Custom Payment Gateway Sending Cart Total as Zero on Checkout

Hi,

I have a custom payment gateway but I am not able to send cart total. It sends cart total as zero, but when I checkout with store currency, it sends out the price so I am guessing I should be adding a specific line or something. I hope you can help me. Below is the code of the payment gateway:

<?php

if ( ! defined( 'ABSPATH' ) ) {
	exit; // Exit if accessed directly
}

/**
 * Cheque Payment Gateway.
 *
 * Provides a Cheque Payment Gateway, mainly for testing purposes.
 *
 * @class 		WC_Gateway_Cheque
 * @extends		WC_Payment_Gateway
 * @version		2.1.0
 * @package		WooCommerce/Classes/Payment
 * @author 		WooThemes
 */
class WC_Gateway_Binga extends WC_Payment_Gateway {

    /**
     * Constructor for the gateway.
     */
	public function __construct() {
		
		session_start();

		$this->id                 = 'binga';
		$this->has_fields         = false;
		$this->method_title       = 'Paiement par Binga';
		$this->method_description = 'Payez en cash sur internet via Binga';

		// Load the settings.
		$this->init_form_fields();
		$this->init_settings();

		$this->version         = $this->settings['versions'];
		$this->storeId         = $this->settings['storeId'];
		$this->privateKey      = $this->settings['privateKey'];
		$this->expirationDelay = $this->settings['expirationDelay'];
		$this->environment     = ($this->settings['environment'] == 'yes') ? "https://api.binga.ma/bingaApi/order/prePay.action": "https://preprod.binga.ma/bingaApi/order/prePay.action";

		// Define user set variables
		$this->title        = $this->get_option( 'title' );
		$this->description  = $this->get_option( 'description' );
		$this->instructions = $this->get_option( 'instructions', $this->description );

	

		$_SESSION['binga'] = $this;

		// Actions
		add_action( 'woocommerce_update_options_payment_gateways_' . $this->id, array( $this, 'process_admin_options' ) );
		
		add_action( 'woocommerce_api_process', array( &$this, 'process' )  );
        add_action( 'woocommerce_api_payurl', array( &$this, 'pay_url' )  );
        add_action( 'woocommerce_api_bookurl', array( &$this, 'book_url' )  );
        add_action( 'woocommerce_api_failureurl', array( &$this, 'failure_url' )  );
        

    }

	function process(){
		@ob_clean();
		if(isset($_GET["id"]))      $order_id = $_GET["id"];
		if(isset($_GET["fname"]))   $fname    = $_GET["fname"];
		if(isset($_GET["lname"]))   $lname    = $_GET["lname"];
		if(isset($_GET["address"])) $address  = $_GET["address"];
		if(isset($_GET["email"]))   $email    = $_GET["email"];
		if(isset($_GET["phone"]))   $phone    = $_GET["phone"];

		$order           = wc_get_order($order_id);
		$base_url        = "https://".$_SERVER['SERVER_NAME'].$_SERVER['SCRIPT_NAME'];
		$amount          = number_format(preg_replace('#[^\d.]#', '', WC()->cart->cart_contents_total), 2, '.', '');
		$orderCheckSum   = md5("PRE-PAY".$amount.$this->storeId.$order_id.$email.$this->privateKey);
		$expirationDelay = gmdate('Y-m-d\TH:i:s\G\M\T', time()+(($this->expirationDelay)*60*60));
            global $woocommerce;
            echo "<pre>";
            print_r($woocommerce->cart);
            echo "</pre>";die;
		echo "Vous allez être redirigé vers le site Binga, patientez svp ...";
	?>

		<form method="POST" id='bingaForm' action="<?=$this->environment?>">
			<input type="hidden" name="externalId" value="<?=$order_id?>"></input>
			<input type="hidden" name="amount" value="<?=$amount?>"></input>
			<input type="hidden" name="buyerFirstName" value="<?=$fname?>"></input>
			<input type="hidden" name="buyerLastName" value="<?=$lname?>"></input>
			<input type="hidden" name="buyerEmail" value="<?=$email?>"></input>
			<input type="hidden" name="buyerAddress" value="<?=$address?>"></input>
			<input type="hidden" name="buyerPhone" value="<?=$phone?>"></input>
			<input type="hidden" name="storeId" value="<?=$this->storeId?>"></input>
			<input type="hidden" name="failureUrl" value="<?=$base_url.'/wc-api/failureurl'?>"></input>
			<input type="hidden" name="bookUrl" value="<?=$base_url.'/wc-api/bookurl'?>"></input>
			<input type="hidden" name="successUrl" value="<?=$this->get_return_url($order)?>"></input>
			<input type="hidden" name="payUrl" value="<?=$base_url.'/wc-api/payurl'?>"></input>
			<input type="hidden" name="orderCheckSum" value="<?=$orderCheckSum?>"></input>
			<input type="hidden" name="apiVersion" value="<?=$this->version?>"></input>
			<input type="hidden" name="expirationDate" value="<?=$expirationDelay?>"></input>	
		</form>
		<script src="https://ajax.googleapis.com/ajax/libs/jquery/1.12.2/jquery.min.js"></script>
		<script type="text/javascript">
		$(function() {
			$("form#bingaForm").submit();
		});	
		</script>
	<?php
		exit();
	}

	function book_url(){
		@ob_clean();
		

		if(isset($_POST['externalId']) && isset($_POST['expirationDate']) && isset($_POST['amount']) && isset($_POST['buyerEmail']) && isset($_POST['orderCheckSum']) ){
		
			$orderCheckSum   = md5("PRE-PAY".$_POST['amount'].$this->storeId.$_POST['externalId'].$_POST['buyerEmail'].$this->privateKey);
			$order = wc_get_order($_POST['externalId']);

			if($_POST['orderCheckSum'] == $orderCheckSum ){
				$order->update_status( 'on-hold', 'En Attente de paiement chez wafacash' );
				WC()->cart->empty_cart();
			}else{
				$order->update_status( 'cancelled', 'Erreur' );
			}

		}

		exit();
	}

	function pay_url(){
		@ob_clean();

		if(isset($_POST['externalId']) && isset($_POST['expirationDate']) && isset($_POST['amount']) && isset($_POST['buyerEmail']) && isset($_POST['orderCheckSum']) ){
		
			$orderCheckSum   = md5("PAY".$_POST['amount'].$this->storeId.$_POST['externalId'].$_POST['buyerEmail'].$this->privateKey);
			$order = wc_get_order($_POST['externalId']);

			if($_POST['orderCheckSum'] == $orderCheckSum ){
				$order->update_status( 'completed', 'Payé chez wafacash' );
				echo '100;'.date('Y-m-d\TH:i:s\G\M\T',strtotime($_POST['expirationDate']));
			}else{
				var_dump($orderCheckSum);die();
				$order->update_status( 'cancelled', 'Erreur' );
				echo '000;'.date('Y-m-d\TH:i:s\G\M\T',strtotime($_POST['expirationDate']));				
			}

		}

		exit();
	}

	function failure_url(){
		@ob_clean();

		if(isset($_POST['externalId']) && isset($_POST['expirationDate']) && isset($_POST['amount']) && isset($_POST['buyerEmail']) && isset($_POST['orderCheckSum']) ){
			$order = wc_get_order($_POST['externalId']);
			$order->update_status( 'cancelled', 'Erreur' );

		}

		exit();
	}

    /**
     * Initialise Gateway Settings Form Fields.
     */
    public function init_form_fields() {

    	$this->form_fields = array(
			'enabled' => array(
				'title'   => __( 'Enable/Disable', 'woocommerce' ),
				'type'    => 'checkbox',
				'label'   => 'Activez les paiements par binga',
				'default' => 'yes'
			),
			'title' => array(
				'title'       => __( 'Title', 'woocommerce' ),
				'type'        => 'text',
				'desc_tip'    => true,
			),
			'description' => array(
				'title'       => __( 'Description', 'woocommerce' ),
				'type'        => 'textarea',
				'desc_tip'    => true,
			),
			'instructions' => array(
				'title'       => __( 'Instructions', 'woocommerce' ),
				'type'        => 'textarea',
				'desc_tip'    => true,
			),
			'versions' => array(
				'title'       => __( 'Versions', 'woocommerce' ),
				'type'        => 'text',
				'desc_tip'    => true,
			),
			'storeId' => array(
				'title'       => __( 'StoreId', 'woocommerce' ),
				'type'        => 'text',
				'desc_tip'    => true,
			),
			'privateKey' => array(
				'title'       => __( 'Private Key', 'woocommerce' ),
				'type'        => 'text',
				'desc_tip'    => true,
			),
			'expirationDelay' => array(
				'title'       => __( 'Expiration Delay (in hour)', 'woocommerce' ),
				'type'        => 'text',
				'desc_tip'    => true,
			),
			'environment' => array(
				'title'   => __( 'Production/Pre-production', 'woocommerce' ),
				'type'    => 'checkbox',
				'label'   => 'Activez le module en mode production',
				'default' => 'yes'
			),
		);
    }
    /**
     * Process the payment and return the result.
     *
     * @param int $order_id
     * @return array
     */
	public function process_payment( $order_id ) {		

		$order = wc_get_order( $order_id );
		

		// // Mark as on-hold
		// $order->update_status( 'on-hold', 'En Attente de paiement par binga' );

		// // Reduce stock levels
		// //$order->reduce_order_stock();

		// // Remove cart
		// WC()->cart->empty_cart();

		if(isset($_POST["billing_first_name"])) $billing_first_name = $_POST["billing_first_name"];
		if(isset($_POST["billing_last_name"]))  $billing_last_name  = $_POST["billing_last_name"];
		if(isset($_POST["billing_company"]))    $billing_company    = $_POST["billing_company"];
		if(isset($_POST["billing_email"]))      $billing_email      = $_POST["billing_email"];
		if(isset($_POST["billing_phone"]))      $billing_phone      = $_POST["billing_phone"];
		if(isset($_POST["billing_country"]))    $billing_country    = $_POST["billing_country"];
		if(isset($_POST["billing_address_1"]))  $billing_address_1  = $_POST["billing_address_1"];
		if(isset($_POST["billing_address_2"]))  $billing_address_2  = $_POST["billing_address_2"];
		if(isset($_POST["billing_city"]))       $billing_city       = $_POST["billing_city"];
		if(isset($_POST["billing_state"]))      $billing_state      = $_POST["billing_state"];
		if(isset($_POST["billing_postcode"]))   $billing_postcode   = $_POST["billing_postcode"];

		$billing_address = $billing_address_1." ".$billing_address_2.", ".$billing_postcode." ".$billing_city.", ".$billing_state;
		$base_url        = "https://".$_SERVER['SERVER_NAME'].$_SERVER['SCRIPT_NAME'];

		return array(
			'result' 	=> 'success',
			'redirect'	=> $base_url.'/wc-api/process?id='.$order_id.'&fname='.$billing_first_name.'&lname='.$billing_last_name.'&address='.$billing_address.'&email='.$billing_email.'&phone='.$billing_phone,
		);

	}

}