#!/usr/bin/python3
import re, sys

def parse(line): #-> [nick, user, host], command, arguments
    prefix, params  = b"", []
    command, arguments = None, []
    nick, user, host = None, None, None

    line = line.rstrip(b"\r\n")
    # handle prefix:
    if line.startswith(b":"):
        prefix, line = line.split(b" ", 1)
    # handle command and arguments:
    while b" " in line and not line.startswith(b":"):
        word, line = line.split(b" ", 1)
        params += [word]
    # handle final parameter:
    params += [line.removeprefix(b":")]

    command, *arguments = params # note: command may also be a numeric reply

    if b"!" in prefix and b"@" in prefix:
        nick, rest = prefix.removeprefix(b":").split(b"!", 1)
        user, host = rest.split(b"@", 1)
    elif prefix: # server
        host = prefix.removeprefix(b":")

    return [nick, user, host], command, arguments

DIM = b"\033[0;2m"
BOLD = b"\033[0;1m"
RESET = b"\033[0m"
REV = b"\033[0;7m"

def say(*args):
    sys.stdout.buffer.write(b"".join(args)+b"\n")
    sys.stdout.buffer.flush()

def sanitize(s):
    # removes control characters so malicious actors can't mess up our terminal
    # with escape sequences. this also removes formatting codes.
    return re.sub(rb"[\001-\011\013\014\016-\037\177]", b"", s)

myself = None
for line in sys.stdin.buffer:
    line = sanitize(line)

    [nick, user, host], command, arguments = parse(line)

    if command in (b"PRIVMSG", b"NOTICE") and len(arguments) == 2 and nick:
        chan, msg = arguments
        nick_start = len(b":")
        nick_end = nick_start+len(nick)
        cmd_start = nick_end+len(b"!")+len(user)+len(b"@")+len(host)+len(b" ")
        cmd_end = cmd_start+len(command)
        chan_start = cmd_end+len(b" ")
        chan_end = chan_start+len(chan)
        msg_start = chan_end+len(b" ")
        msg_end = msg_start+len(msg)
        if line[msg_start] == ord(':'):
            msg_start +=1
            msg_end +=1

        hi_start, hi_end = msg_start, msg_start
        if m := re.search(rb"\b%s\b" % re.escape(myself), msg):
            hi_start = msg_start + m.start(0)
            hi_end = msg_start + m.end(0)

        say(
            DIM,   line[:nick_start],
            BOLD,  line[nick_start:nick_end],
            DIM,   line[nick_end:chan_start],
            BOLD,  line[chan_start:chan_end],
            DIM,   line[chan_end:msg_start],
            RESET, line[msg_start:hi_start],
              REV,   line[hi_start:hi_end],
              RESET, line[hi_end:msg_end],
            REV,   line[msg_end:].rstrip(b"\r\n"),
        RESET)
    elif command in (b"PING", b"PONG"):
        pass # hide
    else:
        if command == b"001" and arguments:
            myself = arguments[0] # store own username for later highlighting it

        say(DIM,   line.rstrip(b"\r\n"), RESET)