# coding:utf-8
from hashlib import sha1
from flask import Flask, request
 
token = 'xxxxxx'
 
app = Flask(__name__)
 
def get_update(token, timestamp, nonce):
 arguments = ''
 for k in sorted([token, timestamp, nonce]):
  arguments = arguments + str(k)
 m = sha1()
 m.update(arguments.encode('utf8'))
 return m.hexdigest()
 
def check_signature():
 signature = request.args.get('signature', '')
 timestamp = request.args.get('timestamp', '')
 nonce = request.args.get('nonce', '')
 check = get_update(token, timestamp, nonce)
 return True if check == signature else False
 
def parse_xml(data):
 try:
  import xml.etree.cElementTree as ET
 except ImportError:
  import xml.etree.ElementTree as ET
  root = ET.fromstring(data)
  datas = '<xml>'
  for child in root:
   if child.tag == 'ToUserName':
    toUser = child.text
    datas += '<FromUserName>%s</FromUserName>' % toUser
   elif child.tag == 'FromUserName':
    fromUser = child.text
    datas += '<ToUserName>%s</ToUserName>' % fromUser
   else:
    datas += '<' + child.tag + '>'
    datas += child.text
    datas += '</' + child.tag + '>'
  datas += '</xml>'
  return datas
 
@app.route('/weixin', methods=['GET', 'POST'])
def weixinInterface():
 if check_signature:
  if request.method == 'GET':
   echostr = request.args.get('echostr', '')
   return echostr
  elif request.method == 'POST':
   data = request.data
   msg = parse_xml(data)
   return msg
 else:
  return 'signature error'
 
if __name__ == '__main__':
 app.run(host='0.0.0.0')