server: Replace hand-rolled IRC with irc (jaraco) library

Switch the IRC server implementation from the custom socket-based parser
to the irc Python library (SingleServerIRCBot), gaining automatic
exponential-backoff reconnection, built-in PING/PONG handling, and
nick-collision recovery for free.

- Add IRCLib server (server/IRCLib.py) extending ThreadedServer:
  _IRCBotAdapter wraps SingleServerIRCBot with a threading.Event stop
  flag so shutdown is clean and on_disconnect skips reconnect when
  stopping. subparse() is implemented directly for alias/grep/rnd/cat.
- Add IRCLib printer (message/printer/IRCLib.py) calling
  connection.privmsg() directly instead of building raw PRIVMSG strings.
- Update factory to use IRCLib for irc:// and ircs://; SSL is now
  passed as a connect_factory kwarg rather than post-hoc socket wrapping.
- Add irc to requirements.txt.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

nemubot/message/printer/IRCLib.py

@@ -0,0 +1,67 @@
+# Nemubot is a smart and modulable IM bot.
+# Copyright (C) 2012-2026  Mercier Pierre-Olivier
+#
+# 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 <http://www.gnu.org/licenses/>.
+
+from nemubot.message.visitor import AbstractVisitor
+
+
+class IRCLib(AbstractVisitor):
+
+    """Visitor that sends bot responses via an irc.client.ServerConnection.
+
+    Unlike the socket-based IRC printer (which builds a raw PRIVMSG string),
+    this calls connection.privmsg() directly so the library handles encoding,
+    line-length capping, and any internal locking.
+    """
+
+    def __init__(self, connection):
+        self._conn = connection
+
+    def _send(self, target, text):
+        try:
+            self._conn.privmsg(target, text)
+        except Exception:
+            pass  # drop silently during reconnection
+
+    # Visitor methods
+
+    def visit_Text(self, msg):
+        if isinstance(msg.message, str):
+            for target in msg.to:
+                self._send(target, msg.message)
+        else:
+            msg.message.accept(self)
+
+    def visit_DirectAsk(self, msg):
+        text = msg.message if isinstance(msg.message, str) else str(msg.message)
+        # Mirrors socket.py logic:
+        # rooms that are NOT the designated nick get a "nick: " prefix
+        others = [to for to in msg.to if to != msg.designated]
+        if len(others) == 0 or len(others) != len(msg.to):
+            for target in msg.to:
+                self._send(target, text)
+        if others:
+            for target in others:
+                self._send(target, "%s: %s" % (msg.designated, text))
+
+    def visit_Command(self, msg):
+        parts = ["!" + msg.cmd] + list(msg.args)
+        for target in msg.to:
+            self._send(target, " ".join(parts))
+
+    def visit_OwnerCommand(self, msg):
+        parts = ["`" + msg.cmd] + list(msg.args)
+        for target in msg.to:
+            self._send(target, " ".join(parts))

nemubot/server/IRCLib.py

@@ -0,0 +1,375 @@
+# Nemubot is a smart and modulable IM bot.
+# Copyright (C) 2012-2026  Mercier Pierre-Olivier
+#
+# 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 <http://www.gnu.org/licenses/>.
+
+from datetime import datetime
+import shlex
+import threading
+
+import irc.bot
+import irc.client
+
+import nemubot.message as message
+from nemubot.server.threaded import ThreadedServer
+
+
+class _IRCBotAdapter(irc.bot.SingleServerIRCBot):
+
+    """Internal adapter that bridges the irc library event model to nemubot.
+
+    Subclasses SingleServerIRCBot to get automatic reconnection, PING/PONG,
+    and nick-collision handling for free.
+    """
+
+    def __init__(self, server_name, push_fn, channels, on_connect_cmds,
+                 nick, server_list, owner=None, realname="Nemubot",
+                 encoding="utf-8", **connect_params):
+        super().__init__(server_list, nick, realname, **connect_params)
+        self._nemubot_name = server_name
+        self._push = push_fn
+        self._channels_to_join = channels
+        self._on_connect_cmds = on_connect_cmds or []
+        self.owner = owner
+        self.encoding = encoding
+        self._stop_event = threading.Event()
+
+
+    # Event loop control
+
+    def start(self):
+        """Run the reactor loop until stop() is called."""
+        self._connect()
+        while not self._stop_event.is_set():
+            self.reactor.process_once(timeout=0.2)
+
+    def stop(self):
+        """Signal the loop to exit and disconnect cleanly."""
+        self._stop_event.set()
+        try:
+            self.connection.disconnect("Goodbye")
+        except Exception:
+            pass
+
+    def on_disconnect(self, connection, event):
+        """Reconnect automatically unless we are shutting down."""
+        if not self._stop_event.is_set():
+            super().on_disconnect(connection, event)
+
+
+    # Connection lifecycle
+
+    def on_welcome(self, connection, event):
+        """001 — run on_connect commands then join channels."""
+        for cmd in self._on_connect_cmds:
+            if callable(cmd):
+                for c in (cmd() or []):
+                    connection.send_raw(c)
+            else:
+                connection.send_raw(cmd)
+
+        for ch in self._channels_to_join:
+            if isinstance(ch, tuple):
+                connection.join(ch[0], ch[1] if len(ch) > 1 else "")
+            elif hasattr(ch, 'name'):
+                connection.join(ch.name, getattr(ch, 'password', "") or "")
+            else:
+                connection.join(str(ch))
+
+    def on_invite(self, connection, event):
+        """Auto-join on INVITE."""
+        if event.arguments:
+            connection.join(event.arguments[0])
+
+
+    # CTCP
+
+    def on_ctcp(self, connection, event):
+        """Handle CTCP requests (irc library >= 19 dispatches all to on_ctcp)."""
+        nick = irc.client.NickMask(event.source).nick
+        ctcp_type = event.arguments[0].upper() if event.arguments else ""
+        ctcp_arg  = event.arguments[1] if len(event.arguments) > 1 else ""
+        self._reply_ctcp(connection, nick, ctcp_type, ctcp_arg)
+
+    # Fallbacks for older irc library versions that dispatch per-type
+    def on_ctcpversion(self, connection, event):
+        import nemubot
+        nick = irc.client.NickMask(event.source).nick
+        connection.ctcp_reply(nick, "VERSION nemubot v%s" % nemubot.__version__)
+
+    def on_ctcpping(self, connection, event):
+        nick = irc.client.NickMask(event.source).nick
+        arg = event.arguments[0] if event.arguments else ""
+        connection.ctcp_reply(nick, "PING %s" % arg)
+
+    def _reply_ctcp(self, connection, nick, ctcp_type, ctcp_arg):
+        import nemubot
+        responses = {
+            "ACTION":     None,  # handled as on_action
+            "CLIENTINFO": "CLIENTINFO ACTION CLIENTINFO FINGER PING SOURCE TIME USERINFO VERSION",
+            "FINGER":     "FINGER nemubot v%s" % nemubot.__version__,
+            "PING":       "PING %s" % ctcp_arg,
+            "SOURCE":     "SOURCE https://github.com/nemunaire/nemubot",
+            "TIME":       "TIME %s" % datetime.now(),
+            "USERINFO":   "USERINFO Nemubot",
+            "VERSION":    "VERSION nemubot v%s" % nemubot.__version__,
+        }
+        if ctcp_type in responses and responses[ctcp_type] is not None:
+            connection.ctcp_reply(nick, responses[ctcp_type])
+
+
+    # Incoming messages
+
+    def _decode(self, text):
+        if isinstance(text, bytes):
+            try:
+                return text.decode("utf-8")
+            except UnicodeDecodeError:
+                return text.decode(self.encoding, "replace")
+        return text
+
+    def _make_message(self, connection, source, target, text):
+        """Convert raw IRC event data into a nemubot bot message."""
+        nick = irc.client.NickMask(source).nick
+        text = self._decode(text)
+        bot_nick = connection.get_nickname()
+        is_channel = irc.client.is_channel(target)
+        to          = [target] if is_channel else [nick]
+        to_response = [target] if is_channel else [nick]
+
+        common = dict(
+            server=self._nemubot_name,
+            to=to,
+            to_response=to_response,
+            frm=nick,
+            frm_owner=(nick == self.owner),
+        )
+
+        # "botname: text" or "botname, text"
+        if (text.startswith(bot_nick + ":") or
+                text.startswith(bot_nick + ",")):
+            inner = text[len(bot_nick) + 1:].strip()
+            return message.DirectAsk(designated=bot_nick, message=inner,
+                                     **common)
+
+        # "!command [args]"
+        if len(text) > 1 and text[0] == '!':
+            inner = text[1:].strip()
+            try:
+                args = shlex.split(inner)
+            except ValueError:
+                args = inner.split()
+            if args:
+                # Extract @key=value named arguments (same logic as IRC.py)
+                kwargs = {}
+                while len(args) > 1:
+                    arg = args[1]
+                    if len(arg) > 2 and arg[0:2] == '\\@':
+                        args[1] = arg[1:]
+                    elif len(arg) > 1 and arg[0] == '@':
+                        arsp = arg[1:].split("=", 1)
+                        kwargs[arsp[0]] = arsp[1] if len(arsp) == 2 else None
+                        args.pop(1)
+                        continue
+                    break
+                return message.Command(cmd=args[0], args=args[1:],
+                                       kwargs=kwargs, **common)
+
+        return message.Text(message=text, **common)
+
+    def on_pubmsg(self, connection, event):
+        msg = self._make_message(
+            connection, event.source, event.target,
+            event.arguments[0] if event.arguments else "",
+        )
+        if msg:
+            self._push(msg)
+
+    def on_privmsg(self, connection, event):
+        nick = irc.client.NickMask(event.source).nick
+        msg = self._make_message(
+            connection, event.source, nick,
+            event.arguments[0] if event.arguments else "",
+        )
+        if msg:
+            self._push(msg)
+
+    def on_action(self, connection, event):
+        """CTCP ACTION (/me) — delivered as a plain Text message."""
+        nick = irc.client.NickMask(event.source).nick
+        text = "/me %s" % (event.arguments[0] if event.arguments else "")
+        is_channel = irc.client.is_channel(event.target)
+        to = [event.target] if is_channel else [nick]
+        self._push(message.Text(
+            message=text,
+            server=self._nemubot_name,
+            to=to, to_response=to,
+            frm=nick, frm_owner=(nick == self.owner),
+        ))
+
+
+class IRCLib(ThreadedServer):
+
+    """IRC server using the irc Python library (jaraco).
+
+    Compared to the hand-rolled IRC.py implementation, this gets:
+      - Automatic exponential-backoff reconnection
+      - PING/PONG handled transparently
+      - Nick-collision suffix logic built-in
+    """
+
+    def __init__(self, host="localhost", port=6667, nick="nemubot",
+                 username=None, password=None, realname="Nemubot",
+                 encoding="utf-8", owner=None, channels=None,
+                 on_connect=None, ssl=False, **kwargs):
+        """Prepare a connection to an IRC server.
+
+        Keyword arguments:
+        host       -- IRC server hostname
+        port       -- IRC server port (default 6667)
+        nick       -- bot's nickname
+        username   -- username for USER command (defaults to nick)
+        password   -- server password (sent as PASS)
+        realname   -- bot's real name
+        encoding   -- fallback encoding for non-UTF-8 servers
+        owner      -- nick of the bot's owner (sets frm_owner on messages)
+        channels   -- list of channel names / (name, key) tuples to join
+        on_connect -- list of raw IRC commands (or a callable returning one)
+                      to send after receiving 001
+        ssl        -- wrap the connection in TLS
+        """
+        name = (username or nick) + "@" + host + ":" + str(port)
+        super().__init__(name=name)
+
+        self._host     = host
+        self._port     = int(port)
+        self._nick     = nick
+        self._username = username or nick
+        self._password = password
+        self._realname = realname
+        self._encoding = encoding
+        self.owner     = owner
+        self._channels = channels or []
+        self._on_connect_cmds = on_connect
+        self._ssl      = ssl
+
+        self._bot    = None
+        self._thread = None
+
+
+    # ThreadedServer hooks
+
+    def _start(self):
+        server_list = [irc.bot.ServerSpec(self._host, self._port,
+                                          self._password)]
+
+        connect_params = {"username": self._username}
+
+        if self._ssl:
+            import ssl as ssl_mod
+            import irc.connection
+            ctx  = ssl_mod.create_default_context()
+            host = self._host  # capture for closure
+            connect_params["connect_factory"] = irc.connection.Factory(
+                wrapper=lambda sock: ctx.wrap_socket(sock,
+                                                     server_hostname=host)
+            )
+
+        self._bot = _IRCBotAdapter(
+            server_name=self.name,
+            push_fn=self._push_message,
+            channels=self._channels,
+            on_connect_cmds=self._on_connect_cmds,
+            nick=self._nick,
+            server_list=server_list,
+            owner=self.owner,
+            realname=self._realname,
+            encoding=self._encoding,
+            **connect_params,
+        )
+        self._thread = threading.Thread(
+            target=self._bot.start,
+            daemon=True,
+            name="nemubot.IRC/" + self.name,
+        )
+        self._thread.start()
+
+    def _stop(self):
+        if self._bot:
+            self._bot.stop()
+        if self._thread:
+            self._thread.join(timeout=5)
+
+
+    # Outgoing messages
+
+    def send_response(self, response):
+        if response is None:
+            return
+        if isinstance(response, list):
+            for r in response:
+                self.send_response(r)
+            return
+        if not self._bot:
+            return
+
+        from nemubot.message.printer.IRCLib import IRCLib as IRCLibPrinter
+        printer = IRCLibPrinter(self._bot.connection)
+        response.accept(printer)
+
+
+    # subparse: re-parse a plain string in the context of an existing message
+    # (used by alias, rnd, grep, cat, smmry, sms modules)
+
+    def subparse(self, orig, cnt):
+        bot_nick = (self._bot.connection.get_nickname()
+                    if self._bot else self._nick)
+        common = dict(
+            server=self.name,
+            to=orig.to,
+            to_response=orig.to_response,
+            frm=orig.frm,
+            frm_owner=orig.frm_owner,
+            date=orig.date,
+        )
+        text = cnt
+
+        if (text.startswith(bot_nick + ":") or
+                text.startswith(bot_nick + ",")):
+            inner = text[len(bot_nick) + 1:].strip()
+            return message.DirectAsk(designated=bot_nick, message=inner,
+                                     **common)
+
+        if len(text) > 1 and text[0] == '!':
+            inner = text[1:].strip()
+            try:
+                args = shlex.split(inner)
+            except ValueError:
+                args = inner.split()
+            if args:
+                kwargs = {}
+                while len(args) > 1:
+                    arg = args[1]
+                    if len(arg) > 2 and arg[0:2] == '\\@':
+                        args[1] = arg[1:]
+                    elif len(arg) > 1 and arg[0] == '@':
+                        arsp = arg[1:].split("=", 1)
+                        kwargs[arsp[0]] = arsp[1] if len(arsp) == 2 else None
+                        args.pop(1)
+                        continue
+                    break
+                return message.Command(cmd=args[0], args=args[1:],
+                                       kwargs=kwargs, **common)
+
+        return message.Text(message=text, **common)

nemubot/server/__init__.py

@@ -24,13 +24,13 @@ def factory(uri, ssl=False, **init_args):
     if o.scheme == "irc" or o.scheme == "ircs":
         # https://www.w3.org/Addressing/draft-mirashi-url-irc-01.txt
         # https://www-archive.mozilla.org/projects/rt-messaging/chatzilla/irc-urls.html
-        args = init_args
+        args = dict(init_args)
 
         if o.scheme == "ircs": ssl = True
         if o.hostname is not None: args["host"] = o.hostname
         if o.port is not None: args["port"] = o.port
         if o.username is not None: args["username"] = o.username
-        if o.password is not None: args["password"] = o.password
+        if o.password is not None: args["password"] = unquote(o.password)
 
         modifiers = o.path.split(",")
         target = unquote(modifiers.pop(0)[1:])
@@ -41,37 +41,27 @@ def factory(uri, ssl=False, **init_args):
         if "msg" in params:
             if "on_connect" not in args:
                 args["on_connect"] = []
-            args["on_connect"].append("PRIVMSG %s :%s" % (target, params["msg"]))
+            args["on_connect"].append("PRIVMSG %s :%s" % (target, params["msg"][0]))
 
         if "key" in params:
             if "channels" not in args:
                 args["channels"] = []
-            args["channels"].append((target, params["key"]))
+            args["channels"].append((target, params["key"][0]))
 
         if "pass" in params:
-            args["password"] = params["pass"]
+            args["password"] = params["pass"][0]
 
         if "charset" in params:
-            args["encoding"] = params["charset"]
+            args["encoding"] = params["charset"][0]
 
-        #
         if "channels" not in args and "isnick" not in modifiers:
-            args["channels"] = [ target ]
+            args["channels"] = [target]
 
-        from nemubot.server.IRC import IRC as IRCServer
+        args["ssl"] = ssl
+
+        from nemubot.server.IRCLib import IRCLib as IRCServer
         srv = IRCServer(**args)
 
-        if ssl:
-            try:
-                from ssl import create_default_context
-                context = create_default_context()
-            except ImportError:
-                # Python 3.3 compat
-                from ssl import SSLContext, PROTOCOL_TLSv1
-                context = SSLContext(PROTOCOL_TLSv1)
-            from ssl import wrap_socket
-            srv._fd = context.wrap_socket(srv._fd, server_hostname=o.hostname)
-
     elif o.scheme == "matrix":
         # matrix://localpart:password@homeserver.tld/!room:homeserver.tld
         # matrix://localpart:password@homeserver.tld/%23alias:homeserver.tld

requirements.txt

@@ -1 +1,2 @@
+irc
 matrix-nio[e2e]