--Int--

local w,h = term.getSize()
local running = true

local selectedItem = 1

--Menu Int--

local MainMenu = {
	[1] = {text = "Programs", handler = function() selectedMenu = "Programs" end},
	[2] = {text = "Control Options", handler = function() selectedMenu = "Control" end},
	[3] = {text = "Redstone Options", handler = function() selectedMenu = "Redstone" end},
	[4] = {text = "Exit", handler = function() running = false end}
}

--Functions--

function centerPrint(string,ypos)
	term.setCursorPos(w/2-#string/2,ypos)
	write(string)
end

function PrintMenu(menu)
	for i=1,#menu do
		if i == selectedItem then
			centerPrint("[ "..menu[i].text.." ]",i+5)
		else
			centerPrint("  "..menu[i].text.."  ",i+5)
		end
	end
end

function Input(key, menu)
	if key == keys.enter then
		menu[selectedItem].handler()
	elseif key == keys.down and selectedItem < #menu then
		selectedItem = selectedItem + 1
	elseif key == keys.up and selectedItem > 1 then
		selectedItem = selectedItem - 1
	end
end

--Main Function--
local selectedMenu = MainMenu
term.clear()
term.setCursorPos(1,1)
while running do
	PrintMenu(selectedMenu)
	local event, key = os.pullEvent("key")
	Input(key, selectedMenu)
end
term.clear()
term.setCursorPos(1,1)