/application/controllers/parent/Payu.php

<?php

if (!defined('BASEPATH'))
    exit('No direct script access allowed');

class Payu extends CI_Controller {

    function __construct() {
        parent::__construct();
        $this->load->helper('file');
        $this->lang->load('message', 'english');
        $this->load->library('auth');
        $this->auth->is_logged_in_parent();
    }

    public function index() {
        $this->session->set_userdata('top_menu', 'Library');
        $this->session->set_userdata('sub_menu', 'book/index');
        $pre_session_data = $this->session->userdata('params');
        $txnid = substr(hash('sha256', mt_rand() . microtime()), 0, 20);
        $pre_session_data['txn_id'] = $txnid;
        $this->session->set_userdata("params", $pre_session_data);
        $session_data = $this->session->userdata('params');
        $session_data['name'] = ($session_data['name'] != "") ? $session_data['name'] : "noname";
        $session_data['email'] = ($session_data['email'] != "") ? $session_data['email'] : "noemail@gmail.com";
        $session_data['guardian_phone'] = ($session_data['guardian_phone'] != "") ? $session_data['guardian_phone'] : "0000000000";
        $session_data['address'] = ($session_data['address'] != "") ? $session_data['address'] : "noaddress";
        $pay_method = $this->paymentsetting_model->getActiveMethod();
        //payumoney details
        $amount = $session_data['payment_detail']->amount;
        $customer_name = $session_data['name'];
        $customer_emial = $session_data['email'];
        $customer_mobile = $session_data['guardian_phone'];
        $customer_address = $session_data['address'];
        $product_info = $session_data['payment_detail']->fee_group_name . " - " . $session_data['payment_detail']->code;
        $MERCHANT_KEY = $pay_method->api_secret_key;
        $SALT = $pay_method->salt;


        //optional udf values 
        $udf1 = '';
        $udf2 = '';
        $udf3 = '';
        $udf4 = '';
        $udf5 = '';

        $hashstring = $MERCHANT_KEY . '|' . $txnid . '|' . $amount . '|' . $product_info . '|' . $customer_name . '|' . $customer_emial . '|' . $udf1 . '|' . $udf2 . '|' . $udf3 . '|' . $udf4 . '|' . $udf5 . '||||||' . $SALT;
        $hash = strtolower(hash('sha512', $hashstring));

        $success = base_url('parent/payu/success');
        $fail = base_url('parent/payu/success');
        $cancel = base_url('parent/payu/success');
        $data = array(
            'mkey' => $MERCHANT_KEY,
            'tid' => $txnid,
            'hash' => $hash,
            'amount' => $amount,
            'fee_group_name' => $session_data['payment_detail']->fee_group_name,
            'fee_code' => $session_data['payment_detail']->code,
            'name' => $customer_name,
            'productinfo' => $product_info,
            'mailid' => $customer_emial,
            'phoneno' => $customer_mobile,
            'address' => $customer_address,
            'action' => "https://secure.payu.in", //for live change action  https://secure.payu.in
            'sucess' => $success,
            'failure' => $fail,
            'cancel' => $cancel
        );
        $data['session_data'] = $session_data;
        $this->load->view('parent/payu', $data);
    }

    function checkout() {

        $this->form_validation->set_rules('firstname', 'Customer Name', 'required|trim|xss_clean');
        $this->form_validation->set_rules('phone', 'Mobile No', 'required|trim|xss_clean');
        $this->form_validation->set_rules('email', 'Email', 'required|valid_email|trim|xss_clean');
        $this->form_validation->set_rules('amount', 'Amount', 'required|trim|xss_clean');

        if ($this->form_validation->run() == false) {
            $data = array(
                'firstname' => form_error('firstname'),
                'phone' => form_error('phone'),
                'email' => form_error('email'),
                'amount' => form_error('amount'),
            );
            $array = array('status' => 'fail', 'error' => $data);
            echo json_encode($array);
        } else {

            $array = array('status' => 'success', 'error' => '');
            echo json_encode($array);
        }
    }

    public function success() {
        if ($this->input->server('REQUEST_METHOD') == 'POST') {
            $session_data = $this->session->userdata('params');

            if ($this->input->post('status') == "success") {
                $mihpayid = $this->input->post('mihpayid');
                $transactionid = $this->input->post('txnid');
                $txn_id = $session_data['txn_id'];

                if ($txn_id == $transactionid) {
                    $params = $this->session->userdata('params');
                    $json_array = array(
                        'amount' => $this->input->post('amount'),
                        'date' => date('Y-m-d'),
                        'amount_discount' => 0,
                        'amount_fine' => 0,
                        'description' => "Online fees deposit through PayU TXN ID: " . $txn_id . " PayU Ref ID: " . $mihpayid,
                        'payment_mode' => 'PayU',
                    );
                    $data = array(
                        'student_fees_master_id' => $params['student_fees_master_id'],
                        'fee_groups_feetype_id' => $params['fee_groups_feetype_id'],
                        'amount_detail' => $json_array
                    );
                    $send_to = $params['guardian_phone'];
                    $inserted_id = $this->studentfeemaster_model->fee_deposit($data, $send_to);

                    if ($inserted_id) {
                        $invoice_detail = json_decode($inserted_id);
                        redirect(base_url("parent/payment/successinvoice/" . $invoice_detail->invoice_id . "/" . $invoice_detail->sub_invoice_id));
                    } else {
                        
                    }
                } else {
                    redirect(site_url('parent/payment/paymentfailed'));
                }
            } else {

                redirect(site_url('parent/payment/paymentfailed'));
            }
        }
    }

}