import json
import os
import time

from six.moves.urllib.parse import urlsplit, urlunsplit
from threading import Thread
from libmproxy import controller, proxy
from netlib import http_auth
from testfixtures import LogCapture

from twisted.internet import defer
from twisted.trial.unittest import TestCase
from scrapy.utils.test import get_crawler
from scrapy.http import Request
from tests.spiders import SimpleSpider, SingleRequestSpider
from tests.mockserver import MockServer


class HTTPSProxy(controller.Master, Thread):

    def __init__(self):
        password_manager = http_auth.PassManSingleUser('scrapy', 'scrapy')
        authenticator = http_auth.BasicProxyAuth(password_manager, "mitmproxy")
        cert_path = os.path.join(os.path.abspath(os.path.dirname(__file__)),
            'keys', 'mitmproxy-ca.pem')
        server = proxy.ProxyServer(proxy.ProxyConfig(
            authenticator = authenticator,
            cacert = cert_path),
            0)
        self.server = server
        Thread.__init__(self)
        controller.Master.__init__(self, server)

    def http_address(self):
        return 'http://scrapy:scrapy@%s:%d' % self.server.socket.getsockname()


def _wrong_credentials(proxy_url):
    bad_auth_proxy = list(urlsplit(proxy_url))
    bad_auth_proxy[1] = bad_auth_proxy[1].replace('scrapy:scrapy@', 'wrong:wronger@')
    return urlunsplit(bad_auth_proxy)

class ProxyConnectTestCase(TestCase):

    def setUp(self):
        self.mockserver = MockServer()
        self.mockserver.__enter__()
        self._oldenv = os.environ.copy()

        self._proxy = HTTPSProxy()
        self._proxy.start()

        # Wait for the proxy to start.
        time.sleep(1.0)
        os.environ['https_proxy'] = self._proxy.http_address()
        os.environ['http_proxy'] = self._proxy.http_address()

    def tearDown(self):
        self.mockserver.__exit__(None, None, None)
        self._proxy.shutdown()
        os.environ = self._oldenv

    @defer.inlineCallbacks
    def test_https_connect_tunnel(self):
        crawler = get_crawler(SimpleSpider)
        with LogCapture() as l:
            yield crawler.crawl(self.mockserver.url("/status?n=200", is_secure=True))
        self._assert_got_response_code(200, l)

    @defer.inlineCallbacks
    def test_https_noconnect(self):
        proxy = os.environ['https_proxy']
        os.environ['https_proxy'] = proxy + '?noconnect'
        crawler = get_crawler(SimpleSpider)
        with LogCapture() as l:
            yield crawler.crawl(self.mockserver.url("/status?n=200", is_secure=True))
        self._assert_got_response_code(200, l)

    @defer.inlineCallbacks
    def test_https_connect_tunnel_error(self):
        crawler = get_crawler(SimpleSpider)
        with LogCapture() as l:
            yield crawler.crawl("https://localhost:99999/status?n=200")
        self._assert_got_tunnel_error(l)

    @defer.inlineCallbacks
    def test_https_tunnel_auth_error(self):
        os.environ['https_proxy'] = _wrong_credentials(os.environ['https_proxy'])
        crawler = get_crawler(SimpleSpider)
        with LogCapture() as l:
            yield crawler.crawl(self.mockserver.url("/status?n=200", is_secure=True))
        # The proxy returns a 407 error code but it does not reach the client;
        # he just sees a TunnelError.
        self._assert_got_tunnel_error(l)

    @defer.inlineCallbacks
    def test_https_tunnel_without_leak_proxy_authorization_header(self):
        request = Request(self.mockserver.url("/echo", is_secure=True))
        crawler = get_crawler(SingleRequestSpider)
        with LogCapture() as l:
            yield crawler.crawl(seed=request)
        self._assert_got_response_code(200, l)
        echo = json.loads(crawler.spider.meta['responses'][0].body)
        self.assertTrue('Proxy-Authorization' not in echo['headers'])

    @defer.inlineCallbacks
    def test_https_noconnect_auth_error(self):
        os.environ['https_proxy'] = _wrong_credentials(os.environ['https_proxy']) + '?noconnect'
        crawler = get_crawler(SimpleSpider)
        with LogCapture() as l:
            yield crawler.crawl(self.mockserver.url("/status?n=200", is_secure=True))
        self._assert_got_response_code(407, l)

    def _assert_got_response_code(self, code, log):
        print(log)
        self.assertEqual(str(log).count('Crawled (%d)' % code), 1)

    def _assert_got_tunnel_error(self, log):
        print(log)
        self.assertIn('TunnelError', str(log))