sadad_gateway.py

import base64
import json
import pytz
from datetime import datetime

import pyDes as pyDes
import requests


class Sadad:
    MERCHANT_ID = '{your_merchant_id}'
    TERMINAL_ID = '{your_terminal_id}'
    TERMINAL_KEY = '{your_terminal_key}'

    BASE_PAYMENT_URL = 'https://sadad.shaparak.ir/VPG/Purchase'
    PAYMENT_REQUEST_URL = 'https://sadad.shaparak.ir/VPG/api/v0/Request/PaymentRequest'
    PAYMENT_VERIFY_URL = 'https://sadad.shaparak.ir/VPG/api/v0/Advice/Verify'

    def __init__(self, amount, order_id, return_url):
        self.order_id = order_id
        self.return_url = return_url
        self.amount = amount * 10  # change to rial
        self.sign_data = self.gen_sign_data()

        self.token = None
        self.payment_url = None

    def payment_request(self):
        data = json.dumps({
            'MerchantId': Sadad.MERCHANT_ID,
            'TerminalId': Sadad.TERMINAL_ID,
            'Amount': self.amount,
            'OrderId': self.order_id,
            'LocalDateTime': Sadad.get_local_time(),
            'ReturnUrl': self.return_url,
            'SignData': self.sign_data})

        response = requests.post(
            Sadad.PAYMENT_REQUEST_URL,
            data=data,
            headers={"Content-Type": "application/json", "Content-Length": str(len(data))}
        )

        if response.status_code != 200:
            raise Exception('Gateway HTTP error: {}\ntext: {}'.format(response.status_code, response.text))

        response = json.loads(response.text)
        if response['ResCode'] != '0':
            raise Exception('Sadad error: {}\ntext: {}'.format(response['ResCode'], response['Description']))

        self.token = response['Token']
        self.payment_url = self.gen_pay_url()
        return self.token

    @staticmethod
    def verify_payment(token):
        # todo: add tenacity package for retrying
        data = json.dumps({'SignData': Sadad.encrypt_3des(token), 'Token': token})
        response = requests.post(
            Sadad.PAYMENT_VERIFY_URL,
            data=data,
            headers={'Content-Type': 'application/json', 'Content-Length': str(len(data))}
        )
        if response.status_code != 200:
            raise Exception('Gateway HTTP error: {}\ntext: {}'.format(response.status_code, response.text))
        return json.loads(response.text)

    def gen_sign_data(self):
        text = '{};{};{}'.format(self.TERMINAL_ID, self.order_id, self.amount)
        return Sadad.encrypt_3des(text)

    def gen_pay_url(self):
        return '{}?Token={}'.format(Sadad.BASE_PAYMENT_URL, self.token)

    @staticmethod
    def get_local_time():
        return datetime.now(pytz.timezone('Asia/Tehran')).strftime('%m/%d/%Y %I:%M:%S %p')

    @staticmethod
    def encrypt_3des(text):
        key = base64.b64decode(Sadad.TERMINAL_KEY)
        des = pyDes.triple_des(key, mode=pyDes.ECB, padmode=pyDes.PAD_PKCS5)
        encrypted_string = des.encrypt(text)
        base64_encoded = base64.b64encode(encrypted_string)
        return base64_encoded.decode('ascii')