local backlight = {}


backlight.hooks = {}
backlight.add_hook = function(callback)
	backlight.hooks[#backlight.hooks + 1] = callback
end

backlight.exec_hooks = function()
	backlight.read(function(status)
		for i=1, #backlight.hooks do
			backlight.hooks[i](status)
		end
	end)
end

backlight.read = function(callback)
	bin.backlight.get(
		function(stdout, stderr, exitreason, exitcode)
			callback(tonumber(stdout))
		end
	)
end


backlight.up = function()
	bin.backlight.up()
	backlight.exec_hooks()
end

backlight.down = function()
	bin.backlight.down()
	backlight.exec_hooks()
end

return backlight