#!/usr/bin/lua
--[[
ByteCnt:  1    1         1          2     1      4
          ---- --------- ---------- ----- ------ -------
FieldName:Type EventCode DataLength Event Status EventId
--]]

--Type
Command = 0x01
Event = 0x04

--OpCode
GapScan_enable = 0xFE51

--EventCode
HCI_LE_ExtEvent = 0xff

--Status
SUCCESS = 0x00

--Event
GAP_HCI_ExtentionCommandStatus = 0x067F
GAP_AdvertiserScannerEvent = 0x0613

--EventId 
GAP_EVT_ADV_REPORT = 0x00400000
GAP_EVT_SCAN_ENABLED = 0x00010000

local write = io.write
function print(...)
    local n = select("#",...)
    for i = 1,n do
        local v = tostring(select(i,...))
        write(v)
        if i~=n then write'\t' end
    end
--    write'\n'
end

function printf(str, ...)
	return print(str:format(...))
end

function lshift(x, by)
  return x * 2 ^ by
end

function GetUint8(Payload, position)
	return string.byte(Payload, position)
end	

function GetUint32(Payload, position)
	return (lshift(string.byte(Payload, position+3),24) + lshift(string.byte(Payload, position+2),16) + lshift(string.byte(Payload, position+1),8) + string.byte(Payload, position))
end

function GetUint16(Payload, position)
	return (lshift(string.byte(Payload, position+1),8) + string.byte(Payload, position))
end

function hexdump(Payload,separator)
	for i=1,Payload:len(), 1 do
		io.write(string.format("%02X", Payload:byte(i)))
		if (i< Payload:len()) then
			io.write(separator)
		end	
	end
end

ibeacon_hdr=string.char(0x1A,0xFF,0x4C,0x00,0x02,0x15)

function DumpAdvertiserData(Payload)
--[[
Len(1byte)+Type(1byte)+Data(Len bytes)
--]]
	while( Payload:len() > 0 ) do
		local Len = GetUint8(Payload,1)
		if (GetUint8(Payload,2) == 0xff) then -- manufacturer data
			print(" MFR=")
			hexdump(Payload:sub(1,Len+1),'')
			if (Payload:sub(1,6) == ibeacon_hdr) then
				print(" [ibeacon]")
			end	
		end
		Payload = string.sub(Payload,Len+2,-1)
	end
end

function DumpAdvertiserScannerEvent(Payload)
	local Status = GetUint8(Payload,3)
	local EventId = GetUint32(Payload,4)
	if((EventId==GAP_EVT_ADV_REPORT) and (Status==SUCCESS))
	then
		local MAC = string.sub(Payload,10,15)
		local TxPower = GetUint8(Payload,19)
		local RSSI = GetUint8(Payload,20)
		printf("MAC=%02X%02X%02X%02X%02X%02X RSI=%d PWR=%d",string.byte(MAC,6),string.byte(MAC,5),string.byte(MAC,4),
			string.byte(MAC,3),string.byte(MAC,2),string.byte(MAC,1),RSSI,TxPower)
		local DataLength = GetUint16(Payload,30)
		DumpAdvertiserData(string.sub(Payload,32,-1))
		print("\n")
	end
end	

function hci_event_paser()
	while true do
		local Header = io.read(3)
		if not Header then break end
		local EventType = GetUint8(Header,1)
		local EventCode = GetUint8(Header,2)
		local DataLength = GetUint8(Header,3)
		
		local Data = io.read(DataLength)
		local Event = GetUint16(Data,1)
--		print(EventType,EventCode,DataLength,Event)
		if not Data then break end
        if(Event==GAP_AdvertiserScannerEvent)
		then
			DumpAdvertiserScannerEvent(Data)
--			hexdump(ibeacon_hdr)
		end
	end
end

hci_event_paser()