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(object):
  """
  支付宝支付接口(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",
      # "qr_pay_mode":4
    }

    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)
    # 排序后的字符串
    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"))
    # ordered_items = self.ordered_data(data)
    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
    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，转换为unicode表示并移除回车
    sign = 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, 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)

from django.shortcuts import render, redirect, HttpResponse
from utils.pay import AliPay
import json
import time
def ali():
  # 沙箱环境地址：https://openhome.alipay.com/platform/appDaily.htm"2016092000554611"
  # 支付宝收到用户的支付,会向商户发两个请求,一个get请求,一个post请求
  # POST请求，用于最后的检测
  notify_url = "http://42.56.89.12:80/page2/"
  # GET请求，用于页面的跳转展示
  return_url = "http://42.56.89.12:80/page2/"
  merchant_private_key_path = "keys/app_private_2048.txt"
  alipay_public_key_path = "keys/alipay_public_2048.txt"
  # 生成一个AliPay的对象
  alipay = AliPay(
    appid=app_id,
    app_notify_url=notify_url,
    return_url=return_url,
    app_private_key_path=merchant_private_key_path,
    alipay_public_key_path=alipay_public_key_path, # 支付宝的公钥，验证支付宝回传消息使用，不是你自己的公钥
    debug=True, # 默认False,
  )
  return alipay


def page1(request):
  if request.method == "GET":

    return render(request, 'page1.html')
  else:
    money = float(request.POST.get('money'))
    # 生成一个对象
    alipay = ali()
    # 生成支付的url
    # 对象调用direct_pay
    query_params = alipay.direct_pay(
      subject="充气娃娃", # 商品简单描述
      out_trade_no="x2" + str(time.time()), # 商户订单号
      total_amount=money, # 交易金额(单位: 元 保留俩位小数)
    )

    pay_url = "https://openapi.alipaydev.com/gateway.do".format(query_params)
    print(pay_url)
    # 朝这个地址发get请求
    return redirect(pay_url)


def page2(request):
  alipay = ali()
  if request.method == "POST":
    # 检测是否支付成功
    # 去请求体中获取所有返回的数据：状态/订单号
    from urllib.parse import parse_qs
    body_str = request.body.decode('utf-8')
    print(body_str)

    post_data = parse_qs(body_str)
    print('支付宝给我的数据:::---------',post_data)
    post_dict = {}
    for k, v in post_data.items():
      post_dict[k] = v[0]
    print('转完之后的字典',post_dict)

    sign = post_dict.pop('sign', None)
    status = alipay.verify(post_dict, sign)
    print('POST验证', status)
    return HttpResponse('POST返回')

  else:
    params = request.GET.dict()
    sign = params.pop('sign', None)
    status = alipay.verify(params, sign)
    print('GET验证', status)
    return HttpResponse('支付成功')