[xOS] Main Menu

--[[
Main Menu File
Written by TheShadow989
]]--

os.pullEvent = os.pullEventRaw

local verNumber = "Alpha 1.24"
local nOption = 1

rRead = fs.open("xos/.usertable", "r")
users = textutils.unserialize(rRead.readAll())
rRead.close()
cu = tonumber(users[1])
cs = tonumber(users[cu+1])

local w,h = term.getSize()

local function drawMenu()
        local time = os.time()
        local formattedTime = textutils.formatTime(time, false)

        term.clear()
        term.setCursorPos(1,1)
        term.write("Logged in as: ")
        term.setTextColor( colors.red )
        term.write(""..users[cu].."")
        term.setTextColor( colors.white )
        term.setCursorPos(1,2)
        write(formattedTime)
        term.setCursorPos(1,19)
        term.write("xOS "..verNumber.." by TheShadow989")

        term.setCursorPos(w-11,1)
        if nOption == 1 then
           term.write("Command ")
        elseif nOption == 2 then
           term.write("Programs")
        elseif nOption == 3 then
           term.write("Accounts")
        elseif nOption == 4 then
           term.write("Details")
        elseif nOption == 5 then
           term.write("Shutdown")
        else
        end
end

function printCentered(y,s)
        local x = math.floor((w - string.len(s)) / 2)
        term.setCursorPos(x,y)
        term.clearLine()
        term.write( s )
end

term.clear()

local function drawFrontend()
   printCentered( math.floor(h/2) - 4, "")
   printCentered( math.floor(h/2) - 3, "Start Menu" )
   printCentered( math.floor(h/2) - 2, "")
   printCentered( math.floor(h/2) - 1, ((nOption == 1) and "[ Command  ]") or "Command " )
   printCentered( math.floor(h/2) + 0, ((nOption == 2) and "[ Programs ]") or "Programs" )
   printCentered( math.floor(h/2) + 1, ((nOption == 3) and "[ Accounts ]") or "Accounts" )
   printCentered( math.floor(h/2) + 2, ((nOption == 4) and "[ Details  ]") or "Details " )
   printCentered( math.floor(h/2) + 3, ((nOption == 5) and "[ Shutdown ]") or "Shutdown" )
   printCentered( math.floor(h/2) + 4, "")
end

drawMenu()
drawFrontend()

while true do
    local e,p = os.pullEvent()
    if e == "key" then
        local key = p
        if key == 17 or key == 200 then
            if nOption > 1 then
                nOption = nOption - 1
                drawMenu()
                drawFrontend()
            end
        elseif key == 31 or key == 208 then
            if nOption < 5 then
                nOption = nOption + 1
                drawMenu()
                drawFrontend()
            end
        elseif key == 28 then
            break
        end
    end
end
term.clear()

if nOption  == 1 then
    shell.run("xos/.command")
elseif nOption == 2 then
    shell.run("xos/.programs")
elseif nOption == 3 then
    shell.run("xos/.accounts")
elseif nOption == 4 then
    shell.run("xos/.details")
else
    os.shutdown()
end