from __future__ import (absolute_import, print_function, division)

import inspect
import socket
import OpenSSL
import pytest
import traceback
import os
import tempfile

from io import BytesIO

from libmproxy.proxy.config import ProxyConfig
from libmproxy.proxy.server import ProxyServer
from libmproxy.cmdline import APP_HOST, APP_PORT

import logging
logging.getLogger("hyper.packages.hpack.hpack").setLevel(logging.WARNING)
logging.getLogger("requests.packages.urllib3.connectionpool").setLevel(logging.WARNING)
logging.getLogger("passlib.utils.compat").setLevel(logging.WARNING)
logging.getLogger("passlib.registry").setLevel(logging.WARNING)
logging.getLogger("PIL.Image").setLevel(logging.WARNING)
logging.getLogger("PIL.PngImagePlugin").setLevel(logging.WARNING)

import netlib
from netlib import tservers as netlib_tservers

import h2
from hyperframe.frame import Frame

from libmproxy import utils
from . import tservers

requires_alpn = pytest.mark.skipif(
    not OpenSSL._util.lib.Cryptography_HAS_ALPN,
    reason="requires OpenSSL with ALPN support")

class _Http2ServerBase(netlib_tservers.ServerTestBase):
    ssl = dict(alpn_select=b'h2')

    class handler(netlib.tcp.BaseHandler):
        def handle(self):
            h2_conn = h2.connection.H2Connection(client_side=False)

            preamble = self.rfile.read(24)
            h2_conn.initiate_connection()
            h2_conn.receive_data(preamble)
            self.wfile.write(h2_conn.data_to_send())
            self.wfile.flush()

            while True:
                raw_frame = utils.http2_read_frame(self.rfile)
                events = h2_conn.receive_data(raw_frame)
                self.wfile.write(h2_conn.data_to_send())
                self.wfile.flush()

                for event in events:
                    try:
                        if not self.server.handle_server_event(event, h2_conn, self.rfile, self.wfile):
                            break
                    except Exception as e:
                        print(repr(e))
                        print(traceback.format_exc())
                        break

    def handle_server_event(self, h2_conn, rfile, wfile):
        raise NotImplementedError()


class _Http2TestBase(object):
    @classmethod
    def setup_class(self):
        self.config = ProxyConfig(**self.get_proxy_config())

        tmaster = tservers.TestMaster(self.config)
        tmaster.start_app(APP_HOST, APP_PORT)
        self.proxy = tservers.ProxyThread(tmaster)
        self.proxy.start()

    @classmethod
    def teardown_class(cls):
        cls.proxy.shutdown()

    @property
    def master(self):
        return self.proxy.tmaster

    @classmethod
    def get_proxy_config(cls):
        cls.cadir = os.path.join(tempfile.gettempdir(), "mitmproxy")
        return dict(
            no_upstream_cert = False,
            cadir = cls.cadir,
            authenticator = None,
        )

    def setup(self):
        self.master.clear_log()
        self.master.state.clear()
        self.server.server.handle_server_event = self.handle_server_event

    def _setup_connection(self):
        self.config.http2 = True

        client = netlib.tcp.TCPClient(("127.0.0.1", self.proxy.port))
        client.connect()

        # send CONNECT request
        client.wfile.write(
            b"CONNECT localhost:%d HTTP/1.1\r\n"
            b"Host: localhost:%d\r\n"
            b"\r\n" % (self.server.server.address.port, self.server.server.address.port)
        )
        client.wfile.flush()

        # read CONNECT response
        while client.rfile.readline() != "\r\n":
            pass

        client.convert_to_ssl(alpn_protos=[b'h2'])

        h2_conn = h2.connection.H2Connection(client_side=True)
        h2_conn.initiate_connection()
        client.wfile.write(h2_conn.data_to_send())
        client.wfile.flush()

        return client, h2_conn

    def _send_request(self, wfile, h2_conn, stream_id=1, headers=[], end_stream=True):
        h2_conn.send_headers(
            stream_id=stream_id,
            headers=headers,
            end_stream=end_stream,
        )
        wfile.write(h2_conn.data_to_send())
        wfile.flush()


@requires_alpn
class TestSimple(_Http2TestBase, _Http2ServerBase):
    @classmethod
    def setup_class(self):
        _Http2TestBase.setup_class()
        _Http2ServerBase.setup_class()

    @classmethod
    def teardown_class(self):
        _Http2TestBase.teardown_class()
        _Http2ServerBase.teardown_class()

    @classmethod
    def handle_server_event(self, event, h2_conn, rfile, wfile):
        if isinstance(event, h2.events.ConnectionTerminated):
            return False
        elif isinstance(event, h2.events.RequestReceived):
            h2_conn.send_headers(1, [
                (':status', '200'),
                ('foo', 'bar'),
            ])
            h2_conn.send_data(1, b'foobar')
            h2_conn.end_stream(1)
            wfile.write(h2_conn.data_to_send())
            wfile.flush()

        return True

    def test_simple(self):
        client, h2_conn = self._setup_connection()

        self._send_request(client.wfile, h2_conn, headers=[
            (':authority', "127.0.0.1:%s" % self.server.server.address.port),
            (':method', 'GET'),
            (':scheme', 'https'),
            (':path', '/'),
        ])

        done = False
        while not done:
            events = h2_conn.receive_data(utils.http2_read_frame(client.rfile))
            client.wfile.write(h2_conn.data_to_send())
            client.wfile.flush()

            for event in events:
                if isinstance(event, h2.events.StreamEnded):
                    done = True

        h2_conn.close_connection()
        client.wfile.write(h2_conn.data_to_send())
        client.wfile.flush()

        assert len(self.master.state.flows) == 1
        assert self.master.state.flows[0].response.status_code == 200
        assert self.master.state.flows[0].response.headers['foo'] == 'bar'
        assert self.master.state.flows[0].response.body == b'foobar'


@requires_alpn
class TestPushPromise(_Http2TestBase, _Http2ServerBase):
    @classmethod
    def setup_class(self):
        _Http2TestBase.setup_class()
        _Http2ServerBase.setup_class()

    @classmethod
    def teardown_class(self):
        _Http2TestBase.teardown_class()
        _Http2ServerBase.teardown_class()

    @classmethod
    def handle_server_event(self, event, h2_conn, rfile, wfile):
        if isinstance(event, h2.events.ConnectionTerminated):
            return False
        elif isinstance(event, h2.events.RequestReceived):
            if event.stream_id != 1:
                # ignore requests initiated by push promises
                return True

            h2_conn.send_headers(1, [(':status', '200')])
            h2_conn.push_stream(1, 2, [
                (':authority', "127.0.0.1:%s" % self.port),
                (':method', 'GET'),
                (':scheme', 'https'),
                (':path', '/pushed_stream_foo'),
                ('foo', 'bar')
            ])
            h2_conn.push_stream(1, 4, [
                (':authority', "127.0.0.1:%s" % self.port),
                (':method', 'GET'),
                (':scheme', 'https'),
                (':path', '/pushed_stream_bar'),
                ('foo', 'bar')
            ])
            wfile.write(h2_conn.data_to_send())
            wfile.flush()

            h2_conn.send_headers(2, [(':status', '202')])
            h2_conn.send_headers(4, [(':status', '204')])
            h2_conn.send_data(1, b'regular_stream')
            h2_conn.send_data(2, b'pushed_stream_foo')
            h2_conn.send_data(4, b'pushed_stream_bar')
            h2_conn.end_stream(1)
            h2_conn.end_stream(2)
            h2_conn.end_stream(4)
            wfile.write(h2_conn.data_to_send())
            wfile.flush()

        return True

    def test_push_promise(self):
        client, h2_conn = self._setup_connection()

        self._send_request(client.wfile, h2_conn, stream_id=1, headers=[
            (':authority', "127.0.0.1:%s" % self.server.server.address.port),
            (':method', 'GET'),
            (':scheme', 'https'),
            (':path', '/'),
            ('foo', 'bar')
        ])

        ended_streams = 0
        pushed_streams = 0
        while ended_streams != 3:
            try:
                events = h2_conn.receive_data(utils.http2_read_frame(client.rfile))
            except:
                break
            client.wfile.write(h2_conn.data_to_send())
            client.wfile.flush()

            for event in events:
                if isinstance(event, h2.events.StreamEnded):
                    ended_streams += 1
                elif isinstance(event, h2.events.PushedStreamReceived):
                    pushed_streams += 1

        assert pushed_streams == 2

        bodies = [flow.response.body for flow in self.master.state.flows]
        assert len(bodies) == 3
        assert b'regular_stream' in bodies
        assert b'pushed_stream_foo' in bodies
        assert b'pushed_stream_bar' in bodies