modulecore.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.
'''

from __future__ import print_function
import os
import re
import time
from configfile import Config

Modules = {}
Commands = {}
Hooks = {}

class CommandError (Exception):
	def __init__ (self, value):
		self.value = value
	def __str__ (self):
		return self.value

#
# init_data()
#
# Initializes command module data
#
def init_data():
	global Commands
	global Modules
	files = os.listdir ('.')
	numHooks = 0

	for fn in files:
		if fn[0:4] != 'mod_' or fn[-3:] != '.py':
			continue

		fn = fn[0:-3]
		globals = {}
		module = __import__ (fn)
		Modules[fn] = module

		for cmd in module.ModuleData['commands']:
			if cmd['args'] == None:
				cmd['args'] = ''

			cmd['module'] = module
			cmd['regex'] = make_regex (cmd['args'])
			cmd['argnames'] = []
			Commands[cmd['name']] = cmd

			for argname in cmd['args'].split (' '):
				argname = argname[1:-1]

				if argname[-3:] == '...':
					argname = argname[0:-3]

				if argname == '':
					continue

				cmd['argnames'].append (argname)

		if 'hooks' in module.ModuleData:
			for key, hooks in module.ModuleData['hooks'].items():
				for hook in hooks:
					if key not in Hooks:
						Hooks[key] = []

					Hooks[key].append ({'name': hook, 'func': getattr (module, hook)})
					numHooks += 1

		print ('''Loaded module %s''' % fn)

	print ('''Loaded %d commands and %d hooks in %d modules''' %
		(len (Commands), numHooks, len (Modules)))

#
# command_error (message)
#
# Raises a command error
#
def command_error (message):
	raise CommandError (message)

#
# is_available (cmd, ident, host)
#
# Is the given command available to the given user?
#
def is_available (cmd, ident, host):
	if cmd['level'] == 'admin' \
	and not "%s@%s" % (ident, host) in Config.get_value ('admins', default=[]):
		return False

	return True

#
# response_function
#
g_responsePages = [[]]
g_responsePageNum = 0
g_lastConfirm = 0
g_confirmCommand = None

class Confirmxeption (Exception):
	def __init__ (self, id, value):
		self.id = id
		self.message = value
	def __str__ (self):
		return self.message

def response_function (message):
	global g_responsePages

	if len (g_responsePages[-1]) > 4:
		g_responsePages.append ([message])
	else:
		g_responsePages[-1].append (message)

def confirm_function (id, message):
	raise Confirmxeption (id, message)

def print_responses (commandObject):
	global g_responsePages
	global g_responsePageNum
	bot = commandObject['bot']
	replyto = commandObject['replyto']

	# Check bounds
	if g_responsePageNum >= len (g_responsePages):
		bot.privmsg (replyto, "No more messages.")
		return

	# Print this page
	for line in g_responsePages[g_responsePageNum]:
		bot.privmsg (replyto, line)

	# Advance page cursor
	g_responsePageNum += 1

	# If this was not the last page, tell the user there's more
	if g_responsePageNum != len (g_responsePages):
		num = (len (g_responsePages) - g_responsePageNum)
		bot.privmsg (replyto, "%d more page%s, use .more to continue output" \
			% (num, 's' if num != 1 else ''))

#
# check_same_caller (comm1, comm2)
#
# Are the two commands called by the same person?
#
def check_same_caller (comm1, comm2):
	return comm1['bot'].name == comm2['bot'].name \
	   and comm1['sender']   == comm2['sender'] \
	   and comm1['ident']    == comm2['ident'] \
	   and comm1['host']     == comm2['host']

def exec_command (commandObject):
	global g_lastConfirm
	global g_confirmCommand

	if 'function' in commandObject:
		func = commandObject['function']
	else:
		cmdname = commandObject['cmdname']

		try:
			func = getattr (commandObject['module'], 'cmd_' + cmdname)
		except AttributeError:
			command_error ('''command '%s' does not have a definition''' % cmdname)

	try:
		func (**commandObject)
	except Confirmxeption as e:
		if time.time() - g_lastConfirm < 15 and g_confirmCommand != None:
			command_error ('''another confirm is underway''')

		g_lastConfirm = time.time()
		response_function (str (e) + ' (.yes/.no)')
		commandObject['confirmed'] = e.id
		g_confirmCommand = commandObject
	except Exception as e:
		command_error (str (e))

#
# call_command (bot, message, cmdname, **kvargs)
#
# Calls a cobalt command
#
def call_command (bot, message, cmdname, **kvargs):
	global g_responsePages
	global g_responsePageNum

	try:
		cmd = Commands[cmdname]
	except KeyError:
		print ('''No such command %s''' % cmdname)
		return

	if not is_available (cmd=cmd, ident=kvargs['ident'], host=kvargs['host']):
		command_error ('''you may not use %s''' % cmdname)

	match = re.compile (cmd['regex']).match (message)

	if match == None:
		# didn't match
		command_error ('''usage: %s %s''' % (cmd['name'], cmd['args']))

	# .more is special as it is an interface to the page system.
	# Anything else resets it.
	if cmdname != 'more':
		g_responsePages = [[]]
		g_responsePageNum = 0

	i = 1
	args = {}

	for argname in cmd['argnames']:
		args[argname] = match.group (i)
		i += 1

	print ('''%s was called by %s''' % (cmdname, kvargs['sender']))
	commandObject = kvargs
	commandObject['bot'] = bot
	commandObject['cmdname'] = cmdname
	commandObject['args'] = args
	commandObject['reply'] = response_function
	commandObject['confirm'] = confirm_function
	commandObject['confirmed'] = 0
	commandObject['commandObject'] = commandObject
	commandObject['info'] = cmd
	commandObject['module'] = cmd['module']
	commandObject['error'] = command_error
	exec_command (commandObject)

	# Print the first page of responses.
	if cmdname != 'more':
		print_responses (commandObject)

def call_hook (bot, hookname, **kvargs):
	global g_responsePages
	global g_responsePageNum
	hookObject = kvargs
	hookObject['bot'] = bot
	g_responsePages = [[]]
	g_responsePageNum = 0

	if 'replyto' in hookObject:
		hookObject['reply'] = response_function

	if hookname in Hooks:
		for hook in Hooks[hookname]:
			hook['func'] (**hookObject)

	print_responses (hookObject)

def confirm (cmd, yes):
	global g_confirmCommand

	if g_confirmCommand == None:
		cmd['reply'] ('%s to what?' % cmd['cmdname'])
		return

	if not check_same_caller (cmd, g_confirmCommand):
		return

	if yes:
		exec_command (g_confirmCommand)
	else:
		cmd['reply'] ('okay then')

	g_confirmCommand = None

#
# get_available_commands
#
# Gets a list of commands available to the given user
#
def get_available_commands (ident, host):
	result=[]

	for cmdname,cmd in Commands.items():
		if not is_available (cmd, ident, host):
			continue

		result.append (cmdname)

	return result

#
# get_command_by_name
#
# Gets a command by name
#
def get_command_by_name (name):
	try:
		return Commands[name]
	except:
		return None

#
# make_regex
#
# Takes the argument list and returns a corresponding regular expression
#
def make_regex (arglist):
	if arglist == None:
		return '^.+$'

	gotoptional = False
	gotvariadic = False
	regex = ''

	for arg in arglist.split (' '):
		if gotvariadic:
			raise CommandError ('''variadic argument is not last''')

		if arg == '':
			continue

		gotliteral = False

		if arg[0] == '[' and arg[-1] == ']':
			arg = arg[1:-1]
			gotoptional = True
		elif arg[0] == '<' and arg[-1] == '>':
			if gotoptional:
				raise CommandError ('''mandatory argument after optional one''')

			arg = arg[1:-1]
		else:
			gotliteral = True

		if arg[-3:] == '...':
			gotvariadic = True
			arg = arg[:-3]

		if gotoptional == False:
			regex += r'\s+'
		else:
			regex += r'\s*'

		if gotliteral:
			regex += arg
		elif gotoptional:
			if gotvariadic:
				regex += r'(.*)'
			else:
				regex += r'([^ ]*)'
		else:
			if gotvariadic:
				regex += r'(.+)'
			else:
				regex += r'([^ ]+)'

	if not gotvariadic:
		regex += r'\s*'

	return '^[^ ]+%s$' % regex