#!/usr/bin/env python
# -*- coding: utf-8 -*-
import os
import base64
import unittest
import contextlib
import six
import json
from werkzeug.http import parse_dict_header
from hashlib import md5, sha256, sha512
from six import BytesIO

import httpbin
from httpbin.helpers import parse_multi_value_header


@contextlib.contextmanager
def _setenv(key, value):
    """Context manager to set an environment variable temporarily."""
    old_value = os.environ.get(key, None)
    if value is None:
        os.environ.pop(key, None)
    else:
        os.environ[key] = value

    yield

    if old_value is None:
        os.environ.pop(key, None)
    else:
        os.environ[key] = value



def _string_to_base64(string):
    """Encodes string to utf-8 and then base64"""
    utf8_encoded = string.encode('utf-8')
    return base64.urlsafe_b64encode(utf8_encoded)

def _hash(data, algorithm):
    """Encode binary data according to specified algorithm, use MD5 by default"""
    if algorithm == 'SHA-256':
        return sha256(data).hexdigest()
    elif algorithm == 'SHA-512':
        return sha512(data).hexdigest()
    else:
        return md5(data).hexdigest()

def _make_digest_auth_header(username, password, method, uri, nonce,
                             realm=None, opaque=None, algorithm=None,
                             qop=None, cnonce=None, nc=None, body=None):
    """Compile a digest authentication header string.

    Arguments:
    - `nonce`: nonce string, received within "WWW-Authenticate" header
    - `realm`: realm string, received within "WWW-Authenticate" header
    - `opaque`: opaque string, received within "WWW-Authenticate" header
    - `algorithm`: type of hashing algorithm, used by the client
    - `qop`: type of quality-of-protection, used by the client
    - `cnonce`: client nonce, required if qop is "auth" or "auth-int"
    - `nc`: client nonce count, required if qop is "auth" or "auth-int"
    - `body`: body of the outgoing request (bytes), used if qop is "auth-int"
    """

    assert username
    assert password
    assert nonce
    assert method
    assert uri
    assert algorithm in ('MD5', 'SHA-256', 'SHA-512', None)

    a1 = ':'.join([username, realm or '', password])
    ha1 = _hash(a1.encode('utf-8'), algorithm)

    a2 = ':'.join([method, uri])
    if qop == 'auth-int':
        a2 = ':'.join([a2, _hash(body or b'', algorithm)])
    ha2 = _hash(a2.encode('utf-8'), algorithm)

    a3 = ':'.join([ha1, nonce])
    if qop in ('auth', 'auth-int'):
        assert cnonce
        assert nc
        a3 = ':'.join([a3, nc, cnonce, qop])

    a3 = ':'.join([a3, ha2])
    auth_response = _hash(a3.encode('utf-8'), algorithm)

    auth_header = \
        'Digest username="{0}", response="{1}", uri="{2}", nonce="{3}"'\
            .format(username, auth_response, uri, nonce)

    # 'realm' and 'opaque' should be returned unchanged, even if empty
    if realm != None:
        auth_header += ', realm="{0}"'.format(realm)
    if opaque != None:
        auth_header += ', opaque="{0}"'.format(opaque)

    if algorithm:
        auth_header += ', algorithm="{0}"'.format(algorithm)
    if cnonce:
        auth_header += ', cnonce="{0}"'.format(cnonce)
    if nc:
        auth_header += ', nc={0}'.format(nc)
    if qop:
        auth_header += ', qop={0}'.format(qop)

    return auth_header

class HttpbinTestCase(unittest.TestCase):
    """Httpbin tests"""

    def setUp(self):
        httpbin.app.debug = True
        self.app = httpbin.app.test_client()

    def test_index(self):   
        response = self.app.get('/', headers={'User-Agent': 'test'})
        self.assertEqual(response.status_code, 200)
 
    def get_data(self, response):
        if 'get_data' in dir(response):
            return response.get_data()
        else:
            return response.data

    def test_response_headers_simple(self):
        supported_verbs = ['get', 'post']
        for verb in supported_verbs:
            method = getattr(self.app, verb)
            response = method('/response-headers?animal=dog')
            self.assertEqual(response.status_code, 200)
            self.assertEqual(response.headers.get_all('animal'), ['dog'])
            assert json.loads(response.data.decode('utf-8'))['animal'] == 'dog'

    def test_response_headers_multi(self):
        supported_verbs = ['get', 'post']
        for verb in supported_verbs:
            method = getattr(self.app, verb)
            response = method('/response-headers?animal=dog&animal=cat')
            self.assertEqual(response.status_code, 200)
            self.assertEqual(response.headers.get_all('animal'), ['dog', 'cat'])
            assert json.loads(response.data.decode('utf-8'))['animal'] == ['dog', 'cat']

    def test_get(self):
        response = self.app.get('/get', headers={'User-Agent': 'test'})
        self.assertEqual(response.status_code, 200)
        data = json.loads(response.data.decode('utf-8'))
        self.assertEqual(data['args'], {})
        self.assertEqual(data['headers']['Host'], 'localhost')
        self.assertEqual(data['headers']['Content-Length'], '0')
        self.assertEqual(data['headers']['User-Agent'], 'test')
        # self.assertEqual(data['origin'], None)
        self.assertEqual(data['url'], 'http://localhost/get')
        self.assertTrue(response.data.endswith(b'\n'))

    def test_anything(self):
        response = self.app.get('/anything')
        self.assertEqual(response.status_code, 200)
        response = self.app.get('/anything/foo/bar')
        self.assertEqual(response.status_code, 200)
        data = json.loads(response.data.decode('utf-8'))
        self.assertEqual(data['args'], {})
        self.assertEqual(data['headers']['Host'], 'localhost')
        self.assertEqual(data['headers']['Content-Length'], '0')
        self.assertEqual(data['url'], 'http://localhost/anything/foo/bar')
        self.assertEqual(data['method'], 'GET')
        self.assertTrue(response.data.endswith(b'\n'))

    def test_base64(self):
        greeting = u'Здравствуй, мир!'
        b64_encoded = _string_to_base64(greeting)
        response = self.app.get(b'/base64/' + b64_encoded)
        content = response.data.decode('utf-8')
        self.assertEqual(greeting, content)

    def test_post_binary(self):
        response = self.app.post('/post',
                                 data=b'\x01\x02\x03\x81\x82\x83',
                                 content_type='application/octet-stream')
        self.assertEqual(response.status_code, 200)

    def test_post_body_text(self):
        with open('httpbin/core.py') as f:
            response = self.app.post('/post', data={"file": f.read()})
        self.assertEqual(response.status_code, 200)

    def test_post_body_binary(self):
        response = self.app.post(
            '/post',
            data={"file": b'\x01\x02\x03\x81\x82\x83'})
        self.assertEqual(response.status_code, 200)

    def test_post_body_unicode(self):
        response = self.app.post('/post', data=u'оживлённым'.encode('utf-8'))
        self.assertEqual(json.loads(response.data.decode('utf-8'))['data'], u'оживлённым')

    def test_post_file_with_missing_content_type_header(self):
        # I built up the form data manually here because I couldn't find a way
        # to convince the werkzeug test client to send files without the
        # content-type of the file set.
        data = '--bound\r\nContent-Disposition: form-data; name="media"; '
        data += 'filename="test.bin"\r\n\r\n\xa5\xc6\n--bound--\r\n'
        response = self.app.post(
            '/post',
            content_type='multipart/form-data; boundary=bound',
            data=data,
        )
        self.assertEqual(response.status_code, 200)

    """
    This is currently a sort of negative-test.
    We validate that when running Flask-only server that
    Transfer-Encoding: chunked requests are unsupported and
    we return 501 Not Implemented
    """
    def test_post_chunked(self):
        data = '{"animal":"dog"}'
        response = self.app.post(
            '/post',
            content_type='application/json',
            headers=[('Transfer-Encoding', 'chunked')],
            data=data,
        )
        self.assertEqual(response.status_code, 501)
        #self.assertEqual(response.status_code, 200)
        #self.assertEqual(json.loads(response.data.decode('utf-8'))['data'], '{"animal":"dog"}')
        #self.assertEqual(json.loads(response.data.decode('utf-8'))['json'], {"animal": "dog"})

    def test_set_cors_headers_after_request(self):
        response = self.app.get('/get')
        self.assertEqual(
            response.headers.get('Access-Control-Allow-Origin'), '*'
        )

    def test_set_cors_credentials_headers_after_auth_request(self):
        response = self.app.get('/basic-auth/foo/bar')
        self.assertEqual(
            response.headers.get('Access-Control-Allow-Credentials'), 'true'
        )

    def test_set_cors_headers_after_request_with_request_origin(self):
        response = self.app.get('/get', headers={'Origin': 'origin'})
        self.assertEqual(
            response.headers.get('Access-Control-Allow-Origin'), 'origin'
        )

    def test_set_cors_headers_with_options_verb(self):
        response = self.app.open('/get', method='OPTIONS')
        self.assertEqual(
            response.headers.get('Access-Control-Allow-Origin'), '*'
        )
        self.assertEqual(
            response.headers.get('Access-Control-Allow-Credentials'), 'true'
        )
        self.assertEqual(
            response.headers.get('Access-Control-Allow-Methods'),
            'GET, POST, PUT, DELETE, PATCH, OPTIONS'
        )
        self.assertEqual(
            response.headers.get('Access-Control-Max-Age'), '3600'
        )
        # FIXME should we add any extra headers?
        self.assertNotIn(
            'Access-Control-Allow-Headers', response.headers
        )
    def test_set_cors_allow_headers(self):
        response = self.app.open('/get', method='OPTIONS', headers={'Access-Control-Request-Headers': 'X-Test-Header'})
        self.assertEqual(
            response.headers.get('Access-Control-Allow-Headers'), 'X-Test-Header'
        )

    def test_headers(self):
        headers = {
            "Accept": "*/*",
            "Host": "localhost:1234",
            "User-Agent": "curl/7.54.0",
            "Via": "bar"
        }
        response = self.app.get('/headers', headers=headers)
        self.assertEqual(response.status_code, 200)
        self.assertTrue({'Accept', 'Host', 'User-Agent'}.issubset(set(response.json['headers'].keys())))
        self.assertNotIn('Via', response.json)

    def test_headers_show_env(self):
        headers = {
            "Accept": "*/*",
            "Host": "localhost:1234",
            "User-Agent": "curl/7.54.0",
            "Via": "bar"
        }
        response = self.app.get('/headers?show_env=true', headers=headers)
        self.assertEqual(response.status_code, 200)
        self.assertTrue({'Accept', 'Host', 'User-Agent', 'Via'}.issubset(set(response.json['headers'].keys())))

    def test_user_agent(self):
        response = self.app.get(
            '/user-agent', headers={'User-Agent': 'test'}
        )
        self.assertIn('test', response.data.decode('utf-8'))
        self.assertEqual(response.status_code, 200)

    def test_gzip(self):
        response = self.app.get('/gzip')
        self.assertEqual(response.status_code, 200)

    def test_brotli(self):
        response = self.app.get('/brotli')
        self.assertEqual(response.status_code, 200)

    def test_bearer_auth(self):
        token = 'abcd1234'
        response = self.app.get(
            '/bearer',
            headers={'Authorization': 'Bearer ' + token}
        )
        self.assertEqual(response.status_code, 200)
        assert json.loads(response.data.decode('utf-8'))['token'] == token

    def test_bearer_auth_with_wrong_authorization_type(self):
        """Sending an non-Bearer Authorization header to /bearer should return a 401"""
        auth_headers = (
            ('Authorization', 'Basic 1234abcd'),
            ('Authorization', ''),
            ('',  '')
        )
        for header in auth_headers:
            response = self.app.get(
                '/bearer',
                headers={header[0]: header[1]}
            )
            self.assertEqual(response.status_code, 401)

    def test_bearer_auth_with_missing_token(self):
        """Sending an 'Authorization: Bearer' header with no token to /bearer should return a 401"""
        response = self.app.get(
            '/bearer',
            headers={'Authorization': 'Bearer'}
        )
        self.assertEqual(response.status_code, 401)

    def test_digest_auth_with_wrong_password(self):
        auth_header = 'Digest username="user",realm="wrong",nonce="wrong",uri="/digest-auth/user/passwd/MD5",response="wrong",opaque="wrong"'
        response = self.app.get(
            '/digest-auth/auth/user/passwd/MD5',
            environ_base={
                # httpbin's digest auth implementation uses the remote addr to
                # build the nonce
                'REMOTE_ADDR': '127.0.0.1',
            },
            headers={
                'Authorization': auth_header,
            }
        )
        self.assertTrue('Digest' in response.headers.get('WWW-Authenticate'))
        self.assertEqual(response.status_code, 401)

    def test_digest_auth(self):
        """Test different combinations of digest auth parameters"""
        username = 'user'
        password = 'passwd'
        for qop in None, 'auth', 'auth-int',:
            for algorithm in None, 'MD5', 'SHA-256', 'SHA-512':
                for body in None, b'', b'request payload':
                    for stale_after in (None, 1, 4) if algorithm else (None,) :
                        self._test_digest_auth(username, password, qop, algorithm, body, stale_after)

    def test_digest_auth_with_wrong_authorization_type(self):
        """Sending an non-digest Authorization header to /digest-auth should return a 401"""
        auth_headers = (
            ('Authorization', 'Basic 1234abcd'),
            ('Authorization', ''),
            ('',  '')
        )
        for header in auth_headers:
            response = self.app.get(
                '/digest-auth/auth/myname/mysecret',
                headers={header[0]: header[1]}
            )
            self.assertEqual(response.status_code, 401)

    def _test_digest_auth(self, username, password, qop, algorithm=None, body=None, stale_after=None):
        uri = self._digest_auth_create_uri(username, password, qop, algorithm, stale_after)

        unauthorized_response = self._test_digest_auth_first_challenge(uri)

        header = unauthorized_response.headers.get('WWW-Authenticate')

        authorized_response, nonce = self._test_digest_response_for_auth_request(header, username, password, qop, uri, body)
        self.assertEqual(authorized_response.status_code, 200)

        if None == stale_after :
            return

        # test stale after scenerio
        self._digest_auth_stale_after_check(header, username, password, uri, body, qop, stale_after)

    def _test_digest_auth_first_challenge(self, uri):
        unauthorized_response = self.app.get(
            uri,
            environ_base={
                # digest auth uses the remote addr to build the nonce
                'REMOTE_ADDR': '127.0.0.1',
            }
        )
        # make sure it returns a 401
        self.assertEqual(unauthorized_response.status_code, 401)
        return unauthorized_response

    def _digest_auth_create_uri(self, username, password, qop, algorithm, stale_after):
        uri = '/digest-auth/{0}/{1}/{2}'.format(qop or 'wrong-qop', username, password)
        if algorithm:
            uri += '/' + algorithm
        if stale_after:
            uri += '/{0}'.format(stale_after)
        return uri

    def _digest_auth_stale_after_check(self, header, username, password, uri, body, qop, stale_after):
        for nc in range(2, stale_after + 1):
            authorized_response, nonce = self._test_digest_response_for_auth_request(header, username, password, qop, uri, \
                                                                              body, nc)
            self.assertEqual(authorized_response.status_code, 200)
        stale_response, nonce = self._test_digest_response_for_auth_request(header, username, password, qop, uri, \
                                                                     body, stale_after + 1)
        self.assertEqual(stale_response.status_code, 401)
        header = stale_response.headers.get('WWW-Authenticate')
        self.assertIn('stale=TRUE', header)

    def _test_digest_response_for_auth_request(self, header, username, password, qop, uri, body, nc=1, nonce=None):
        auth_type, auth_info = header.split(None, 1)
        self.assertEqual(auth_type, 'Digest')

        d = parse_dict_header(auth_info)

        nonce = nonce or d['nonce']
        realm = d['realm']
        opaque = d['opaque']
        if qop :
            self.assertIn(qop, [x.strip() for x in d['qop'].split(',')], 'Challenge should contains expected qop')
        algorithm = d['algorithm']

        cnonce, nc = (_hash(os.urandom(10), "MD5"), '{:08}'.format(nc)) if qop in ('auth', 'auth-int') else (None, None)

        auth_header = _make_digest_auth_header(
            username, password, 'GET', uri, nonce, realm, opaque, algorithm, qop, cnonce, nc, body)

        # make second request
        return self.app.get(
            uri,
            environ_base={
                # httpbin's digest auth implementation uses the remote addr to
                # build the nonce
                'REMOTE_ADDR': '127.0.0.1',
            },
            headers={
                'Authorization': auth_header,
            },
            data=body
        ), nonce

    def test_digest_auth_wrong_pass(self):
        """Test different combinations of digest auth parameters"""
        username = 'user'
        password = 'passwd'
        for qop in None, 'auth', 'auth-int',:
            for algorithm in None, 'MD5', 'SHA-256', 'SHA-512':
                for body in None, b'', b'request payload':
                    self._test_digest_auth_wrong_pass(username, password, qop, algorithm, body, 3)

    def _test_digest_auth_wrong_pass(self, username, password, qop, algorithm=None, body=None, stale_after=None):
        uri = self._digest_auth_create_uri(username, password, qop, algorithm, stale_after)
        unauthorized_response = self._test_digest_auth_first_challenge(uri)

        header = unauthorized_response.headers.get('WWW-Authenticate')

        wrong_pass_response, nonce = self._test_digest_response_for_auth_request(header, username, "wrongPassword", qop, uri, body)
        self.assertEqual(wrong_pass_response.status_code, 401)
        header = wrong_pass_response.headers.get('WWW-Authenticate')
        self.assertNotIn('stale=TRUE', header)

        reused_nonce_response, nonce =  self._test_digest_response_for_auth_request(header, username, password, qop, uri, \
                                                                              body, nonce=nonce)
        self.assertEqual(reused_nonce_response.status_code, 401)
        header = reused_nonce_response.headers.get('WWW-Authenticate')
        self.assertIn('stale=TRUE', header)

    def test_drip(self):
        response = self.app.get('/drip?numbytes=400&duration=2&delay=1')
        self.assertEqual(response.content_length, 400)
        self.assertEqual(len(self.get_data(response)), 400)
        self.assertEqual(response.status_code, 200)

    def test_drip_with_invalid_numbytes(self):
        for bad_num in -1, 0:
            uri = '/drip?numbytes={0}&duration=2&delay=1'.format(bad_num)
            response = self.app.get(uri)
            self.assertEqual(response.status_code, 400)

    def test_drip_with_custom_code(self):
        response = self.app.get('/drip?numbytes=400&duration=2&code=500')
        self.assertEqual(response.content_length, 400)
        self.assertEqual(len(self.get_data(response)), 400)
        self.assertEqual(response.status_code, 500)

    def test_get_bytes(self):
        response = self.app.get('/bytes/1024')
        self.assertEqual(len(self.get_data(response)), 1024)
        self.assertEqual(response.status_code, 200)

    def test_bytes_with_seed(self):
        response = self.app.get('/bytes/10?seed=0')
        # The RNG changed in python3, so even though we are
        # setting the seed, we can't expect the value to be the
        # same across both interpreters.
        if six.PY3:
            self.assertEqual(
                response.data, b'\xc5\xd7\x14\x84\xf8\xcf\x9b\xf4\xb7o'
            )
        else:
            self.assertEqual(
                response.data, b'\xd8\xc2kB\x82g\xc8Mz\x95'
            )

    def test_stream_bytes(self):
        response = self.app.get('/stream-bytes/1024')
        self.assertEqual(len(self.get_data(response)), 1024)
        self.assertEqual(response.status_code, 200)

    def test_stream_bytes_with_seed(self):
        response = self.app.get('/stream-bytes/10?seed=0')
        # The RNG changed in python3, so even though we are
        # setting the seed, we can't expect the value to be the
        # same across both interpreters.
        if six.PY3:
            self.assertEqual(
                response.data, b'\xc5\xd7\x14\x84\xf8\xcf\x9b\xf4\xb7o'
            )
        else:
            self.assertEqual(
                response.data, b'\xd8\xc2kB\x82g\xc8Mz\x95'
            )

    def test_delete_endpoint_returns_body(self):
        response = self.app.delete(
            '/delete',
            data={'name': 'kevin'},
            content_type='application/x-www-form-urlencoded'
        )
        form_data = json.loads(response.data.decode('utf-8'))['form']
        self.assertEqual(form_data, {'name': 'kevin'})

    def test_methods__to_status_endpoint(self):
        methods = [
            'GET',
            'HEAD',
            'POST',
            'PUT',
            'DELETE',
            'PATCH',
            'TRACE',
        ]
        for m in methods:
            response = self.app.open(path='/status/418', method=m)
            self.assertEqual(response.status_code, 418)

    def test_status_endpoint_invalid_code(self):
        response = self.app.get(path='/status/4!9')
        self.assertEqual(response.status_code, 400)

    def test_status_endpoint_invalid_codes(self):
        response = self.app.get(path='/status/200,402,foo')
        self.assertEqual(response.status_code, 400)

    def test_xml_endpoint(self):
        response = self.app.get(path='/xml')
        self.assertEqual(
            response.headers.get('Content-Type'), 'application/xml'
        )

    def test_x_forwarded_proto(self):
        response = self.app.get(path='/get', headers={
            'X-Forwarded-Proto':'https'
        })
        assert json.loads(response.data.decode('utf-8'))['url'].startswith('https://')

    def test_redirect_n_higher_than_1(self):
        response = self.app.get('/redirect/5')
        self.assertEqual(
            response.headers.get('Location'), '/relative-redirect/4'
        )

    def test_redirect_to_post(self):
        response = self.app.post('/redirect-to?url=/post&status_code=307',
                                 data=b'\x01\x02\x03\x81\x82\x83',
                                 content_type='application/octet-stream')
        self.assertEqual(response.status_code, 307)
        self.assertEqual(
            response.headers.get('Location'), '/post'
        )

    def test_redirect_absolute_param_n_higher_than_1(self):
        response = self.app.get('/redirect/5?absolute=true')
        self.assertEqual(
            response.headers.get('Location'), 'http://localhost/absolute-redirect/4'
        )

    def test_redirect_n_equals_to_1(self):
        response = self.app.get('/redirect/1')
        self.assertEqual(response.status_code, 302)
        self.assertEqual(
            response.headers.get('Location'), '/get'
        )

    def test_relative_redirect_n_equals_to_1(self):
        response = self.app.get('/relative-redirect/1')
        self.assertEqual(
            response.headers.get('Location'), '/get'
        )

    def test_relative_redirect_n_higher_than_1(self):
        response = self.app.get('/relative-redirect/7')
        self.assertEqual(response.status_code, 302)
        self.assertEqual(
            response.headers.get('Location'), '/relative-redirect/6'
        )

    def test_absolute_redirect_n_higher_than_1(self):
        response = self.app.get('/absolute-redirect/5')
        self.assertEqual(
            response.headers.get('Location'), 'http://localhost/absolute-redirect/4'
        )

    def test_absolute_redirect_n_equals_to_1(self):
        response = self.app.get('/absolute-redirect/1')
        self.assertEqual(response.status_code, 302)
        self.assertEqual(
            response.headers.get('Location'), 'http://localhost/get'
        )

    def test_request_range(self):
        response1 = self.app.get('/range/1234')
        self.assertEqual(response1.status_code, 200)
        self.assertEqual(response1.headers.get('ETag'), 'range1234')
        self.assertEqual(response1.headers.get('Content-range'), 'bytes 0-1233/1234')
        self.assertEqual(response1.headers.get('Accept-ranges'), 'bytes')
        self.assertEqual(len(self.get_data(response1)), 1234)

        response2 = self.app.get('/range/1234')
        self.assertEqual(response2.status_code, 200)
        self.assertEqual(response2.headers.get('ETag'), 'range1234')
        self.assertEqual(self.get_data(response1), self.get_data(response2))

    def test_request_range_with_parameters(self):
        response = self.app.get(
            '/range/100?duration=1.5&chunk_size=5',
            headers={ 'Range': 'bytes=10-24' }
        )

        self.assertEqual(response.status_code, 206)
        self.assertEqual(response.headers.get('ETag'), 'range100')
        self.assertEqual(response.headers.get('Content-range'), 'bytes 10-24/100')
        self.assertEqual(response.headers.get('Accept-ranges'), 'bytes')
        self.assertEqual(response.headers.get('Content-Length'), '15')
        self.assertEqual(self.get_data(response), 'klmnopqrstuvwxy'.encode('utf8'))

    def test_request_range_first_15_bytes(self):
        response = self.app.get(
            '/range/1000',
            headers={ 'Range': 'bytes=0-15' }
        )

        self.assertEqual(response.status_code, 206)
        self.assertEqual(response.headers.get('ETag'), 'range1000')
        self.assertEqual(self.get_data(response), 'abcdefghijklmnop'.encode('utf8'))
        self.assertEqual(response.headers.get('Content-range'), 'bytes 0-15/1000')

    def test_request_range_open_ended_last_6_bytes(self):
        response = self.app.get(
            '/range/26',
            headers={ 'Range': 'bytes=20-' }
        )

        self.assertEqual(response.status_code, 206)
        self.assertEqual(response.headers.get('ETag'), 'range26')
        self.assertEqual(self.get_data(response), 'uvwxyz'.encode('utf8'))
        self.assertEqual(response.headers.get('Content-range'), 'bytes 20-25/26')
        self.assertEqual(response.headers.get('Content-Length'), '6')

    def test_request_range_suffix(self):
        response = self.app.get(
            '/range/26',
            headers={ 'Range': 'bytes=-5' }
        )

        self.assertEqual(response.status_code, 206)
        self.assertEqual(response.headers.get('ETag'), 'range26')
        self.assertEqual(self.get_data(response), 'vwxyz'.encode('utf8'))
        self.assertEqual(response.headers.get('Content-range'), 'bytes 21-25/26')
        self.assertEqual(response.headers.get('Content-Length'), '5')

    def test_request_out_of_bounds(self):
        response = self.app.get(
            '/range/26',
            headers={ 'Range': 'bytes=10-5',
            }
        )

        self.assertEqual(response.status_code, 416)
        self.assertEqual(response.headers.get('ETag'), 'range26')
        self.assertEqual(len(self.get_data(response)), 0)
        self.assertEqual(response.headers.get('Content-range'), 'bytes */26')
        self.assertEqual(response.headers.get('Content-Length'), '0')

        response = self.app.get(
            '/range/26',
            headers={ 'Range': 'bytes=32-40',
            }
        )

        self.assertEqual(response.status_code, 416)
        response = self.app.get(
            '/range/26',
            headers={ 'Range': 'bytes=0-40',
            }
        )
        self.assertEqual(response.status_code, 416)

    def test_etag_if_none_match_matches(self):
        response = self.app.get(
            '/etag/abc',
            headers={ 'If-None-Match': 'abc' }
        )
        self.assertEqual(response.status_code, 304)
        self.assertEqual(response.headers.get('ETag'), 'abc')

    def test_etag_if_none_match_matches_list(self):
        response = self.app.get(
            '/etag/abc',
            headers={ 'If-None-Match': '"123", "abc"' }
        )
        self.assertEqual(response.status_code, 304)
        self.assertEqual(response.headers.get('ETag'), 'abc')

    def test_etag_if_none_match_matches_star(self):
        response = self.app.get(
            '/etag/abc',
            headers={ 'If-None-Match': '*' }
        )
        self.assertEqual(response.status_code, 304)
        self.assertEqual(response.headers.get('ETag'), 'abc')

    def test_etag_if_none_match_w_prefix(self):
        response = self.app.get(
            '/etag/c3piozzzz',
            headers={ 'If-None-Match': 'W/"xyzzy", W/"r2d2xxxx", W/"c3piozzzz"' }
        )
        self.assertEqual(response.status_code, 304)
        self.assertEqual(response.headers.get('ETag'), 'c3piozzzz')

    def test_etag_if_none_match_has_no_match(self):
        response = self.app.get(
            '/etag/abc',
            headers={ 'If-None-Match': '123' }
        )
        self.assertEqual(response.status_code, 200)
        self.assertEqual(response.headers.get('ETag'), 'abc')

    def test_etag_if_match_matches(self):
        response = self.app.get(
            '/etag/abc',
            headers={ 'If-Match': 'abc' }
        )
        self.assertEqual(response.status_code, 200)
        self.assertEqual(response.headers.get('ETag'), 'abc')

    def test_etag_if_match_matches_list(self):
        response = self.app.get(
            '/etag/abc',
            headers={ 'If-Match': '"123", "abc"' }
        )
        self.assertEqual(response.status_code, 200)
        self.assertEqual(response.headers.get('ETag'), 'abc')

    def test_etag_if_match_matches_star(self):
        response = self.app.get(
            '/etag/abc',
            headers={ 'If-Match': '*' }
        )
        self.assertEqual(response.status_code, 200)
        self.assertEqual(response.headers.get('ETag'), 'abc')

    def test_etag_if_match_has_no_match(self):
        response = self.app.get(
            '/etag/abc',
            headers={ 'If-Match': '123' }
        )
        self.assertEqual(response.status_code, 412)
        self.assertNotIn('ETag', response.headers)

    def test_etag_with_no_headers(self):
        response = self.app.get(
            '/etag/abc'
        )
        self.assertEqual(response.status_code, 200)
        self.assertEqual(response.headers.get('ETag'), 'abc')

    def test_parse_multi_value_header(self):
        self.assertEqual(parse_multi_value_header('xyzzy'), [ "xyzzy" ])
        self.assertEqual(parse_multi_value_header('"xyzzy"'), [ "xyzzy" ])
        self.assertEqual(parse_multi_value_header('W/"xyzzy"'), [ "xyzzy" ])
        self.assertEqual(parse_multi_value_header('"xyzzy", "r2d2xxxx", "c3piozzzz"'), [ "xyzzy", "r2d2xxxx", "c3piozzzz" ])
        self.assertEqual(parse_multi_value_header('W/"xyzzy", W/"r2d2xxxx", W/"c3piozzzz"'), [ "xyzzy", "r2d2xxxx", "c3piozzzz" ])
        self.assertEqual(parse_multi_value_header('*'), [ "*" ])

if __name__ == '__main__':
    unittest.main()