mdword=memory.readdwordunsigned
mbyte=memory.readbyte
rshift=bit.rshift

-- Initialize on Script Startup
local frame = 0
local iframe = 0
local seed = 0
local initial = 0

memory.registerwrite(0x021D15AC, function() frame = frame + 1 end)
memory.registerwrite(0x0210F6CC, function() iframe = iframe + 1 end)

function buildseed()
	delay=mdword(0x021D1138)
	timehex=mdword(0x023FFDEC)
	datehex=mdword(0x023FFDE8)
	hour=string.format("%02X",(timehex%0x100)%0x40)	-- memory stores as decimal, but Lua reads as hex. Convert.
	minute=string.format("%02X",(rshift(timehex%0x10000,8)))
	second=string.format("%02X",(mbyte(0x02FFFDEE)))
	year=string.format("%02X",(mbyte(0x02FFFDE8)))
	month=string.format("%02X",(mbyte(0x02FFFDE9)))
	day=string.format("%02X",(mbyte(0x02FFFDEA)))
	ab=(month*day+minute+second)%256		-- Build Seed
	cd=hour
	cgd=delay%65536 +1 -- can tweak for calibration
	abcd=ab*0x100+cd
	efgh=(year+cgd)%0x10000
	nextseed=ab*0x1000000+cd*0x10000+efgh		-- Seed is built
	return nextseed
end

function main()
	currseed = mdword(0x021D15A8)
	seed = mdword(0x021D15AC)

	-- Detect initial seeding
	if mdword(0x021D15AC) == currseed then
		initial = mdword(0x021D15A8)
		if currseed ~= 0x00000000 then
			iframe = 0
			frame = 0
		end
	end
	if mdword(0x021D15A8) == 0 then	-- if seed is 0, reset everything
		iframe = 0
		frame = 0
	end

	-- Print variables in corner of bottom screen
	if frame == 0 then
		gui.text(0,-10,string.format("Next Seed: %08X", buildseed()))
	end
	gui.text(0,180,string.format("Initial Seed: %08X", initial))
	gui.text(0,170,string.format("Current Seed: %08X", currseed))
	gui.text(0,160,string.format("IRNG Frame: %d", iframe))
	gui.text(0,150,string.format("PRNG Frame: %d", frame))
	gui.text(0,140,string.format("Delay: %d", mdword(0x021D1138)))
end

gui.register(main)