# -*- coding: utf-8 -*-

"""
requests.adapters
~~~~~~~~~~~~~~~~~

This module contains the transport adapters that Requests uses to define
and maintain connections.
"""

import os.path
import socket

from urllib3.poolmanager import PoolManager, proxy_from_url
from urllib3.response import HTTPResponse
from urllib3.util import parse_url
from urllib3.util import Timeout as TimeoutSauce
from urllib3.util.retry import Retry
from urllib3.exceptions import ClosedPoolError
from urllib3.exceptions import ConnectTimeoutError
from urllib3.exceptions import HTTPError as _HTTPError
from urllib3.exceptions import MaxRetryError
from urllib3.exceptions import NewConnectionError
from urllib3.exceptions import ProxyError as _ProxyError
from urllib3.exceptions import ProtocolError
from urllib3.exceptions import ReadTimeoutError
from urllib3.exceptions import SSLError as _SSLError
from urllib3.exceptions import ResponseError
from urllib3.exceptions import LocationValueError

from .models import Response
from .compat import urlparse, basestring
from .utils import (DEFAULT_CA_BUNDLE_PATH, extract_zipped_paths,
                    get_encoding_from_headers, prepend_scheme_if_needed,
                    get_auth_from_url, urldefragauth, select_proxy)
from .structures import CaseInsensitiveDict
from .cookies import extract_cookies_to_jar
from .exceptions import (ConnectionError, ConnectTimeout, ReadTimeout, SSLError,
                         ProxyError, RetryError, InvalidSchema, InvalidProxyURL,
                         InvalidURL)
from .auth import _basic_auth_str

try:
    from urllib3.contrib.socks import SOCKSProxyManager
except ImportError:
    def SOCKSProxyManager(*args, **kwargs):
        raise InvalidSchema("Missing dependencies for SOCKS support.")

DEFAULT_POOLBLOCK = False
DEFAULT_POOLSIZE = 10
DEFAULT_RETRIES = 0
DEFAULT_POOL_TIMEOUT = None


class BaseAdapter(object):
    """The Base Transport Adapter"""

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

    def send(self, request, stream=False, timeout=None, verify=True,
             cert=None, proxies=None):
        """Sends PreparedRequest object. Returns Response object.

        :param request: The :class:`PreparedRequest <PreparedRequest>` being sent.
        :param stream: (optional) Whether to stream the request content.
        :param timeout: (optional) How long to wait for the server to send
            data before giving up, as a float, or a :ref:`(connect timeout,
            read timeout) <timeouts>` tuple.
        :type timeout: float or tuple
        :param verify: (optional) Either a boolean, in which case it controls whether we verify
            the server's TLS certificate, or a string, in which case it must be a path
            to a CA bundle to use
        :param cert: (optional) Any user-provided SSL certificate to be trusted.
        :param proxies: (optional) The proxies dictionary to apply to the request.
        """
        raise NotImplementedError

    def close(self):
        """Cleans up adapter specific items."""
        raise NotImplementedError


class HTTPAdapter(BaseAdapter):
    """The built-in HTTP Adapter for urllib3.

    Provides a general-case interface for Requests sessions to contact HTTP and
    HTTPS urls by implementing the Transport Adapter interface. This class will
    usually be created by the :class:`Session <Session>` class under the
    covers.

    :param pool_connections: The number of urllib3 connection pools to cache.
    :param pool_maxsize: The maximum number of connections to save in the pool.
    :param max_retries: The maximum number of retries each connection
        should attempt. Note, this applies only to failed DNS lookups, socket
        connections and connection timeouts, never to requests where data has
        made it to the server. By default, Requests does not retry failed
        connections. If you need granular control over the conditions under
        which we retry a request, import urllib3's ``Retry`` class and pass
        that instead.
    :param pool_block: Whether the connection pool should block for connections.

    Usage::

      >>> import requests
      >>> s = requests.Session()
      >>> a = requests.adapters.HTTPAdapter(max_retries=3)
      >>> s.mount('http://', a)
    """
    __attrs__ = ['max_retries', 'config', '_pool_connections', '_pool_maxsize',
                 '_pool_block']

    def __init__(self, pool_connections=DEFAULT_POOLSIZE,
                 pool_maxsize=DEFAULT_POOLSIZE, max_retries=DEFAULT_RETRIES,
                 pool_block=DEFAULT_POOLBLOCK):
        if max_retries == DEFAULT_RETRIES:
            self.max_retries = Retry(0, read=False)
        else:
            self.max_retries = Retry.from_int(max_retries)
        self.config = {}
        self.proxy_manager = {}

        super(HTTPAdapter, self).__init__()

        self._pool_connections = pool_connections
        self._pool_maxsize = pool_maxsize
        self._pool_block = pool_block

        self.init_poolmanager(pool_connections, pool_maxsize, block=pool_block)

    def __getstate__(self):
        return {attr: getattr(self, attr, None) for attr in self.__attrs__}

    def __setstate__(self, state):
        # Can't handle by adding 'proxy_manager' to self.__attrs__ because
        # self.poolmanager uses a lambda function, which isn't pickleable.
        self.proxy_manager = {}
        self.config = {}

        for attr, value in state.items():
            setattr(self, attr, value)

        self.init_poolmanager(self._pool_connections, self._pool_maxsize,
                              block=self._pool_block)

    def init_poolmanager(self, connections, maxsize, block=DEFAULT_POOLBLOCK, **pool_kwargs):
        """Initializes a urllib3 PoolManager.

        This method should not be called from user code, and is only
        exposed for use when subclassing the
        :class:`HTTPAdapter <requests.adapters.HTTPAdapter>`.

        :param connections: The number of urllib3 connection pools to cache.
        :param maxsize: The maximum number of connections to save in the pool.
        :param block: Block when no free connections are available.
        :param pool_kwargs: Extra keyword arguments used to initialize the Pool Manager.
        """
        # save these values for pickling
        self._pool_connections = connections
        self._pool_maxsize = maxsize
        self._pool_block = block

        self.poolmanager = PoolManager(num_pools=connections, maxsize=maxsize,
                                       block=block, strict=True, **pool_kwargs)

    def proxy_manager_for(self, proxy, **proxy_kwargs):
        """Return urllib3 ProxyManager for the given proxy.

        This method should not be called from user code, and is only
        exposed for use when subclassing the
        :class:`HTTPAdapter <requests.adapters.HTTPAdapter>`.

        :param proxy: The proxy to return a urllib3 ProxyManager for.
        :param proxy_kwargs: Extra keyword arguments used to configure the Proxy Manager.
        :returns: ProxyManager
        :rtype: urllib3.ProxyManager
        """
        if proxy in self.proxy_manager:
            manager = self.proxy_manager[proxy]
        elif proxy.lower().startswith('socks'):
            username, password = get_auth_from_url(proxy)
            manager = self.proxy_manager[proxy] = SOCKSProxyManager(
                proxy,
                username=username,
                password=password,
                num_pools=self._pool_connections,
                maxsize=self._pool_maxsize,
                block=self._pool_block,
                **proxy_kwargs
            )
        else:
            proxy_headers = self.proxy_headers(proxy)
            manager = self.proxy_manager[proxy] = proxy_from_url(
                proxy,
                proxy_headers=proxy_headers,
                num_pools=self._pool_connections,
                maxsize=self._pool_maxsize,
                block=self._pool_block,
                **proxy_kwargs)

        return manager

    def cert_verify(self, conn, url, verify, cert):
        """Verify a SSL certificate. This method should not be called from user
        code, and is only exposed for use when subclassing the
        :class:`HTTPAdapter <requests.adapters.HTTPAdapter>`.

        :param conn: The urllib3 connection object associated with the cert.
        :param url: The requested URL.
        :param verify: Either a boolean, in which case it controls whether we verify
            the server's TLS certificate, or a string, in which case it must be a path
            to a CA bundle to use
        :param cert: The SSL certificate to verify.
        """
        if url.lower().startswith('https') and verify:

            cert_loc = None

            # Allow self-specified cert location.
            if verify is not True:
                cert_loc = verify

            if not cert_loc:
                cert_loc = extract_zipped_paths(DEFAULT_CA_BUNDLE_PATH)

            if not cert_loc or not os.path.exists(cert_loc):
                raise IOError("Could not find a suitable TLS CA certificate bundle, "
                              "invalid path: {}".format(cert_loc))

            conn.cert_reqs = 'CERT_REQUIRED'

            if not os.path.isdir(cert_loc):
                conn.ca_certs = cert_loc
            else:
                conn.ca_cert_dir = cert_loc
        else:
            conn.cert_reqs = 'CERT_NONE'
            conn.ca_certs = None
            conn.ca_cert_dir = None

        if cert:
            if not isinstance(cert, basestring):
                conn.cert_file = cert[0]
                conn.key_file = cert[1]
            else:
                conn.cert_file = cert
                conn.key_file = None
            if conn.cert_file and not os.path.exists(conn.cert_file):
                raise IOError("Could not find the TLS certificate file, "
                              "invalid path: {}".format(conn.cert_file))
            if conn.key_file and not os.path.exists(conn.key_file):
                raise IOError("Could not find the TLS key file, "
                              "invalid path: {}".format(conn.key_file))

    def build_response(self, req, resp):
        """Builds a :class:`Response <requests.Response>` object from a urllib3
        response. This should not be called from user code, and is only exposed
        for use when subclassing the
        :class:`HTTPAdapter <requests.adapters.HTTPAdapter>`

        :param req: The :class:`PreparedRequest <PreparedRequest>` used to generate the response.
        :param resp: The urllib3 response object.
        :rtype: requests.Response
        """
        response = Response()

        # Fallback to None if there's no status_code, for whatever reason.
        response.status_code = getattr(resp, 'status', None)

        # Make headers case-insensitive.
        response.headers = CaseInsensitiveDict(getattr(resp, 'headers', {}))

        # Set encoding.
        response.encoding = get_encoding_from_headers(response.headers)
        response.raw = resp
        response.reason = response.raw.reason

        if isinstance(req.url, bytes):
            response.url = req.url.decode('utf-8')
        else:
            response.url = req.url

        # Add new cookies from the server.
        extract_cookies_to_jar(response.cookies, req, resp)

        # Give the Response some context.
        response.request = req
        response.connection = self

        return response

    def get_connection(self, url, proxies=None):
        """Returns a urllib3 connection for the given URL. This should not be
        called from user code, and is only exposed for use when subclassing the
        :class:`HTTPAdapter <requests.adapters.HTTPAdapter>`.

        :param url: The URL to connect to.
        :param proxies: (optional) A Requests-style dictionary of proxies used on this request.
        :rtype: urllib3.ConnectionPool
        """
        proxy = select_proxy(url, proxies)

        if proxy:
            proxy = prepend_scheme_if_needed(proxy, 'http')
            proxy_url = parse_url(proxy)
            if not proxy_url.host:
                raise InvalidProxyURL("Please check proxy URL. It is malformed"
                                      " and could be missing the host.")
            proxy_manager = self.proxy_manager_for(proxy)
            conn = proxy_manager.connection_from_url(url)
        else:
            # Only scheme should be lower case
            parsed = urlparse(url)
            url = parsed.geturl()
            conn = self.poolmanager.connection_from_url(url)

        return conn

    def close(self):
        """Disposes of any internal state.

        Currently, this closes the PoolManager and any active ProxyManager,
        which closes any pooled connections.
        """
        self.poolmanager.clear()
        for proxy in self.proxy_manager.values():
            proxy.clear()

    def request_url(self, request, proxies):
        """Obtain the url to use when making the final request.

        If the message is being sent through a HTTP proxy, the full URL has to
        be used. Otherwise, we should only use the path portion of the URL.

        This should not be called from user code, and is only exposed for use
        when subclassing the
        :class:`HTTPAdapter <requests.adapters.HTTPAdapter>`.

        :param request: The :class:`PreparedRequest <PreparedRequest>` being sent.
        :param proxies: A dictionary of schemes or schemes and hosts to proxy URLs.
        :rtype: str
        """
        proxy = select_proxy(request.url, proxies)
        scheme = urlparse(request.url).scheme