import asyncio
import functools
import socket

from asyncio import sleep as aio_sleep
from http.client import _encode
from json import JSONDecodeError

import httpcore
import requests_async as requests

from httpcore import PoolTimeout

from sanic import Sanic, server
from sanic.response import text
from sanic.testing import HOST, PORT, SanicTestClient


# import traceback


CONFIG_FOR_TESTS = {"KEEP_ALIVE_TIMEOUT": 2, "KEEP_ALIVE": True}

old_conn = None


class ReusableSanicConnectionPool(httpcore.ConnectionPool):
    async def acquire_connection(self, url, ssl, timeout):
        global old_conn
        if timeout.connect_timeout and not timeout.pool_timeout:
            timeout.pool_timeout = timeout.connect_timeout
        key = (url.scheme, url.hostname, url.port, ssl, timeout)
        try:
            connection = self._keepalive_connections[key].pop()
            if not self._keepalive_connections[key]:
                del self._keepalive_connections[key]
            self.num_keepalive_connections -= 1
            self.num_active_connections += 1

        except (KeyError, IndexError):
            ssl_context = await self.get_ssl_context(url, ssl)
            try:
                await asyncio.wait_for(
                    self._max_connections.acquire(), timeout.pool_timeout
                )
            except asyncio.TimeoutError:
                raise PoolTimeout()
            release = functools.partial(self.release_connection, key=key)
            connection = httpcore.connections.Connection(
                timeout=timeout, on_release=release
            )
            self.num_active_connections += 1
            await connection.open(url.hostname, url.port, ssl=ssl_context)

        if old_conn is not None:
            if old_conn != connection:
                raise RuntimeError(
                    "We got a new connection, wanted the same one!"
                )
        old_conn = connection

        return connection


class ReusableSanicAdapter(requests.adapters.HTTPAdapter):
    def __init__(self):
        self.pool = ReusableSanicConnectionPool()

    async def send(
        self,
        request,
        stream=False,
        timeout=None,
        verify=True,
        cert=None,
        proxies=None,
    ):

        method = request.method
        url = request.url
        headers = [
            (_encode(k), _encode(v)) for k, v in request.headers.items()
        ]

        if not request.body:
            body = b""
        elif isinstance(request.body, str):
            body = _encode(request.body)
        else:
            body = request.body

        if isinstance(timeout, tuple):
            timeout_kwargs = {
                "connect_timeout": timeout[0],
                "read_timeout": timeout[1],
            }
        else:
            timeout_kwargs = {
                "connect_timeout": timeout,
                "read_timeout": timeout,
            }

        ssl = httpcore.SSLConfig(cert=cert, verify=verify)
        timeout = httpcore.TimeoutConfig(**timeout_kwargs)

        try:
            response = await self.pool.request(
                method,
                url,
                headers=headers,
                body=body,
                stream=stream,
                ssl=ssl,
                timeout=timeout,
            )
        except (httpcore.BadResponse, socket.error) as err:
            raise ConnectionError(err, request=request)
        except httpcore.ConnectTimeout as err:
            raise requests.exceptions.ConnectTimeout(err, request=request)
        except httpcore.ReadTimeout as err:
            raise requests.exceptions.ReadTimeout(err, request=request)

        return self.build_response(request, response)


class ResusableSanicSession(requests.Session):
    def __init__(self, *args, **kwargs) -> None:
        super().__init__(*args, **kwargs)
        adapter = ReusableSanicAdapter()
        self.mount("http://", adapter)
        self.mount("https://", adapter)


class ReuseableSanicTestClient(SanicTestClient):
    def __init__(self, app, loop=None):
        super().__init__(app)
        if loop is None:
            loop = asyncio.get_event_loop()
        self._loop = loop
        self._server = None
        self._tcp_connector = None
        self._session = None

    # Copied from SanicTestClient, but with some changes to reuse the
    # same loop for the same app.
    def _sanic_endpoint_test(
        self,
        method="get",
        uri="/",
        gather_request=True,
        debug=False,
        server_kwargs={"return_asyncio_server": True},
        *request_args,
        **request_kwargs,
    ):
        loop = self._loop
        results = [None, None]
        exceptions = []
        if gather_request:

            def _collect_request(request):
                if results[0] is None:
                    results[0] = request

            self.app.request_middleware.appendleft(_collect_request)

        if uri.startswith(
            ("http:", "https:", "ftp:", "ftps://", "//", "ws:", "wss:")
        ):
            url = uri
        else:
            uri = uri if uri.startswith("/") else "/{uri}".format(uri=uri)
            scheme = "http"
            url = "{scheme}://{host}:{port}{uri}".format(
                scheme=scheme, host=HOST, port=PORT, uri=uri
            )

        @self.app.listener("after_server_start")
        async def _collect_response(loop):
            try:
                response = await self._local_request(
                    method, url, *request_args, **request_kwargs
                )
                results[-1] = response
            except Exception as e2:
                # traceback.print_tb(e2.__traceback__)
                exceptions.append(e2)

        if self._server is not None:
            _server = self._server
        else:
            _server_co = self.app.create_server(
                host=HOST, debug=debug, port=PORT, **server_kwargs
            )

            server.trigger_events(
                self.app.listeners["before_server_start"], loop
            )

            try:
                loop._stopping = False
                _server = loop.run_until_complete(_server_co)
            except Exception as e1:
                # traceback.print_tb(e1.__traceback__)
                raise e1
            self._server = _server
        server.trigger_events(self.app.listeners["after_server_start"], loop)
        self.app.listeners["after_server_start"].pop()

        if exceptions:
            raise ValueError("Exception during request: {}".format(exceptions))

        if gather_request:
            self.app.request_middleware.pop()
            try:
                request, response = results
                return request, response
            except Exception:
                raise ValueError(
                    "Request and response object expected, got ({})".format(
                        results
                    )
                )
        else:
            try:
                return results[-1]
            except Exception:
                raise ValueError(
                    "Request object expected, got ({})".format(results)
                )

    def kill_server(self):
        try:
            if self._server:
                self._server.close()
                self._loop.run_until_complete(self._server.wait_closed())
                self._server = None
                self.app.stop()

            if self._session:
                self._loop.run_until_complete(self._session.close())
                self._session = None

        except Exception as e3:
            raise e3

    # Copied from SanicTestClient, but with some changes to reuse the
    # same TCPConnection and the sane ClientSession more than once.
    # Note, you cannot use the same session if you are in a _different_
    # loop, so the changes above are required too.
    async def _local_request(self, method, url, *args, **kwargs):
        raw_cookies = kwargs.pop("raw_cookies", None)
        request_keepalive = kwargs.pop(
            "request_keepalive", CONFIG_FOR_TESTS["KEEP_ALIVE_TIMEOUT"]
        )
        if self._session:
            _session = self._session
        else:
            _session = ResusableSanicSession()
            self._session = _session
        async with _session as session:
            try:
                response = await getattr(session, method.lower())(
                    url,
                    verify=False,
                    timeout=request_keepalive,
                    *args,
                    **kwargs,
                )
            except NameError:
                raise Exception(response.status_code)

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

            response.body = await response.read()
            response.status = response.status_code
            response.content_type = response.headers.get("content-type")

            if raw_cookies:
                response.raw_cookies = {}
                for cookie in response.cookies:
                    response.raw_cookies[cookie.name] = cookie

        return response


keep_alive_timeout_app_reuse = Sanic("test_ka_timeout_reuse")
keep_alive_app_client_timeout = Sanic("test_ka_client_timeout")
keep_alive_app_server_timeout = Sanic("test_ka_server_timeout")

keep_alive_timeout_app_reuse.config.update(CONFIG_FOR_TESTS)
keep_alive_app_client_timeout.config.update(CONFIG_FOR_TESTS)
keep_alive_app_server_timeout.config.update(CONFIG_FOR_TESTS)


@keep_alive_timeout_app_reuse.route("/1")
async def handler1(request):
    return text("OK")


@keep_alive_app_client_timeout.route("/1")
async def handler2(request):
    return text("OK")


@keep_alive_app_server_timeout.route("/1")
async def handler3(request):
    return text("OK")


def test_keep_alive_timeout_reuse():
    """If the server keep-alive timeout and client keep-alive timeout are
     both longer than the delay, the client _and_ server will successfully
     reuse the existing connection."""
    loop = asyncio.new_event_loop()
    asyncio.set_event_loop(loop)
    client = ReuseableSanicTestClient(keep_alive_timeout_app_reuse, loop)
    headers = {"Connection": "keep-alive"}
    request, response = client.get("/1", headers=headers)
    assert response.status == 200
    assert response.text == "OK"
    loop.run_until_complete(aio_sleep(1))
    request, response = client.get("/1")
    assert response.status == 200
    assert response.text == "OK"
    client.kill_server()


def test_keep_alive_client_timeout():
    """If the server keep-alive timeout is longer than the client
    keep-alive timeout, client will try to create a new connection here."""
    loop = asyncio.new_event_loop()
    asyncio.set_event_loop(loop)
    client = ReuseableSanicTestClient(keep_alive_app_client_timeout, loop)
    headers = {"Connection": "keep-alive"}
    try:
        request, response = client.get(
            "/1", headers=headers, request_keepalive=1
        )
        assert response.status == 200
        assert response.text == "OK"
        loop.run_until_complete(aio_sleep(2))
        exception = None
        request, response = client.get("/1", request_keepalive=1)
    except ValueError as e:
        exception = e
    assert exception is not None
    assert isinstance(exception, ValueError)
    assert "got a new connection" in exception.args[0]
    client.kill_server()


def test_keep_alive_server_timeout():
    """If the client keep-alive timeout is longer than the server
    keep-alive timeout, the client will either a 'Connection reset' error
    _or_ a new connection. Depending on how the event-loop handles the
    broken server connection."""
    loop = asyncio.new_event_loop()
    asyncio.set_event_loop(loop)
    client = ReuseableSanicTestClient(keep_alive_app_server_timeout, loop)
    headers = {"Connection": "keep-alive"}
    try:
        request, response = client.get(
            "/1", headers=headers, request_keepalive=60
        )
        assert response.status == 200
        assert response.text == "OK"
        loop.run_until_complete(aio_sleep(3))
        exception = None
        request, response = client.get("/1", request_keepalive=60)
    except ValueError as e:
        exception = e
    assert exception is not None
    assert isinstance(exception, ValueError)
    assert (
        "Connection reset" in exception.args[0]
        or "got a new connection" in exception.args[0]
    )
    client.kill_server()