local run = true
local sItem = 1
local tW,tH = term.getSize()
local tMen = {}
local run = true
local cMen = 1

-- Menu functions
function sMenu(menu)
	local h = fs.open("menus","a")
	h.writeLine(textutils.serialize(menu))
	h.close()
end

function ex()
	for i=1, #tMen do
		for j=1,#(tMen[i].choice) do
			if tMen[i].choice[j].name == tMen[cMen].name then
				cMen = i
				sItem = 1
				return
			end
		end
	end
	term.clear()
	term.setCursorPos(1,1)
	run = false
end

function wizard()
	local counter = 1
	local name = nil
	local choice = {}
	term.clear()
	term.setCursorPos(1,1)
	print("This wizards guides you through the Menu Creation!")
	print("Please insert a Name for your Menu")
	name = read()
	print("Please insert the Choices of your Menu;Exit by typing 'exit'")
	while true do
		print("Choice "..tostring(counter))
		local tmp = read()
		if tmp == "exit" then
			break
		elseif counter > 7 then
			print("To much entries; Please create SubMenus")
			break
		end
		choice[counter] = {}
		print("please insert the Function it should start;for a submenu type 'submenu'")
		local tmp2 = read()
		if tmp2 == "submenu" then
			print("What is the name of the connected Menu?")
			local tmp3 = read()
			choice[counter].name = tmp3
		else
			choice[counter].name = nil
		end

		choice[counter].text = tmp
		choice[counter].handler = tmp2

		counter = counter + 1
	end
	choice[counter] = {}
	choice[counter].text = "Exit"
	choice[counter].handler = "exx"


	local menu = {}
	menu.name = name
	menu.choice = choice
	sMenu(menu)
end

function gMenuCount()
	if not fs.exists("menus") then
		return 0
	else
		local counter = 0
		local h = fs.open("menus","r")
		while h.readLine() ~= nil do
			counter = counter + 1
		end
		h.close()
		return counter
	end
end

function gMenu(nr)
	if not fs.exists("menus") then
		return "no file"
	elseif nr > gMenuCount() then
		return "does not exist"
	else
		local h = fs.open("menus","r")
		for i = 1,(nr-1) do
			h.readLine()
		end
		local menu = textutils.unserialize(h.readLine())
		if menu == nil then
			return "menu was nil"
		else
			return menu
		end
	end
end

function gtMen()
	if not fs.exists("menus") then
		return false
	end
	print("done gtMen test")
	local i = 1
	local h = fs.open("menus","r")
	local tmp = h.readLine()
	while not (tmp == nil) do
		print("gtMen inLoop")
		tmp = textutils.unserialize(tmp)
		print("start gtMen test 2 ")
		if not (tmp == nil) then
			tMen[i] = {}
			tMen[i] = tmp
		end
		print("done gtMen test 2")
		i = i +1
		tmp = h.readLine()
	end
	h.close()
	print("done gtMen")
end

-- Print
function cbstr(str,char)
	if char == nil then
		char = " "
	end
	local v = math.floor((tW-string.len(str))/2)
	for i=1,(v-1) do
		str = string.format(char..str)
	end
	for i = string.len(str),tW-1 do
		str = string.format(str..char)
	end
	return str
end

function chprint(strtbl)
	if strtbl == nil then
		strtbl = {"Test1","Test2","Test3"}
	end
	local space = 3
	local k = 0
	local v = math.floor((tH-#strtbl)/2)
	if v > space then
		while k < (space*2 -tH + #strtbl)/(#strtbl-1) do
			k = k+1
		end
	else
		space = 0
	end
	for i=1,#strtbl do
		for j=1,space do
			print(" ")
		end
		print(strtbl[i])
		for j=1,k do
			print(" ")
		end
	end
end

function printMenu()
	print(cbstr(tMen[cMen].name,"-"))
	local strtbl = {}
	for i=1,#(tMen[cMen].choice) do
		if i == sItem then
			strtbl[i] =cbstr("[ "..tostring(tMen[cMen].choice[i].text).." ]")
		else
			strtbl[i] =cbstr("  "..tostring(tMen[cMen].choice[i].text).."  ")
		end
	end
	chprint(strtbl)
end

-- Handler
function onKeyPressed(key)
	if key == keys.enter then
		onItemS()
	elseif key == keys.up then
		if sItem > 1 then
			sItem = sItem - 1
		end
	elseif key == keys.down then
		if sItem < #(tMen[cMen].choice) then
			sItem = sItem + 1
		end
	end
end

function onItemS()
	if tMen[cMen].choice[sItem].handler == "submenu" then
		for i = 1,#tMen do
			if tMen[i].name == tMen[cMen].choice[sItem].name then
				cMen = i
				return
			end
		end
	elseif tMen[cMen].choice[sItem].handler == "exx" then
		ex()
	else
		local h = loadstring(tMen[cMen].choice[sItem].handler)
		h()
	end
end

-- Main
function main()
	run = true
	gtMen()
	while run do
		term.clear()
		term.setCursorPos(1,1)
		printMenu()
		local event,key = os.pullEvent("key")
		onKeyPressed(key)
	end
end