#!/usr/bin/env python3

import attr
import asyncio
import aiohttp
import os
import json

from aiohttp import web, ClientSession
from nio import AsyncClient, LoginResponse
from appdirs import user_data_dir
from json import JSONDecodeError

HOMESERVER = "https://localhost:8448"


@attr.s
class ProxyDaemon:
    homeserver = attr.ib()
    proxy = attr.ib(default=None)
    ssl = attr.ib(default=None)

    client_sessions = attr.ib(init=False, default=attr.Factory(dict))
    default_session = attr.ib(init=False, default=None)

    def get_access_token(self, request):
        # type: (aiohttp.BaseRequest) -> str
        """Extract the access token from the request.

        This method extracts the access token either from the query string or
        from the Authorization header of the request.

        Returns the access token if it was found.
        """
        access_token = request.query.get("access_token", "")

        if not access_token:
            access_token = request.headers.get(
                "Authorization",
                ""
            ).strip("Bearer ")

        return access_token

    async def router(self, request):
        path = request.path
        method = request.method
        data = await request.text()
        headers = request.headers
        params = request.query

        print(method, path, data)

        session = None

        token = self.get_access_token(request)
        client = self.client_sessions.get(token, None)

        if client:
            session = client.client_session

        if not session:
            if not self.default_session:
                self.default_session = ClientSession()
            session = self.default_session

        async with session.request(
            method,
            HOMESERVER + path,
            data=data,
            params=params,
            headers=headers,
            proxy=self.proxy,
            ssl=False
        ) as resp:
            print("Returning resp {}".format(resp))
            return(web.Response(text=await resp.text()))

    async def login(self, request):
        try:
            body = await request.json()
        except JSONDecodeError:
            # TODO what to do here, quaternion retries the login if we raise an
            # exception here, throws an error if we send out an 400 and hangs
            # if we forward it to the router() method.
            print("JSON ERROR IN LOGIN")
            raise
            # return web.Response(
            #     status=400,
            #     text=json.dumps({
            #         "errcode": "M_NOT_JSON",
            #         "error": "Request did not contain valid JSON."
            #     })
            # )

        print("Login request")
        print(body)

        identifier = body.get("identifier", None)

        if identifier:
            user = identifier.get("user", None)

            if not user:
                user = body.get("user", "")
        else:
            user = body.get("user", "")

        password = body.get("password", "")
        device_id = body.get("device_id", "")
        device_name = body.get("initial_device_display_name", "")

        store_path = user_data_dir("pantalaimon", "")

        try:
            os.makedirs(store_path)
        except OSError:
            pass

        client = AsyncClient(
            HOMESERVER,
            user,
            device_id,
            store_path=store_path,
            ssl=self.ssl,
            proxy=self.proxy
        )

        print("Logging in")

        response = await client.login(password, device_name)

        if isinstance(response, LoginResponse):
            self.client_sessions[response.access_token] = client
        else:
            # TODO close the client and its session.
            pass

        return web.Response(
            status=response.transport_response.status,
            text=await response.transport_response.text()
        )

    async def sync(self, request):
        return web.Response(
            status=405,
            text="Not implemented"
        )


async def init():
    """Initialize the proxy and the http server."""
    proxy = ProxyDaemon(HOMESERVER, proxy="http://localhost:8080", ssl=False)
    app = web.Application()
    app.add_routes([
        web.post("/_matrix/client/r0/login", proxy.login),
        web.get("/_matrix/client/r0/sync", proxy.sync),
    ])
    app.router.add_route('*', "/" + '{proxyPath:.*}', proxy.router)
    return proxy, app


def main():
    loop = asyncio.get_event_loop()
    proxy, app = loop.run_until_complete(init())

    web.run_app(app, host="127.0.0.1", port=8081)


if __name__ == "__main__":
    main()