Simplify handler registration

.flake8

@@ -0,0 +1,2 @@
+[flake8]
+max-line-length = 100

paircd/command_handler.py

@@ -0,0 +1,18 @@
+from dataclasses import dataclass
+from typing import Awaitable, Callable
+
+from paircd.client import Client
+from paircd.message import Message
+from paircd.server import Server
+
+HandlerFunc = Callable[
+    [Server, Client, Message],
+    Awaitable[None],
+]
+
+
+@dataclass
+class CommandHandler:
+    cmd: str
+    argc: int
+    handler: HandlerFunc

paircd/handle.py

@@ -1,27 +0,0 @@
-import logging
-from typing import Any, Awaitable, Callable, Dict
-
-from paircd.client import Client
-from paircd.log import log_client
-from paircd.message import Message
-from paircd.server import Server
-
-CMD_HANDLERS: Dict[str, Any] = {}
-CMD_EXPECTED_ARGC: Dict[str, int] = {}
-
-CmdHandler = Callable[
-    [Server, Client, Message],
-    Awaitable[None],
-]
-
-
-def register_cmd_handler(cmd: str, argc: int, handler: CmdHandler) -> None:
-    CMD_EXPECTED_ARGC[cmd] = argc
-    CMD_HANDLERS[cmd] = handler
-
-
-async def handle_cmd(server: Server, client: Client, msg: Message) -> None:
-    if msg.cmd not in CMD_HANDLERS:
-        log_client(client, f"used unknown command {msg.cmd}", level=logging.WARN)
-        return
-    await CMD_HANDLERS[msg.cmd](server, client, msg)

paircd/handler/join.py

@@ -1,8 +1,7 @@
-from asyncio import create_task
 import logging
 
-from paircd.channel import Channel
 from paircd.client import Client
+from paircd.command_handler import CommandHandler
 from paircd.log import log_client
 from paircd.message import Message
 from paircd.server import Server
@@ -27,3 +26,6 @@ async def handle_join(server: Server, client: Client, msg: Message) -> None:
     await channel.msg_queue.put(
         Message(cmd="JOIN", args=[channel_name], prefix=client.id()).encode()
     )
+
+
+JOIN = CommandHandler("JOIN", 1, handle_join)

paircd/handler/nick.py

@@ -1,4 +1,5 @@
 from paircd.client import Client
+from paircd.command_handler import CommandHandler
 from paircd.log import log_client
 from paircd.message import Message
 from paircd.server import Server
@@ -17,3 +18,6 @@ async def handle_nick(server: Server, client: Client, msg: Message) -> None:
     if client.username and client.realname:
         client.registered = True
         log_client(client, "registered")
+
+
+NICK = CommandHandler("NICK", 1, handle_nick)

paircd/handler/privmsg.py

@@ -1,7 +1,8 @@
 import logging
 
-from paircd.log import log_client
 from paircd.client import Client
+from paircd.command_handler import CommandHandler
+from paircd.log import log_client
 from paircd.message import Message
 from paircd.server import Server
 
@@ -23,3 +24,6 @@ async def handle_privmsg(server: Server, client: Client, msg: Message) -> None:
             return
 
     log_client(client, "unknown recipient", level=logging.WARN)
+
+
+PRIVMSG = CommandHandler("PRIVMSG", 2, handle_privmsg)

paircd/handler/user.py

@@ -1,6 +1,7 @@
 import logging
 
 from paircd.client import Client
+from paircd.command_handler import CommandHandler
 from paircd.log import log_client
 from paircd.message import Message
 from paircd.server import Server
@@ -17,3 +18,6 @@ async def handle_user(server: Server, client: Client, msg: Message) -> None:
     if client.nickname:
         client.registered = True
         log_client(client, "registered")
+
+
+USER = CommandHandler("USER", 4, handle_user)

paircd/handlers.py

@@ -0,0 +1,34 @@
+from logging import WARN
+from typing import Dict
+
+from paircd.client import Client
+from paircd.command_handler import CommandHandler
+from paircd.log import log_client
+from paircd.message import Message
+from paircd.server import Server
+
+from paircd.handler.join import JOIN
+from paircd.handler.nick import NICK
+from paircd.handler.privmsg import PRIVMSG
+from paircd.handler.user import USER
+
+ALL_HANDLERS = [
+    JOIN,
+    NICK,
+    PRIVMSG,
+    USER,
+]
+
+CMD_HANDLERS: Dict[str, CommandHandler] = {}
+
+
+def register_cmd_handlers() -> None:
+    for handler in ALL_HANDLERS:
+        CMD_HANDLERS[handler.cmd] = handler
+
+
+async def handle_cmd(server: Server, client: Client, msg: Message) -> None:
+    if msg.cmd not in CMD_HANDLERS:
+        log_client(client, f"used unknown command {msg.cmd}", level=WARN)
+        return
+    await CMD_HANDLERS[msg.cmd].handler(server, client, msg)

paircd/main.py

@@ -4,11 +4,7 @@ import logging
 import os
 
 from paircd.client import Client
-from paircd.handle import handle_cmd, register_cmd_handler
-from paircd.handler.join import handle_join
-from paircd.handler.nick import handle_nick
-from paircd.handler.privmsg import handle_privmsg
-from paircd.handler.user import handle_user
+from paircd.handlers import handle_cmd, register_cmd_handlers
 from paircd.message import parse_message
 from paircd.server import Server
 
@@ -30,12 +26,8 @@ async def main() -> None:
     bind_addr = os.getenv("BIND_ADDR") or "0.0.0.0"
     port = os.getenv("PORT") or 6667
 
-    register_cmd_handler("JOIN", 1, handle_join)
-    register_cmd_handler("NICK", 1, handle_nick)
-    register_cmd_handler("PRIVMSG", 2, handle_privmsg)
-    register_cmd_handler("USER", 4, handle_user)
-
     irc_server = Server()
+    register_cmd_handlers()
 
     async def register_client(reader: StreamReader, writer: StreamWriter) -> None:
         client = Client(