import socket
from sys import exit


class IRC:
    """Methods for basic IRC communication."""

    debug = False

    def send(self, command, text, *args, **kwargs):
        """Send messages given the IRC command and text. Optionally specify a 
        message recipient with `recvr=user`."""
        recvr = kwargs.get("recvr", "")
        if recvr != "":
            recvr += " :"
        if self.debug:
            print("[debug][send] " + command + " " + recvr + text)
        bs = bytes(command + " " + recvr + text + "\r\n", "utf-8")
        try:
            self.sock.sendall(bs)
        except BrokenPipeError as err:
            if self.debug:
                print("[debug] " + str(err) + " at `" + \
                    bs.decode("utf-8").strip() + "`")
            pass

    def connect(self, server, bot_nick):
        """Connect to the server and sends user/nick information."""
        try:
            self.sock = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
            self.sock.connect(server)
        except ConnectionError as err:
            exit("[debug] " + str(err))   
        self.send("USER", bot_nick + " " + bot_nick + " " + \
            bot_nick + " " + bot_nick)
        self.send("NICK", bot_nick)

    def disconnect(self, resp_msg, quit_msg, admin_user):
        """Notify the admin user and disconnect from the server."""
        self.send("PRIVMSG", resp_msg, recvr=admin_user)
        self.send("QUIT", ":" + quit_msg)
    
    def receive(self, *args, **kwargs):
        """Get messages from the connected socket."""
        data = self.sock.recv(2040).decode("utf-8").strip("\n\r")
        if self.debug:
            print("[debug][recv] " + data)
        return data

    def keep_alive(self, line):
        """Stay connected to a server by responding to server pings."""
        if "PING" in line:
            self.send("PONG", ":" + line.split(":", 2)[1].split(" ", 1)[0])

    def join_channels(self, channels):
        """Join channels given a list of channel names."""
        for c in channels:
            if c.strip() != "" or c.strip() != "#":
                self.send("JOIN", c)

    def parse_msg(self, line, req_prefix):
        """Extract the request, the nick and username of the requester, 
        the channel where the request originated and returns a dictionary of
        values."""
        data = {"req": "", "req_chan": "", "nick": "", "user": ""}
        if (":" + req_prefix) in line:
            data["req"] = line.split("PRIVMSG", 1)[1].split(":" + \
                req_prefix, 1)[1].strip()
            data["req_chan"] = line.split("PRIVMSG ", \
                1)[1].split(" :", 1)[0]
            data["nick"] = line.split("!~", 1)[0][1:]
            data["user"] = line.split("!~", 2)[1][0:].split("@", 1)[0]
        return data