mod_bridge.py

'''
	Copyright 2014-2015 Teemu Piippo
	All rights reserved.

	Redistribution and use in source and binary forms, with or without
	modification, are permitted provided that the following conditions
	are met:

	1. Redistributions of source code must retain the above copyright
	   notice, this list of conditions and the following disclaimer.
	2. Redistributions in binary form must reproduce the above copyright
	   notice, this list of conditions and the following disclaimer in the
	   documentation and/or other materials provided with the distribution.
	3. The name of the author may not be used to endorse or promote products
	   derived from this software without specific prior written permission.

	THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
	IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
	OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
	IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
	INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
	NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
	DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
	THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
	(INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
	THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
'''

import re
from configfile import Config
import irc as Irc

ModuleData = {
	'commands':
	[
		{
			'name': 'bridge',
			'description': 'Creates a bridge between two channels',
			'args': '<destination>',
			'level': 'admin',
		},

		{
			'name': 'unbridge',
			'description': 'Removes a bridge between two channels',
			'args': '<destination>',
			'level': 'admin',
		},
	],

	'hooks':
	{
		'chanmsg': ['hook_chanmsg'],
	}
}

def get_destination (bot, target, destination, error):
	match = re.match (r'^([A-Za-z0-9_]+)/(#[#A-Za-z0-9_]*)$', destination)
	if not match:
		error ('malformed destination')

	destHost, destChannel = match.group (1, 2)
	dest = None

	# ensure we know this target
	for conndata in Config.get_nodelist ('connections'):
		if conndata.get_value('name') == destHost:
			break
	else:
		error ('unknown connection %s' % destHost)

	for channel in conndata.get_value('channels'):
		if channel['name'] == destChannel:
			break
	else:
		error ('unknown channel %s' % destChannel)

	if destHost == bot.name and destChannel == target:
		error ('cannot establish a bridge to self!')

	return (destHost, destChannel)

def cmd_bridge (bot, target, args, reply, error, **rest):
	source = (bot.name, target)
	dest = get_destination (bot, target, args['destination'], error)
	sourceName = '%s/%s' % source
	destName = '%s/%s' % dest
	bridges = Config.get_node('bridges')

	if destName in bridges.get_value (sourceName, []) \
	or sourceName in bridges.get_value (destName, []):
		error ('bridge to %s already established' % destName)

	bridges.append_value ('%s/%s' % source, '%s/%s' % dest)
	bridges.append_value ('%s/%s' % dest, '%s/%s' % source)
	reply ('bridge to %s established' % destName)

def cmd_unbridge (bot, target, args, reply, error, **rest):
	source = (bot.name, target)
	dest = get_destination (bot, target, args['destination'], error)
	sourceName = '%s/%s' % source
	destName = '%s/%s' % dest
	bridges = Config.get_node('bridges')

	if destName in bridges.get_value (sourceName, []) \
	or sourceName in bridges.get_value (destName, []):
		try:
			bridges.get_value (sourceName, []).remove (destName)
			bridges.get_value (destName, []).remove (sourceName)
		except ValueError:
			pass
		reply ('bridge to %s dropped' % destName)
	else:
		error ('no bridge to %s established' % destName)

def hook_chanmsg (bot, channel, sender, message, **rest):
	sourceName = '%s/%s' % (bot.name, channel)

	for dest in Config.get_node('bridges').get_value (sourceName, []):
		try:
			# Stuff some control characters into the name so that this doesn't cause people who
			# are on both ends of the bridge to highlight themselves
			# sender = sender[0:len(sender)/2] + (Irc.BoldChar * 2)
			# sender += '_'
			sender = sender[:len(sender)/2] + '`' + sender[len(sender)/2:]

			clientName, channelName = dest.split ('/')
			Irc.get_client (clientName).privmsg (channelName,
				'[%s/%s] <%s> %s' % (bot.name, channel, sender, message))
		except Exception as e:
			Irc.broadcast ('Error while bridging from %s to %s: %s' %
				(sourceName, dest, e))
			pass