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
import base64
import json


class AliPay(object):
    """
    创建支付对象，里面是常用的请求参数
    """
    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  #  异步通知
        self.return_url = return_url # 同步通知
        self.app_private_key_path = app_private_key_path

        # 加签
        with open(self.app_private_key_path) as fp:
            self.app_private_key = RSA.importKey(fp.read())
        # 验签
        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:
            # 沙箱网关
            self.gateway = "https://openapi.alipaydev.com/gateway.do"
        else:
            # 正式网关
            self.gateway = "https://openapi.alipay.com/gateway.do"

    def direct_pay(self, subject, out_trade_no, total_amount, return_url=None, **kwargs):

        # 支付
        # 业务参数
        biz_content = {
            "subject": subject, # 标题
            "out_trade_no": out_trade_no, # uuid的订单号，只要不重复就可以，appid下不能有重复的
            "total_amount": total_amount, # 支付的金额
            "return_url":return_url,
            "product_code": "FAST_INSTANT_TRADE_PAY", # 交易方式：即时到账

        }
       # 可以传入额外的参数，都更新到这个里面了
        biz_content.update(kwargs)
        data = self.build_body("alipay.trade.page.pay", biz_content, self.return_url)
        return self.sign_data(data)

    def direct_query(self,out_trade_no,trade_no):
        biz_content = {
            "out_trade_no": out_trade_no,
            "trade_no": trade_no,
        }
        data = self.build_body("alipay.trade.query", biz_content)


        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) # 删除sign
        # 排序后的字符串
        unsigned_items = self.ordered_data(data)  # 排序，如何对字典排序
        # app_id=sad&
        # 待签名字符串
        unsigned_string = "&".join("{0}={1}".format(k, v) for k, v in unsigned_items)
        # 签名
        sign = self.sign(unsigned_string.encode("utf-8"))
        # 添加上‘’
        quoted_string = "&".join("{0}={1}".format(k, quote_plus(v)) for k, v in unsigned_items)

        # 获得最终的订单信息字符串
        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)

        # 将字典类型的数据dump出来 针对biz-content
        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):
        # 开始计算签名
        key = self.app_private_key
        signer = PKCS1_v1_5.new(key)
        signature = signer.sign(SHA256.new(unsigned_string))
        # base64 编码
        sign = base64.encodebytes(signature).decode("utf8").replace("\n", "")
        return sign

    def _verify(self, raw_content, signature):
        # 开始计算签名
        key = self.alipay_public_key
        signer = PKCS1_v1_5.new(key)
        digest = SHA256.new()
        digest.update(raw_content.encode("utf8"))
        if signer.verify(digest, base64.decodebytes(signature.encode("utf8"))):
            return True
        return False

    def verify(self, data, signature):
        if "sign_type" in data:
            sign_type = data.pop("sign_type")
        # 排序后的字符串
        unsigned_items = self.ordered_data(data)
        message = "&".join(u"{}={}".format(k, v) for k, v in unsigned_items)

        return self._verify(message, signature)


if __name__ == '__main__':
    ali = AliPay(app_notify_url='http://127.0.0.1',return_url='http://127.0.0.1',appid='2016073100136733',
                 app_private_key_path='app_private_key',alipay_public_key_path='app_public_key')
    print('https://openapi.alipaydev.com/gateway.do?'+ali.direct_pay(subject='asdsad',total_amount='0.01',
                                                                     out_trade_no='1000000000000000'))
    return_data = input('请输入返回的参数\r\n').strip()
    d = dict([(item.split('=')) for item in return_data.split('&')])
    sign = d.pop('sign')
    print(ali.verify(d,sign))