.shutdown

os.pullEvent = os.pullEventRaw

local w,h = term.getSize()

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

local nOption = 1

local function drawMenu()
   term.clear()
   term.setCursorPos(1,1)
   term.write("Diamond OS // 1.2.1 //")
term.setCursorPos(1,2)
shell.run("id")

   term.setCursorPos(w-11,1)
   if nOption == 1 then
   term.write("Shutdown")
elseif nOption == 2 then
   term.write("Reboot")
elseif nOption == 3 then
   term.write("Sleep")
else
   term.write("Back")
end
end

--GUI
term.clear()
local function drawFrontend()
   printCentered( math.floor(h/2) - 2, "")
   printCentered( math.floor(h/2) - 1, "Shutdown dialog" )
   printCentered( math.floor(h/2) + 0, "")
   printCentered( math.floor(h/2) + 1, ((nOption == 1) and "[ Shutdown ]") or "Shutdown" )
   printCentered( math.floor(h/2) + 2, ((nOption == 2) and "[  Reboot  ]") or "Reboot " )
   printCentered( math.floor(h/2) + 3, ((nOption == 3) and "[  Sleep   ]") or "Sleep ")
   printCentered( math.floor(h/2) + 4, ((nOption == 4) and "[   Back   ]") or "Back" )
   printCentered( math.floor(h/2) + 5, "")
end

--Display
drawMenu()
drawFrontend()

while true do
    local e,p = os.pullEvent("key")
        if p == keys.up then
            if nOption > 1 then
                nOption = nOption - 1
                drawMenu()
                drawFrontend()
            end
        elseif p == keys.down then
            if nOption < 4 then
                nOption = nOption + 1
                drawMenu()
                drawFrontend()
            end
        elseif p == keys.enter then
            break
        end
end
term.clear()

--Conditions
if nOption  == 1 then
os.shutdown()
elseif nOption == 2 then
os.reboot()
elseif nOption == 3 then
shell.run("/bin/.sleep")
else
shell.run("/bin/main")
end