startup

local function version()
  print("You are running...")
  print("OS version 0.7")
  print("Music version " ..musicAPI.version())
  print("Calculator version " ..calculatorAPI.version())
end

local function clear()
  term.clear()
  term.setCursorPos(1,1)
end

local function GUI(arg1)
  --define variables
  x, y = term.getSize()
  spacingy = math.ceil(y/(math.ceil(#arg1/3)))
  if #arg1 < 3 then
    spacingx = math.ceil(x/#arg1)
  else
    spacingx = math.ceil(x/3)
  end
  --grid
  for i=1, math.ceil(#arg1/3), 1 do
    paintutils.drawLine(1, spacingy * i, x, spacingy * i, colors.white)
  end
  for i=1, math.ceil(x/spacingx), 1 do
    paintutils.drawLine(spacingx * i, 1, spacingx * i, y, colors.white)
  end
  paintutils.drawLine(1, 1, x, 1, colors.white)
  paintutils.drawLine(1, 1, 1, y, colors.white)
  paintutils.drawLine(1, y, x, y, colors.white)
  term.setBackgroundColor(colors.black)
  --text
  counter = 1
  i = 1
  while i < #arg1 do
    for k=1, math.ceil(x/spacingx), 1 do
      if i > #arg1 then
        break
      end
      length = string.len(arg1[i])
      if length > spacingx then
        search = string.find(arg1[i], " ", length/2, spacingx)
        if search == nil then
          search = string.find(arg1[i], " ")
        end
        length1 = string.len(string.sub(arg1[i], 1, search))
        term.setCursorPos((spacingx/2 + spacingx * (k - 1)) - math.ceil(length1/2), (spacingy / 2) + (spacingy * (counter - 1)))
        term.write(string.sub(arg1[i], 1, search))
        length2 = string.len(string.sub(arg1[i], search))
        term.setCursorPos((spacingx/2 + spacingx * (k - 1)) - math.ceil(length2/2), (spacingy / 2) + (spacingy * (counter - 1) + 1))
        term.write(string.sub(arg1[i], search))
      else
        term.setCursorPos((spacingx/2 + spacingx * (k - 1)) + 1 - math.ceil(length/2), (spacingy / 2) + (spacingy * (counter - 1)))
        term.write(arg1[i])
      end
      i = i + 1
    end
    counter = counter + 1
  end
  --mapping
  event, button, x, y = os.pullEvent("mouse_click")
  counter = 1
  l = 1
  while l < #arg1 do
    for k=1, math.ceil(x/spacingx), 1 do
      if l > #arg1 then
        return false
      end
      if (((1 + (spacingx * (k - 1))) <= x) and ( x <= (spacingx * k))) and (((1 + (spacingy * (counter - 1))) <= y) and (y <= (1 + spacingy * counter))) then
        return arg1[l]
      end
      l = l + 1
    end
    counter = counter + 1
  end
end

local function menu(arg1)
  tMenu = arg1
  counter = 1
  textutils.tabulate(tMenu)
  term.write(tMenu[1])
  while true do
    event, keycode = os.pullEvent("key")
    if keycode == 200 then
      if counter == 1 then
        counter = #tMenu
        term.clearLine()
        local x, y = term.getCursorPos()
        term.setCursorPos(1, y)
        term.write(tMenu[counter])
      else
        counter = counter - 1
        term.clearLine()
        local x, y = term.getCursorPos()
        term.setCursorPos(1, y)
        term.write(tMenu[counter])
      end
    elseif keycode == 208 then
      if counter == #tMenu then
        counter = 1
        term.clearLine()
        local x, y = term.getCursorPos()
        term.setCursorPos(1, y)
        term.write(tMenu[counter])
      else
        counter = counter + 1
        term.clearLine()
        local x, y = term.getCursorPos()
        term.setCursorPos(1, y)
        term.write(tMenu[counter])
      end
    elseif keycode == 28 then
      break
    end
  end
return tMenu[counter]
end

--os.loadAPI("OS/helpAPI")
os.loadAPI("OS/scrollAPI")
sProcess = nil
drive = peripheral.wrap("right")
history = fs.open("OS/history_OS", "a")
--os.pullEvent = os.pullEventRaw
clear()
while true do
  if term.isColor() then
    sProcess = GUI(scrollAPI.mainmenu())
    history.writeLine(sProcess)
  else
    sProcess = menu(scrollAPI.mainmenu())
    history.writeLine(sProcess)
  end
  if sProcess == "music" then
    clear()
    os.loadAPI("OS/musicAPI")
    musicAPI.music()
    os.unloadAPI("OS/musicAPI")
    sProcess = nil
    clear()
  elseif sProcess == "calculator" then
    clear()
    os.loadAPI("OS/calculatorAPI")
    calculatorAPI.calculator()
    os.unloadAPI("OS/calculatorAPI")
    sProcess = nil
    clear()
  elseif sProcess == "command_prompt" or (sProcess == "command prompt") or (sProcess == "cmd_prmt") or (sProcess == "cmd prmt") then
    clear()
    print("Please enter username and password for authenication.")
    sUsername = read()
    history.writeLine(sUsername)
    sPassword = read("*")
    history.writeLine(sPassword)
    if ((sUsername == "Too_Quataz") and (sPassword == "fripSide")) or ((sUsername == "L2") and (sPassword == "bees")) then
      clear()
      print("Are you sure you want to exit the OS?")
      sExitDecision = read()
      if sExitDecision == "yes" then
        break
      else
        sProcess = nil
      end
    else
      clear()
      print("Authentication failed.")
      sProcess = nil
    end
  elseif sProcess == "history" then
    clear()
    print("Please enter username and password for authentication.")
    sUsername = read()
    sPassword = read("*")
    if ((sUsername == "Too_Quataz") and (sPassword == "fripSide")) or ((sUsername == "L2") and (sPassword == "bees")) then
      clear()
      history.close()
      history = fs.open("OS/history_OS", "r")
      print(history.readAll())
      history.close()
      history = fs.open("OS/history_OS", "a")
      sProcess = nil
    else
      clear()
      history.writeLine(sUsername)
      history.writeLine(sPassword)
      print("Authentication failed.")
      sProcess = nil
    end
  elseif sProcess == "peripheral_help" then
    clear()
    helpAPI.peripheral_help()
    sProcess = nil
  elseif sProcess == "clear" then
    clear()
    sProcess = nil
  elseif sProcess == "clear_history" then
    clear()
    history.close()
    fs.delete("OS/history_OS")
    history = fs.open("OS/history_OS", "a")
    sProcess = nil
  elseif sProcess == "about" then
    clear()
    os.loadAPI("OS/musicAPI")
    os.loadAPI("OS/calculatorAPI")
    version()
    os.unloadAPI("OS/musicAPI")
    os.unloadAPI("OS/calculatorAPI")
    sProcess = nil
  elseif sProcess == "reboot" then
    clear()
    print("Are you sure you want to restart the OS?")
    sRebootDecision = read()
    if sRebootDecision == "yes" then
      print("Rebooting...")
      sleep(1.5)
      history.close()
      os.reboot()
    else
      sProcess = nil
    end
  elseif sProcess == "shutdown" then
    clear()
    print("Are you sure you want to shut down the OS?")
    sShutdownDecision = read()
    if sShutdownDecision == "yes" then
      print("Shutting down...")
      sleep(1.5)
      history.close()
      os.shutdown()
    else
      sProcess = nil
    end
  elseif sProcess == "help" then
    clear()
    print("List of available commands:")
    helpAPI.generalhelp()
    print(" ")
    sProcess = nil
  end
end
clear()
history.close()