import requests
from lxml.html import document_fromstring


class AutoProxy:
    checked_url = 'https://httpbin.org/ip'

    @staticmethod
    def __strip(text):
        return text.text_content().strip(' \n\t\r\0')

    def _s(self, item):
        td = item.cssselect('td')
        proxy = self.__strip(td[4])  # proxy type
        https = self.__strip(td[6])  # https (yes|no)
        if (
                proxy == 'anonymous'
                or proxy == 'elite proxy'
        ) and https == 'yes':
            return self.__strip(td[0]) + ':' + self.__strip(td[1])
        return None

    def _test_proxy(self, url):
        proxies = {
            'http': url,
            'https': url,
        }
        try:
            requests.head(url=self.checked_url, proxies=proxies, timeout=6)
        except Exception:
            return False
        return proxies

    def _change_checked_url(self, checked_url):
        if checked_url:
            self.checked_url = checked_url

    def auto_proxy(self, checked_url=None):
        self._change_checked_url(checked_url)
        url = 'https://www.us-proxy.org'
        items = document_fromstring(requests.get(url).text)
        items = items.cssselect('#proxylisttable tbody tr')
        for n, i in enumerate(items):
            proxy = self._s(i)
            test = False
            if proxy:
                test = self._test_proxy(proxy)
            if test:
                return test
        return None


auto_proxy = AutoProxy().auto_proxy