounts = false;
         }
 
@@ -562,7 +576,7 @@ public function toPriceFactor($Locale = null, $Customer = null)
                 'calculation' => $calculation,
                 'basis' => $basis,
                 'value' => $this->getAttribute('discount') * -1,
-                'visible' => $hideDiscounts ? false : true,
+                'visible' => !$hideDiscounts,
                 'vat' => $this->getAttribute('vat')
             ]);
         }
@@ -577,7 +591,6 @@ public function toPriceFactor($Locale = null, $Customer = null)
             'calculation' => $calculation,
             'basis' => $basis,
             'value' => $this->getAttribute('discount') * -1,
-            'visible' => $hideDiscounts ? false : true
         ]);
     }
 
@@ -586,7 +599,7 @@ public function toPriceFactor($Locale = null, $Customer = null)
      *
      * @throws QUI\ExceptionStack|QUI\Exception
      */
-    public function update()
+    public function update(): void
     {
         $this->Events->fireEvent('saveBegin');
         $this->Events->fireEvent('updateBegin');
@@ -595,18 +608,16 @@ public function update()
         $savedData = [];
 
         foreach ($needles as $needle) {
-            if (!\array_key_exists($needle, $this->attributes)) {
+            if (!array_key_exists($needle, $this->attributes)) {
                 continue;
             }
 
             $value = $this->getAttribute($needle);
 
-            switch ($needle) {
-                case 'user_groups':
-                    if (!empty($value)) {
-                        $value = ',' . $value . ',';
-                    }
-                    break;
+            if ($needle == 'user_groups') {
+                if (!empty($value)) {
+                    $value = ',' . $value . ',';
+                }
             }
 
             $savedData[$needle] = $value;
diff --git a/src/QUI/ERP/Discount/EventHandling.php b/src/QUI/ERP/Discount/EventHandling.php
index ebb506aa8c659a58160e1e8b3af0626430057cbe..c1de6ebd394ac430919641bce93713eadfcdec9a 100644
--- a/src/QUI/ERP/Discount/EventHandling.php
+++ b/src/QUI/ERP/Discount/EventHandling.php
@@ -7,11 +7,15 @@
 namespace QUI\ERP\Discount;
 
 use QUI;
+use QUI\Database\Exception;
 use QUI\ERP\Accounting\Calc as ErpCalc;
 use QUI\ERP\Products\Product\UniqueProduct;
 use QUI\ERP\Products\Utils\Calc;
 use QUI\ERP\Products\Product\ProductList;
 
+use function array_filter;
+use function explode;
+
 /**
  * Class EventHandling
  *
@@ -20,19 +24,19 @@
 class EventHandling
 {
     /**
-     * @var null
+     * @var Handler|null
      */
-    protected static $Handler = null;
+    protected static ?Handler $Handler = null;
 
     /**
      * @var array
      */
-    protected static $userDiscounts = [];
+    protected static array $userDiscounts = [];
 
     /**
      * Return the global
      *
-     * @return Handler
+     * @return Handler|null
      */
     protected static function getHandler(): ?Handler
     {
@@ -48,16 +52,17 @@ protected static function getHandler(): ?Handler
      *
      * @param QUI\Interfaces\Users\User $User
      * @return array
+     * @throws Exception
      */
     protected static function getUserDiscounts(QUI\Interfaces\Users\User $User): array
     {
-        if (isset(self::$userDiscounts[$User->getId()])) {
-            return self::$userDiscounts[$User->getId()];
+        if (isset(self::$userDiscounts[$User->getUUID()])) {
+            return self::$userDiscounts[$User->getUUID()];
         }
 
-        self::$userDiscounts[$User->getId()] = Utils::getActiveUserDiscounts($User);
+        self::$userDiscounts[$User->getUUID()] = Utils::getActiveUserDiscounts($User);
 
-        return self::$userDiscounts[$User->getId()];
+        return self::$userDiscounts[$User->getUUID()];
     }
 
     /**
@@ -65,10 +70,10 @@ protected static function getUserDiscounts(QUI\Interfaces\Users\User $User): arr
      * - Einkaufsmengeprüfung
      *
      * @param Discount $Discount
-     * @param integer|double $quantity
+     * @param double|integer $quantity
      * @return bool
      */
-    public static function isDiscountUsableWithQuantity(Discount $Discount, $quantity): bool
+    public static function isDiscountUsableWithQuantity(Discount $Discount, float|int $quantity): bool
     {
         $purchaseQuantityFrom = $Discount->getAttribute('purchase_quantity_from');
         $purchaseQuantityUntil = $Discount->getAttribute('purchase_quantity_until');
@@ -93,14 +98,14 @@ public static function isDiscountUsableWithQuantity(Discount $Discount, $quantit
     }
 
     /**
-     * Discount pirchase value check for usage
+     * Discount purchase value check for usage
      * - Einkaufswertprüfung
      *
      * @param Discount $Discount
-     * @param integer|double $value
+     * @param float|integer $value
      * @return bool
      */
-    public static function isDiscountUsableWithPurchaseValue(Discount $Discount, $value): bool
+    public static function isDiscountUsableWithPurchaseValue(Discount $Discount, float|int $value): bool
     {
         $purchaseValueFrom = $Discount->getAttribute('purchase_value_from');
         $purchaseValueUntil = $Discount->getAttribute('purchase_value_until');
@@ -136,18 +141,19 @@ public static function isDiscountUsableWithPurchaseValue(Discount $Discount, $va
      *
      * @param QUI\ERP\Products\Utils\Calc $Calc
      * @param UniqueProduct $Product
+     * @throws Exception
      */
     public static function onQuiqqerProductsCalcListProduct(
         Calc $Calc,
         UniqueProduct $Product
-    ) {
+    ): void {
         $userDiscounts = self::getUserDiscounts($Calc->getUser());
 
-        if (!\is_array($userDiscounts) || empty($userDiscounts)) {
+        if (empty($userDiscounts)) {
             return;
         }
 
-        $userDiscounts = \array_filter($userDiscounts, function ($Discount) {
+        $userDiscounts = array_filter($userDiscounts, function ($Discount) {
             /* @var $Discount Discount */
 
             // don't use manuel usage type
@@ -158,18 +164,11 @@ public static function onQuiqqerProductsCalcListProduct(
             return (int)$Discount->getAttribute('scope') === Handler::DISCOUNT_SCOPE_EVERY_PRODUCT;
         });
 
-        if (!\is_array($userDiscounts) || empty($userDiscounts)) {
-            return;
-        }
-
-        try {
-            $attributes = $Product->getAttributes();
-        } catch (QUI\Exception $Exception) {
-            QUI\System\Log::writeDebugException($Exception);
-
+        if (empty($userDiscounts)) {
             return;
         }
 
+        $attributes = $Product->getAttributes();
         $PriceFactors = $Product->getPriceFactors();
         $productQuantity = $Product->getQuantity();
         $productNettoSum = $attributes['calculated_nettoSum'];
@@ -184,7 +183,7 @@ public static function onQuiqqerProductsCalcListProduct(
                 continue;
             }
 
-            // check if Pricefactor is already in
+            // check if price factor is already in
             $factors = $PriceFactors->toArray();
             $Factor = $Discount->toPriceFactor(
                 $Calc->getUser()->getLocale(),
@@ -210,20 +209,17 @@ public static function onQuiqqerProductsCalcListProduct(
      *
      * @param Calc $Calc
      * @param ProductList $List
-     * @param integer|double $nettoSum
+     * @param float|integer $nettoSum
+     * @throws Exception
      */
     public static function onQuiqqerProductsCalcList(
         Calc $Calc,
         ProductList $List,
-        $nettoSum
-    ) {
+        float|int $nettoSum
+    ): void {
         $userDiscounts = self::getUserDiscounts($Calc->getUser());
 
-        if (!\is_array($userDiscounts)) {
-            return;
-        }
-
-        $userDiscounts = \array_filter($userDiscounts, function ($Discount) {
+        $userDiscounts = array_filter($userDiscounts, function ($Discount) {
             /* @var $Discount Discount */
 
             // don't use manuel usage type
@@ -234,10 +230,6 @@ public static function onQuiqqerProductsCalcList(
             return (int)$Discount->getAttribute('scope') == Handler::DISCOUNT_SCOPE_TOTAL;
         });
 
-        if (!\is_array($userDiscounts)) {
-            return;
-        }
-
         $listQuantity = $List->getQuantity();
         $products = $List->getProducts();
         $PriceFactors = $List->getPriceFactors();
@@ -256,7 +248,7 @@ public static function onQuiqqerProductsCalcList(
             $productIds = $Discount->getAttribute('articles');
 
             if ($productIds) {
-                $productIds = \explode(',', $productIds);
+                $productIds = explode(',', $productIds);
 
                 // product id check
                 $existProductIdInList = function ($products, $productIds) {
@@ -281,7 +273,7 @@ public static function onQuiqqerProductsCalcList(
             $categories = $Discount->getAttribute('categories');
 
             if ($categories) {
-                $categories = \explode(',', $categories);
+                $categories = explode(',', $categories);
 
                 // product category check
                 $existCategoryInList = function ($products, $categories) {
diff --git a/src/QUI/ERP/Discount/Handler.php b/src/QUI/ERP/Discount/Handler.php
index bde72a9ebd37cfaf313880c6a69b5d7ed851079b..a2f58611c513f7e73ea10695a18f379548be4fb3 100644
--- a/src/QUI/ERP/Discount/Handler.php
+++ b/src/QUI/ERP/Discount/Handler.php
@@ -7,6 +7,7 @@
 namespace QUI\ERP\Discount;
 
 use QUI;
+use QUI\Database\Exception;
 use QUI\Permissions\Permission;
 
 /**
@@ -49,7 +50,7 @@ class Handler extends QUI\CRUD\Factory
     const DISCOUNT_SCOPE_GRAND_TOTAL = 4;
 
     /**
-     * pricefactor discount type
+     * price factor discount type
      */
     const DISCOUNT_PRICEFACTOR_TYPE = 'DISCOUNT_PRICE_FACTOR';
 
@@ -163,7 +164,7 @@ public function __construct()
      *
      * @return string
      */
-    public function getDataBaseTableName()
+    public function getDataBaseTableName(): string
     {
         return QUI::getDBTableName('discounts');
     }
@@ -173,7 +174,7 @@ public function getDataBaseTableName()
      *
      * @return string
      */
-    public function getChildClass()
+    public function getChildClass(): string
     {
         return 'QUI\ERP\Discount\Discount';
     }
@@ -183,7 +184,7 @@ public function getChildClass()
      *
      * @return array
      */
-    public function getChildAttributes()
+    public function getChildAttributes(): array
     {
         return [
             'active',
@@ -217,8 +218,9 @@ public function getChildAttributes()
      *
      * @param array $queryParams
      * @return array - [Child, Child, Child]
+     * @throws Exception
      */
-    public function getChildrenData($queryParams = [])
+    public function getChildrenData(array $queryParams = []): array
     {
         if (!isset($queryParams['order'])) {
             $queryParams['order'] = 'priority ASC';
diff --git a/src/QUI/ERP/Discount/PriceFactor.php b/src/QUI/ERP/Discount/PriceFactor.php
index be19e27273f46d0dd669d241860de14e455d9343..c18cdb2bc519e1891f46b97ce27636445e3d91fe 100644
--- a/src/QUI/ERP/Discount/PriceFactor.php
+++ b/src/QUI/ERP/Discount/PriceFactor.php
@@ -10,22 +10,18 @@
 
 /**
  * Class PriceFactor
- * This pricefactors is used by Handler::DISCOUNT_SCOPE_TOTAL
+ * This price factor is used by Handler::DISCOUNT_SCOPE_TOTAL
  *
  * @package QUI\ERP\Discount
  */
-class PriceFactor extends QUI\ERP\Products\Utils\PriceFactor implements QUI\ERP\Products\Interfaces\PriceFactorWithVatInterface
+class PriceFactor extends QUI\ERP\Products\Utils\PriceFactor implements
+    QUI\ERP\Products\Interfaces\PriceFactorWithVatInterface
 {
     /**
      * @var string
      */
     protected string $type = Handler::DISCOUNT_PRICEFACTOR_TYPE;
 
-    /**
-     * @var string|null
-     */
-    protected $vat = null;
-
     /**
      * PriceFactor constructor.
      * @param array $params
@@ -45,7 +41,7 @@ public function __construct(array $params)
      * @return QUI\ERP\Tax\TaxType
      * @throws QUI\Exception
      */
-    public function getVatType()
+    public function getVatType(): QUI\ERP\Tax\TaxType
     {
         if (!$this->vat) {
             return QUI\ERP\Tax\Utils::getShopTaxType();
@@ -61,7 +57,7 @@ public function getVatType()
             $Handler = new QUI\ERP\Tax\Handler();
 
             return $Handler->getTaxType($standardTax[1]);
-        } catch (QUI\Exception $Exception) {
+        } catch (QUI\Exception) {
         }
 
         return QUI\ERP\Tax\Utils::getShopTaxType();
diff --git a/src/QUI/ERP/Discount/Utils.php b/src/QUI/ERP/Discount/Utils.php
index 4e843db45cbcc4b29ce1b7c71e3db190b670312e..1861bc43fdf63ab5f291d780f1a60d31fcb0d2bd 100644
--- a/src/QUI/ERP/Discount/Utils.php
+++ b/src/QUI/ERP/Discount/Utils.php
@@ -10,6 +10,10 @@
 use QUI\Utils\UserGroups;
 use QUI\Interfaces\Users\User as UserInterface;
 
+use function array_filter;
+use function array_merge;
+use function str_replace;
+
 /**
  * Class Utils
  *
@@ -20,7 +24,7 @@ class Utils
     /**
      * Return all discounts which are usable by the user
      *
-     * @param \QUI\Interfaces\Users\User $User
+     * @param UserInterface $User
      * @return array
      *
      * @throws \QUI\Database\Exception
@@ -28,7 +32,7 @@ class Utils
     public static function getUserDiscounts(UserInterface $User): array
     {
         $guString = UserGroups::getUserGroupStringFromUser($User);
-        $guString = ',' . \str_replace(',', ',|,', $guString) . ',';
+        $guString = ',' . str_replace(',', ',|,', $guString) . ',';
 
         $result = [];
         $Discounts = new Handler();
@@ -50,11 +54,11 @@ public static function getUserDiscounts(UserInterface $User): array
 
 
         if (!empty($personalDiscounts)) {
-            $result = \array_merge($personalDiscounts, $result);
+            $result = array_merge($personalDiscounts, $result);
         }
 
         if (!empty($discounts)) {
-            $result = \array_merge($discounts, $result);
+            $result = array_merge($discounts, $result);
         }
 
         return $result;
@@ -90,11 +94,11 @@ public static function getProductDiscounts(Product $Product): array
 
 
         if (!empty($productDiscounts)) {
-            $result = \array_merge($productDiscounts, $result);
+            $result = array_merge($productDiscounts, $result);
         }
 
         if (!empty($discounts)) {
-            $result = \array_merge($discounts, $result);
+            $result = array_merge($discounts, $result);
         }
 
         return $result;
@@ -103,7 +107,7 @@ public static function getProductDiscounts(Product $Product): array
     /**
      * Return all active discounts which are usable by the user
      *
-     * @param \QUI\Interfaces\Users\User $User
+     * @param UserInterface $User
      * @return array
      *
      * @throws \QUI\Database\Exception
@@ -111,7 +115,7 @@ public static function getProductDiscounts(Product $Product): array
     public static function getActiveUserDiscounts(UserInterface $User): array
     {
         $guString = UserGroups::getUserGroupStringFromUser($User);
-        $guString = ',' . \str_replace(',', ',|,', $guString) . ',';
+        $guString = ',' . str_replace(',', ',|,', $guString) . ',';
 
         $result = [];
         $Discounts = new Handler();
@@ -140,19 +144,19 @@ public static function getActiveUserDiscounts(UserInterface $User): array
             ]
         ]);
 
-        $discounts = \array_merge($discounts, $discountsNULL);
+        $discounts = array_merge($discounts, $discountsNULL);
 
         if (!empty($personalDiscounts)) {
-            $result = \array_merge($personalDiscounts, $result);
+            $result = array_merge($personalDiscounts, $result);
         }
 
         if (!empty($discounts)) {
-            $result = \array_merge($discounts, $result);
+            $result = array_merge($discounts, $result);
         }
 
         $alreadyAttached = [];
 
-        $result = \array_filter($result, function ($Discount) use (&$alreadyAttached) {
+        return array_filter($result, function ($Discount) use (&$alreadyAttached) {
             /* @var $Discount Discount */
             $id = $Discount->getId();
 
@@ -164,15 +168,12 @@ public static function getActiveUserDiscounts(UserInterface $User): array
 
             return true;
         });
-
-
-        return $result;
     }
 
     /**
      * Return all active and usable discounts which are usable by the user
      *
-     * @param \QUI\Interfaces\Users\User $User
+     * @param UserInterface $User
      * @return array
      *
      * @throws \QUI\Database\Exception
diff --git a/tests/phpstan-bootstrap.php b/tests/phpstan-bootstrap.php
new file mode 100644
index 0000000000000000000000000000000000000000..b61ff4b8300a965e0f46025ba64745a22b118e74
--- /dev/null
+++ b/tests/phpstan-bootstrap.php
@@ -0,0 +1,13 @@
+<?php
+
+if (!defined('QUIQQER_SYSTEM')) {
+    define('QUIQQER_SYSTEM', true);
+}
+
+if (!defined('QUIQQER_AJAX')) {
+    define('QUIQQER_AJAX', true);
+}
+
+putenv("QUIQQER_OTHER_AUTOLOADERS=KEEP");
+
+require_once __DIR__ . '/../../../../bootstrap.php';