pincer.core.gateway

Complexity

Total Complexity

11

Size/Duplication

Total Lines	169
Duplicated Lines	0 %

Importance

Changes

0

5 Methods

Rating	Name	Duplication	Size	Complexity
A	Dispatcher.run()	0	10	1
A	Dispatcher.__dispatcher()	0	21	5
A	Dispatcher.close()	0	7	1
A	Dispatcher.__init__()	0	46	2
A	Dispatcher.handler_manager()	0	22	2

# -*- coding: utf-8 -*-

Missing module docstring

# MIT License
#
# Copyright (c) 2021 Pincer
#
# Permission is hereby granted, free of charge, to any person obtaining a copy
# of this software and associated documentation files (the "Software"), to deal
# in the Software without restriction, including without limitation the rights
# to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
# copies of the Software, and to permit persons to whom the Software is
# furnished to do so, subject to the following conditions:
#
# The above copyright notice and this permission notice shall be included in all
# copies or substantial portions of the Software.
#
# THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
# IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
# FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
# AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
# LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
# OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
# SOFTWARE.
from __future__ import annotations

from asyncio import get_event_loop, AbstractEventLoop, ensure_future
from platform import system
from typing import Dict, Callable, Awaitable

from websockets import connect

The name connect does not seem to exist in module websockets.

from websockets.exceptions import ConnectionClosedError
from websockets.legacy.client import WebSocketClientProtocol

from pincer import __package__

This seems to re-define the built-in __package__.

from pincer._config import GatewayConfig
# TODO: Implement logging

TODO and FIXME comments should generally be avoided.

from pincer.core.dispatch import GatewayDispatch
from pincer.core.handlers.heartbeat import handle_hello, handle_heartbeat
from pincer.exceptions import PincerError, InvalidTokenError, \
    UnhandledException

Handler = Callable[[WebSocketClientProtocol, GatewayDispatch], Awaitable[None]]


class Dispatcher:

    """
    The Dispatcher handles all interactions with the discord websocket
    API. This also contains the main event loop, and handles the heartbeat.

    Running the dispatcher will create a connection with the
    Discord WebSocket API on behalf of the provided token. This token
    must be a bot token. (Which can be found on
    `/developers/applications/<bot_id>/bot`)
    """

    # TODO: Add intents argument

TODO and FIXME comments should generally be avoided.

    # TODO: Add handlers argument

TODO and FIXME comments should generally be avoided.

    def __init__(self, token: str) -> None:
        """
        :param token:
            Bot token for discord's API.
        """

        if len(token) != 59:
            raise InvalidTokenError(
                "Discord Token must have exactly 59 characters."
            )

        self.__token = token
        self.__keep_alive = True

        async def identify_and_handle_hello(socket: WebSocketClientProtocol,
                                            payload: GatewayDispatch):
            """
            Identifies the client to the Discord Websocket API, this
            gets done when the client receives the `hello` (opcode 10)
            message from discord. Right after we send our identification
            the heartbeat starts.

            :param socket:
                The current socket, which can be used to interact
                with the Discord API.

            :param payload: The received payload from Discord.
            """
            await socket.send(str(GatewayDispatch(2, {
                "token": token,
                "intents": 0,
                "properties": {
                    "$os": system(),
                    "$browser": __package__,
                    "$device": __package__
                }
            })))
            await handle_hello(socket, payload)

        self.__dispatch_handlers: Dict[int, Handler] = {
            10: identify_and_handle_hello,
            11: handle_heartbeat
        }

        self.__dispatch_errors: Dict[int, PincerError] = {
            4004: InvalidTokenError()
        }

    async def handler_manager(self, socket: WebSocketClientProtocol,
                              payload: GatewayDispatch,
                              loop: AbstractEventLoop):
        """
        This manages all handles for given OP codes.
        This method gets invoked for every message that is received from
        Discord.

        :param socket:
            The current socket, which can be used to interact
            with the Discord API.
        :param payload: The received payload from Discord.
        :param loop: The current async loop on which the future is bound.
        """
        # TODO: Implement given handlers.

TODO and FIXME comments should generally be avoided.

        # TODO: Implement logging

TODO and FIXME comments should generally be avoided.

        handler: Handler = self.__dispatch_handlers.get(payload.op)

        if not handler:
            raise UnhandledException(f"Unhandled payload: {payload}")

        ensure_future(handler(socket, payload), loop=loop)

    async def __dispatcher(self, loop: AbstractEventLoop):
        """
        The main event loop.
        This handles all interactions with the websocket API.
        """
        # TODO: Implement logging

TODO and FIXME comments should generally be avoided.

        async with connect(GatewayConfig.uri()) as socket:
            while self.__keep_alive:
                try:
                    await self.handler_manager(
                        socket,
                        GatewayDispatch.from_string(await socket.recv()),
                        loop)

                except ConnectionClosedError as exc:
                    self.close()

                    exception = self.__dispatch_errors.get(exc.code)

                    raise exception if exception else UnhandledException(
                        f"Dispatch error ({exc.code}): {exc.reason}")

    def run(self):
        """
        Instantiate the dispatcher, this will create a connection to the
        Discord websocket API on behalf of the client who's token has
        been passed.
        """
        # TODO: Implement logging

TODO and FIXME comments should generally be avoided.

        loop = get_event_loop()
        loop.run_until_complete(self.__dispatcher(loop))
        loop.close()

    def close(self):
        """
        Stop the dispatcher from listening and responding to gateway
        events. This should let the client close on itself.
        """
        # TODO: Implement logging

TODO and FIXME comments should generally be avoided.

        self.__keep_alive = False