epush.php

<?php
/*
   * Plugin Name: Selcom Push WP
   * Plugin URI: https://www.aspiretz.com/
   * Description: A plugin to enable Selcom USSD Push to Wallet from WooCommerce website. Currently available for Tigopesa & Airtel Money only.
   * Version: 1.0.2
   * Author: Aspire Creative
   * Author URI: https://www.aspiretz.com/
   * License: GNU General Public License v3 or later
   * License URI: https://www.gnu.org/licenses/gpl-3.0.en.html
   * Text Domain: Selcom Push WP
   * GitHub Plugin URI: https://github.com/wallace-stev/selcom-push-wp 
   * Domain Path: /i18n
*/

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

require_once ('apiconnect.php');

add_action( 'plugins_loaded', 'selcom_init' );

function selcom_init() {
   class SelcomGateway extends WC_Payment_Gateway {
      function __construct(){
         $this->id                 = 'wc_selcompay';
         $this->icon               = apply_filters('wp_selcom_icon', plugins_url('assets/mobilepay.png' , __FILE__));
         $this->method_title       = 'Selcom USSD Push';
         $this->title              = 'Selcom USSD Push';
         $this->has_fields         = true;
         $this->method_description = 'Pay directly from your mobile phone.';

         //Load plugin on WP Dashboard settings
         $this->init_form_fields();
         $this->init_settings();
         $this->enabled = $this->get_option('enabled');
         $this->title = $this->get_option( 'title' );
         $this->description = $this->get_option('description');
         $this->vendor  = $this->get_option('merchant_id');
			$this->api_key      = $this->get_option('api_key');
			$this->api_secret   = $this->get_option('secret_key');
         $this->api_url   = $this->get_option('api_url');

         //process settings with parent method
         add_action( 'woocommerce_update_options_payment_gateways_' . $this->id, array( $this, 'process_admin_options' ) );
      }

      public function init_form_fields(){
         $this->form_fields = array(
            'enabled' => array(
               'title'         => __( 'Enable/Disable', 'woocommerce' ),
               'type'          => 'checkbox',
               'label'         => __( 'Enable Selcom payments', 'woocommerce' ),
               'default'       => 'yes'
            ),
            'title' => array(
               'title'         => __( 'Title', 'woocommerce' ),
               'type'          => 'text',
               'description'   => __( 'This controls the title which the user sees during checkout.', 'woocommerce' ),
               'default'       => __( 'Pay via mobile phone', 'woocommerce' ),
               'desc_tip'      => true,
            ),
            'description' => array(
               'title'         => __( 'Customer Message', 'woocommerce' ),
               'type'          => 'textarea',
               'default'       => 'Pay directly from your mobile phone. Conveniently, securely & efficiently.',
               'description'   => 'This controls the description which the user sees during checkout.',
            ),
            'merchant_id' => array(
					'title'       => __('Vendor/Merchant ID', 'woocommerce'),
					'type'        => 'text',
					'description' => __('Your merchant id from Selcom.', $this->id),
					'default'     => '',
					'desc_tip'    => true,
				),
				'api_key'         => array(
					'title'       => __('API Key', 'woocommerce'),
					'type'        => 'text',
					'description' => __('Your API Key from Selcom.', $this->id),
					'default'     => '',
					'desc_tip'    => true,
				),
				'secret_key'      => array(
					'title'       => __('Secret Key', 'woocommerce'),
					'type'        => 'text',
					'description' => __('Your Secret Key from Selcom.', $this->id),
					'default'     => '',
					'desc_tip'    => true,
            ),
            'api_url'      => array(
					'title'       => __('API URL', 'woocommerce'),
					'type'        => 'text',
					'description' => __('URL to connect to Selcom API.', $this->id),
					'default'     => 'https://apigwtest.selcommobile.com/v1',
					'desc_tip'    => true,
				)
         );
      }
        
      function process_payment( $order_id ) {
         global $woocommerce;

         // Get an instance of the WC_Order object
         $order = new WC_Order( $order_id );

         //Selcom API prerequisites
         $api_key = $this->api_key;
         $api_secret = $this->api_secret;
         $base_url = $this->api_url;
         date_default_timezone_set('Africa/Dar_es_Salaam');

         //Minimal order array
         $min_order = array(
            "vendor"=> $this->vendor,
            "order_id"=>$order->get_id(),
            "buyer_email"=>$order->get_billing_email(),
            "buyer_name"=>$order->get_billing_first_name() ." ". $order->get_billing_last_name(),
            "buyer_phone"=>$order->get_billing_phone(),
            "amount"=>$order->get_total(),
            "currency"=>"TZS",
            "no_of_items"=>$woocommerce->cart->cart_contents_count
         );
            
         //Send Minimal Order Request
         $order_resp = sendMinOrder($min_order, $api_key, $api_secret, $base_url);

         //Based on the order response, continue implementing USSD Push                        
         if ($order_resp->result == 'FAIL') {
            //Update order status
            $order->update_status('failed', __( 'Order not created', 'woocommerce' ));

            //Display error message
            wc_add_notice( __('Error: ', 'woothemes') . 'Order could not be created.', 'error' );
         }
         else if ($order_resp->result == 'SUCCESS') {
            //Order is sent, set Push USSD Request Variables
            // TODO: Generate a random encrypted transid here
            $transid = substr(strtoupper('SPW'.md5(time().$order->get_id().rand (10,1000))),0,8);
            $push_req = array(
               "transid"=> $transid,
               "order_id"=>$order->get_id(),
               "msisdn"=>"255".substr($order->get_billing_phone(), -9),
            );

            //Send Push USSD Request
            $pay_resp = sendUSSDPush($push_req, $api_key, $api_secret, $base_url);

            if ($pay_resp->result == 'FAIL') {
               //Update order status
               $order->update_status('failed', __( 'Payment failed', 'woocommerce' ));

               //Display error message
               wc_add_notice( __('Error: ', 'woothemes') . 'Payment not completed.', 'error' );
            }
            else if ($pay_resp->result == 'SUCCESS' && $pay_resp->payment_status=='COMPLETE') {
               //Payment successfully initiated, update order status
               $order->update_status('processing', __( 'Payment is being processed, awaiting delivery', 'woocommerce' ));

               //Update update stock & cart information
               WC()->cart->empty_cart();
               wc_reduce_stock_levels($order);

               //Return to thank you page
               return array(
                  'result' => 'success',
                  'redirect' => $this->get_return_url( $order )
               );
            }
            else {
               //Update order status
               $order->update_status('on-hold', __( 'Payment could not be completed.', 'woocommerce' ));

               //Display error message
               wc_add_notice( __('Payment error: ', 'woothemes') . 'Something went wrong during payment.', 'error' );
            }
         }
         else {
            //Update order status
            $order->update_status('on-hold', __( 'Order could not be completed', 'woocommerce' ));

            //Display error message
            wc_add_notice( __('Order error: ', 'woothemes') . 'Something went wrong with the order.', 'error' );
         }
      }
   }
}

//Creating a minimal order to send to Checkout API before initiating payment
function sendMinOrder ($min_order, $api_key, $api_secret, $base_url) {
   //Set API endpoint
   $api_endpoint = "/checkout/create-order-minimal";
   $url = $base_url.$api_endpoint;

   //Set POST request variables
   $isPost =1;
   $timestamp = date('c');
   $authorization = base64_encode($api_key);
   $signed_fields  = implode(',', array_keys($min_order));
   $digest = computeSignature($min_order, $signed_fields, $timestamp, $api_secret);

   //Make HTTP POST Request for Minimal Order
   return sendHTTPRequest($url, $isPost, json_encode($min_order), $authorization, $digest, $signed_fields, $timestamp);
}

//Initiating payment via Push USSD
function sendUSSDPush ($push_req, $api_key, $api_secret, $base_url) {
   //Set API endpoint
   $api_endpoint = "/checkout/wallet-payment";
   $url = $base_url.$api_endpoint;

   //Set POST request variables
   $isPost =1;
   $timestamp = date('c');
   $authorization = base64_encode($api_key);
   $signed_fields  = implode(',', array_keys($push_req));
   $digest = computeSignature($push_req, $signed_fields, $timestamp, $api_secret);

   //Make HTTP POST Request for USSD Push to Wallet
   return sendHTTPRequest($url, $isPost, json_encode($push_req), $authorization, $digest, $signed_fields, $timestamp);
}

//Encrypting parameter values
function computeSignature($parameters, $signed_fields, $request_timestamp, $api_secret){
   $fields_order = explode(',', $signed_fields);
   $sign_data = "timestamp=$request_timestamp";
   foreach ($fields_order as $key) {
      $sign_data .= "&$key=".$parameters[$key];
   }

   //HS256 Signature Method
   return base64_encode(hash_hmac('sha256', $sign_data, $api_secret, true));
}

//Finally, add Selcom payment to list of payment methods
function add_selcom( $methods ) {
    $methods[] = 'SelcomGateway'; 
    return $methods;
}

add_filter( 'woocommerce_payment_gateways', 'add_selcom' );

?>