# coding=utf-8

import certifi
import ssl
import os
import socket
import logging
import requests
import xmlrpclib
import dns.resolver

from collections import OrderedDict
from requests import exceptions
from requests.utils import default_user_agent
from urllib3.util import connection
from retry.api import retry_call
from exceptions import APIThrottled
from dogpile.cache.api import NO_VALUE
from subliminal.cache import region
from cfscrape import CloudflareScraper

try:
    from urlparse import urlparse
except ImportError:
    from urllib.parse import urlparse

from subzero.lib.io import get_viable_encoding

logger = logging.getLogger(__name__)
pem_file = os.path.normpath(os.path.join(os.path.dirname(os.path.realpath(unicode(__file__, get_viable_encoding()))), "..", certifi.where()))
try:
    default_ssl_context = ssl.create_default_context(cafile=pem_file)
except AttributeError:
    # < Python 2.7.9
    default_ssl_context = None


custom_resolver = dns.resolver.Resolver(configure=False)

# 8.8.8.8 is Google's public DNS server
custom_resolver.nameservers = ['8.8.8.8', '1.1.1.1']


class TimeoutSession(requests.Session):
    timeout = 10

    def __init__(self, timeout=None):
        super(TimeoutSession, self).__init__()
        self.timeout = timeout or self.timeout

    def request(self, method, url, *args, **kwargs):
        if kwargs.get('timeout') is None:
            kwargs['timeout'] = self.timeout

        return super(TimeoutSession, self).request(method, url, *args, **kwargs)


class CertifiSession(TimeoutSession):
    def __init__(self):
        super(CertifiSession, self).__init__()
        self.verify = pem_file


class CFSession(CloudflareScraper, CertifiSession, TimeoutSession):
    def __init__(self):
        super(CFSession, self).__init__()
        self.headers = OrderedDict([
            ('User-Agent', default_user_agent()),
            ('Accept', 'text/html,application/xhtml+xml,application/xml;q=0.9,*/*;q=0.8'),
            ('Accept-Language', 'en-US,en;q=0.5'),
            ('Accept-Encoding', 'gzip, deflate'),
            ('Connection', 'keep-alive'),
            ('Pragma', 'no-cache'),
            ('Cache-Control', 'no-cache'),
            ('Upgrade-Insecure-Requests', '1'),
            ('DNT', '1'),
        ])
        self.debug = os.environ.get("CF_DEBUG", False)

    def request(self, method, url, *args, **kwargs):
        parsed_url = urlparse(url)
        domain = parsed_url.netloc

        cache_key = "cf_data_%s" % domain

        if not self.cookies.get("__cfduid", "", domain=domain):
            cf_data = region.get(cache_key)
            if cf_data is not NO_VALUE:
                cf_cookies, user_agent = cf_data
                logger.debug("Trying to use old cf data for %s: %s", domain, cf_data)
                for cookie, value in cf_cookies.iteritems():
                    self.cookies.set(cookie, value, domain=domain)

                self.headers['User-Agent'] = user_agent

        ret = super(CFSession, self).request(method, url, *args, **kwargs)

        try:
            cf_data = self.get_live_tokens(domain)
        except:
            pass
        else:
            if cf_data != region.get(cache_key) and self.cookies.get("__cfduid", "", domain=domain)\
                    and self.cookies.get("cf_clearance", "", domain=domain):
                logger.debug("Storing cf data for %s: %s", domain, cf_data)
                region.set(cache_key, cf_data)

        return ret


class RetryingSession(CFSession):
    proxied_functions = ("get", "post")

    def __init__(self):
        super(RetryingSession, self).__init__()

        proxy = os.environ.get('SZ_HTTP_PROXY')
        if proxy:
            self.proxies = {
                "http": proxy,
                "https": proxy
            }

    def retry_method(self, method, *args, **kwargs):
        if self.proxies:
            # fixme: may be a little loud
            logger.debug("Using proxy %s for: %s", self.proxies["http"], args[0])

        return retry_call(getattr(super(RetryingSession, self), method), fargs=args, fkwargs=kwargs, tries=3, delay=5,
                          exceptions=(exceptions.ConnectionError,
                                      exceptions.ProxyError,
                                      exceptions.SSLError,
                                      exceptions.Timeout,
                                      exceptions.ConnectTimeout,
                                      exceptions.ReadTimeout,
                                      socket.timeout))

    def get(self, *args, **kwargs):
        if self.proxies and "timeout" in kwargs and kwargs["timeout"]:
            kwargs["timeout"] = kwargs["timeout"] * 3
        return self.retry_method("get", *args, **kwargs)

    def post(self, *args, **kwargs):
        if self.proxies and "timeout" in kwargs and kwargs["timeout"]:
            kwargs["timeout"] = kwargs["timeout"] * 3
        return self.retry_method("post", *args, **kwargs)


class SubZeroRequestsTransport(xmlrpclib.SafeTransport):
    """
    Drop in Transport for xmlrpclib that uses Requests instead of httplib

    Based on: https://gist.github.com/chrisguitarguy/2354951#gistcomment-2388906

    """
    # change our user agent to reflect Requests
    user_agent = "Python XMLRPC with Requests (python-requests.org)"
    proxies = None

    def __init__(self, use_https=True, verify=None, user_agent=None, timeout=10, *args, **kwargs):
        self.verify = pem_file if verify is None else verify
        self.use_https = use_https
        self.user_agent = user_agent if user_agent is not None else self.user_agent
        self.timeout = timeout
        proxy = os.environ.get('SZ_HTTP_PROXY')
        if proxy:
            self.proxies = {
                "http": proxy,
                "https": proxy
            }

        xmlrpclib.SafeTransport.__init__(self, *args, **kwargs)

    def request(self, host, handler, request_body, verbose=0):
        """
        Make an xmlrpc request.
        """
        headers = {'User-Agent': self.user_agent}
        url = self._build_url(host, handler)
        try:
            resp = requests.post(url, data=request_body, headers=headers,
                                 stream=True, timeout=self.timeout, proxies=self.proxies,
                                 verify=self.verify)
        except ValueError:
            raise
        except Exception:
            raise  # something went wrong
        else:
            resp.raise_for_status()

            try:
                if 'x-ratelimit-remaining' in resp.headers and int(resp.headers['x-ratelimit-remaining']) <= 2:
                    raise APIThrottled()
            except ValueError:
                logger.info('Couldn\'t parse "x-ratelimit-remaining": %r' % resp.headers['x-ratelimit-remaining'])

            self.verbose = verbose
            try:
                return self.parse_response(resp.raw)
            except:
                logger.debug("Bad response data: %r", resp.raw)

    def _build_url(self, host, handler):
        """
        Build a url for our request based on the host, handler and use_http
        property
        """
        scheme = 'https' if self.use_https else 'http'
        handler = handler[1:] if handler and handler[0] == "/" else handler
        return '%s://%s/%s' % (scheme, host, handler)


_orig_create_connection = connection.create_connection


dns_cache = {}


def set_custom_resolver():
    def patched_create_connection(address, *args, **kwargs):
        """Wrap urllib3's create_connection to resolve the name elsewhere"""
        # resolve hostname to an ip address; use your own
        # resolver here, as otherwise the system resolver will be used.
        host, port = address
        if host in dns_cache:
            ip = dns_cache[host]
            logger.debug("Using %s=%s from cache", host, ip)
        else:
            try:
                ip = custom_resolver.query(host)[0].address
                dns_cache[host] = ip
            except dns.exception.DNSException:
                logger.warning("Couldn't resolve %s with DNS: %s", host, custom_resolver.nameservers)
                return _orig_create_connection((host, port), *args, **kwargs)

            logger.debug("Resolved %s to %s using %s", host, ip, custom_resolver.nameservers)

        return _orig_create_connection((ip, port), *args, **kwargs)

    connection.create_connection = patched_create_connection