#!/usr/bin/env python3
"""
The core bot class for Fulvia.
"""
import os
import sys
import time
import threading
import traceback
from datetime import datetime

from twisted.internet import protocol, reactor
from twisted.words.protocols import irc

import db
import tools
import config
import loader
import scheduler
from trigger import Trigger

class Fulvia(irc.IRCClient):
	def __init__(self):
		self.nickname = config.nickname
		self.nick = config.nickname
		"""The bot's current nickname."""

		self.realname = config.realname
		"""The bot's 'real name', used in whois."""

		self.username = config.username
		"""The bot's username ident used for logging into the server."""

		self.host = ""
		"""The bot's host, virtual or otherwise. To be filled in later."""

		self.static = "static"
		os.makedirs(self.static, exist_ok=True)
		"""The path to the bot's static file directory."""

		self.log_path = "logs"
		os.makedirs(self.log_path, exist_ok=True)
		"""The path to the bot's log files."""

		self._log_dump = tools.FulviaMemoryDefault(list)
		"""
		Internal thread-safe dictionary containing log dumps yet to be
		written.
		"""

		self._last_log_dump = 0
		"""The last time logs were dumped."""

		self.channels = tools.FulviaMemory()
		"""
		A dictionary of all channels the bot is currently in and the users
		in them.
		"""

		self.memory = tools.FulviaMemory()
		"""
		A thread-safe general purpose dictionary to be used by whatever
		modules need it.
		"""

		self.db = db.FulviaDB()
		"""
		A class with some basic interactions for the bot's sqlite3 databse.
		"""

		self._hooks = []
		"""
		A list containing all function names to be hooked with every message
		received.
		"""

		self.commands = {}
		"""
		A dictionary containing all commands to look for and the name
		of the function they call.
		"""

		self._times = {}
		"""
		A dictionary full of times when certain functions were called for
		use with the @rate decorator. Keys are function names.
		"""

		self.url_callbacks = {}
		"""
		A dictionary of URL callbacks to allow other modules interact with
		the URL module.
		"""

		self._user_joined = []
		"""These get called when a user joins a channel."""

		self._disabled_modules = config.disabled_modules
		"""These modules will NOT be loaded when load_modules() is called."""

		self.scheduler = scheduler.Scheduler(self)
		"""The bot's task scheduler."""

		self.load_modules()


	def load_modules(self):
		"""
		Find and load all of our modules.
		"""
		print(f"Loading modules...")
		self._hooks = []
		self.commands = {}
		self._times = {}
		self.url_callbacks = {}
		# ensure they're empty

		modules = loader.find_modules()
		loaded = 0
		failed = 0
		for name, path in modules.items():
			try:
				if name in self._disabled_modules:
					continue
				loader.load_module(self, path)
				loaded += 1
			except Exception as e:
				print(f"{name} failed to load.")
				print(e)
				traceback.print_exc()
				failed += 1
				continue
		print(f"Registered {loaded} modules,")
		print(f"{failed} modules failed to load")


	def register_callable(self, func):
		"""
		Registers all callable functions loaded from modules into one
		convenient table.
		"""
		if hasattr(func, 'commands'):
			for cmd in func.commands:
				self.commands[cmd] = func

		if func.hook:
			self._hooks.append(func)

		if func.rate or func.channel_rate or func.global_rate:
			self._times[func.__name__] = {}

		if hasattr(func, 'url_callback'):
			for url in func.url_callback:
				self.url_callbacks[url] = func

		if func.user_joined:
			self._user_joined.append(func)


	def unregister_callable(self, func):
		"""
		Removes the provided function object from the internal list of
		module functions.
		"""
		if not callable(func) or not loader.is_triggerable(func):
			return

		if hasattr(func, 'commands'):
			for command in func.commands:
				self.commands.pop(command)

		if func.hook:
			self._hooks.remove(func)

		if func.rate or func.channel_rate or func.global_rate:
			self._times.pop(func)

		if hasattr(func, 'url_callback'):
			for url in func.url_callback:
				self.url_callbacks.pop(url)

		if func.user_joined:
			self._user_joined.remove(func)


	def add_shutdown(self, func):
		"""Adds the given function to the reactor's shutdown sequence."""
		reactor.addSystemEventTrigger('before','shutdown', func)


	def stillConnected(self):
		"""Returns true if the bot is still connected to the server."""
		if self._heartbeat:
			return True
		else:
			return False


	def call(self, func, bot, trigger):
		"""
		A wrapper for calling module functions so that we can have nicer
		error handling.
		"""
		try:
			func(bot, trigger)
		except Exception as e:
			msg = type(e).__name__ + ": " + str(e)
			self.msg(trigger.channel, msg)
			traceback.print_exc()


	def log(self, channel, text):
		"""
		Logs text to file. Logging structure is
		{self.log_path}/{self.server}/{channel}/{date}.log

		Only permits log dumping once per second.
		"""
		# TODO: use time module instead of datetime
		t = datetime.fromtimestamp(time.time())
		timestamp = t.strftime(config.default_time_format)
		self._log_dump[channel].append(timestamp + " " + text)

		if time.time() - self._last_log_dump > 1:
			for ch in self._log_dump.keys():
				fname = t.strftime("%Y-%m-%d") + ".log"
				path = os.path.join(self.log_path, self.hostname, ch)
				os.makedirs(path, exist_ok=True)
				with open(os.path.join(path, fname), "a+") as file:
					file.write("\n".join(self._log_dump[ch]) + "\n")

			del(self._log_dump)
			self._log_dump = tools.FulviaMemoryDefault(list)


	## Actions involving the bot directly.
	## These will get called automatically.

	def privmsg(self, user, channel, message):
		"""
		Called when the bot receives a PRIVMSG, which can come from channels
		or users alike.
		"""
		nick = user.partition("!")[0].partition("@")[0]
		if channel.startswith("#"):
			opSym = self.channels[channel].users[nick].op_level
		else:
			opSym = ''
			channel = nick
		line = f"<{opSym}{nick}> {message}"
		self.log(channel, line)

		funcs = []
		if message.startswith(config.prefix) and message != config.prefix:
			command = message.partition(" ")[0]
			command = command.replace(config.prefix, "", 1)
			cmd = self.commands.get(command)
			if not cmd:
				return
			funcs.append(cmd)

		funcs += self._hooks

		for func in funcs:
			trigger = Trigger(user, channel, message)
			bot = FulviaWrapper(self, trigger)

			if func.rate:
				t = self._times[func.__name__].get(trigger.nick, 0)
				if time.time() - t < func.rate and not trigger.admin:
					return
				self._times[func.__name__][trigger.nick] = time.time()

			if func.channel_rate:
				t = self._times[func.__name__].get(trigger.channel, 0)
				if time.time() - t < func.channel_rate and not trigger.admin:
					return
				self._times[func.__name__][trigger.channel] = time.time()

			if func.global_rate:
				t = self._times[func.__name__].get("global", 0)
				if time.time() - t < func.channel_rate and not trigger.admin:
					return
				self._times[func.__name__]["global"] = time.time()

			if func.thread == True:
				t = threading.Thread(target=self.call,args=(func, bot, trigger))
				t.start()
			else:
				self.call(func, bot, trigger)


	def joined(self, channel):
		"""Called when the bot joins a new channel."""
		line = f"-!- {self.nickname} [{self.username}@{self.host}] "
		line += f"has joined {channel}"
		self.log(channel, line)

		print(f"Joined {channel}")
		self.channels[channel] = tools.Channel(channel)
		user = tools.User(self.nickname)
		self.channels[channel].users[self.nickname] = user


	def left(self, channel, reason=""):
		"""Called when the bot leaves a channel."""
		line = f"-!- {self.nickname} [{self.username}@{self.host}] "
		line += f"has left {channel} [{reason}]"
		self.log(channel, line)

		print(f"Parted {channel}")
		self.channels.pop(channel)


	def noticed(self, user, channel, message):
		"""Called when the bot receives a NOTICE from a user or channel."""
		# TODO: something?
		pass


	def modeChanged(self, user, channel, add_mode, modes, args):
		"""Called when users or channel's modes are changed."""
		line = f"-!- mode/{channel} ["
		if add_mode:
			line += "+"
		else:
			line += "-"
		line += modes
		if any(args):
			line += " " + " ".join(args)
		line += "] by " + user.partition("!")[0].partition("@")[0]
		self.log(channel, line)

		if not channel.startswith("#"): # server level
			return

		for n, mode in enumerate(modes):
			if args[n] == None: # channel mode
				if add_mode:
					self.channels[channel].modes.add(mode)
				else:
					self.channels[channel].modes.remove(mode)

			elif mode in tools.op_level.keys(): # user mode, op_level mode
				nick = args[n]
				user = self.channels[channel].users[nick]
				if add_mode:
					user.op_level += mode
				else:
					user.op_level.replace(mode, '', 1)

			else: # user mode, non-op_level mode
				continue


	def signedOn(self):
		"""Called when the bot successfully connects to the server."""
		if config.oper_password:
			self.sendLine("OPER " + config.nickname + ' ' + config.oper_password)
		print(f"Signed on as {self.nickname}")
		self.whois(self.nickname)

		line = f"*** Signed onto {self.hostname} as "
		line += f"{self.nickname}!{self.username}@{self.host}"
		self.log(self.hostname, line)

		for channel in config.channels:
			self.join(channel)


	def kickedFrom(self, channel, kicker, message):
		"""Called when the bot is kicked from a channel."""
		line = f"-!- {self.nickname} was kicked from {channel} "
		line += f"by {kicker} [{message}]"
		self.log(channel, line)

		self.channels.pop(channel)


	def nickChanged(self, nick):
		"""Called when the bot changes it's nickname."""
		line = f"-!- you are now known as {nick}"

		for channel_name, channel in self.channels.items():
			self.log(channel_name, line)

			user = channel.users.pop(self.nickname)
			user.nick = nick
			channel.users[nick] = user


	## Actions the bot observes other users doing in the channel.
	## These will get called automatically.

	def userJoined(self, user, channel):
		"""Called when the bot sees another user join a channel."""
		nick, _, host = user.partition("!")

		line = f"-!- {nick} [{host}] has joined {channel}"
		self.log(channel, line)

		new_user = tools.User(nick)
		self.channels[channel].users[nick] = new_user

		for func in self._user_joined:
			trigger = Trigger(user, channel, f"{user} has joined")
			bot = FulviaWrapper(self, trigger)
			t = threading.Thread(target=self.call, args=(func, bot, trigger))
			t.start()


	def userLeft(self, user, channel, reason=""):
		"""Called when the bot sees another user leave a channel."""
		nick, _, host = user.partition("!")

		line = f"-!- {nick} [{host}] has left {channel} [{reason}]"
		self.log(channel, line)

		self.channels[channel].users.pop(nick)


	def userQuit(self, user, quitMessage):
		"""Called when the bot sees another user disconnect from the network."""
		nick, _, host = user.partition("!")
		line = f"-!- {nick} [{host}] has quit [{quitMessage}]"

		for channel_name, channel in self.channels.items():
			if not nick in channel.users:
				continue
			self.log(channel_name, line)

			channel.users.pop(nick)


	def userKicked(self, kickee, channel, kicker, message):
		"""
		Called when the bot sees another user getting kicked from the channel.
		"""
		line =f"-!- {kickee} was kicked from {channel} by {kicker} [{message}]"
		self.log(channel, line)

		self.channels[channel].users.pop(kickee)


	def topicUpdated(self, user, channel, newTopic):
		"""Called when the bot sees a user update the channel's topic."""
		line = f"-!- {user} changed the topic of {channel} to: {newTopic}"
		self.log(channel, line)

		self.channels[channel].topic = newTopic


	def userRenamed(self, oldname, newname):
		"""Called when the bot sees a user change their nickname."""
		line = "-!- {oldname} is now known as {newname}"

		for channel_name, channel in self.channels.items():
			if oldname not in channel.users.keys():
				continue
			self.log(channel_name, line)

			user = channel.users.pop(oldname)
			user.nick = newname
			channel.users[newname] = user


	def namesReceived(self, channel, channel_type, nicklist):
		"""
		Called when the bot receives a list of names in the channel from the
		server.
		"""
		self.channels[channel].channel_type = channel_type
		for nick in nicklist:
			op_level = ''
			if nick[0] in tools.op_level.keys():
				op_level = nick[0]
				nick = nick[1:]
			user = tools.User(nick)
			user.op_level = op_level
			self.channels[channel].users[nick] = user


	def whoisUser(self, nick, ident, host, realname):
		"""
		Called when the bot receives a WHOIS about a particular user.
		"""
		if nick == self.nickname:
			self.username = ident
			self.host = host
			self.realname = realname
		else:
			for channel_name, channel in self.channels.items():
				if nick in channel:
					user = channel[nick]
					user.ident = ident
					user.host = host
					user.realname = realname
	

	def whoisIdle(self, nick, idle, signon):
		"""
		Called when the bot receives a WHOIS about a particular user.
		nick - nickname of the user
		idle - seconds since last activity from user
		signon - unix timestamp when user signed on
		"""
		if self.memory.get("idle_callbacks"):
			self.memory["idle_callbacks"][nick].callback((nick, idle, signon))
			self.memory["idle_callbacks"].pop(nick)


	## User commands, from client->server

	def msg(self, user, message, length=None):
		"""
		Sends a message 'message' to 'user' (can be a user or a channel).
		If 'length' is specified, the message will be split into lengths
		of that size. If 'length' is not specified, the bot will determine
		an appropriate length automatically.
		"""
		if user.startswith("#"):
			opSym = self.channels[user].users[self.nickname].op_level
		else:
			opSym = ''
		line = f"<{opSym}{self.nickname}> {message}"
		self.log(user, line)

		super().msg(user, message, length)


	def reply(self, text, dest, reply_to, notice=False):
		"""
		Sends a message to 'dest' prefixed with 'reply_to' and a colon,
		ala "reply_to: text". More useful with the wrapper class.
		"""
		text = reply_to + ": " + text
		self.msg(dest, text)


	def quit(self, message=""):
		"""
		Disconnects from quitting normally results in the factory
		reconnecting us, so we need to include shutting down the factory.
		"""
		print("Quit from server")
		irc.IRCClient.quit(self, message)
		self.factory.stopTrying()
		sys.exit(0) # why doesn't this work?


	## Raw server->client messages

	def irc_RPL_NAMREPLY(self, prefix, params):
		"""
		Called when we have received a list of names in the channel from the
		server.
		"""
		channel_types = {"@": "secret", "*": "private", "=": "public"}
		channel_type = channel_types[params[1]]
		channel = params[2]
		nicklist = params[3].split()
		self.namesReceived(channel, channel_type, nicklist)


	def irc_JOIN(self, prefix, params):
		"""
		Called when a user joins a channel.
		"""
		nick = prefix.split('!')[0]
		channel = params[-1]
		if nick == self.nickname:
			self.joined(channel)
		else:
			self.userJoined(prefix, channel)


	def irc_PART(self, prefix, params):
		"""
		Called when a user leaves a channel.
		"""
		nick = prefix.split('!')[0]
		channel = params[0]
		if len(params) > 1:
			reason = params[1]
		else:
			reason = ""

		if nick == self.nickname:
			self.left(channel, reason)
		else:
			self.userLeft(prefix, channel, reason)


	def irc_QUIT(self, prefix, params):
		"""
		Called when a user has quit.
		"""
		nick = prefix.split('!')[0]
		self.userQuit(prefix, params[0])


	def irc_RPL_WHOISUSER(self, prefix, params):
		"""
		Called when we receive the server's response from our "WHOIS [user]"
		query. Contains hostmask information.
		"""
		_, nick, ident, host, _, realname = params
		self.whoisUser(nick, ident, host, realname)


	def irc_RPL_WHOISIDLE(self, prefix, params):
		"""
		Called when we receive the server's response from our "WHOIS [user]"
		query. Contains idle and signon time information.
		"""
		_, nick, idle, signon, _ = params
		self.whoisIdle(nick, idle, signon)


	def lineReceived(self, line):
		"""Overridden to fix broken unicode issues."""
		if bytes != str and isinstance(line, bytes):
			line = line.decode('utf-8', errors='surrogateescape')
		super().lineReceived(line)


class FulviaWrapper():
	"""
	A wrapper class for Fulvia to provide default destinations for msg
	methods and so forth.
	"""
	def __init__(self, fulvia, trigger):
		object.__setattr__(self, '_bot', fulvia)
		object.__setattr__(self, '_trigger', trigger)
		# directly setting these values would cause a recursion loop
		# overflow

	def __getattr__(self, attr):
		"""Redirects getting attributes to the master bot instance."""
		return getattr(self._bot, attr)

	def __setattr__(self, attr, value):
		"""Redirects setting attributes to the master bot instance."""
		return setattr(self._bot, attr, value)

	def msg(self, user=None, message=None, length=None):
		"""
		If user is None it will default to the channel the message was
		received on.
		"""
		if user == None:
			raise TypeError("msg() missing 2 required positional " \
				+ "arguments: 'user' and 'message'")
		if message == None:
			# assume the first argument is the message
			message = user
			user = self._trigger.channel
		self._bot.msg(user, message, length)

	def reply(self, message, destination=None, reply_to=None, notice=False):
		"""
		If destination is None, it defaults to the channel the message
		was received on.
		If reply_to is None, it defaults to the person who sent the
		message.
		"""
		if destination is None:
			destination = self._trigger.channel
		if reply_to is None:
			reply_to = self._trigger.nick
		self._bot.reply(message, destination, reply_to, notice)


class FulviaFactory(protocol.ReconnectingClientFactory):
	protocol = Fulvia