import socket
from time import sleep, time
from json import load, dump
import re

channel_re = re.compile(r"PRIVMSG (#*\w+)")
name_re = re.compile(r"^:([^!]*)!")

timeout = 86400 # 24 hours
messages_within_24h = 100
host = "localhost"
port = 6667
helptext = "i am a bot by ~nebula. i try to make it easier for users to discover new and more obscure channels on irc. instructions for use (or to block me from showing messages in your client) are available at https://git.tilde.town/nebula/chatterbot"
helptext_short = "see https://git.tilde.town/nebula/chatterbot for instructions" 

class IRCBot():
    def __init__(self):
        try:
            with open("config.json", "r") as f:
                self.config = load(f)
        except FileNotFoundError:
            exit("no config.json")
        self.s = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
        self.s.connect((host, port))
        self.nick = self.config["nick"]
        self.sendline(f"NICK {self.nick}")
        self.sendline(f"USER {self.nick} 0 * :{self.config['realname']}")
        for channel in self.config["channels"]:
            self.sendline(f"JOIN {channel}")
        self.commands = [
            ("invite", self.invite)
            ("kick", self.kick)
        ]
        
    def write_config(self):
        with open("config.json", "w") as f:
            dump(self.config, f, indent=2)

    def join_channel(self, channel):
        self.sendline(f"JOIN {channel}")
        self.config["channels"].append(channel)
        self.write_config()

    def part_channel(self, channel):
        if channel == "#tildetown":
            self.sendline("i will not leave #tildetown. want to block me? see https://git.tilde.town/nebula/chatterbot")
            return
        elif channel == "#bots":
            self.sendline("i will not leave #bots. want to block me? see https://git.tilde.town/nebula/chatterbot")
            return
        self.sendline(f"PART {channel}")
        self.config["channels"].remove(channel)
        self.write_config()

    def sendline(self, line):
        if line:
            return self.s.send(bytes(f"{line}\r\n", "UTF-8"))
        return None

    def send(self, channel, content):
        if isinstance(content, list):
            for line in content:
                self.sendline(f"PRIVMSG {channel} :{line}")
                sleep(0.5)
        elif isinstance(content, str):
            self.sendline(f"PRIVMSG {channel} :{content}")

    def help(_, __):
        return helptext

    def invite(self, _, arguments):
        if not arguments:
            return helptext_short
        lines = []
        for channel in arguments:
            if not channel.startswith("#"):
                lines.append("channel name must start with #")
                continue
            elif channel in self.config["channels"]:
                lines.append(f"i am already in {channel}!")
            else:
                self.join_channel(channel)
                lines.append(f"i have (allegedly) joined {channel}")
        return lines

    def kick(self, channel, arguments):
        if not arguments:
            self.part_channel(channel)
            return None
        for channel in arguments:
            self.part_channel(channel)

    def check_time(self, channel):
        try:
            this_time = self.config["times"][channel]
        except KeyError:
            this_time = time()
            self.config["times"][channel] = this_time
            self.write_config()
        return this_time
    
    def set_time(self, channel, this_time):
        self.config["times"][channel] = this_time

    def counter(self, channel):
        try:
            self.config["counts"][channel] += 1
            value = self.config["counts"][channel]
        except KeyError:
            value = self.config["counts"][channel] = 1
        self.write_config()
        return value

    def command_loop(self):
        while True:
            char = self.s.recv(1)
            if not char:
                exit(f"{self.nick}: no response from IRC server")
            line = b""
            while char != b"\n":
                if char != b"\r":
                    line += char
                char = self.s.recv(1)
            line = line.decode("UTF-8").strip()
            if line.startswith("PING"):
                pong = "PONG " + line[5:]
                self.sendline(pong)
                continue
            channel_search = channel_re.search(line)
            if not channel_search:
                continue
            channel = channel_search.group(1)
            name_search = name_re.search(line)
            if name_search:
                name = name_search.group(1)
            else:
                name = None
            if name and not channel.startswith("#"):
                channel = name
            try:
                message_body = line[line.index(" :") + 2:]
            except (IndexError, ValueError):
                message_body = ""
            if message_body:
                if message_body.startswith("!rollcall"):
                    self.send(helptext)
                    continue
                elif message_body.startswith("!chatterbot"):
                    arguments = message_body.strip().lower()[11:]
                    if not arguments:
                        self.send(helptext)
                        continue
                    arguments = arguments.split()
                    for command, callback in self.commands:
                        if command not in arguments:
                            continue
                        self.send(callback(channel, arguments[1:]))
                else:
                    if channel in ("#tildetown", "#bots"):
                        continue
                    channel_time = self.check_time(channel)
                    now = time()
                    if self.counter(channel) > messages_within_24h and now - channel_time > timeout:
                        self.send("#tildetown", f"i hear activity in {channel}...")
                    self.set_time(channel, now)
                    self.config["counts"][channel] = 0

if __name__ == "__main__":
    bot = IRCBot()
    try:
        bot.command_loop()
    except KeyboardInterrupt:
        exit()