#!/usr/bin/env python

# Contributors Listed Below - COPYRIGHT 2015
# [+] International Business Machines Corp.
#
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
#     http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or
# implied. See the License for the specific language governing
# permissions and limitations under the License.

import sys
import dbus
import dbus.service
import dbus.mainloop.glib
import gobject
from OpenBMCMapper import Path, IntrospectionParser
import OpenBMCMapper

class DictionaryCache:
	def __init__(self):
		self.items = {'/': {} }

	def _merge_item(self, item):
		path, bus, iface = item
		if bus in self.items[path]:
			self.items[path][bus].append(iface)
		else:
			self.items[path][bus] = [ iface ]

	def add_item(self, item):
		path, bus, iface = item
		if path != '/':
			parent = Path(path).fq(last = -1)
			if parent not in self.items:
				self.add_item((parent, None, None))

		items = self.items.get(path, None)
		if bus and items:
			self._merge_item(item)
		elif items:
			pass
		elif bus:
			self.items[path] = { bus: [ iface ] }
		else:
			self.items[path] = {}

	def add_items(self, items):
		for i in items:
			self.add_item(i)

	def _has_children(self, path):
		return len(self.get_subtree_paths(path, 1, 'fuzzy')) != 1

	def _try_remove_path(self, path):
		if path == '/':
			return None

		if not self._has_children(path):
			del self.items[path]

			# try and remove the parent
			parent = Path(path).fq(last = -1)
			if not self.items[parent]:
				self._try_remove_path(parent)

	def _remove_bus(self, path, bus):
		del self.items[path][bus]
		if not self.items[path]:
			self._try_remove_path(path)

	def _remove_iface(self, path, bus, iface):
		self.items[path][bus].remove(iface)
		if not self.items[path][bus]:
			self._remove_bus(path, bus)

	def remove_item(self, item):
		self._remove_iface(*item)

	def remove_items(self, items):
		for x in items:
			self.remove_item(x)

	def remove_bus(self, name):
		for path,x in self.items.items():
			for bus,ifaces in x.items():
				if name != bus:
					continue
				self.remove_items([ (path, bus, iface) \
						for iface in ifaces ])

	def remove_busses(self, names):
		for x in names:
			self.remove_bus(name)

	def _get_busses(self):
		busses = [ y.iterkeys() for y in [ x for x in self.items.itervalues() ] ]
		return set( x for y in busses for x in y ) # flatten nested lists

	def has_bus(self, bus):
		return any(bus in b for b in self._get_busses())

	def get_subtree_paths(self, root, depth, match_type):
		return filter(PathMatch(root, depth, match_type),
				self.items.iterkeys())

	def get_subtree(self, root, depth, match_type):
		return dict(filter(ObjectMatch(root, depth, match_type),
				self.items.iteritems()))

	@staticmethod
	def _iface__str__(ifaces):
		return '\n'.join(["    %s" %(x) for x in ifaces ])

	@staticmethod
	def _bus__str__(busses):
		return '\n'.join([ "%s\n%s" %(x, DictionaryCache._iface__str__(y)) \
				for x,y in busses.iteritems() ])

	def __str__(self):
		return '\n'.join([ "%s\n%s" %(x, DictionaryCache._bus__str__(y)) \
				for x,y in self.items.iteritems() ])

class PathMatch(object):
	def __init__(self, path, depth, match_type):
		p = Path(path)
		self.path = p.fq()
		self.depth = p.depth()
		self.match_type = match_type
		self.match_depth = None
		if depth != -1:
			self.match_depth = p.depth() + depth

	def __call__(self, path):
		p = Path(path)
		depth = p.depth()

		# 'is not None' is really needed because
		# the match depth can be zero
		if self.match_depth is not None and depth > self.match_depth:
			return False

		fuzzy_match = p.fq(last = self.depth) == self.path or \
				not self.depth
		depth_match = self.match_depth == depth

		if self.match_type == 'fuzzy':
			return fuzzy_match

		return fuzzy_match and depth_match

class ObjectMatch(PathMatch):
	def __init__(self, path, depth, match_type):
		super(ObjectMatch, self).__init__(path, depth, match_type)

	def __call__(self, tup):
		if not super(ObjectMatch, self).__call__(tup[0]):
			return False
		return tup[1]

class ObjectMapper(dbus.service.Object):
	def __init__(self, bus, path,
			name_match = OpenBMCMapper.org_dot_openbmc_match,
			intf_match = OpenBMCMapper.org_dot_openbmc_match):
		super(ObjectMapper, self).__init__(bus.dbus, path)
		self.cache = DictionaryCache()
		self.bus = bus
		self.name_match = name_match
		self.intf_match = intf_match
		self.tag_match = OpenBMCMapper.TagListMatch(['children', 'interface'])

		self.discovery_done = False

		gobject.idle_add(self.discover)
		self.bus.dbus.add_signal_receiver(self.bus_handler,
			dbus_interface = dbus.BUS_DAEMON_IFACE,
			signal_name = 'NameOwnerChanged')
		self.bus.dbus.add_signal_receiver(self.interfaces_added_handler,
			dbus_interface = dbus.BUS_DAEMON_IFACE + '.ObjectManager',
			signal_name = 'InterfaceesAdded',
			sender_keyword = 'sender')
		self.bus.dbus.add_signal_receiver(self.interfaces_removed_handler,
			dbus_interface = dbus.BUS_DAEMON_IFACE + '.ObjectManager',
			signal_name = 'InterfacesRemoved',
			sender_keyword = 'sender')

	def interfaces_added_handler(self, path, iprops, **kw):
		for x in iprops.iterkeys():
			if self.intf_match(x):
				self.cache.add_item((path, kw['sender'], x))

	def interfaces_removed_handler(self, path, interfaces, **kw):
		for x in interfaces:
			self.cache.remove_item((path, kw['sender'], x))

	def process_new_owner(self, name):
		# unique name
		return self.discover([ IntrospectionParser(name,
			self.bus.dbus, self.tag_match, self.intf_match) ])

	def process_old_owner(self, name):
		# unique name
		self.cache.remove_bus(name)

	def bus_handler(self, service, old, new):
		if not self.discovery_done or \
				not self.name_match(service):
			return

		if new:
			self.process_new_owner(new)
		if old:
			self.process_old_owner(old)

	def add_interfaces(self, owner, path, interfaces):
		for x in interfaces:
			self.cache.add_item((path, owner, x))

	def add_items(self, owner, bus_items):
		for x,y in bus_items.iteritems():
			self.add_interfaces(owner, x, y['interfaces'])

	def discover(self, owners = None):
		discovery = not self.discovery_done
		if not owners:
			owners = [ IntrospectionParser(x, self.bus.dbus,
				self.tag_match, self.intf_match) \
						for x in self.bus.get_owner_names(self.name_match) ]
			self.discovery_done = True
		for o in owners:

			# this only happens when an app
			# grabs more than one well known name
			if self.cache.has_bus(o.name):
				continue

			self.add_items(o.name, o.introspect())

		if discovery:
			print "ObjectMapper discovery complete..."

	@dbus.service.method(OpenBMCMapper.MAPPER_IFACE, 'sis', 'as')
	def GetTreePaths(self, path, depth, match_type):
		return self.cache.get_subtree_paths(path, depth, match_type)

	@dbus.service.method(OpenBMCMapper.MAPPER_IFACE, 'sis', 'a{sa{sas}}')
	def GetTree(self, path, depth, match_type):
		return self.cache.get_subtree(path, depth, match_type)

	@dbus.service.method(OpenBMCMapper.MAPPER_IFACE, 'asis', 'a{sa{sas}}')
	def GetTrees(self, paths, depth, match_type):
		values = {}
		for x in paths:
			values.update(self.GetTree(x, depth, match_type))
		return values

class BusWrapper:
	def __init__(self, bus):
		self.dbus = bus

	def get_service_names(self, match):
		# these are well known names
		return [ x for x in self.dbus.list_names() \
				if match(x) and x != OpenBMCMapper.MAPPER_NAME ]

	def get_owner_names(self, match):
		# these are unique connection names
		return list( set( [ self.dbus.get_name_owner(x) \
				for x in self.get_service_names(match) ] ) )

if __name__ == '__main__':
	dbus.mainloop.glib.DBusGMainLoop(set_as_default=True)
	bus = dbus.SystemBus()
	s = dbus.service.BusName(OpenBMCMapper.MAPPER_NAME, bus)
	o = ObjectMapper(BusWrapper(bus), OpenBMCMapper.MAPPER_PATH)
	loop = gobject.MainLoop()

	loop.run()