local nv_time = 3

for nv = 1,2,1 do

  if nv == 1 then
  nv_time = 5 -- time for 1st node
  else
  nv_time = 20 -- time for 2nd node
  end

minetest.register_node("lottpotion:night_vis_"..nv, {
	description = "Potion of Night Vision ("..nv_time.." sec.)",
	drawtype = "plantlike",
	tiles = {"lottpotion_night_vis.png^vessels_glass_bottle.png"},
	is_ground_content = false,
	walkable = false,
	paramtype = "light",
	selection_box = {
		type = "fixed",
		fixed = {-0.25, -0.5, -0.25, 0.25, 0.4, 0.25}
	},
	groups = {vessel=1,dig_immediate=3,attached_node=1, potion=1},
	sounds = default.node_sound_glass_defaults(),
	stack_max = 1,
	wield_image = "lottpotion_night_vis.png^vessels_glass_bottle.png",
	inventory_image = "lottpotion_night_vis.png^vessels_glass_bottle.png",
	on_use = function(item, user, pointed_thing)
			local player = user:get_player_name()
			lightchange(user, nv_time) -- here time is 20 for both nodes
			--effect
			local playerpos = user:getpos();
			minetest.add_particlespawner(
			7, --amount
			0.1, --time
			{x=playerpos.x-1, y=playerpos.y+1, z=playerpos.z-1}, --minpos
			{x=playerpos.x+1, y=playerpos.y+1, z=playerpos.z+1}, --maxpos
			{x=-0, y=3, z=-0}, --minvel
			{x=0, y=4, z=0}, --maxvel
			{x=-0.5,y=0,z=-0.5}, --minacc
			{x=0.5,y=1,z=0.5}, --maxacc
			0.1, --minexptime
			0.2, --maxexptime
			1, --minsize
			2, --maxsize
			false, --collisiondetection
			"bubble.png" --texture
		)
		item:replace("vessels:glass_bottle")
	return item
	end
})

end

function lightchange(person, duration)
	local mtime = minetest.get_timeofday()
	if mtime <= 0.25 or mtime >= 0.75 then
	person:override_day_night_ratio(mtime+0.5)
	minetest.after(duration, function()
	person:override_day_night_ratio(nil)
	end)
	end
end