local programOptions = {
    {"Button1", button1},
}

local varY = 3
local s = 1
local w,h = term.getSize()
local function center(text, line, col)
    term.setCursorPos(math.floor(w/2)-string.len(text)/2, line)
    term.setBackgroundColour(col)
    term.clearLine()
    print(text)
end

local function space()
 print("")
end

local function cPrint(str)
    x, _ = term.getSize()
    _, y = term.getCursorPos()
    term.setCursorPos((x-#str)/2, y)
    print(str)
end

local function drawTitle()
    term.setTextColor(32)
    term.clear()
    term.setCursorPos(1,1)
    cPrint("[ SelectOS BETA ]")
    space()
    space()
end

local function drawMain(_table)
    for i = 1, #_table do
        if s == i then
            center(_table[i][1], varY + i, colours.cyan)
        else
            center(_table[i][1], varY + i, colours.blue)
        end
    end
end

local function gui(_table)
    while true do
        term.clear()
        term.setCursorPos(1,1)
        term.setBackgroundColor(colors.blue)
        drawTitle()
        term.setTextColor(colors.white)
        drawMain(_table)
        local event, p1, p2, p3 = os.pullEvent()
        if event == "key" then
            if p1 == keys.down or p1 == 31 then
                s = s + 1
                if s >= #_table + 1 then s = 1 end
            elseif p1 == keys.up or p1 == 17 then
                s = s - 1
                if s <= 0 then s = #_table end
            elseif p1 == keys.enter then
                term.setBackgroundColor(colors.black)
                term.setTextColor(colors.white)
                print(type(_table[s][2])) sleep(1)
                _table[s][2]()
            end
        elseif event == "mouse_click" then
            if _table[p3 - 3] ~= nil then
                start=math.floor(math.floor(51/2)-(string.len(_table[p3-3][1])+4)/2)-1
                if start <p2 and start+(string.len(_table[p3-3][1])+5)>p2 then
                    term.setBackgroundColor(colors.black)
                    term.setTextColor(colors.white)
                    _table[p3-3][2]()
                end
            end
        elseif event == "mouse_scroll" then
            s = s + p1
            if s >= #_table + 1 then s = 1 end
            if s <= 0 then s = #_table end
        end
    end
end

local function drawPrograms()
    gui(programOptions)
end

local mainOptions = {
    {"Programs", drawPrograms},
    {"Control Panal", drawCP},
    {"File Browser", bFile},
    {"Command Prompt", drawCMD},
    {"Exit to CraftOS", function() term.clear() term.setCursorPos(1,1) error();end},
    {"Restart Computer", os.reboot},
    {"Shutdown Computer", os.shutdown},
}

gui(mainOptions)