import irc.bot
import irc.strings
from irc.client import ip_numstr_to_quad, ip_quad_to_numstr, Event, ServerConnection
from irc.client_aio import AioReactor
import multiprocessing as mp
from typing import Any, Dict


class IRCBot(irc.bot.SingleServerIRCBot):
    reactor_class = AioReactor

    def __init__(self, zulip_client, stream, topic, channel,
                 nickname, server, nickserv_password='', port=6667):
        # type: (Any, str, str, irc.bot.Channel, str, str, str, int) -> None
        self.channel = channel  # type: irc.bot.Channel
        self.zulip_client = zulip_client
        self.stream = stream
        self.topic = topic
        self.IRC_DOMAIN = server
        self.nickserv_password = nickserv_password
        # Make sure the bot is subscribed to the stream
        self.check_subscription_or_die()
        # Initialize IRC bot after proper connection to Zulip server has been confirmed.
        irc.bot.SingleServerIRCBot.__init__(self, [(server, port)], nickname, nickname)

    def zulip_sender(self, sender_string):
        # type: (str) -> str
        nick = sender_string.split("!")[0]
        return nick + "@" + self.IRC_DOMAIN

    def connect(self, *args, **kwargs):
        # type: (*Any, **Any) -> None
        # Taken from
        # https://github.com/jaraco/irc/blob/master/irc/client_aio.py,
        # in particular the method of AioSimpleIRCClient
        self.reactor.loop.run_until_complete(
            self.connection.connect(*args, **kwargs)
        )
        print("Listening now. Please send an IRC message to verify operation")

    def check_subscription_or_die(self):
        # type: () -> None
        resp = self.zulip_client.list_subscriptions()
        if resp["result"] != "success":
            print("ERROR: %s" % (resp["msg"],))
            exit(1)
        subs = [s["name"] for s in resp["subscriptions"]]
        if self.stream not in subs:
            print("The bot is not yet subscribed to stream '%s'. Please subscribe the bot to the stream first." % (self.stream,))
            exit(1)

    def on_nicknameinuse(self, c, e):
        # type: (ServerConnection, Event) -> None
        c.nick(c.get_nickname().replace("_zulip", "__zulip"))

    def on_welcome(self, c, e):
        # type: (ServerConnection, Event) -> None
        if len(self.nickserv_password) > 0:
            msg = 'identify %s' % (self.nickserv_password,)
            c.privmsg('NickServ', msg)
        c.join(self.channel)

        def forward_to_irc(msg):
            # type: (Dict[str, Any]) -> None
            not_from_zulip_bot = msg["sender_email"] != self.zulip_client.email
            if not not_from_zulip_bot:
                # Do not forward echo
                return
            is_a_stream = msg["type"] == "stream"
            if is_a_stream:
                in_the_specified_stream = msg["display_recipient"] == self.stream
                at_the_specified_subject = msg["subject"].casefold() == self.topic.casefold()
                if in_the_specified_stream and at_the_specified_subject:
                    msg["content"] = ("@**%s**: " % msg["sender_full_name"]) + msg["content"]
                    send = lambda x: c.privmsg(self.channel, x)
                else:
                    return
            else:
                recipients = [u["short_name"] for u in msg["display_recipient"] if
                              u["email"] != msg["sender_email"]]
                if len(recipients) == 1:
                    send = lambda x: c.privmsg(recipients[0], x)
                else:
                    send = lambda x: c.privmsg_many(recipients, x)
            for line in msg["content"].split("\n"):
                send(line)

        z2i = mp.Process(target=self.zulip_client.call_on_each_message, args=(forward_to_irc,))
        z2i.start()

    def on_privmsg(self, c, e):
        # type: (ServerConnection, Event) -> None
        content = e.arguments[0]
        sender = self.zulip_sender(e.source)
        if sender.endswith("_zulip@" + self.IRC_DOMAIN):
            return

        # Forward the PM to Zulip
        print(self.zulip_client.send_message({
            "sender": sender,
            "type": "private",
            "to": "username@example.com",
            "content": content,
        }))

    def on_pubmsg(self, c, e):
        # type: (ServerConnection, Event) -> None
        content = e.arguments[0]
        sender = self.zulip_sender(e.source)
        if sender.endswith("_zulip@" + self.IRC_DOMAIN):
            return

        # Forward the stream message to Zulip
        print(self.zulip_client.send_message({
            "type": "stream",
            "to": self.stream,
            "subject": self.topic,
            "content": content,
            "content": "**{}**: {}".format(sender, content),
        }))

    def on_dccmsg(self, c, e):
        # type: (ServerConnection, Event) -> None
        c.privmsg("You said: " + e.arguments[0])

    def on_dccchat(self, c, e):
        # type: (ServerConnection, Event) -> None
        if len(e.arguments) != 2:
            return
        args = e.arguments[1].split()
        if len(args) == 4:
            try:
                address = ip_numstr_to_quad(args[2])
                port = int(args[3])
            except ValueError:
                return
            self.dcc_connect(address, port)