text: #!/usr/bin/env python
  """
  The MIT License (MIT)
  Copyright (c) 2015 Maker Musings
  Permission is hereby granted, free of charge, to any person obtaining a copy
  of this software and associated documentation files (the "Software"), to deal
  in the Software without restriction, including without limitation the rights
  to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
  copies of the Software, and to permit persons to whom the Software is
  furnished to do so, subject to the following conditions:
  The above copyright notice and this permission notice shall be included in
  all copies or substantial portions of the Software.
  THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
  IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
  AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
  LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
  OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
  THE SOFTWARE.
  """
  
  # For a complete discussion, see http://www.makermusings.com
  
  import email.utils
  import requests
  import select
  import socket
  import struct
  import sys
  import time
  import urllib
  import uuid
  import RPi.GPIO as GPIO
  import threading
  
  def onoff(pin):
      GPIO.output(pin, 1)
      time.sleep(5)
      GPIO.output(pin, 0)
  
  # This XML is the minimum needed to define one of our virtual switches
  # to the Amazon Echo
  
  SETUP_XML = """<?xml version="1.0"?>
  <root>
    <device>
      <deviceType>urn:MakerMusings:device:controllee:1</deviceType>
      <friendlyName>%(device_name)s</friendlyName>
      <manufacturer>Belkin International Inc.</manufacturer>
      <modelName>Emulated Socket</modelName>
      <modelNumber>3.1415</modelNumber>
      <UDN>uuid:Socket-1_0-%(device_serial)s</UDN>
    </device>
  </root>
  """
  
  
  DEBUG = False
  
  def dbg(msg):
      global DEBUG
      if DEBUG:
          print msg
          sys.stdout.flush()
  
  
  # A simple utility class to wait for incoming data to be
  # ready on a socket.
  
  class poller:
      def __init__(self):
          if 'poll' in dir(select):
              self.use_poll = True
              self.poller = select.poll()
          else:
              self.use_poll = False
          self.targets = {}
  
      def add(self, target, fileno = None):
          if not fileno:
              fileno = target.fileno()
          if self.use_poll:
              self.poller.register(fileno, select.POLLIN)
          self.targets[fileno] = target
  
      def remove(self, target, fileno = None):
          if not fileno:
              fileno = target.fileno()
          if self.use_poll:
              self.poller.unregister(fileno)
          del(self.targets[fileno])
  
      def poll(self, timeout = 0):
          if self.use_poll:
              ready = self.poller.poll(timeout)
          else:
              ready = []
              if len(self.targets) > 0:
                  (rlist, wlist, xlist) = select.select(self.targets.keys(), [], [], timeout)
                  ready = [(x, None) for x in rlist]
          for one_ready in ready:
              target = self.targets.get(one_ready[0], None)
              if target:
                  target.do_read(one_ready[0])
   
  
  # Base class for a generic UPnP device. This is far from complete
  # but it supports either specified or automatic IP address and port
  # selection.
  
  class upnp_device(object):
      this_host_ip = None
  
      @staticmethod
      def local_ip_address():
          if not upnp_device.this_host_ip:
              temp_socket = socket.socket(socket.AF_INET, socket.SOCK_DGRAM)
              try:
                  temp_socket.connect(('8.8.8.8', 53))
                  upnp_device.this_host_ip = temp_socket.getsockname()[0]
              except:
                  upnp_device.this_host_ip = '127.0.0.1'
              del(temp_socket)
              dbg("got local address of %s" % upnp_device.this_host_ip)
          return upnp_device.this_host_ip
          
  
      def __init__(self, listener, poller, port, root_url, server_version, persistent_uuid, other_headers = None, ip_address = None):
          self.listener = listener
          self.poller = poller
          self.port = port
          self.root_url = root_url
          self.server_version = server_version
          self.persistent_uuid = persistent_uuid
          self.uuid = uuid.uuid4()
          self.other_headers = other_headers
  
          if ip_address:
              self.ip_address = ip_address
          else:
              self.ip_address = upnp_device.local_ip_address()
  
          self.socket = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
          self.socket.bind((self.ip_address, self.port))
          self.socket.listen(5)
          if self.port == 0:
              self.port = self.socket.getsockname()[1]
          self.poller.add(self)
          self.client_sockets = {}
          self.listener.add_device(self)
  
      def fileno(self):
          return self.socket.fileno()
  
      def do_read(self, fileno):
          if fileno == self.socket.fileno():
              (client_socket, client_address) = self.socket.accept()
              self.poller.add(self, client_socket.fileno())
              self.client_sockets[client_socket.fileno()] = client_socket
          else:
              data, sender = self.client_sockets[fileno].recvfrom(4096)
              if not data:
                  self.poller.remove(self, fileno)
                  del(self.client_sockets[fileno])
              else:
                  self.handle_request(data, sender, self.client_sockets[fileno])
  
      def handle_request(self, data, sender, socket):
          pass
  
      def get_name(self):
          return "unknown"
          
      def respond_to_search(self, destination, search_target):
          dbg("Responding to search for %s" % self.get_name())
          date_str = email.utils.formatdate(timeval=None, localtime=False, usegmt=True)
          location_url = self.root_url % {'ip_address' : self.ip_address, 'port' : self.port}
          message = ("HTTP/1.1 200 OK\r\n"
                    "CACHE-CONTROL: max-age=86400\r\n"
                    "DATE: %s\r\n"
                    "EXT:\r\n"
                    "LOCATION: %s\r\n"
                    "OPT: \"http://schemas.upnp.org/upnp/1/0/\"; ns=01\r\n"
                    "01-NLS: %s\r\n"
                    "SERVER: %s\r\n"
                    "ST: %s\r\n"
                    "USN: uuid:%s::%s\r\n" % (date_str, location_url, self.uuid, self.server_version, search_target, self.persistent_uuid, search_target))
          if self.other_headers:
              for header in self.other_headers:
                  message += "%s\r\n" % header
          message += "\r\n"
          temp_socket = socket.socket(socket.AF_INET, socket.SOCK_DGRAM)
          temp_socket.sendto(message, destination)
   
  
  # This subclass does the bulk of the work to mimic a WeMo switch on the network.
  
  class fauxmo(upnp_device):
      @staticmethod
      def make_uuid(name):
          return ''.join(["%x" % sum([ord(c) for c in name])] + ["%x" % ord(c) for c in "%sfauxmo!" % name])[:14]
  
      def __init__(self, name, listener, poller, ip_address, port, action_handler = None):
          self.serial = self.make_uuid(name)
          self.name = name
          self.ip_address = ip_address
          persistent_uuid = "Socket-1_0-" + self.serial
          other_headers = ['X-User-Agent: redsonic']
          upnp_device.__init__(self, listener, poller, port, "http://%(ip_address)s:%(port)s/setup.xml", "Unspecified, UPnP/1.0, Unspecified", persistent_uuid, other_headers=other_headers, ip_address=ip_address)
          if action_handler:
              self.action_handler = action_handler
          else:
              self.action_handler = self
          dbg("FauxMo device '%s' ready on %s:%s" % (self.name, self.ip_address, self.port))
  
      def get_name(self):
          return self.name
  
      def handle_request(self, data, sender, socket):
          if data.find('GET /setup.xml HTTP/1.1') == 0:
              dbg("Responding to setup.xml for %s" % self.name)
              xml = SETUP_XML % {'device_name' : self.name, 'device_serial' : self.serial}
              date_str = email.utils.formatdate(timeval=None, localtime=False, usegmt=True)
              message = ("HTTP/1.1 200 OK\r\n"
                         "CONTENT-LENGTH: %d\r\n"
                         "CONTENT-TYPE: text/xml\r\n"
                         "DATE: %s\r\n"
                         "LAST-MODIFIED: Sat, 01 Jan 2000 00:01:15 GMT\r\n"
                         "SERVER: Unspecified, UPnP/1.0, Unspecified\r\n"
                         "X-User-Agent: redsonic\r\n"
                         "CONNECTION: close\r\n"
                         "\r\n"
                         "%s" % (len(xml), date_str, xml))
              socket.send(message)
          elif data.find('SOAPACTION: "urn:Belkin:service:basicevent:1#SetBinaryState"') != -1:
              success = False
              if data.find('<BinaryState>1</BinaryState>') != -1:
                  # on
                  dbg("Responding to ON for %s" % self.name)
                  success = self.action_handler.on()
              elif data.find('<BinaryState>0</BinaryState>') != -1:
                  # off
                  dbg("Responding to OFF for %s" % self.name)
                  success = self.action_handler.off()
              else:
                  dbg("Unknown Binary State request:")
                  dbg(data)
              if success:
                  # The echo is happy with the 200 status code and doesn't
                  # appear to care about the SOAP response body
                  soap = ""
                  date_str = email.utils.formatdate(timeval=None, localtime=False, usegmt=True)
                  message = ("HTTP/1.1 200 OK\r\n"
                             "CONTENT-LENGTH: %d\r\n"
                             "CONTENT-TYPE: text/xml charset=\"utf-8\"\r\n"
                             "DATE: %s\r\n"
                             "EXT:\r\n"
                             "SERVER: Unspecified, UPnP/1.0, Unspecified\r\n"
                             "X-User-Agent: redsonic\r\n"
                             "CONNECTION: close\r\n"
                             "\r\n"
                             "%s" % (len(soap), date_str, soap))
                  socket.send(message)
          else:
              dbg(data)
  
      def on(self):
          return False
  
      def off(self):
          return True
  
  
  # Since we have a single process managing several virtual UPnP devices,
  # we only need a single listener for UPnP broadcasts. When a matching
  # search is received, it causes each device instance to respond.
  #
  # Note that this is currently hard-coded to recognize only the search
  # from the Amazon Echo for WeMo devices. In particular, it does not
  # support the more common root device general search. The Echo
  # doesn't search for root devices.
  
  class upnp_broadcast_responder(object):
      TIMEOUT = 0
  
      def __init__(self):
          self.devices = []
  
      def init_socket(self):
          ok = True
          self.ip = '239.255.255.250'
          self.port = 1900
          try:
              #This is needed to join a multicast group
              self.mreq = struct.pack("4sl",socket.inet_aton(self.ip),socket.INADDR_ANY)
  
              #Set up server socket
              self.ssock = socket.socket(socket.AF_INET,socket.SOCK_DGRAM,socket.IPPROTO_UDP)
              self.ssock.setsockopt(socket.SOL_SOCKET,socket.SO_REUSEADDR,1)
  
              try:
                  self.ssock.bind(('',self.port))
              except Exception, e:
                  dbg("WARNING: Failed to bind %s:%d: %s" , (self.ip,self.port,e))
                  ok = False
  
              try:
                  self.ssock.setsockopt(socket.IPPROTO_IP,socket.IP_ADD_MEMBERSHIP,self.mreq)
              except Exception, e:
                  dbg('WARNING: Failed to join multicast group:',e)
                  ok = False
  
          except Exception, e:
              dbg("Failed to initialize UPnP sockets:",e)
              return False
          if ok:
              dbg("Listening for UPnP broadcasts")
  
      def fileno(self):
          return self.ssock.fileno()
  
      def do_read(self, fileno):
          data, sender = self.recvfrom(1024)
          if data:
              if data.find('M-SEARCH') == 0 and data.find('urn:Belkin:device:**') != -1:
                  for device in self.devices:
                      time.sleep(0.1)
                      device.respond_to_search(sender, 'urn:Belkin:device:**')
              else:
                  pass
  
      #Receive network data
      def recvfrom(self,size):
          if self.TIMEOUT:
              self.ssock.setblocking(0)
              ready = select.select([self.ssock], [], [], self.TIMEOUT)[0]
          else:
              self.ssock.setblocking(1)
              ready = True
  
          try:
              if ready:
                  return self.ssock.recvfrom(size)
              else:
                  return False, False
          except Exception, e:
              dbg(e)
              return False, False
  
      def add_device(self, device):
          self.devices.append(device)
          dbg("UPnP broadcast listener: new device registered")
  
  
  # This is an example handler class. The fauxmo class expects handlers to be
  # instances of objects that have on() and off() methods that return True
  # on success and False otherwise.
  #
  # This example class takes two full URLs that should be requested when an on
  # and off command are invoked respectively. It ignores any return data.
  
  class rest_api_handler(object):
      def __init__(self, on_cmd, off_cmd):
          self.on_cmd = on_cmd
          self.off_cmd = off_cmd
  
      def on(self):
          r = requests.get(self.on_cmd)
          return r.status_code == 200
  
      def off(self):
          r = requests.get(self.off_cmd)
          return r.status_code == 200
  
  class dummy_handler(object):
      def __init__(self, name):
          self.name = name
  
      def on(self):
          print(self.name, "ON")
          return True
  
      def off(self):
          print(self.name, "OFF")
          return True
  
  class gpio_handler(object):
      def __init__(self, pin_number):
          self.pin = pin_number
          GPIO.setmode(GPIO.BOARD)
          GPIO.setup(pin_number, GPIO.OUT)
  
      def on(self):
          print(self.pin, "ON")
          thr = threading.Thread(target=onoff, args=(self.pin,), kwargs={})
          thr.start()
          return True
  
      def off(self):
          print(self.pin, "OFF")
          GPIO.output(self.pin, 0)
          return True
  
  # Each entry is a list with the following elements:
  #
  # name of the virtual switch
  # object with 'on' and 'off' methods
  # port # (optional; may be omitted)
  
  # NOTE: As of 2015-08-17, the Echo appears to have a hard-coded limit of
  # 16 switches it can control. Only the first 16 elements of the FAUXMOS
  # list will be used.
  
  # FAUXMOS = [
  #     ['office lights', rest_api_handler('http://192.168.5.4/ha-api?cmd=on&a=office', 'http://192.168.5.4/ha-api?cmd=off&a=office')],
  #     ['kitchen lights', rest_api_handler('http://192.168.5.4/ha-api?cmd=on&a=kitchen', 'http://192.168.5.4/ha-api?cmd=off&a=kitchen')],
  # ]
  
  FAUXMOS = [
          ['Smart Candle', gpio_handler(7)]
      ]
  
  # FAUXMOS = [
  #         ['office lights', dummy_handler("officelight")],
  #         ['kitchen lights', dummy_handler("kitchenlight")],
  #     ]
  
  if len(sys.argv) > 1 and sys.argv[1] == '-d':
      DEBUG = True
  
  # Set up our singleton for polling the sockets for data ready
  p = poller()
  
  # Set up our singleton listener for UPnP broadcasts
  u = upnp_broadcast_responder()
  u.init_socket()
  
  # Add the UPnP broadcast listener to the poller so we can respond
  # when a broadcast is received.
  p.add(u)
  
  # Create our FauxMo virtual switch devices
  for one_faux in FAUXMOS:
      if len(one_faux) == 2:
          # a fixed port wasn't specified, use a dynamic one
          one_faux.append(0)
      switch = fauxmo(one_faux[0], u, p, None, one_faux[2], action_handler = one_faux[1])
  
  dbg("Entering main loop\n")
  
  while True:
      try:
          # Allow time for a ctrl-c to stop the process
          p.poll(100)
          time.sleep(0.1)
      except Exception, e:
          GPIO.cleanup()
          dbg(e)
          break