# encoding=utf8

import requests
import hashlib,sys,os,shutil
down_url = "https://user.ipip.net/download.php?type=datx&token=TOKEN" # 下载地址
response = requests.get(down_url) # 发起http请求
etag_value = response.headers.get("ETag") #获取ETag值
if not etag_value:           # ETag不存在就退出
    print("etag not exists")
    sys.exit(0)
with open("c:/tmp/ipip_temp.datx", 'wb+') as fd: #写临时文件
    for chunk in response.iter_content(4096):
        fd.write(chunk)
with open("c:/tmp/ipip_temp.datx", 'rb') as fd: #读取临时文件
    sha1 = hashlib.sha1()
    while True:
        content = fd.read(4096)
        if not content:
            break
        sha1.update(content)
    content_sha1_value = sha1.hexdigest() #计算临时文件sha1
    etag_sha1_value = etag_value[5:]
    if etag_sha1_value != content_sha1_value: # sha1 不一致退出
        print("etag err")
        sys.exit(0)
shutil.copyfile("c:/tmp/ipip_temp.datx", "c:/tmp/ipip_station.datx") # 覆盖正式文件，目标目录必须有可写权限。
print("ok")