wheemo.rb

###
# Find WeMo Insight switches and turn them on or off.
#
# Usage:
#
#   WheeMo::Switch.each do |switch|
#     p switch.friendly_name
#     if switch.on?
#       switch.off!
#     else
#       switch.on!
#     end
#   end
#
# License: Public Domain

require 'socket'
require 'net/http'

module WheeMo
  class Switch < Struct.new :location
    class << self; include Enumerable; end

    def self.each
      UPNP.each("upnp:rootdevice") { |response|
        usn = response['usn'].split ':'
        if usn.length == 2 && usn.last =~ /Insight/
          yield Switch.new URI.parse response['location']
        end
      }
    end

    def friendly_name
      doc = Net::HTTP.get location
      /<friendlyName>([^<]*)<\/friendlyName>/.match(doc)[1]
    end

    def on?; !off?; end

    def off?
      res = do_req make_binary_state_req 'Get', '1'
      /<BinaryState>([^<]*)<\/BinaryState>/.match(res.body)[1] == '0'
    end

    def on!
      do_req make_binary_state_req 'Set', '1'
      self
    end

    def off!
      do_req make_binary_state_req 'Set', '0'
      self
    end

    private

    def do_req req
      http = Net::HTTP.new location.host, location.port
      http.request req
    end

    def make_binary_state_req get_or_set, state
      req = Net::HTTP::Post.new '/upnp/control/basicevent1'
      req['SOAPACTION'] = "\"urn:Belkin:service:basicevent:1##{get_or_set}BinaryState\""
      req['Content-Type'] = "text/xml; charset=\"utf-8\""
      req.body = <<-eoxml
<?xml version="1.0" encoding="utf-8"?>
<s:Envelope xmlns:s="http://schemas.xmlsoap.org/soap/envelope/" s:encodingStyle="http://schemas.xmlsoap.org/soap/encoding/">
  <s:Body>
    <u:#{get_or_set}BinaryState xmlns:u="urn:Belkin:service:basicevent:1">
      <BinaryState>#{state}</BinaryState>
    </u:#{get_or_set}BinaryState>
  </s:Body>
</s:Envelope>
      eoxml
      req
    end
  end

  class UPNP
    BROADCAST_ADDR = '239.255.255.250'
    BROADCAST_PORT = 1900
    SEARCH = [
      "M-SEARCH * HTTP/1.1",
      "HOST: #{BROADCAST_ADDR}:#{BROADCAST_PORT}",
      "MAN: \"ssdp:discover\"",
      "MX: 5",
      "ST: ssdp:all",
    ]

    def self.each type = nil, timeout = 2
      sock = UDPSocket.new
      query = SEARCH
      query += ["ST: #{type}"] if type

      sock.send(query.join("\r\n") + "\r\n\r\n", 0, BROADCAST_ADDR, BROADCAST_PORT)
      buf = Net::BufferedIO.new sock

      loop do
        rd, = IO.select [sock], nil, nil, timeout
        break unless rd
        yield Net::HTTPResponse.read_new buf
      end
    ensure
      sock.close if sock
    end
  end
end