Define command handlers with class

paircd/command_handler.py

@@ -1,18 +1,18 @@
-from dataclasses import dataclass
-from typing import Awaitable, Callable
+from abc import abstractmethod, ABC
 
 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:
+class CommandHandler(ABC):
     cmd: str
     argc: int
-    handler: HandlerFunc
+
+    def __init__(self, cmd: str, argc: int) -> None:
+        self.cmd = cmd
+        self.argc = argc
+
+    @abstractmethod
+    async def handle(self, server: Server, client: Client, msg: Message) -> None:
+        pass

paircd/handler/join.py

@@ -7,25 +7,26 @@ from paircd.message import Message
 from paircd.server import Server
 
 
-async def handle_join(server: Server, client: Client, msg: Message) -> None:
-    if not client.registered:
-        log_client(client, "join: not registered", level=logging.WARN)
-        return
+class JoinHandler(CommandHandler):
+    def __init__(self) -> None:
+        super().__init__("JOIN", 1)
 
-    channel_name = msg.args[0]
-    if not channel_name.startswith("#"):
-        log_client(client, "tried to join invalid channel", level=logging.WARN)
-        return
+    async def handle(self, server: Server, client: Client, msg: Message) -> None:
+        if not client.registered:
+            log_client(client, "join: not registered", level=logging.WARN)
+            return
 
-    channel = server.get_channel_by_name(channel_name)
-    channel.add_client(client)
+        channel_name = msg.args[0]
+        if not channel_name.startswith("#"):
+            log_client(client, "tried to join invalid channel", level=logging.WARN)
+            return
 
-    client.channels.add(channel_name)
-    log_client(client, f"joined {channel_name}")
+        channel = server.get_channel_by_name(channel_name)
+        channel.add_client(client)
 
-    await channel.msg_queue.put(
-        Message(cmd="JOIN", args=[channel_name], prefix=client.id()).encode()
-    )
+        client.channels.add(channel_name)
+        log_client(client, f"joined {channel_name}")
 
-
-JOIN = CommandHandler("JOIN", 1, handle_join)
+        await channel.msg_queue.put(
+            Message(cmd="JOIN", args=[channel_name], prefix=client.id()).encode()
+        )

paircd/handler/nick.py

@@ -5,19 +5,20 @@ from paircd.message import Message
 from paircd.server import Server
 
 
-async def handle_nick(server: Server, client: Client, msg: Message) -> None:
-    nickname = msg.args[0]
+class NickHandler(CommandHandler):
+    def __init__(self) -> None:
+        super().__init__("NICK", 1)
 
-    if client.nickname:
-        del server.clients_by_nick[client.nickname]
-        # TODO: Update all channel references
+    async def handle(self, server: Server, client: Client, msg: Message) -> None:
+        nickname = msg.args[0]
 
-    client.nickname = nickname
-    server.add_client(client)
+        if client.nickname:
+            del server.clients_by_nick[client.nickname]
+            # TODO: Update all channel references
 
-    if client.username and client.realname:
-        client.registered = True
-        log_client(client, "registered")
+        client.nickname = nickname
+        server.add_client(client)
 
-
-NICK = CommandHandler("NICK", 1, handle_nick)
+        if client.username and client.realname:
+            client.registered = True
+            log_client(client, "registered")

paircd/handler/privmsg.py

@@ -7,23 +7,26 @@ from paircd.message import Message
 from paircd.server import Server
 
 
-async def handle_privmsg(server: Server, client: Client, msg: Message) -> None:
-    recipient = msg.args[0]
-    raw_msg = msg.args[1]
+class PrivmsgHandler(CommandHandler):
+    def __init__(self) -> None:
+        super().__init__("PRIVMSG", 2)
 
-    out = Message("PRIVMSG", [recipient, f":{raw_msg}"], prefix=client.id()).encode()
+    async def handle(self, server: Server, client: Client, msg: Message) -> None:
+        recipient = msg.args[0]
+        raw_msg = msg.args[1]
 
-    for name, other_client in server.clients_by_nick.items():
-        if name == recipient:
-            other_client.msg_queue.put_nowait(out)
-            return
+        out = Message(
+            "PRIVMSG", [recipient, f":{raw_msg}"], prefix=client.id()
+        ).encode()
 
-    for name, channel in server.channels_by_name.items():
-        if name == recipient:
-            channel.msg_queue.put_nowait(out)
-            return
+        for name, other_client in server.clients_by_nick.items():
+            if name == recipient:
+                other_client.msg_queue.put_nowait(out)
+                return
 
-    log_client(client, "unknown recipient", level=logging.WARN)
+        for name, channel in server.channels_by_name.items():
+            if name == recipient:
+                channel.msg_queue.put_nowait(out)
+                return
 
-
-PRIVMSG = CommandHandler("PRIVMSG", 2, handle_privmsg)
+        log_client(client, "unknown recipient", level=logging.WARN)

paircd/handler/user.py

@@ -7,17 +7,18 @@ from paircd.message import Message
 from paircd.server import Server
 
 
-async def handle_user(server: Server, client: Client, msg: Message) -> None:
-    if client.registered:
-        log_client(client, "USER issued after registration", level=logging.WARN)
-        return
+class UserHandler(CommandHandler):
+    def __init__(self) -> None:
+        super().__init__("USER", 4)
 
-    client.username = msg.args[0]
-    client.realname = msg.args[3]
+    async def handle(self, server: Server, client: Client, msg: Message) -> None:
+        if client.registered:
+            log_client(client, "USER issued after registration", level=logging.WARN)
+            return
 
-    if client.nickname:
-        client.registered = True
-        log_client(client, "registered")
+        client.username = msg.args[0]
+        client.realname = msg.args[3]
 
-
-USER = CommandHandler("USER", 4, handle_user)
+        if client.nickname:
+            client.registered = True
+            log_client(client, "registered")

paircd/handlers.py

@@ -7,23 +7,24 @@ 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,
+from paircd.handler.join import JoinHandler
+from paircd.handler.nick import NickHandler
+from paircd.handler.privmsg import PrivmsgHandler
+from paircd.handler.user import UserHandler
+
+HANDLER_CLASSES = [
+    JoinHandler,
+    NickHandler,
+    PrivmsgHandler,
+    UserHandler,
 ]
 
 CMD_HANDLERS: Dict[str, CommandHandler] = {}
 
 
 def register_cmd_handlers() -> None:
-    for handler in ALL_HANDLERS:
+    for handler_cls in HANDLER_CLASSES:
+        handler = handler_cls()  # type: ignore
         CMD_HANDLERS[handler.cmd] = handler
 
 
@@ -31,4 +32,4 @@ 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)
+    await CMD_HANDLERS[msg.cmd].handle(server, client, msg)