from datetime import datetime
from Crypto.PublicKey import RSA
from Crypto.Signature import PKCS1_v1_5
from Crypto.Hash import SHA256
from urllib.parse import quote_plus
from base64 import decodebytes, encodebytes
import json

class AliPay:
    """
    支付寶支付接口(PC端支付接口)
    """

    def __init__(self, appid, app_notify_url, app_private_key_path,
                 alipay_public_key_path, return_url, debug=False):
        self.appid = appid
        self.app_notify_url = app_notify_url
        self.app_private_key_path = app_private_key_path
        self.app_private_key = None
        self.return_url = return_url
        with open(self.app_private_key_path) as fp:
            self.app_private_key = RSA.importKey(fp.read())
        self.alipay_public_key_path = alipay_public_key_path
        with open(self.alipay_public_key_path) as fp:
            self.alipay_public_key = RSA.importKey(fp.read())

        if debug is True:
            self.__gateway = "https://openapi.alipaydev.com/gateway.do"
        else:
            self.__gateway = "https://openapi.alipay.com/gateway.do"

    def direct_pay(self, subject, out_trade_no, total_amount, return_url=None, **kwargs):
        biz_content = {
            "subject": subject,
            "out_trade_no": out_trade_no,
            "total_amount": total_amount,
            "product_code": "FAST_INSTANT_TRADE_PAY",
        }

        biz_content.update(kwargs)
        data = self.build_body("alipay.trade.page.pay", biz_content, self.return_url)
        return self.sign_data(data)

    def build_body(self, method, biz_content, return_url=None):
        data = {
            "app_id": self.appid,
            "method": method,
            "charset": "utf-8",
            "sign_type": "RSA2",
            "timestamp": datetime.now().strftime("%Y-%m-%d %H:%M:%S"),
            "version": "1.0",
            "biz_content": biz_content
        }

        if return_url is not None:
            data["notify_url"] = self.app_notify_url
            data["return_url"] = self.return_url

        return data

    def sign_data(self, data):
        data.pop("sign", None)
        unsigned_items = self.ordered_data(data)
        unsigned_string = "&".join("{0}={1}".format(k, v) for k, v in unsigned_items)
        sign = self.sign(unsigned_string.encode("utf-8"))
        quoted_string = "&".join("{0}={1}".format(k, quote_plus(v)) for k, v in unsigned_items)

        signed_string = quoted_string + "&sign=" + quote_plus(sign)
        return signed_string

    def ordered_data(self, data):
        complex_keys = []
        for key, value in data.items():
            if isinstance(value, dict):
                complex_keys.append(key)

        for key in complex_keys:
            data[key] = json.dumps(data[key], separators=(',', ':'))

        return sorted([(k, v) for k, v in data.items()])

    def sign(self, unsigned_string):
        key = self.app_private_key
        signer = PKCS1_v1_5.new(key)
        signature = signer.sign(SHA256.new(unsigned_string))
        sign = encodebytes(signature).decode("utf8").replace("\n", "")
        return sign

    def _verify(self, raw_content, signature):
        key = self.alipay_public_key
        signer = PKCS1_v1_5.new(key)
        digest = SHA256.new()
        digest.update(raw_content.encode("utf8"))
        if signer.verify(digest, decodebytes(signature.encode("utf8"))):
            return True
        return False

    def verify(self, data, signature):
        if "sign_type" in data:
            data.pop("sign_type")
        unsigned_items = self.ordered_data(data)
        message = "&".join(u"{}={}".format(k, v) for k, v in unsigned_items)
        return self._verify(message, signature)

def init_alipay():
    # 初始化Alipay
    alipay = AliPay(
        appid="appid",
        app_notify_url="回調(diào)地址",
        return_url="回調(diào)地址",
        app_private_key_path="私鑰相對路徑",
        alipay_public_key_path="公鑰相對路徑",
        debug=True  # 支付環(huán)境
    )
    return alipay

async def get(self):
  
    alipay = init_alipay()
    # 傳一個(gè)標(biāo)題  訂單號  訂單價(jià)格
    params = alipay.direct_pay("三方廣告平臺", order_no, money)
    url = f"https://openapi.alipaydev.com/gateway.do?{params}"
    return self.write(ret_json(url))

# 構(gòu)建一個(gè)回調(diào)地址,用于支付成功后回調(diào),在回調(diào)地址中可以獲取訂單號(out_trade_no)、金額(total_amount)、時(shí)間戳(timestamp),然后進(jìn)行處理業(yè)務(wù)邏輯。