# File: a (Python 3.4)

'''
requests.auth
~~~~~~~~~~~~~

This module contains the authentication handlers for Requests.
'''
import os
import re
import time
import hashlib
from base64 import b64encode
from compat import urlparse, str
from cookies import extract_cookies_to_jar
from utils import parse_dict_header, to_native_string
from status_codes import codes

CONTENT_TYPE_FORM_URLENCODED = 'application/x-www-form-urlencoded'
CONTENT_TYPE_MULTI_PART = 'multipart/form-data'


def _basic_auth_str(username, password):
    '''Returns a Basic Auth string.'''
    authstr = 'Basic ' + to_native_string(b64encode(('%s:%s' % (username, password)).encode('latin1')).strip())
    return authstr


class AuthBase(object):
    __qualname__ = 'AuthBase'
    __doc__ = 'Base class that all auth implementations derive from'

    def __call__(self, r):
        raise NotImplementedError('Auth hooks must be callable.')


class HTTPBasicAuth(AuthBase):
    __qualname__ = 'HTTPBasicAuth'
    __doc__ = 'Attaches HTTP Basic Authentication to the given Request object.'

    def __init__(self, username, password):
        self.username = username
        self.password = password

    def __call__(self, r):
        r.headers['Authorization'] = _basic_auth_str(self.username, self.password)
        return r


class HTTPProxyAuth(HTTPBasicAuth):
    __qualname__ = 'HTTPProxyAuth'
    __doc__ = 'Attaches HTTP Proxy Authentication to a given Request object.'

    def __call__(self, r):
        r.headers['Proxy-Authorization'] = _basic_auth_str(self.username, self.password)
        return r


class HTTPDigestAuth(AuthBase):
    __qualname__ = 'HTTPDigestAuth'
    __doc__ = 'Attaches HTTP Digest Authentication to the given Request object.'

    def __init__(self, username, password):
        self.username = username
        self.password = password
        self.last_nonce = ''
        self.nonce_count = 0
        self.chal = {}
        self.pos = None

    def build_digest_header(self, method, url):
        realm = self.chal['realm']
        nonce = self.chal['nonce']
        qop = self.chal.get('qop')
        algorithm = self.chal.get('algorithm')
        opaque = self.chal.get('opaque')
        if algorithm is None:
            _algorithm = 'MD5'
        else:
            _algorithm = algorithm.upper()
        if _algorithm == 'MD5' or _algorithm == 'MD5-SESS':

            def md5_utf8(x):
                if isinstance(x, str):
                    x = x.encode('utf-8')
                return hashlib.md5(x).hexdigest()

            hash_utf8 = md5_utf8
        elif _algorithm == 'SHA':

            def sha_utf8(x):
                if isinstance(x, str):
                    x = x.encode('utf-8')
                return hashlib.sha1(x).hexdigest()

            hash_utf8 = sha_utf8

        KD = lambda s, d: hash_utf8('%s:%s' % (s, d))
        if hash_utf8 is None:
            return None
        entdig = (None,)
        p_parsed = urlparse(url)
        path = p_parsed.path
        if p_parsed.query:
            path += '?' + p_parsed.query
        A1 = '%s:%s:%s' % (self.username, realm, self.password)
        A2 = '%s:%s' % (method, path)
        HA1 = hash_utf8(A1)
        HA2 = hash_utf8(A2)
        if nonce == self.last_nonce:
            self.nonce_count += 1
        else:
            self.nonce_count = 1
        ncvalue = '%08x' % self.nonce_count
        s = str(self.nonce_count).encode('utf-8')
        s += nonce.encode('utf-8')
        s += time.ctime().encode('utf-8')
        s += os.urandom(8)
        cnonce = hashlib.sha1(s).hexdigest()[:16]
        noncebit = '%s:%s:%s:%s:%s' % (nonce, ncvalue, cnonce, qop, HA2)
        if _algorithm == 'MD5-SESS':
            HA1 = hash_utf8('%s:%s:%s' % (HA1, nonce, cnonce))
        if qop is None:
            respdig = KD(HA1, '%s:%s' % (nonce, HA2))
        elif qop == 'auth' or 'auth' in qop.split(','):
            respdig = KD(HA1, noncebit)
        else:
            return None
        self.last_nonce = None
        base = 'username="%s", realm="%s", nonce="%s", uri="%s", response="%s"' % (
        self.username, realm, nonce, path, respdig)
        if opaque:
            base += ', opaque="%s"' % opaque
        if algorithm:
            base += ', algorithm="%s"' % algorithm
        if entdig:
            base += ', digest="%s"' % entdig
        if qop:
            base += ', qop="auth", nc=%s, cnonce="%s"' % (ncvalue, cnonce)
        return 'Digest %s' % base

    def handle_redirect(self, r, **kwargs):
        '''Reset num_401_calls counter on redirects.'''
        if r.is_redirect:
            setattr(self, 'num_401_calls', 1)

    def handle_401(self, r, **kwargs):
        '''Takes the given response and tries digest-auth, if needed.'''
        if self.pos is not None:
            r.request.body.seek(self.pos)
        num_401_calls = getattr(self, 'num_401_calls', 1)
        s_auth = r.headers.get('www-authenticate', '')
        if 'digest' in s_auth.lower() and num_401_calls < 2:
            setattr(self, 'num_401_calls', num_401_calls + 1)
            pat = re.compile('digest ', flags=re.IGNORECASE)
            self.chal = parse_dict_header(pat.sub('', s_auth, count=1))
            r.raw.release_conn()
            prep = r.request.copy()
            extract_cookies_to_jar(prep._cookies, r.request, r.raw)
            prep.prepare_cookies(prep._cookies)
            prep.headers['Authorization'] = self.build_digest_header(prep.method, prep.url)
            _r = r.connection.send(prep, **None)
            _r.history.append(r)
            _r.request = prep
            return _r
        None(self, 'num_401_calls', num_401_calls + 1)
        return r

    def __call__(self, r):
        if self.last_nonce:
            r.headers['Authorization'] = self.build_digest_header(r.method, r.url)

        try:
            self.pos = r.body.tell()
        except AttributeError:
            self.pos = None

        r.register_hook('response', self.handle_401)
        r.register_hook('response', self.handle_redirect)
        return r