#!/usr/bin/python3

import 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":")]

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

    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 findall(needle, haystack):
    if not needle: return []
    spans, offset, length = [], 0, len(needle)
    nickchars = (
        br"ABCDEFGHIJKLMNOPQRSTUVWXYZ"
        br"abcdefghijklmnopqrstuvwxyz"
        br"0123456789-[\]^_`{|}")

    while offset < len(haystack):
        try:
            offset = haystack.index(needle, offset)
            # check for a word boundary before and after nick:
            if (offset==0 or haystack[offset-1] not in nickchars) \
            and (offset+length==len(haystack) or haystack[offset+length] not in nickchars):
                spans += [(offset, length)]
            offset += length
        except ValueError as e:
            break # no more matches
    return spans

myself = None
for line in sys.stdin.buffer:
    [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_msg = line[msg_start:msg_end]
        for s,l in reversed(findall(myself, hi_msg)):
            hi_msg = hi_msg[:s] + REV + hi_msg[s:s+l] + RESET + hi_msg[s+l:]

        # maybe todo:
        # - support mIRC highlighting (colors, bold, etc)
        #   https://modern.ircdocs.horse/formatting.html
        #   including \x01ACTION privmsg prefix
        # - highlight own nick and/or user-def'd strings

        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, hi_msg,
            REV,   line[msg_end:].rstrip(b"\r\n"),
        RESET)
    elif command in (b"PING", b"PONG"):
        pass # hide (could also do "JOIN", "QUIT", motd, names, ...)
    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)