Class-based IRC bot

irc_bot.py

import socket

# change these
HOST = 'irc.undernet.org'
PORT = 6667
NICK = 'rex'
CHAN = '#dashin'

ADMIN = 'Humphrey'


class IRCBot:
    def __init__(self, host: str, port: int, nick: str, chan: str, admin: str):
        self.socket = socket.socket()
        self.host = host
        self.port = port
        self.nick = nick
        self.chan = chan
        self.admin = admin
        self.buff = b''

    # this is where I do my work
    def run(self):
        self.socket.connect((self.host, self.port))
        print(f'** connected to {self.host}')
        # identify myself to the IRC server
        self.send_line(f'NICK {self.nick}')
        self.send_line(f'USER {self.nick} {self.host} x :{self.nick}')

        while True:
            # receive what the server has sent me
            self.buff = self.buff + self.socket.recv(4096)
            # split it into lines
            lines = self.buff.split(b'\n')
            # the last line might be incomplete, put it back in the buffer
            self.buff = lines.pop()
            # handle each of the lines that the server sent me
            for line in lines:
                self.handle_line(line)

    # this is the function I will use when I want to send a message to the IRC server
    def send_line(self, line: str):
        print(f'=> {line}')
        # add \r\n to the end of the line and convert it from string to bytes, then send
        self.socket.send(f'{line}\r\n'.encode())

    # this is the function I will use when I want to process a message I received from the IRC server
    def handle_line(self, line: bytes):
        # convert line from bytes to string, and remove leading and trailing whitespace
        line = line.decode().strip()
        print(f'<= {line}')
        # split the line on whitespace into a list of tokens
        tokens = line.split()
        if tokens[0] == 'PING':
            self.handle_ping(tokens[1])
        elif tokens[1] in ('376', '422'):
            # 376 means the server has finished sending the message of the day
            # 422 means there is no message of the day to send
            self.handle_server_connect_done()
        elif tokens[1] == 'PRIVMSG' and tokens[2] == self.nick:
            self.handle_private_message(tokens)
        elif tokens[1] == 'PRIVMSG' and tokens[2] == self.chan:
            self.handle_public_message(tokens)

    def handle_ping(self, message):
        # when the server sends PING, I automatically reply with PONG
        self.send_line(f'PONG {message}')

    def handle_server_connect_done(self):
        # when the server connection and introduction is complete, join my channel
        self.send_line(f'JOIN {self.chan}')

    def handle_private_message(self, tokens):
        # when I get a message sent directly to me, not the channel
        sender = self.get_nick(tokens[0])
        command = tokens[3]
        if command == ':!changename' and sender == self.admin:
            self.nick = tokens[4]
            print(f'COMMAND: Change nickname to {self.nick}')
            self.send_line(f'NICK {self.nick}')

    def handle_public_message(self, tokens):
        # when I get a message sent to the channel
        sender = self.get_nick(tokens[0])
        command = tokens[3]
        if command == ':!jump':
            print('COMMAND: Jump')
            self.send_line(f'PRIVMSG {self.chan} :\x01ACTION does jumping jacks!')

    @staticmethod
    def get_nick(prefix: str):
        # ':nick!user@host' => 'nick'
        prefix = prefix.lstrip(':')
        nick = prefix.split('!')[0]
        return nick


def main():
    irc = IRCBot(HOST, PORT, NICK, CHAN, ADMIN)
    irc.run()


if __name__ == '__main__':
    main()