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- First version only support OnePay payment
- Hope you like that!

``markdown


OnePay Payment Integration

This guide demonstrates how to use the OnepayPaymentService class from the vn-paymentgate library to create a payment URL and handle IPN (Instant Payment Notification) from OnePay.

Installation

Ensure that you have installed the vn-paymentgate library:

`bash
npm install vn-paymentgate
`

Importing the Service

Import the OnepayPaymentService class from the vn-paymentgate library in your project:

`typescript
import { OnepayPaymentService } from 'vn-paymentgate';
`

Environment Configuration

To use the OnepayPaymentService, you must configure the following environment variables:

`env
VPC_VERSION=
VPC_COMMAND=
AGAIN_LINK=
VPC_RETURN_URL=
VPC_LOCALE=
VPC_ACCESS_CODE=
VPC_MERCHANT=
VPC_PAYMENT_CLIENT_URL=
VPC_SECURE_SECRET=
`

If you want to config promotion
`
VPC_PROMOTION_LIST=string
VPC_THEME=string
`

Set these variables in your .env file or directly in your environment.

Creating a Payment URL

Use the createPaymentUrl function to generate a payment URL. This function requires two parameters:

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The PaymentRequest interface contains the following properties:

- ipClient: string; - The IP address of the client.
- merchTxnRef: string; - The merchant transaction reference.
- orderInfo: string; - Information about the order.
- title: string; - The title of the transaction.
- amount: number; - The amount to be paid.

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An object containing custom parameters that need to be sent to OnePay and will be returned when OnePay sends back data.

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`typescript
import { OnepayPaymentService } from 'vn-paymentgate';

const paymentRequest: PaymentRequest = {
ipClient: '192.168.1.1',
merchTxnRef: 'MTX123456789',
orderInfo: 'Payment for Order #1234',
title: 'Order #1234',
amount: 100000, // in VND
};

const customParams = {
user_email: 'customer@example.com',
user_phone: '0123456789',
};

const paymentUrl = OnepayPaymentService.createPaymentUrl(paymentRequest, customParams);

console.log(paymentUrl);
`

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`typescript
static createPaymentUrl(
{ ipClient, merchTxnRef, orderInfo, title, amount }: PaymentRequest,
customParams: Record = {}
): string
`

Handling IPN (Instant Payment Notification)

The ipn function is used to handle the parameters returned by OnePay after the payment process. Ensure that your server correctly handles the IPN data.

`typescript
import { OnepayPaymentService } from 'vn-paymentgate';

// Example IPN data received from OnePay
const ipnData = {
vpc_TxnResponseCode: '0',
vpc_TransactionNo: '1234567890',
vpc_OrderInfo: 'Payment for Order #1234',
// other parameters...
};

export interface IpnResponse {
isValid: boolean;
code: string | null;
responseData?: Record;
}

const isValid = OnepayPaymentService.ipn(ipnData);

if (ipnResponse.isValid) {
console.log('IPN data is valid.');
console.log('Response Data:', ipnResponse.responseData);
} else {
console.log('IPN data is invalid.');
console.log('Error Code:', ipnResponse.code);
}
`

Conclusion

This documentation provides an overview of how to integrate OnePay with your Node.js application using the vn-paymentgate library. For more details, refer to the library's official documentation.
``