#!/usr/bin/env python3
"""
Some helper functions and other tools.
"""
import re
import threading

op_level = {
	"voice":  1,
	"v":      1,
	"+":      1,
	"halfop": 2,
	"h":      2,
	"%":      2,
	"op":     4,
	"o":      4,
	"@":      4,
	"admin":  8,
	"a":      8,
	"&":      8,
	"owner":  16,
	"q":      16,
	"~":      16
}

class FulviaMemory(dict):
	"""
	A simple thread-safe dict implementation.

	In order to prevent exceptions when iterating over the values and changing
	them at the same time from different threads, we use a blocking lock on
	``__setitem__`` and ``__contains__``.
	"""
	def __init__(self, *args):
		dict.__init__(self, *args)
		self.lock = threading.Lock()


	def __setitem__(self, key, value):
		self.lock.acquire()
		result = dict.__setitem__(self, key, value)
		self.lock.release()
		return result


	def __contains__(self, key):
		"""
		Check if a key is in the dict.

		It locks it for writes when doing so.
		"""
		self.lock.acquire()
		result = dict.__contains__(self, key)
		self.lock.release()
		return result


class User(object):
	"""A representation of a user Fulvia is aware of."""
	def __init__(self, nick):
		self.nick = nick
		"""The user's nickname."""

		self.ident = ""
		self.user = self.ident
		"""The user's local username/ident."""

		self.host = ""
		"""The user's hostname."""

		self.channels = {}
		"""The channels the user is in."""

		self.away = None
		"""Whether the user is marked as away."""

	hostmask = property(lambda self: '{}!{}@{}'.format(self.nick, self.user,
													   self.host))
	"""The user's full hostmask."""


class Channel(object):
	"""A representation of a channel Fulvia is in."""
	def __init__(self, name):
		self.name = name
		"""The name of the channel."""

		self.type = ""
		"""
		The type of channel this is. Options are 'secret', 'private' or
		'public' per RFC 2812.
		"""

		self.topic = ""
		"""The topic of the channel."""

		self.users = {}
		"""The users in the channel. A set to ensure there are no duplicates."""

		self.privileges = {}
		"""The op levels of the users in the channel."""	

		self.modes = ""
		"""The mode of the channel."""
		# NOTE: this doesn't work yet

	def remove_user(self, nick):
		"""
		Removes a user from the channel.
		"""
		user = self.users.pop(nick, None)
		self.privileges.pop(nick, None)
		if user != None:
			user.channels.pop(self.name, None)

	def add_user(self, user):
		"""
		Adds a user to the channel.
		"""
		assert isinstance(user, User)
		self.users[user.nick] = user
		self.privileges[user.nick] = 0
		user.channels[self.name] = self

	def rename_user(self, old, new):
		"""
		Renames the user.
		"""
		if old in self.users:
			self.users[new] = self.users.pop(old)
		if old in self.privileges:
			self.privileges[new] = self.privileges.pop(old)


class Command():
	"""
	A representation of a command and associated documentation and other
	atributes.
	"""
	def __init__(self, name):
		self.name = name
		self._func_name = ""
		self.priv = 0
		self.doc = None
		self.canonical = True
		self.aliases = []


def configureHostMask(mask):
	"""
	Returns a valid hostmask based on user input.
	"""
	if mask == '*!*@*':
		return mask
	if re.match('^[^.@!/]+$', mask) is not None:
		return '%s!*@*' % mask
	if re.match('^[^@!]+$', mask) is not None:
		return '*!*@%s' % mask

	m = re.match('^([^!@]+)@$', mask)
	if m is not None:
		return '*!%s@*' % m.group(1)

	m = re.match('^([^!@]+)@([^@!]+)$', mask)
	if m is not None:
		return '*!%s@%s' % (m.group(1), m.group(2))

	m = re.match('^([^!@]+)!(^[!@]+)@?$', mask)
	if m is not None:
		return '%s!%s@*' % (m.group(1), m.group(2))
	return ''