mautrix-signal/mautrix_signal/commands/handler.py

# mautrix-signal - A Matrix-Signal puppeting bridge
# Copyright (C) 2020 Tulir Asokan
#
# This program is free software: you can redistribute it and/or modify
# it under the terms of the GNU Affero General Public License as published by
# the Free Software Foundation, either version 3 of the License, or
# (at your option) any later version.
#
# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
# GNU Affero General Public License for more details.
#
# You should have received a copy of the GNU Affero General Public License
# along with this program.  If not, see <https://www.gnu.org/licenses/>.
from typing import Awaitable, Callable, List, Optional, NamedTuple, TYPE_CHECKING

from mautrix.types import RoomID, EventID, MessageEventContent
from mautrix.bridge.commands import (HelpSection, CommandEvent as BaseCommandEvent,
                                     CommandHandler as BaseCommandHandler,
                                     CommandProcessor as BaseCommandProcessor,
                                     CommandHandlerFunc, command_handler as base_command_handler)

from .. import user as u

if TYPE_CHECKING:
    from ..__main__ import SignalBridge

HelpCacheKey = NamedTuple('HelpCacheKey', is_management=bool, is_portal=bool, is_admin=bool,
                          is_logged_in=bool)
SECTION_AUTH = HelpSection("Authentication", 10, "")
SECTION_CONNECTION = HelpSection("Connection management", 15, "")


class CommandEvent(BaseCommandEvent):
    sender: u.User
    bridge: 'SignalBridge'

    def __init__(self, processor: 'CommandProcessor', room_id: RoomID, event_id: EventID,
                 sender: u.User, command: str, args: List[str], content: MessageEventContent,
                 is_management: bool, is_portal: bool) -> None:
        super().__init__(processor, room_id, event_id, sender, command, args, content,
                         is_management, is_portal)
        self.bridge = processor.bridge
        self.config = processor.config

    @property
    def print_error_traceback(self) -> bool:
        return self.sender.is_admin

    async def get_help_key(self) -> HelpCacheKey:
        return HelpCacheKey(self.is_management, self.is_portal, self.sender.is_admin,
                            await self.sender.is_logged_in())


class CommandHandler(BaseCommandHandler):
    name: str

    management_only: bool
    needs_auth: bool
    needs_admin: bool

    def __init__(self, handler: Callable[[CommandEvent], Awaitable[EventID]],
                 management_only: bool, name: str, help_text: str, help_args: str,
                 help_section: HelpSection, needs_auth: bool, needs_admin: bool) -> None:
        super().__init__(handler, management_only, name, help_text, help_args, help_section,
                         needs_auth=needs_auth, needs_admin=needs_admin)

    async def get_permission_error(self, evt: CommandEvent) -> Optional[str]:
        if self.management_only and not evt.is_management:
            return (f"`{evt.command}` is a restricted command: "
                    "you may only run it in management rooms.")
        elif self.needs_admin and not evt.sender.is_admin:
            return "This command requires administrator privileges."
        elif self.needs_auth and not await evt.sender.is_logged_in():
            return "This command requires you to be logged in."
        return None

    def has_permission(self, key: HelpCacheKey) -> bool:
        return ((not self.management_only or key.is_management) and
                (not self.needs_admin or key.is_admin) and
                (not self.needs_auth or key.is_logged_in))


def command_handler(_func: Optional[CommandHandlerFunc] = None, *, needs_auth: bool = True,
                    needs_admin: bool = False, management_only: bool = False,
                    name: Optional[str] = None, help_text: str = "", help_args: str = "",
                    help_section: HelpSection = None) -> Callable[[CommandHandlerFunc],
                                                                  CommandHandler]:
    return base_command_handler(_func, _handler_class=CommandHandler, name=name,
                                help_text=help_text, help_args=help_args,
                                help_section=help_section, management_only=management_only,
                                needs_auth=needs_auth, needs_admin=needs_admin)


class CommandProcessor(BaseCommandProcessor):
    def __init__(self, bridge: 'SignalBridge') -> None:
        super().__init__(bridge=bridge, event_class=CommandEvent)