Tjakka5 Todo Bugfix

term.clear()
term.setCursorPos(1, 1)

local side = nil
for _, s in pairs(rs.getSides()) do
  if peripheral.getType(s) == "monitor" then
    side = s
  end
end
if not side then
  print("You don't have a monitor attached")
  print("  Please add one.")
  error()
end

mon = peripheral.wrap(side)

local x
local y
x, y = mon.getSize()
local page = 1
m = peripheral.wrap("right")

local things = {""}

function saveAll()
  local file = fs.open("tasks", "w")
  file.write(textutils.serialize(things))
  file.close()
end

function loadAll()
  local file = fs.open("tasks", "r")
  local data = file.readAll()
  file.close()
  data = textutils.unserialize(data)
  for i = 1, #data do
    things[i] = data[i]
  end
end

function mainLoop()
  loadAll()
  mon.clear()
  printTop()
  for i = 1, y-2 do
    printLine(i)
  end
  printButtons()
  term.clear()
  term.setCursorPos(1, 1)
  term.setTextColor(colors.white)
  print("Do you want to delete or add a task?")
  term.setTextColor(colors.lime)
  term.write("  Add")
  term.setTextColor(colors.red)
  print("       Delete")
  term.setTextColor(colors.white)

  event, a, b, c = os.pullEvent()
  if event == "mouse_click" then
    if c == 2 then
      if (b == 3) or (b == 4) or (b == 5) then
        print("")
        print("What task do you want to add?")
        task = read()
        things[#things+1] = task
        saveAll()
        sleep(0.2)
        print("Task added!")
        sleep(0.5)
      elseif (c == 12) or (b >= 13) or (b <= 18) then
        print("")
        print("Which task do you want to delete? (Number)")
        task = read()
        print("Are you sure? (y/n)")
        answ = read()
        if (answ == "y") or (answ == "Y") then
          print("Deleting task " ..task)
          for i = task, #things - 1 do
            things[i] = things[i+1]
          end
          things[#things] = nil
          saveAll()
          sleep(0.2)
          print("Task deleted!")
          sleep(0.5)
        end
      end
    end
  end

  if event == "monitor_touch" then
    if c == y then
      if (b == 2) or (b == 3) or (b == 4) or (b ==5) then
        if page > 1 then
          page = page-1
        end
      elseif (b == x-4) or (b == x-3) or (b == x-2) or (b == x-1) then
        page = page+1
      end
    end
  end
  mainLoop()
end


function printButtons()
  mon.setCursorPos(2, y)
  if page == 1 then
    mon.setTextColor(colors.lightGray)
  else
    mon.setTextColor(colors.black)
  end
  mon.setBackgroundColor(colors.white)
  mon.write("Back")

  mon.setTextColor(colors.black)
  mon.setCursorPos(x/2, y)
  mon.write("" ..page)
  mon.setCursorPos(x-4, y)
  mon.write("Next")
end

function printTop()
  mon.setBackgroundColor(colors.white)
  mon.setTextColor(colors.black)
  mon.setCursorPos(x/2-5, 1)
  mon.write("To-Do List")
end

function printLine(num)
  if num % 2 == 0 then
    mon.setBackgroundColor(colors.gray)
  else
    mon.setBackgroundColor(colors.lightGray)
  end
  mon.setCursorPos(1, num+1)
  if page > 1 then
    num = num+(x*(page-1))
  end
  mon.write("" ..num)
  mon.write(": ")

  if things[num] ~= nil then
    mon.write("" ..things[num])
    mon.write("                                                                                           ")
  else
    mon.write("                                                                                           ")
  end
end

mainLoop()