#!/usr/bin/env python3
# -*- coding: utf-8 -*-
#
#  main.py
#
#  Copyright 2014 Fanir <projects@mail.fanir.de>
#
#  This program is free software; you can redistribute it and/or modify
#  it under the terms of the GNU General Public License as published by
#  the Free Software Foundation; either version 2 of the License, or
#  (at your option) any later version.
#
#  This program is distributed in the hope that it will be useful,
#  but WITHOUT ANY WARRANTY; without even the implied warranty of
#  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
#  GNU General Public License for more details.
#
#  You should have received a copy of the GNU General Public License
#  along with this program; if not, write to the Free Software
#  Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston,
#  MA 02110-1301, USA.
#
#


# SETTINGS CAN BE FOUND AT THE BOTTOM OF THE FILE


import sys, time, string, socket, re, signal, struct
from select import poll, POLLIN, POLLPRI, POLLOUT,\
                        POLLERR, POLLHUP, POLLNVAL
from threading import Thread, Event

from APIcollection import Twitter

bot = None


class log():
    DEBUG, INFO, WARNING, ERROR, FATAL, SILENT =\
        0,    1,       2,     3,     4,      5
    
    def show(level, msg):
        if level in range(log.DEBUG, log.SILENT):
            if LOGLEVEL <= level: print(msg)
        else:
            raise ValueError("That's not a loglevel!")



class pircbot():
    def encode(self, textstring):
        for codec in self.encodings:
            try: return textstring.encode(codec)
            except UnicodeDecodeError: continue
        return textstring.encode(self.encodings[0], 'ignore')
    
    def decode(self, textstring):
        for codec in self.encodings:
            try: return textstring.decode(codec)
            except UnicodeDecodeError: continue
        return textstring.decode(self.encodings[0], 'ignore')
    
    def __init__(self, nicknames, server, port=6667, ident="pircbot",
                realname="pircbot", encodings=("utf-8", "latin-1"),
                command_prefix=".", admins="", serverpasswd="", parser_wait_time=0.1):
        self.server = server
        self.port = port
        self.serverpasswd = serverpasswd
        self.encodings = encodings
        
        self.nicknames = nicknames
        self.ident = ident
        self.realname = realname
        
        self.admins = admins
        self.cmdprefix = command_prefix
        
        self.parser_wait_time=parser_wait_time
        
        self.user = {}
        
        self.socket = None
        self.recvloop = None
        self.recvbuffer = bytearray(1024)
        
        self.ready = False
        
        self.die_event = Event()
    
    def recv_loop(self):
        """
        Loop for reciving data
        """
        parser = Thread(target=self.parse_loop, name="parser")
        p = poll()
        p.register(self.socket.fileno(), POLLIN)
        while not self.die_event.is_set():
            ap = p.poll(1000)
            if (self.socket.fileno(), POLLIN) in ap:
                self.recvbuffer.extend(self.socket.recv(1024))
                if not parser.is_alive():
                    parser = Thread(target=self.parse_loop, name="parser")
                    parser.start()
        print("--- RECVLOOP EXITING ---")
    
    def parse_loop(self):
        """
        Loop for parsing incoming data
        """
        while not self.die_event.is_set():# and self.recvbuffer.endswith(b"\r\n"):# != b"":
            if self.recvbuffer.endswith(b"\r\n"):
                # get and decode line from buffer
                rawline, _, self.recvbuffer = self.recvbuffer.partition(b"\r\n")
                rawline = self.decode(rawline)
                # prepare line
                line = rawline.split(" :", 1)
                head = line[0].lstrip("\x00").split(" ")
                larg = line[1] if len(line)>1 else ""
                # parse prefix
                origin = {}
                if head[0].startswith(":"):
                    prefix = head.pop(0)[1:]
                    if "@" in prefix:
                        origin["nick"], origin["ident"], origin["host"] = re.match(r"(\S+)!(\S+)@(\S+)", prefix).groups()
                    else:
                        origin["server"] = prefix
                else:
                    prefix = ""
                # parse command
                command = head.pop(0)
                # parse params
                params = head
                params.append(larg)
                
                log.show(log.DEBUG, " > %s" % rawline)
                
                # PING
                if command == "PING":
                    self.send("PONG %s" % params[0])
                # PRIVMSG
                elif command == "PRIVMSG":
                    if params[1].startswith(self.cmdprefix):
                        args = params[1].lstrip(self.cmdprefix).split(" ")
                        sndline = self.on_command(prefix, origin, params[0], args[0], args[1:])
                        if sndline != None:
                            self.send(sndline)
                # 001 (RPL_WELCOME)
                elif command == "001":
                    self.user["mask"] = re.search(r" (\S+!\S+@\S+)$", rawline.split(" :", 1)[1]).groups()[0]
                    self.user["nick"], self.user["ident"], self.user["host"] = re.match(r"(\S+)!(\S+)@(\S+)", self.user["mask"]).groups()
                    self.ready = True
                # 433 (ERR_NICKNAMEINUSE)
                elif command == "433":
                    self.send("NICK %s" % self.nicknames.pop(0))
                # KILL
                elif command == "KILL":
                    log.show(log.WARNING, "Got killed by %s: %s" % (params[0], params[1:]))
                    self.quit(send=False)
            else:
                time.sleep(self.parser_wait_time)
        print("--- PARSELOOP EXITING ---")
    
    def send(self, data):
        log.show(log.DEBUG, "<  %s" % data)
        try: self.socket.send(self.encode("".join((data, "\r\n"))))
        except BrokenPipeError as e:
            log.show(log.FATAL, e)
            self.quit(send=False)
    
    def connect(self):
        # connect
        self.socket = socket.socket()
        try:
            self.socket.connect((self.server, self.port))
        except socket.error as e:
            log.show(log.FATAL, "Fehler: %s" % e)
            return
        
        # start getting data
        self.recvloop = Thread(target=self.recv_loop, name="recvloop")
        self.recvloop.start()
        
        # optionally send a server password
        if self.serverpasswd != "": self.send("PASS %s" % self.serverpasswd)
        # get a nick
        self.send("NICK %s" % self.nicknames.pop(0))
        # set user data
        self.send("USER %s 0 * :%s" % (self.ident, self.realname))
    
    def is_admin(self, user):
        for admin in self.admins:
            if re.search(admin, user) != None:
                return True
        return False
    
    def quit(self, reason="", send=True):
        if send:
            try:
                self.send("QUIT :%s" % reason)
            except: pass
        self.die_event.set()
        print("--- SOCKET CLOSING ---")
        try:
            self.socket.shutdown(socket.SHUT_RDWR)
            self.socket.close()
        except: pass
    
    def join(self, channel):
        while not self.ready: time.sleep(1)
        self.send("JOIN %s" % channel)
    
    def part(self, channel):
        while not self.ready: time.sleep(1)
        self.send("PART %s" % channel)
    
    def set_mode(self, modes):
        while not self.ready: time.sleep(1)
        self.send("MODE %s :%s" % (self.user["nick"], modes))
    
    def on_command(self, prefix, origin, source, command, params):
        """
        Executed when getting a PRIVMSG starting with self.cmdprefix
        Prefix contains the optional prefix of the raw line.
        Origin is a map holding the parsed prefix, containing
            "nick", "ident" and "host" for users and "server" for servers.
        Source is the first parameter after the irc-command, specifying
            the channel or user, from where the line comes.
        Command is the command for the bot.
        Params contains a list of originally space separated parameters.
        """
        # hello
        if command == "hello":
            greeting = "".join(("Hi " + origin["nick"] +"!"))
            if source[0] in {"#", "+", "!", "&"}:
                return "PRIVMSG %s :%s" % (source, greeting)
            else:
                return "PRIVMSG %s :%s" % (origin["nick"], greeting)
        # join <channel>
        elif command == "join" and len(params)>0:
            if self.is_admin(origin["nick"]): self.join(params[0])
            else: return "PRIVMSG %s :You can't do that!" % origin["nick"]
        # part <channel>
        elif command == "part" and len(params)>0:
            if self.is_admin(origin["nick"]): self.part(params[0])
            else: return "PRIVMSG %s :You can't do that!" % origin["nick"]
        # die [<quitmsg>]
        elif command == "die":
            if self.is_admin(origin["nick"]):
                self.quit("".join(params) if len(params)>0 else "".join((origin["nick"], " shot me, dying now... Bye...")))



def parseargs():
    import argparse
    p = argparse.ArgumentParser(
        description = "i think my desc is missing")
    p.add_argument("action", default="help", choices = ["start", "stop"], help="What to do?")
    #p.add_argument("--daemon", "-d", type = bool, choices = [1, 0], default=1, help="Daemonize, Default: 1")
    return p.parse_args()

def main():
    global bot
    args = parseargs()
    if args.action == "start":
        bot = pircbot(nicknames=NICKNAMES, ident=IDENT, realname=REALNAME,
            server=SERVER, port=PORT, encodings=ENCODINGS, command_prefix=COMMAND_PREFIX,
            admins=ADMINS, serverpasswd=SERVERPASSWD, parser_wait_time=PARSER_WAIT_TIME)
        try:
            bot.connect()
            # wait for the bot to become ready
            while bot.ready and not bot.die_event.is_set() == False:
                time.sleep(1)
            
            if not bot.die_event.is_set():
                # set modes and join channels
                bot.set_mode(MODES)
                for channel in CHANNELS:
                    bot.join(channel)
            
            # while bot is active, do nothing
            while not bot.die_event.is_set():
                time.sleep(1)
        except KeyboardInterrupt:
            log.show(log.INFO, "Got Ctrl-C, dying now...")
            bot.quit()
    
    elif args.action == "stop": print("nope!")
    print("--- MAIN EXITING ---")
    return 0


if __name__ == '__main__':
    
    ################
    ### SETTINGS ###
    ################
    
    # With how much information do you want to be annoyed?
    # DEBUG spams most, FATAL least. WARNING should be a good tradeoff.
    # One of: log.DEBUG, log.INFO, log.WARNING, log.ERROR, log.FATAL
    LOGLEVEL = log.DEBUG
    
    
    # Also known as username. Some IRC-internal.
    # By default, the nickname will be used as ident.
    IDENT = "chalkbot"
    
    # The list of nicknames to try. If the first one is not aviable, it will
    # try the second, and so on...
    # You should specfy at least two nicks.
    NICKNAMES = ["chalkbot", "chalkbot_", "chalkbot__"]
    
    REALNAME = "A ChalkBot Instance"
    
    # Command for registering with nickserv, without leading slash.
    NICKSERVCMD = ""
    
    MODES = "+B"
    
    
    # The Server name to connect to. Duh!
    #SERVER = "fanir.de"
    SERVER = "localhost"
    
    # "Default" is 6667. An often used port for SSL would be 6697, if SSL would be
    # supported. Maybe in a future, far far away...
    PORT = 6667
    
    SERVERPASSWD = ""
    
    # A comma-seperated list of channels to join, enclosed by braces.
    CHANNELS = ["#bots", "#main"]
    
    # The encodings to try when getting messages from IRC. Will be tried in the given order.
    # The first one is used to encode data when sending stuff.
    # The list given shoud do just fine in most networks, I assume.
    # Also comma seperated and enclosed by braces.
    ENCODINGS = ['utf-8', 'latin-1', 'iso-8859-1', 'cp1252']
    
    
    # List of users (hostmasks, will be parsed as regex) who can do important stuff,
    # like joining and parting channels and shutting down the bot.
    ADMINS = ["Fanir.*"]
    
    COMMAND_PREFIX = "."
    
    
    # The time the parser for incoming data should wait between each attempt to read new data in seconds.
    # High values will certainly make the bot reply slowly while very low values increads cpu load and therefore will perform badly on slow machines.
    # You should keep it between 1 and 0.001 seconds.
    # For gods sake, don't set it to 0!
    PARSER_WAIT_TIME = 0.05
    
    #######################
    ### END OF SETTINGS ###
    #######################
    
    
    main()