"""
.. module:: IRCCore
   :synopsis: IRC protocol class

.. moduleauthor:: Dave Pedu <dave@davepedu.com>

"""

import socket
import asynchat
import asyncore
import logging
import traceback
from socket import SHUT_RDWR

try:
	from cStringIO import StringIO
except:
	from io import BytesIO as StringIO

class IRCCore(asynchat.async_chat):
	
	def __init__(self):
		asynchat.async_chat.__init__(self)
		
		self.connected=False
		"""If we're connected or not"""
		
		self.log = logging.getLogger('IRCCore')
		"""Reference to logger object"""
		
		self.buffer = StringIO()
		"""cSTringIO used as a buffer"""
		
		self.alive = True
		""" True if we should try to stay connected"""
		
		# Connection details
		self.server = None
		self.port = 0
		self.ipv6 = False
		
		# IRC Messages are terminated with \r\n
		self.set_terminator(b"\r\n")
		
		# Set up hooks for modules
		self.initHooks()
		
		# Map for asynchat
		self.asynmap = {}
	
	def loop(self):
		asyncore.loop(map=self.asynmap)
	
	def kill(self):
		"""TODO close the socket"""
		pass
	
	" Net related code here on down "
	
	def getBuf(self):
		"""Return the network buffer and clear it"""
		self.buffer.seek(0)
		data = self.buffer.read()
		self.buffer = StringIO()
		return data
	
	def collect_incoming_data(self, data):
		"""Recieve data from the IRC server, append it to the buffer
		
		:param data: the data that was recieved
		:type data: str"""
		#self.log.debug("<< %(message)s", {"message":repr(data)})
		self.buffer.write(data)
	
	def found_terminator(self):
		"""A complete command was pushed through, so clear the buffer and process it."""
		line = None
		buf = self.getBuf()
		try:
			line = buf.decode("UTF-8")
		except UnicodeDecodeError as ude:
			self.log.error("found_terminator(): could not decode input as UTF-8")
			self.log.error("found_terminator(): data: %s" % line)
			self.log.error("found_terminator(): repr(data): %s" % repr(line))
			self.log.error("found_terminator(): error: %s" % str(ude))
			return
		self.process_data(line)
	
	def handle_close(self):
		"""Called when the socket is disconnected. We will want to reconnect. """
		self.log.debug("handle_close")
		self.connected=False
		self.close()
		self.fire_hook("_DISCONNECT")
	
	def handle_error(self, *args, **kwargs):
		"""Called on fatal network errors."""
		self.log.warning("Connection failed.")
	
	def _connect(self):
		"""Connect to IRC"""
		self.log.debug("Connecting to %(server)s:%(port)i", {"server":self.server, "port":self.port})
		socket_type = socket.AF_INET
		if self.ipv6:
			self.log.info("IPv6 is enabled.")
			socket_type = socket.AF_INET6
		socketInfo = socket.getaddrinfo(self.server, self.port, socket_type)
		self.create_socket(socket_type, socket.SOCK_STREAM)
		
		self.connect(socketInfo[0][4])
		self.asynmap[self._fileno] = self # http://willpython.blogspot.com/2010/08/multiple-event-loops-with-asyncore-and.html
	
	def handle_connect(self):
		"""When asynchat indicates our socket is connected, fire the connect hook"""
		self.connected=True
		# TODO move to an event
		self.log.debug("handle_connect: setting USER and NICK")
		self.fire_hook("_CONNECT")
		self.log.debug("handle_connect: complete")
	
	def sendRaw(self, text):
		"""Send a raw string to the IRC server
		
		:param text: the string to send
		:type text: str"""
		if self.connected:
			#self.log.debug(">> "+text)
			self.send( (text+"\r\n").encode("UTF-8").decode().encode("UTF-8"))
		else:
			self.log.warning("Send attempted while disconnected. >> "+text)
	
	def process_data(self, data):
		"""Process one line of tet irc sent us
		
		:param data: the data to process
		:type data: str"""
		if data.strip() == "":
			return
			
		prefix = None
		command = None
		args=[]
		trailing=None
		
		if data[0]==":":
			prefix=data.split(" ")[0][1:]
			data=data[data.find(" ")+1:]
		command = data.split(" ")[0]
		data=data[data.find(" ")+1:]
		if(data[0]==":"):
			# no args
			trailing = data[1:].strip()
		else:
			trailing = data[data.find(" :")+2:].strip()
			data = data[:data.find(" :")]
			args = data.split(" ")
		for index,arg in enumerate(args):
			args[index]=arg.strip()
		if not command in self.hookcalls:
			self.log.warning("Unknown command: cmd='%s' prefix='%s' args='%s' trailing='%s'" % (command, prefix, args, trailing))
		else:
			self.fire_hook(command, args=args, prefix=prefix, trailing=trailing)
	
	
	" Module related code "
	def initHooks(self):
		"""Defines hooks that modules can listen for events of"""
		self.hooks = [
			'_CONNECT', # Called when the bot connects to IRC on the socket level
			'_DISCONNECT', # Called when the irc socket is forcibly closed
			'NOTICE',	# :irc.129irc.com NOTICE AUTH :*** Looking up your hostname...
			'MODE',		# :CloneABCD MODE CloneABCD :+iwx
			'PING',		# PING :irc.129irc.com
			'JOIN',		# :CloneA!dave@hidden-B4F6B1AA.rit.edu JOIN :#clonea
			'QUIT',		# :HCSMPBot!~HCSMPBot@108.170.48.18 QUIT :Quit: Disconnecting!
			'NICK',		# :foxiAway!foxi@irc.hcsmp.com NICK :foxi
			'PART',		# :CloneA!dave@hidden-B4F6B1AA.rit.edu PART #clonea
			'PRIVMSG',	# :CloneA!dave@hidden-B4F6B1AA.rit.edu PRIVMSG #clonea :aaa
			'KICK',		# :xMopxShell!~rduser@host KICK #xMopx2 xBotxShellTest :xBotxShellTest
			'INVITE',	# :gmx!~gmxgeek@irc.hcsmp.com INVITE Tyrone :#hcsmp'
			'001',		# :irc.129irc.com 001 CloneABCD :Welcome to the 129irc IRC Network CloneABCD!CloneABCD@djptwc-laptop1.rit.edu
			'002',		# :irc.129irc.com 002 CloneABCD :Your host is irc.129irc.com, running version Unreal3.2.8.1
			'003',		# :irc.129irc.com 003 CloneABCD :This server was created Mon Jul 19 2010 at 03:12:01 EDT
			'004',		# :irc.129irc.com 004 CloneABCD irc.129irc.com Unreal3.2.8.1 iowghraAsORTVSxNCWqBzvdHtGp lvhopsmntikrRcaqOALQbSeIKVfMCuzNTGj
			'005',		# :irc.129irc.com 005 CloneABCD CMDS=KNOCK,MAP,DCCALLOW,USERIP UHNAMES NAMESX SAFELIST HCN MAXCHANNELS=10 CHANLIMIT=#:10 MAXLIST=b:60,e:60,I:60 NICKLEN=30 CHANNELLEN=32 TOPICLEN=307 KICKLEN=307 AWAYLEN=307 :are supported by this server
			'250',		# :chaos.esper.net 250 xBotxShellTest :Highest connection count: 1633 (1632 clients) (186588 connections received)
			'251',		# :irc.129irc.com 251 CloneABCD :There are 1 users and 48 invisible on 2 servers
			'252',		# :irc.129irc.com 252 CloneABCD 9 :operator(s) online
			'254',		# :irc.129irc.com 254 CloneABCD 6 :channels formed
			'255',		# :irc.129irc.com 255 CloneABCD :I have 42 clients and 1 servers
			'265',		# :irc.129irc.com 265 CloneABCD :Current Local Users: 42  Max: 47
			'266',		# :irc.129irc.com 266 CloneABCD :Current Global Users: 49  Max: 53
			'332',		# :chaos.esper.net 332 xBotxShellTest #xMopx2 :/ #XMOPX2 / https://code.google.com/p/pyircbot/ (Channel Topic)
			'333',		# :chaos.esper.net 333 xBotxShellTest #xMopx2 xMopxShell!~rduser@108.170.60.242 1344370109
			'353',		# :irc.129irc.com 353 CloneABCD = #clonea :CloneABCD CloneABC 
			'366',		# :irc.129irc.com 366 CloneABCD #clonea :End of /NAMES list.
			'372',		# :chaos.esper.net 372 xBotxShell :motd text here
			'375',		# :chaos.esper.net 375 xBotxShellTest :- chaos.esper.net Message of the Day -
			'376',		# :chaos.esper.net 376 xBotxShell :End of /MOTD command.
			'422',		# :irc.129irc.com 422 CloneABCD :MOTD File is missing
			'433',		# :nova.esper.net 433 * pyircbot3 :Nickname is already in use.
		]
		" mapping of hooks to methods "
		self.hookcalls = {}
		for command in self.hooks:
			self.hookcalls[command]=[]
	
	def fire_hook(self, command, args=None, prefix=None, trailing=None):
		"""Run any listeners for a specific hook
		
		:param command: the hook to fire
		:type command: str
		:param args: the list of arguments, if any, the command was passed
		:type args: list
		:param prefix: prefix of the sender of this command
		:type prefix: str
		:param trailing: data payload of the command
		:type trailing: str"""
		
		for hook in self.hookcalls[command]:
			try:
				hook(args, prefix, trailing)
			except:
				self.log.warning("Error processing hook: \n%s"% self.trace())
	
	def addHook(self, command, method):
		"""**Internal.** Enable (connect) a single hook of a module
		
		:param command: command this hook will trigger on
		:type command: str
		:param method: callable method object to hook in
		:type method: object"""
		" add a single hook "
		if command in self.hooks:
			self.hookcalls[command].append(method)
		else:
			self.log.warning("Invalid hook - %s" % command)
			return False
	
	def removeHook(self, command, method):
		"""**Internal.** Disable (disconnect) a single hook of a module
		
		:param command: command this hook triggers on
		:type command: str
		:param method: callable method that should be removed
		:type method: object"""
		" remove a single hook "
		if command in self.hooks:
			for hookedMethod in self.hookcalls[command]:
				if hookedMethod == method:
					self.hookcalls[command].remove(hookedMethod)
		else:
			self.log.warning("Invalid hook - %s" % command)
			return False
	
	" Utility methods "
	@staticmethod
	def decodePrefix(prefix):
		"""Given a prefix like nick!username@hostname, return an object with these properties
		
		:param prefix: the prefix to disassemble
		:type prefix: str
		:returns: object -- an UserPrefix object with the properties `nick`, `username`, `hostname` or a ServerPrefix object with the property `hostname`"""
		if "!" in prefix:
			ob = type('UserPrefix', (object,), {})
			ob.nick, prefix = prefix.split("!")
			ob.username, ob.hostname = prefix.split("@")
			return ob
		else:
			ob = type('ServerPrefix', (object,), {})
			ob.hostname = prefix
			return ob
	
	@staticmethod
	def trace():
		"""Return the stack trace of the bot as a string"""
		return traceback.format_exc()
	
	" Data Methods "
	def get_nick(self):
		"""Get the bot's current nick
		
		:returns: str - the bot's current nickname"""
		return self.nick
	
	" Action Methods "
	def act_PONG(self, data):
		"""Use the `/pong` command - respond to server pings
		
		:param data: the string or number the server sent with it's ping
		:type data: str"""
		self.sendRaw("PONG :%s" % data)
	
	def act_USER(self, username, hostname, realname):
		"""Use the USER protocol command. Used during connection
		
		:param username: the bot's username
		:type username: str
		:param hostname: the bot's hostname
		:type hostname: str
		:param realname: the bot's realname
		:type realname: str"""
		self.sendRaw("USER %s %s %s :%s" % (username, hostname, self.server, realname))
	
	def act_NICK(self, newNick):
		"""Use the `/nick` command
		
		:param newNick: new nick for the bot
		:type newNick: str"""
		self.nick = newNick
		self.sendRaw("NICK %s" % newNick)
	
	def act_JOIN(self, channel):
		"""Use the `/join` command
		
		:param channel: the channel to attempt to join
		:type channel: str"""
		self.sendRaw("JOIN %s"%channel)
	
	def act_PRIVMSG(self, towho, message):
		"""Use the `/msg` command
		
		:param towho: the target #channel or user's name
		:type towho: str
		:param message: the message to send
		:type message: str"""
		self.sendRaw("PRIVMSG %s :%s"%(towho,message))
	
	def act_MODE(self, channel, mode, extra=None):
		"""Use the `/mode` command
		
		:param channel: the channel this mode is for
		:type channel: str
		:param mode: the mode string. Example: +b
		:type mode: str
		:param extra: additional argument if the mode needs it. Example: user@*!*
		:type extra: str"""
		if extra != None:
			self.sendRaw("MODE %s %s %s" % (channel,mode,extra))
		else:
			self.sendRaw("MODE %s %s" % (channel,mode))
	
	def act_ACTION(self, channel, action):
		"""Use the `/me <action>` command
		
		:param channel: the channel name or target's name the message is sent to
		:type channel: str
		:param action: the text to send
		:type action: str"""
		self.sendRaw("PRIVMSG %s :\x01ACTION %s"%(channel,action))
	
	def act_KICK(self, channel, who, comment=""):
		"""Use the `/kick <user> <message>` command
		
		:param channel: the channel from which the user will be kicked
		:type channel: str
		:param who: the nickname of the user to kick
		:type action: str
		:param comment: the kick message
		:type comment: str"""
		self.sendRaw("KICK %s %s :%s" % (channel, who, comment))
	
	def act_QUIT(self, message):
		"""Use the `/quit` command
		
		:param message: quit message
		:type message: str"""
		self.sendRaw("QUIT :%s" % message)