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

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

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

import os
import socket

from .models import Response
from .auth import HTTPProxyAuth
from .packages.urllib3.poolmanager import PoolManager
from .hooks import dispatch_hook
from .compat import urlparse
from .utils import DEFAULT_CA_BUNDLE_PATH, get_encoding_from_headers
from .structures import CaseInsensitiveDict
from .packages.urllib3.exceptions import MaxRetryError
from .packages.urllib3.exceptions import TimeoutError
from .packages.urllib3.exceptions import SSLError as _SSLError
from .packages.urllib3.exceptions import HTTPError as _HTTPError
from .cookies import extract_cookies_to_jar
from .exceptions import ConnectionError, Timeout, SSLError

DEFAULT_POOLSIZE = 10
DEFAULT_RETRIES = 0


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

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

    def send(self):
        raise NotImplementedError

    def close(self):
        raise NotImplementedError


class HTTPAdapter(BaseAdapter):
    """Built-In HTTP Adapter for Urllib3."""
    def __init__(self, pool_connections=DEFAULT_POOLSIZE, pool_maxsize=DEFAULT_POOLSIZE):
        self.max_retries = DEFAULT_RETRIES
        self.config = {}

        super(HTTPAdapter, self).__init__()

        self.init_poolmanager(pool_connections, pool_maxsize)

    def init_poolmanager(self, connections, maxsize):
        self.poolmanager = PoolManager(num_pools=connections, maxsize=maxsize)

    def cert_verify(self, conn, url, verify, cert):
        if url.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 = DEFAULT_CA_BUNDLE_PATH

            if not cert_loc:
                raise Exception("Could not find a suitable SSL CA certificate bundle.")

            conn.cert_reqs = 'CERT_REQUIRED'
            conn.ca_certs = cert_loc
        else:
            conn.cert_reqs = 'CERT_NONE'
            conn.ca_certs = None

        if cert:
            if len(cert) == 2:
                conn.cert_file = cert[0]
                conn.key_file = cert[1]
            else:
                conn.cert_file = cert


    def build_response(self, req, resp):
        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

        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

        # Run the Response hook.
        response = dispatch_hook('response', req.hooks, response)
        return response

    def get_connection(self, url, proxies=None):
        """Returns a connection for the given URL."""
        proxies = proxies or {}
        proxy = proxies.get(urlparse(url).scheme)

        if proxy:
            conn = self.poolmanager.ProxyManager(self.poolmanager.proxy_from_url(proxy))
        else:
            conn = self.poolmanager.connection_from_url(url)

        return conn


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

        Currently, this just closes the PoolManager, which closes pooled
        connections.
        """
        self.poolmanager.clear()

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

        conn = self.get_connection(request.url, proxies)

        self.cert_verify(conn, request.url, verify, cert)

        try:
            # Send the request.
            resp = conn.urlopen(
                method=request.method,
                url=request.path_url,
                body=request.body,
                headers=request.headers,
                redirect=False,
                assert_same_host=False,
                preload_content=False,
                decode_content=False,
                retries=self.max_retries,
                timeout=timeout,
            )

        except socket.error as sockerr:
            raise ConnectionError(sockerr)

        except MaxRetryError as e:
            raise ConnectionError(e)

        except (_SSLError, _HTTPError) as e:
            if isinstance(e, _SSLError):
                raise SSLError(e)
            elif isinstance(e, TimeoutError):
                raise Timeout(e)
            else:
                raise Timeout('Request timed out.')

        r = self.build_response(request, resp)

        if not stream:
            r.content

        return r