from json import JSONDecodeError

from sanic import Sanic
import asyncio
from sanic.response import text
from sanic.config import Config
import aiohttp
from aiohttp import TCPConnector
from sanic.testing import SanicTestClient, HOST

try:
    try:
        # direct use
        import packaging
        version = packaging.version
    except (ImportError, AttributeError):
        # setuptools v39.0 and above.
        try:
            from setuptools.extern import packaging
        except ImportError:
            # Before setuptools v39.0
            from pkg_resources.extern import packaging
    version = packaging.version
except ImportError:
    raise RuntimeError("The 'packaging' library is missing.")


aiohttp_version = version.parse(aiohttp.__version__)


class DelayableTCPConnector(TCPConnector):

    class RequestContextManager(object):
        def __new__(cls, req, delay):
            cls = super(DelayableTCPConnector.RequestContextManager, cls).\
                __new__(cls)
            cls.req = req
            cls.send_task = None
            cls.resp = None
            cls.orig_send = getattr(req, 'send')
            cls.orig_start = None
            cls.delay = delay
            cls._acting_as = req
            return cls

        def __getattr__(self, item):
            acting_as = self._acting_as
            return getattr(acting_as, item)

        async def start(self, connection, read_until_eof=False):
            if self.send_task is None:
                raise RuntimeError("do a send() before you do a start()")
            resp = await self.send_task
            self.send_task = None
            self.resp = resp
            self._acting_as = self.resp
            self.orig_start = getattr(resp, 'start')

            try:
                if aiohttp_version >= version.parse("3.3.0"):
                    ret = await self.orig_start(connection)
                else:
                    ret = await self.orig_start(connection, read_until_eof)
            except Exception as e:
                raise e
            return ret

        def close(self):
            if self.resp is not None:
                self.resp.close()
            if self.send_task is not None:
                self.send_task.cancel()

        async def delayed_send(self, *args, **kwargs):
            req = self.req
            if self.delay and self.delay > 0:
                # sync_sleep(self.delay)
                await asyncio.sleep(self.delay)
            t = req.loop.time()
            print("sending at {}".format(t), flush=True)
            next(iter(args))  # first arg is connection

            try:
                return await self.orig_send(*args, **kwargs)
            except Exception as e:
                if aiohttp_version < version.parse("3.1.0"):
                    return aiohttp.ClientResponse(req.method, req.url)
                kw = dict(
                    writer=None,
                    continue100=None,
                    timer=None,
                    request_info=None,
                    traces=[],
                    loop=req.loop,
                    session=None
                )
                if aiohttp_version < version.parse("3.3.0"):
                    kw['auto_decompress'] = None
                return aiohttp.ClientResponse(req.method, req.url, **kw)

        def _send(self, *args, **kwargs):
            gen = self.delayed_send(*args, **kwargs)
            task = self.req.loop.create_task(gen)
            self.send_task = task
            self._acting_as = task
            return self

        if aiohttp_version >= version.parse("3.1.0"):
            # aiohttp changed the request.send method to async
            async def send(self, *args, **kwargs):
                return self._send(*args, **kwargs)
        else:
            send = _send

    def __init__(self, *args, **kwargs):
        _post_connect_delay = kwargs.pop('post_connect_delay', 0)
        _pre_request_delay = kwargs.pop('pre_request_delay', 0)
        super(DelayableTCPConnector, self).__init__(*args, **kwargs)
        self._post_connect_delay = _post_connect_delay
        self._pre_request_delay = _pre_request_delay

    async def connect(self, req, *args, **kwargs):
        d_req = DelayableTCPConnector.\
            RequestContextManager(req, self._pre_request_delay)
        conn = await super(DelayableTCPConnector, self).\
            connect(req, *args, **kwargs)
        if self._post_connect_delay and self._post_connect_delay > 0:
            await asyncio.sleep(self._post_connect_delay,
                                loop=self._loop)
        req.send = d_req.send
        t = req.loop.time()
        print("Connected at {}".format(t), flush=True)
        return conn


class DelayableSanicTestClient(SanicTestClient):
    def __init__(self, app, loop, request_delay=1):
        super(DelayableSanicTestClient, self).__init__(app)
        self._request_delay = request_delay
        self._loop = None

    async def _local_request(self, method, uri, cookies=None, *args,
                             **kwargs):
        if self._loop is None:
            self._loop = asyncio.get_event_loop()
        if uri.startswith(('http:', 'https:', 'ftp:', 'ftps://' '//')):
            url = uri
        else:
            url = 'http://{host}:{port}{uri}'.format(
                host=HOST, port=self.port, uri=uri)
        conn = DelayableTCPConnector(pre_request_delay=self._request_delay,
                                     verify_ssl=False, loop=self._loop)
        async with aiohttp.ClientSession(cookies=cookies, connector=conn,
                                         loop=self._loop) as session:
            # Insert a delay after creating the connection
            # But before sending the request.

            async with getattr(session, method.lower())(
                    url, *args, **kwargs) as response:
                try:
                    response.text = await response.text()
                except UnicodeDecodeError:
                    response.text = None

                try:
                    response.json = await response.json()
                except (JSONDecodeError,
                        UnicodeDecodeError,
                        aiohttp.ClientResponseError):
                    response.json = None

                response.body = await response.read()
                return response


Config.REQUEST_TIMEOUT = 0.6
request_timeout_default_app = Sanic('test_request_timeout_default')
request_no_timeout_app = Sanic('test_request_no_timeout')


@request_timeout_default_app.route('/1')
async def handler1(request):
    return text('OK')


@request_no_timeout_app.route('/1')
async def handler2(request):
    return text('OK')


def test_default_server_error_request_timeout():
    client = DelayableSanicTestClient(request_timeout_default_app, None, 2)
    request, response = client.get('/1')
    assert response.status == 408
    assert response.text == 'Error: Request Timeout'


def test_default_server_error_request_dont_timeout():
    client = DelayableSanicTestClient(request_no_timeout_app, None, 0.2)
    request, response = client.get('/1')
    assert response.status == 200
    assert response.text == 'OK'