Ender OS (Computer Craft)

-- Just know that this is still a work in progress.
-- I'll make it so you can download it as an official os later. ok cool.
-- after all this is a hobby project. although, I will show a list of shit im gonna add in later
function getTime()
    local osTime = os.time()
    local minutes = math.floor(osTime%13)
    local seconds = osTime - math.floor(osTime)
    seconds = seconds * 100
    seconds = seconds / (100/60)
    seconds = math.floor(seconds)
    if seconds < 10 then
        seconds = 0 .. seconds
    end
    local timeBracket = " AM"
    if osTime / 13 >= 1 then
        timeBracket = " PM"
    end
    return minutes .. ":" .. seconds .. timeBracket
end

function newLine(lines)
    for a = 1, lines do
        print("")
    end
end

function printCenter(message, force)
    local x,y = term.getSize()
    local x2,y2 = term.getCursorPos()
    term.setCursorPos(math.floor((x / 2) - (message:len() / 2))+0.5, y2+0.5)
    if not force then
        print(message)
    else
        write(message)
    end
end

function colorChange(menuBarColor)
    if menuBarColor == colors.red then
        menuBarColor = colors.orange
    elseif menuBarColor == colors.orange then
        menuBarColor = colors.yellow
    elseif menuBarColor == colors.yellow then
        menuBarColor = colors.green
    elseif menuBarColor == colors.green then
        menuBarColor = colors.blue
    elseif menuBarColor == colors.blue then
        menuBarColor = colors.purple
    elseif menuBarColor == colors.purple then
        menuBarColor = colors.black
    elseif menuBarColor == colors.black then
        menuBarColor = colors.red
    end
    return menuBarColor
end

local selection = 0
local screen = 0
local maxSelection = 1
local menuBarColor = colors.red
local backgroundColor = colors.black

function keyMain()
    while true do
        local event, key, isHeld = os.pullEvent("key")
        if key == keys.up then
            selection = selection - 1
        elseif key == keys.down then
            selection = selection + 1
        end
        if key == keys.enter and screen == 0 and selection == 0 then
            term.clear()
            error("Goodnight.")
        elseif key == keys.enter and screen == 0 and selection == 2 then
            screen = 1
            selection = 0
        elseif key == keys.enter and screen == 0 and selection == 1 then
            screen = 2
            selection = 0
        elseif key == keys.enter and screen == 1 and selection == 0 then
            screen = 0
            selection = 1
        elseif key == keys.enter and screen == 1 and selection == 1 then
            menuBarColor = colorChange(menuBarColor)
        elseif key == keys.enter and screen == 1 and selection == 2 then
            backgroundColor = colorChange(backgroundColor)
        elseif key == keys.enter and screen == 2 and selection == 0 then
            screen = 0
            selection = 0
        elseif key == keys.enter and screen == 2 and selection == 1 then
            screen = 3
            selection = 0
        elseif key == keys.enter and screen == 3 then
            screen = 2
            selection = 1
        end
    end
end

local win = window.create(term.current(),1,1,term.getSize())
term.redirect(win)
function main()
while true do
    win.setVisible(false)
    term.clear()
    term.setCursorPos(1,1)
    local termX, termY = term.getSize()
    if selection > maxSelection then
        selection = 0
    elseif selection < 0 then
        selection = maxSelection
    end
    local bg = term.getBackgroundColor()
    term.setBackgroundColor(backgroundColor)
    for b = 1, termY do
        for a = 1, termX do
            write(" ")
        end
    end
    term.setCursorPos(1, 1)
    term.setBackgroundColor(menuBarColor)
    for a = 1, termX do
        write(" ")
    end
    term.setCursorPos(1, 1)
    write("Ender OS")
    printCenter(getTime(), true)
    term.setBackgroundColor(backgroundColor)
    newLine(1)
    if screen == 0 then
        maxSelection = 2
        newLine(3)
        if selection == 0 then
            printCenter("<Exit>")
        else
            printCenter("Exit")
        end
        if selection == 1 then
            printCenter("<Utilities>")
        else
            printCenter("Utilities")
        end
        if selection == 2 then
            printCenter("<Settings>")
        else
            printCenter("Settings")
        end
    elseif screen == 1 then
        maxSelection = 2
        newLine(2)
        printCenter("[Settings]")
        if selection == 0 then
            printCenter("<Back>")
        else
            printCenter("Back")
        end
        if selection == 1 then
            printCenter("<Menu Bar Color>")
        else
            printCenter("Menu Bar Color")
        end
        if selection == 2 then
            printCenter("<Background Color>")
        else
            printCenter("Background Color")
        end
    elseif screen == 2 then
        maxSelection = 1
        newLine(2)
        printCenter("[Utilities]")
        if selection == 0 then
            printCenter("<Back>")
        else
            printCenter("Back")
        end
        if selection == 1 then
            printCenter("<Autocraft>")
        else
            printCenter("Autocraft")
        end
    elseif screen == 3 then
        newLine(1)
        printCenter("[Autocrafter]")
        print("This will automatically craft with anything in the current inventory. Does NOT work for computers, for turtles only. Only crafts in a 3x3 area. It will deposit anything it crafts below it into a chest. Enjoy!")
        newLine(2)
        printCenter("[Enter] to stop autocrafting")
        local totalcount = 0
        local itemCount = 0
        local maxSelection = 0
        local firstEmpty = 0
        for a = 1, 16 do
            local itemData = turtle.getItemDetail(a)
            if itemData ~= nil then
                itemCount = itemCount + 1
                if itemData.count >= 2 then
                    maxSelection = maxSelection + 1
                end
            else
                if firstEmpty == 0 then
                    firstEmpty = a
                end
            end
        end
        if firstEmpty ~= 0 then
            if maxSelection == itemCount then
                turtle.craft(1)
                turtle.select(firstEmpty)
                turtle.dropDown()
            end
        end
    end
    win.setVisible(true)
    os.sleep(0.1)
end
end

parallel.waitForAny(main, keyMain)