import asyncio

HOST = '127.0.0.1'
PORT = 6667

clients = {}
channels = {}

class IRCProtocol(asyncio.Protocol):
    def __init__(self):
        self.transport = None
        self.current_channel = None
        self.peername = None

    def connection_made(self, transport):
        self.transport = transport
        self.peername = transport.get_extra_info('peername')
        clients[self] = self.peername
        print(f"Connection from {self.peername}")

    def data_received(self, data):
        message = data.decode('utf-8').strip()
        if message:
            if message.startswith('/join '):
                channel_name = message.split(' ', 1)[1].strip()
                if channel_name not in channels:
                    channels[channel_name] = set()
                channels[channel_name].add(self)
                self.current_channel = channel_name
                self.transport.write(f"Joined channel {channel_name}\n".encode('utf-8'))
            elif message.startswith('/leave'):
                if self.current_channel and self in channels.get(self.current_channel, set()):
                    channels[self.current_channel].remove(self)
                    self.transport.write(f"Left channel {self.current_channel}\n".encode('utf-8'))
                    self.current_channel = None
            elif message.startswith('/list'):
                channel_list = ', '.join(channels.keys())
                self.transport.write(f"Channels: {channel_list}\n".encode('utf-8'))
            elif message.startswith('/users '):
                channel_name = message.split(' ', 1)[1].strip()
                users = [str(c.transport.get_extra_info('peername')) for c in channels.get(channel_name, set())]
                user_list = ', '.join(users)
                self.transport.write(f"Users in {channel_name}: {user_list}\n".encode('utf-8'))
            elif message.startswith('/shutdown'):
                # For simplicity, shutdown server
                self.transport.write("Server is shutting down...\n".encode('utf-8'))
                asyncio.get_event_loop().stop()
            elif message.startswith('/quit'):
                self.transport.close()
            else:
                if self.current_channel and self in channels.get(self.current_channel, set()):
                    for client in channels[self.current_channel]:
                        if client != self:
                            client.transport.write(f"{self.peername}: {message}\n".encode('utf-8'))
                else:
                    self.transport.write("You are not in a channel. Use /join <channel> to join one.\n".encode('utf-8'))
        else:
            self.transport.close()

    def connection_lost(self, exc):
        if self.current_channel and self in channels.get(self.current_channel, set()):
            channels[self.current_channel].remove(self)
        if self in clients:
            del clients[self]
        print(f"Connection lost from {self.peername}")

async def main():
    loop = asyncio.get_running_loop()
    server = await loop.create_server(lambda: IRCProtocol(), HOST, PORT)
    print(f"Asyncio IRC server started on {HOST}:{PORT}")
    async with server:
        await server.serve_forever()

if __name__ == '__main__':
    asyncio.run(main())