Move command handlers to own module and add clean-rooms command (ref #59)

mautrix_telegram/commands/handler.py

@@ -0,0 +1,114 @@
+# mautrix-telegram - A Matrix-Telegram puppeting bridge
+# Copyright (C) 2018 Tulir Asokan
+#
+# This program is free software: you can redistribute it and/or modify
+# it under the terms of the GNU 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 General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with this program.  If not, see <http://www.gnu.org/licenses/>.
+import markdown
+import logging
+
+from telethon.errors import FloodWaitError
+
+command_handlers = {}
+
+
+def command_handler(needs_auth=True, management_only=False, needs_admin=False, name=None):
+    def decorator(func):
+        def wrapper(evt):
+            if management_only and not evt.is_management:
+                return evt.reply(f"`{evt.command}` is a restricted command:"
+                                 + "you may only run it in management rooms.")
+            elif needs_auth and not evt.sender.logged_in:
+                return evt.reply("This command requires you to be logged in.")
+            elif needs_admin and not evt.sender.is_admin:
+                return evt.reply("This is command requires administrator privileges.")
+            return func(evt)
+
+        command_handlers[name or func.__name__.replace("_", "-")] = wrapper
+        return wrapper
+
+    return decorator
+
+
+class CommandEvent:
+    def __init__(self, handler, room, sender, command, args, is_management, is_portal):
+        self.az = handler.az
+        self.log = handler.log
+        self.loop = handler.loop
+        self.command_prefix = handler.command_prefix
+        self.room_id = room
+        self.sender = sender
+        self.command = command
+        self.args = args
+        self.is_management = is_management
+        self.is_portal = is_portal
+
+    def reply(self, message, allow_html=False, render_markdown=True):
+        message = message.replace("$cmdprefix+sp ",
+                                  "" if self.is_management else f"{self.command_prefix} ")
+        message = message.replace("$cmdprefix", self.command_prefix)
+        html = None
+        if render_markdown:
+            html = markdown.markdown(message, safe_mode="escape" if allow_html else False)
+        elif allow_html:
+            html = message
+        return self.az.intent.send_notice(self.room_id, message, html=html)
+
+
+def format_duration(seconds):
+    def pluralize(count, singular): return singular if count == 1 else singular + "s"
+
+    def include(count, word): return f"{count} {pluralize(count, word)}" if count > 0 else ""
+
+    minutes, seconds = divmod(seconds, 60)
+    hours, minutes = divmod(minutes, 60)
+    days, hours = divmod(hours, 24)
+    parts = [a for a in [
+        include(days, "day"),
+        include(hours, "hour"),
+        include(minutes, "minute"),
+        include(seconds, "second")] if a]
+    if len(parts) > 2:
+        return "{} and {}".format(", ".join(parts[:-1]), parts[-1])
+    return " and ".join(parts)
+
+
+class CommandHandler:
+    log = logging.getLogger("mau.commands")
+
+    def __init__(self, context):
+        self.az, self.db, self.config, self.loop = context
+        self.command_prefix = self.config["bridge.command_prefix"]
+
+    # region Utility functions for handling commands
+
+    async def handle(self, room, sender, command, args, is_management, is_portal):
+        evt = CommandEvent(self, room, sender, command, args,
+                           is_management, is_portal)
+        command = command.lower()
+        try:
+            command = command_handlers[command]
+        except KeyError:
+            if sender.command_status and "next" in sender.command_status:
+                args.insert(0, command)
+                evt.command = ""
+                command = sender.command_status["next"]
+            else:
+                command = command_handlers["unknown_command"]
+        try:
+            await command(evt)
+        except FloodWaitError as e:
+            return evt.reply(f"Flood error: Please wait {format_duration(e.seconds)}")
+        except Exception:
+            self.log.exception(f"Fatal error handling command "
+                               + f"{evt.command} {' '.join(args)} from {sender.mxid}")
+            return evt.reply("Fatal error while handling command. Check logs for more details.")