#!/usr/bin/python3

import socket
from os import _exit
from random import randint

class IRC:
    """A set of methods for basic IRC communication."""

    def __init__(self):
        self.sock = socket.socket(socket.AF_INET, socket.SOCK_STREAM)

    def set_prefs(self, prefs):
        """Set environment variables from a dictionary of values."""
        self.server = prefs["server"]
        self.channels = prefs["channels"]
        self.bot_nick = prefs["bot_nick"]
        self.admin_user = prefs["admin_user"]
        self.admin_code = prefs["admin_code"]
        self.req_prefix = prefs["req_prefix"]
        self.is_debug = prefs["is_debug"]

    def msg(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 += " :"
        self.sock.sendall(bytes(command + " " + recvr + text + "\n", "utf-8"))

    def pm(self, text, recipient):
        """Alias of msg() with the PRIVMSG IRC command and a recipient."""
        self.msg("PRIVMSG", text, recvr=recipient)

    def connect(self):
        """Connect to the server and sends user/nick information."""
        self.sock.connect(self.server)
        self.msg("USER", self.bot_nick + " " + self.bot_nick + " " + \
                self.bot_nick + " ehlo")
        self.msg("NICK", self.bot_nick)

    def parse_line(self, line):
        """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 (":" + self.req_prefix) in self.line:
            data["req"] = line.split("PRIVMSG", 1)[1].split(":" + \
                    self.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

    def keep_alive(self):
        """Stay connected to a server by responding to server pings."""
        self.line = self.sock.recv(2040).decode("utf-8").strip("\n\r")
        if "PING" in self.line:
            self.msg("PONG", ":" + self.server[0])
        if self.is_debug:
            print(self.line)

    def join_chans(self):
        """Join channels from a list provided in environment settings."""
        for c in self.channels:
            if c.strip() != "" or c.strip() != "#":
                self.msg("JOIN", c)

    def map_actions(self, channel):
        """Listen for bot requests in a channel and match responses."""
        data = self.parse_line(self.line)
        
        # Respond only in the channel the request was made
        if channel == data["req_chan"]:
            # General commands
            if data["req"] == "rollcall" or data["req"] == "help":
                rollcall = (
                    "一、二、三、らーめん缶！ "
                    "Hello, I am a ramen vending machine. "
                    "Please type a code to request service: "
                    "!help "
                    "Support: +81 012-700-1MIO "
                    "どうぞめしあがれ。"
                    )
                self.pm(rollcall, data["req_chan"])
            
            elif data["req"] == ("water " + self.bot_nick):
                resp = [
                    ("\x01ACTION happily pours the hot liquid into a bowl of "
                    "noodles and offers it to ") + data["nick"] + "\x01",
                    "（ ^_^）o自自o（^_^ ）Cheers!",
                    "Water Level [/////////] 200% - Thanks! (^▽^)"
                    ]
                self.pm(resp[randint(0, len(resp)-1)], data["req_chan"])
            
            elif data["req"] == ("botsnack " + self.bot_nick):
                self.pm("Ramen time anytime! ヽ(´▽`)/", data["req_chan"])

        # Respond to some commands only in private message
        if data["req_chan"] == self.bot_nick:
            if data["req"] == ("exit " + self.admin_code) and \
                    data["user"].lower() == self.admin_user.lower():
                self.pm("Okay, okay, I'll leave. (´･ω･`)", self.admin_user)
                self.msg("QUIT", ":noodling off")
                _exit(0)