#!/usr/bin/env lua

function run_command(cmd)

  local file = assert(io.popen(cmd, 'r'))
  local output = file:read('*all')
  file:close()

end

function open_dump()

  f = assert(io.popen ("hcidump --raw"))
  run_command("kill `pgrep hcitool`")
  run_command("hciconfig hci0 down")
  run_command("hciconfig hci0 up")
  f_null = assert(io.popen ("hcitool lescan --duplicates"))

  return f

end

function dump(o)
   if type(o) == 'table' then
      local s = '{ '
      for k,v in pairs(o) do
         if type(k) ~= 'number' then k = '"'..k..'"' end
--         s = s .. '['..k..'] = ' .. dump(v) .. ','
         s = s .. dump(v) .. ','
      end
      return s .. '} '
   else
      return tostring(o)
   end
end

function trim(s)
  return (s:gsub("^%s*(.-)%s*$", "%1"))
end

function process_packet(packet)

  bytes={}
  idx=1

  if packet:len()>1 then

    while packet:len()>2 do
      bytes[idx]=trim(packet:sub(1,3))
      idx=idx+1
      packet=packet:sub(4)
    end
    len = idx-1

    if bytes[1]=='04' and bytes[2]=='3E' then
      -- BLE Beacon?
      type=""
      mac=bytes[13]..':'..bytes[12]..':'..bytes[11]..':'..bytes[10]..':'..bytes[9]..':'..bytes[8]
      flags=bytes[14]
      power=tonumber("0x"..bytes[len-1])-256
      tx=tonumber("0x"..bytes[len])-256
      j = 15
      while j<len-2 do
        paysublen=tonumber('0x'..bytes[j])
	if bytes[j+1]=="FF" and bytes[j+2]=="4C" and bytes[j+3]=="00" and bytes[j+4]=="02" and bytes[j+5]=="15" then
	  -- Standard UUID iBeacon
          type="ibeacon"
	  uuid1=bytes[j+6]..bytes[j+7]..bytes[j+8]..bytes[j+9]
	  uuid2=bytes[j+10]..bytes[j+11]
	  uuid3=bytes[j+12]..bytes[j+13]
	  uuid4=bytes[j+14]..bytes[j+15]
	  uuid5=bytes[j+16]..bytes[j+17]..bytes[j+18]..bytes[j+19]..bytes[j+20]..bytes[j+21]
	  uuid=string.lower(uuid1..'-'..uuid2..'-'..uuid3..'-'..uuid4..'-'..uuid5)
          major=bytes[j+23]..bytes[j+22]
          minor=bytes[j+25]..bytes[j+24]
	end
        j=j+1+paysublen
      end
      if type=="ibeacon" then
        print(string.format("{type:'ibeacon',mac:'%s',uuid:'%s',major:'%s',minor:'%s',power:%d,tx:%d}",mac,uuid,major,minor,power,tx))
      else
        print(dump(bytes))
      end
    end
  end

end

function read_loop()

  packet = ""

  for line in inp:lines() do

    lchr=line:sub(1,1)
    line=trim(line)

    if lchr=="<" or lchr==">" then
      line = trim(line:sub(2))
    end

    if not (lchr == " ") then
      process_packet(packet)
      packet = ""
    end

    llen=line:len()

    if llen<59 then
      packet = packet .. " " .. line
      process_packet(packet)
      packet=""
    else
      packet = packet .. " " .. line
    end    
    
  end

end

inp = open_dump()

read_loop()