bluetooth4

#!/usr/bin/env lua
--[[ SimpleDBus example script

Get info from the bluetoothd daemon about the different bluetooth adapters,
and then make them all discover remote devices.

Tested with bluez 4.29
--]]

local printlist, printproperties
do
   local type, ipairs, write, format, sort =
         type, ipairs, io.write, string.format, table.sort

   printlist = function(list, spacing)
      if not spacing then spacing = '' end

      for i = 1, #list do
         write(spacing, format('%4i: ', i), list[i], '\n')
      end
   end

   printproperties = function(prop, spacing)
      if not spacing then spacing = '' end
      local keys, i, width = {}, 0, 0
      for k, _ in pairs(prop) do
         i = i+1
         keys[i] = k
         if #k > width then width = #k end
      end
      sort(keys)
      for _, k in ipairs(keys) do
         write(spacing, k, ': ')
         for i = 1, width - #k do
            write(' ')
         end
         local v = prop[k]
         if type(v) == 'table' then v = '...' end
         write(tostring(v), '\n')
      end
   end
end

-- Import the simpledbus module
local DBus = require 'simpledbus'

-- Get the system bus
local dbus = assert(DBus.SystemBus())

-- Make a new proxy object for the / object connected at org.bluez
local bluez = dbus:new_proxy('org.bluez', '/')

-- Add methods manually
bluez:add_method('ListAdapters', 'org.bluez.Manager')
bluez:add_method('DefaultAdapter', 'org.bluez.Manager')

-- Get a list of the adapters and print it
local adapters, msg = bluez:ListAdapters()
if not adapters then
   print('Couldn\'t get adapters: '..msg)
   os.exit(1)
end
if #adapters == 0 then
   print 'No adapters found'
   os.exit(0)
end
print('Adapters:')
printlist(adapters)

-- Show the default adapter too
print('\nDefault: '..assert(bluez:DefaultAdapter()))

-- Now go through the adapters, create proxies for each of them
-- and dump lots of information
for i, objpath in ipairs(adapters) do
   -- This time we use the auto_proxy() method to
   -- parse the introspection xml and create the
   -- proxy for us
   local a = assert(dbus:auto_proxy('org.bluez', objpath))
   adapters[i] = a

   print('\n'..objpath..':')

   local info = assert(a:GetProperties())
   printproperties(info, '   ')

   local devices = info.Devices
   if devices then
      for _, objpath in ipairs(devices) do
         print('\n   '..objpath..':')

         -- This time we don't even create a proxy object,
         -- but just use call_method() directly
         local info = assert(dbus:call_method(
            'org.bluez',         -- target
            objpath,             -- object path
            'org.bluez.Device',  -- interface
            'GetProperties'))    -- method name
            -- '',               -- signature (defaults to '')
            -- ...))             -- arguments

         printproperties(info, '      ')
      end
   end
end

-- Define signal handlers

local discovering = 0

local function DeviceFoundFunc(id)
   return function(address, prop)
      print(id..': Found device')
      printproperties(prop, '   ')
   end
end

local function PropertyChangedFunc(id, adapter)
   return function(name, value)
      print(id..': Property changed')
      print('   '..name..' -> '..tostring(value))
      if name == 'Discovering' then
         if value then
            discovering = discovering + 1
         else
            adapter:StopDiscovery()
            discovering = discovering - 1
            if discovering == 0 then DBus.stop() end
         end
      end
   end
end

-- Register signal handlers

for _, a in ipairs(adapters) do
   local id = a.object:gsub('.*/(.*)', '%1')

   --[[ You can register for signals like this
   assert(dbus:register_signal(a.object,
   'org.bluez.Adapter',
   'DeviceFound',
   DeviceFoundFunc(id)))
   --]]
   --![[ ..but since auto_proxy() already found
   --    much of this information we can just do
   assert(dbus:register_auto_signal(a.DeviceFound, DeviceFoundFunc(id)))
   --]]

   assert(dbus:register_auto_signal(a.PropertyChanged, PropertyChangedFunc(id, a)))
end

-- Start discovery on all adapters

print '\nStarting discovery on all devices:'
for _, a in ipairs(adapters) do
   a:StartDiscovery()
end

-- Run the main loop

local r, msg = DBus.mainloop(dbus)
if not r then
   print(msg)
   os.exit(1)
end

print 'Success!'

-- vi: syntax=lua ts=3 sw=3 et: