diff --git a/src/GatewayResolver.php b/src/GatewayResolver.php
index 9217b2b4..b1a88c78 100644
--- a/src/GatewayResolver.php
+++ b/src/GatewayResolver.php
@@ -2,168 +2,129 @@
 
 namespace Larabookir\Gateway;
 
+use Illuminate\Support\Facades\DB;
+use Larabookir\Gateway\Asanpardakht\Asanpardakht;
+use Larabookir\Gateway\Exceptions\InvalidRequestException;
+use Larabookir\Gateway\Exceptions\NotFoundTransactionException;
+use Larabookir\Gateway\Exceptions\PortNotFoundException;
+use Larabookir\Gateway\Exceptions\RetryException;
 use Larabookir\Gateway\Irankish\Irankish;
+use Larabookir\Gateway\Mellat\Mellat;
 use Larabookir\Gateway\Parsian\Parsian;
+use Larabookir\Gateway\Pasargad\Pasargad;
+use Larabookir\Gateway\Payir\Payir;
 use Larabookir\Gateway\Paypal\Paypal;
 use Larabookir\Gateway\Sadad\Sadad;
-use Larabookir\Gateway\Mellat\Mellat;
-use Larabookir\Gateway\Pasargad\Pasargad;
 use Larabookir\Gateway\Saman\Saman;
-use Larabookir\Gateway\Asanpardakht\Asanpardakht;
 use Larabookir\Gateway\Shahr\Shahr;
 use Larabookir\Gateway\Zarinpal\Zarinpal;
-use Larabookir\Gateway\Payir\Payir;
-use Larabookir\Gateway\Exceptions\RetryException;
-use Larabookir\Gateway\Exceptions\PortNotFoundException;
-use Larabookir\Gateway\Exceptions\InvalidRequestException;
-use Larabookir\Gateway\Exceptions\NotFoundTransactionException;
-use Illuminate\Support\Facades\DB;
 
 class GatewayResolver
 {
+    protected $request;
+    protected $config;
+    protected $port;
+
+    private const PORT_MAP = [
+        Mellat::class => Enum::MELLAT,
+        Parsian::class => Enum::PARSIAN,
+        Saman::class => Enum::SAMAN,
+        Zarinpal::class => Enum::ZARINPAL,
+        Sadad::class => Enum::SADAD,
+        Asanpardakht::class => Enum::ASANPARDAKHT,
+        Paypal::class => Enum::PAYPAL,
+        Payir::class => Enum::PAYIR,
+        Pasargad::class => Enum::PASARGAD,
+        Shahr::class => Enum::SHAHR,
+        Irankish::class => Enum::IRANKISH,
+    ];
+
+    public function __construct($config = null, $port = null)
+    {
+        $this->config = app('config');
+        $this->request = app('request');
+
+        if ($this->config->has('gateway.timezone')) {
+            date_default_timezone_set($this->config->get('gateway.timezone'));
+        }
 
-	protected $request;
-
-	/**
-	 * @var Config
-	 */
-	public $config;
-
-	/**
-	 * Keep current port driver
-	 *
-	 * @var Mellat|Saman|Sadad|Zarinpal|Payir|Parsian
-	 */
-	protected $port;
-
-	/**
-	 * Gateway constructor.
-	 * @param null $config
-	 * @param null $port
-	 */
-	public function __construct($config = null, $port = null)
-	{
-		$this->config = app('config');
-		$this->request = app('request');
-
-		if ($this->config->has('gateway.timezone'))
-			date_default_timezone_set($this->config->get('gateway.timezone'));
-
-		if (!is_null($port)) $this->make($port);
-	}
-
-	/**
-	 * Get supported ports
-	 *
-	 * @return array
-	 */
-	public function getSupportedPorts()
-	{
-		return (array) Enum::getIPGs();
-	}
-
-	/**
-	 * Call methods of current driver
-	 *
-	 * @return mixed
-	 */
-	public function __call($name, $arguments)
-	{
-
-		// calling by this way ( Gateway::mellat()->.. , Gateway::parsian()->.. )
-		if(in_array(strtoupper($name),$this->getSupportedPorts())){
-			return $this->make($name);
-		}
-
-		return call_user_func_array([$this->port, $name], $arguments);
-	}
-
-	/**
-	 * Gets query builder from you transactions table
-	 * @return mixed
-	 */
-	function getTable()
-	{
-		return DB::table($this->config->get('gateway.table'));
-	}
-
-	/**
-	 * Callback
-	 *
-	 * @return $this->port
-	 *
-	 * @throws InvalidRequestException
-	 * @throws NotFoundTransactionException
-	 * @throws PortNotFoundException
-	 * @throws RetryException
-	 */
-	public function verify()
-	{
-		if (!$this->request->has('transaction_id') && !$this->request->has('iN'))
-			throw new InvalidRequestException;
-		if ($this->request->has('transaction_id')) {
-			$id = $this->request->get('transaction_id');
-		}else {
-			$id = $this->request->get('iN');
-		}
-
-		$transaction = $this->getTable()->whereId($id)->first();
-
-		if (!$transaction)
-			throw new NotFoundTransactionException;
-
-		if (in_array($transaction->status, [Enum::TRANSACTION_SUCCEED, Enum::TRANSACTION_FAILED]))
-			throw new RetryException;
-
-		$this->make($transaction->port);
-
-		return $this->port->verify($transaction);
-	}
-
-
-	/**
-	 * Create new object from port class
-	 *
-	 * @param int $port
-	 * @throws PortNotFoundException
-	 */
-	function make($port)
+        if ($port !== null) {
+            $this->make($port);
+        }
+    }
+
+    public function getSupportedPorts(): array
     {
-        if ($port InstanceOf Mellat) {
-            $name = Enum::MELLAT;
-        } elseif ($port InstanceOf Parsian) {
-            $name = Enum::PARSIAN;
-        } elseif ($port InstanceOf Saman) {
-            $name = Enum::SAMAN;
-        } elseif ($port InstanceOf Zarinpal) {
-            $name = Enum::ZARINPAL;
-        } elseif ($port InstanceOf Sadad) {
-            $name = Enum::SADAD;
-        } elseif ($port InstanceOf Asanpardakht) {
-            $name = Enum::ASANPARDAKHT;
-        } elseif ($port InstanceOf Paypal) {
-            $name = Enum::PAYPAL;
-        } elseif ($port InstanceOf Payir) {
-            $name = Enum::PAYIR;
-        } elseif ($port InstanceOf Pasargad) {
-            $name = Enum::PASARGAD;
-        } elseif ($port InstanceOf Shahr) {
-            $name = Enum::SHAHR;
-        } elseif ($port InstanceOf Irankish) {
-            $name = Enum::IRANKISH;
-        } elseif (in_array(strtoupper($port), $this->getSupportedPorts())) {
-            $port = ucfirst(strtolower($port));
-            $name = strtoupper($port);
-            $class = __NAMESPACE__ . '\\' . $port . '\\' . $port;
+        return (array) Enum::getIPGs();
+    }
+
+    public function __call($name, $arguments)
+    {
+        if (in_array(strtoupper($name), $this->getSupportedPorts(), true)) {
+            return $this->make($name);
+        }
+
+        return call_user_func_array([$this->port, $name], $arguments);
+    }
+
+    public function getTable()
+    {
+        return DB::table($this->config->get('gateway.table'));
+    }
+
+    public function verify()
+    {
+        if (!$this->request->has('transaction_id') && !$this->request->has('iN')) {
+            throw new InvalidRequestException;
+        }
+
+        $id = $this->request->get('transaction_id', $this->request->get('iN'));
+        $transaction = $this->getTable()->whereId($id)->first();
+
+        if (!$transaction) {
+            throw new NotFoundTransactionException;
+        }
+
+        if (in_array($transaction->status, [Enum::TRANSACTION_SUCCEED, Enum::TRANSACTION_FAILED], true)) {
+            throw new RetryException;
+        }
+
+        $this->make($transaction->port);
+
+        return $this->port->verify($transaction);
+    }
+
+    public function make($port)
+    {
+        $name = $this->resolvePortName($port);
+        
+        if ($name === null && in_array(strtoupper($port), $this->getSupportedPorts(), true)) {
+            $portName = ucfirst(strtolower($port));
+            $name = strtoupper($portName);
+            $class = __NAMESPACE__ . '\\' . $portName . '\\' . $portName;
             $port = new $class;
-        } else
+        }
+
+        if ($name === null) {
             throw new PortNotFoundException;
+        }
 
         $this->port = $port;
-        $this->port->setConfig($this->config); // injects config
-        $this->port->setPortName($name); // injects config
+        $this->port->setConfig($this->config);
+        $this->port->setPortName($name);
         $this->port->boot();
 
         return $this;
     }
+
+    private function resolvePortName($port): ?string
+    {
+        foreach (self::PORT_MAP as $class => $portName) {
+            if ($port instanceof $class) {
+                return $portName;
+            }
+        }
+
+        return null;
+    }
 }