# -- coding: utf-8 --

# Note that we import as `DjangoRequestFactory` and `DjangoClient` in order
# to make it harder for the user to import the wrong thing without realizing.
from __future__ import unicode_literals

import io

from django.conf import settings
from django.core.exceptions import ImproperlyConfigured
from django.core.handlers.wsgi import WSGIHandler
from django.test import testcases
from django.test.client import Client as DjangoClient
from django.test.client import RequestFactory as DjangoRequestFactory
from django.test.client import ClientHandler
from django.utils import six
from django.utils.encoding import force_bytes
from django.utils.http import urlencode

from rest_framework.compat import coreapi, requests
from rest_framework.settings import api_settings


def force_authenticate(request, user=None, token=None):
    request._force_auth_user = user
    request._force_auth_token = token


if requests is not None:
    class HeaderDict(requests.packages.urllib3._collections.HTTPHeaderDict):
        def get_all(self, key, default):
            return self.getheaders(key)

    class MockOriginalResponse(object):
        def __init__(self, headers):
            self.msg = HeaderDict(headers)
            self.closed = False

        def isclosed(self):
            return self.closed

        def close(self):
            self.closed = True

    class DjangoTestAdapter(requests.adapters.HTTPAdapter):
        """
        A transport adapter for `requests`, that makes requests via the
        Django WSGI app, rather than making actual HTTP requests over the network.
        """
        def __init__(self):
            self.app = WSGIHandler()
            self.factory = DjangoRequestFactory()

        def get_environ(self, request):
            """
            Given a `requests.PreparedRequest` instance, return a WSGI environ dict.
            """
            method = request.method
            url = request.url
            kwargs = {}

            # Set request content, if any exists.
            if request.body is not None:
                if hasattr(request.body, 'read'):
                    kwargs['data'] = request.body.read()
                else:
                    kwargs['data'] = request.body
            if 'content-type' in request.headers:
                kwargs['content_type'] = request.headers['content-type']

            # Set request headers.
            for key, value in request.headers.items():
                key = key.upper()
                if key in ('CONNECTION', 'CONTENT-LENGTH', 'CONTENT-TYPE'):
                    continue
                kwargs['HTTP_%s' % key.replace('-', '_')] = value

            return self.factory.generic(method, url, **kwargs).environ

        def send(self, request, *args, **kwargs):
            """
            Make an outgoing request to the Django WSGI application.
            """
            raw_kwargs = {}

            def start_response(wsgi_status, wsgi_headers):
                status, _, reason = wsgi_status.partition(' ')
                raw_kwargs['status'] = int(status)
                raw_kwargs['reason'] = reason
                raw_kwargs['headers'] = wsgi_headers
                raw_kwargs['version'] = 11
                raw_kwargs['preload_content'] = False
                raw_kwargs['original_response'] = MockOriginalResponse(wsgi_headers)

            # Make the outgoing request via WSGI.
            environ = self.get_environ(request)
            wsgi_response = self.app(environ, start_response)

            # Build the underlying urllib3.HTTPResponse
            raw_kwargs['body'] = io.BytesIO(b''.join(wsgi_response))
            raw = requests.packages.urllib3.HTTPResponse(**raw_kwargs)

            # Build the requests.Response
            return self.build_response(request, raw)

        def close(self):
            pass

    class RequestsClient(requests.Session):
        def __init__(self, *args, **kwargs):
            super(RequestsClient, self).__init__(*args, **kwargs)
            adapter = DjangoTestAdapter()
            self.mount('http://', adapter)
            self.mount('https://', adapter)

        def request(self, method, url, *args, **kwargs):
            if not url.startswith('http'):
                raise ValueError('Missing "http:" or "https:". Use a fully qualified URL, eg "http://testserver%s"' % url)
            return super(RequestsClient, self).request(method, url, *args, **kwargs)

else:
    def RequestsClient(*args, **kwargs):
        raise ImproperlyConfigured('requests must be installed in order to use RequestsClient.')


if coreapi is not None:
    class CoreAPIClient(coreapi.Client):
        def __init__(self, *args, **kwargs):
            self._session = RequestsClient()
            kwargs['transports'] = [coreapi.transports.HTTPTransport(session=self.session)]
            return super(CoreAPIClient, self).__init__(*args, **kwargs)

        @property
        def session(self):
            return self._session

else:
    def CoreAPIClient(*args, **kwargs):
        raise ImproperlyConfigured('coreapi must be installed in order to use CoreAPIClient.')


class APIRequestFactory(DjangoRequestFactory):
    renderer_classes_list = api_settings.TEST_REQUEST_RENDERER_CLASSES
    default_format = api_settings.TEST_REQUEST_DEFAULT_FORMAT

    def __init__(self, enforce_csrf_checks=False, **defaults):
        self.enforce_csrf_checks = enforce_csrf_checks
        self.renderer_classes = {}
        for cls in self.renderer_classes_list:
            self.renderer_classes[cls.format] = cls
        super(APIRequestFactory, self).__init__(**defaults)

    def _encode_data(self, data, format=None, content_type=None):
        """
        Encode the data returning a two tuple of (bytes, content_type)
        """

        if data is None:
            return ('', content_type)

        assert format is None or content_type is None, (
            'You may not set both `format` and `content_type`.'
        )

        if content_type:
            # Content type specified explicitly, treat data as a raw bytestring
            ret = force_bytes(data, settings.DEFAULT_CHARSET)

        else:
            format = format or self.default_format

            assert format in self.renderer_classes, (
                "Invalid format '{0}'. Available formats are {1}. "
                "Set TEST_REQUEST_RENDERER_CLASSES to enable "
                "extra request formats.".format(
                    format,
                    ', '.join(["'" + fmt + "'" for fmt in self.renderer_classes.keys()])
                )
            )

            # Use format and render the data into a bytestring
            renderer = self.renderer_classes[format]()
            ret = renderer.render(data)

            # Determine the content-type header from the renderer
            content_type = "{0}; charset={1}".format(
                renderer.media_type, renderer.charset
            )

            # Coerce text to bytes if required.
            if isinstance(ret, six.text_type):
                ret = bytes(ret.encode(renderer.charset))

        return ret, content_type

    def get(self, path, data=None, **extra):
        r = {
            'QUERY_STRING': urlencode(data or {}, doseq=True),
        }
        if not data and '?' in path:
            # Fix to support old behavior where you have the arguments in the
            # url. See #1461.
            query_string = force_bytes(path.split('?')[1])
            if six.PY3:
                query_string = query_string.decode('iso-8859-1')
            r['QUERY_STRING'] = query_string
        r.update(extra)
        return self.generic('GET', path, **r)

    def post(self, path, data=None, format=None, content_type=None, **extra):
        data, content_type = self._encode_data(data, format, content_type)
        return self.generic('POST', path, data, content_type, **extra)

    def put(self, path, data=None, format=None, content_type=None, **extra):
        data, content_type = self._encode_data(data, format, content_type)
        return self.generic('PUT', path, data, content_type, **extra)

    def patch(self, path, data=None, format=None, content_type=None, **extra):
        data, content_type = self._encode_data(data, format, content_type)
        return self.generic('PATCH', path, data, content_type, **extra)

    def delete(self, path, data=None, format=None, content_type=None, **extra):
        data, content_type = self._encode_data(data, format, content_type)
        return self.generic('DELETE', path, data, content_type, **extra)

    def options(self, path, data=None, format=None, content_type=None, **extra):
        data, content_type = self._encode_data(data, format, content_type)
        return self.generic('OPTIONS', path, data, content_type, **extra)

    def request(self, **kwargs):
        request = super(APIRequestFactory, self).request(**kwargs)
        request._dont_enforce_csrf_checks = not self.enforce_csrf_checks
        return request


class ForceAuthClientHandler(ClientHandler):
    """
    A patched version of ClientHandler that can enforce authentication
    on the outgoing requests.
    """

    def __init__(self, *args, **kwargs):
        self._force_user = None
        self._force_token = None
        super(ForceAuthClientHandler, self).__init__(*args, **kwargs)

    def get_response(self, request):
        # This is the simplest place we can hook into to patch the
        # request object.
        force_authenticate(request, self._force_user, self._force_token)
        return super(ForceAuthClientHandler, self).get_response(request)


class APIClient(APIRequestFactory, DjangoClient):
    def __init__(self, enforce_csrf_checks=False, **defaults):
        super(APIClient, self).__init__(**defaults)
        self.handler = ForceAuthClientHandler(enforce_csrf_checks)
        self._credentials = {}

    def credentials(self, **kwargs):
        """
        Sets headers that will be used on every outgoing request.
        """
        self._credentials = kwargs

    def force_authenticate(self, user=None, token=None):
        """
        Forcibly authenticates outgoing requests with the given
        user and/or token.
        """
        self.handler._force_user = user
        self.handler._force_token = token
        if user is None:
            self.logout()  # Also clear any possible session info if required

    def request(self, **kwargs):
        # Ensure that any credentials set get added to every request.
        kwargs.update(self._credentials)
        return super(APIClient, self).request(**kwargs)

    def get(self, path, data=None, follow=False, **extra):
        response = super(APIClient, self).get(path, data=data, **extra)
        if follow:
            response = self._handle_redirects(response, **extra)
        return response

    def post(self, path, data=None, format=None, content_type=None,
             follow=False, **extra):
        response = super(APIClient, self).post(
            path, data=data, format=format, content_type=content_type, **extra)
        if follow:
            response = self._handle_redirects(response, **extra)
        return response

    def put(self, path, data=None, format=None, content_type=None,
            follow=False, **extra):
        response = super(APIClient, self).put(
            path, data=data, format=format, content_type=content_type, **extra)
        if follow:
            response = self._handle_redirects(response, **extra)
        return response

    def patch(self, path, data=None, format=None, content_type=None,
              follow=False, **extra):
        response = super(APIClient, self).patch(
            path, data=data, format=format, content_type=content_type, **extra)
        if follow:
            response = self._handle_redirects(response, **extra)
        return response

    def delete(self, path, data=None, format=None, content_type=None,
               follow=False, **extra):
        response = super(APIClient, self).delete(
            path, data=data, format=format, content_type=content_type, **extra)
        if follow:
            response = self._handle_redirects(response, **extra)
        return response

    def options(self, path, data=None, format=None, content_type=None,
                follow=False, **extra):
        response = super(APIClient, self).options(
            path, data=data, format=format, content_type=content_type, **extra)
        if follow:
            response = self._handle_redirects(response, **extra)
        return response

    def logout(self):
        self._credentials = {}

        # Also clear any `force_authenticate`
        self.handler._force_user = None
        self.handler._force_token = None

        if self.session:
            super(APIClient, self).logout()


class APITransactionTestCase(testcases.TransactionTestCase):
    client_class = APIClient


class APITestCase(testcases.TestCase):
    client_class = APIClient


class APISimpleTestCase(testcases.SimpleTestCase):
    client_class = APIClient


class APILiveServerTestCase(testcases.LiveServerTestCase):
    client_class = APIClient
