mc code

-- todo.lua  — Simple TODO viewer for ComputerCraft: Tweaked
-- Works on a connected monitor (preferred) or falls back to the computer screen.
-- Keys: ↑/↓ scroll • SPACE toggle • a add • d delete • q quit
-- On an advanced monitor: touch an item to toggle it.

local SAVE_FILE = "todos.txt"

-- ---------- Utils ----------
local function trim(s) return (s:gsub("^%s+", ""):gsub("%s+$", "")) end

local function loadTodos()
  local t = {}
  if not fs.exists(SAVE_FILE) then return t end
  local f = fs.open(SAVE_FILE, "r")
  if not f then return t end
  while true do
    local line = f.readLine()
    if not line then break end
    local done, text = line:match("^([01])\t(.*)$")
    if done then
      table.insert(t, { done = (done == "1"), text = text })
    else
      -- backward-compat: lines without flag are treated as not done
      table.insert(t, { done = false, text = line })
    end
  end
  f.close()
  return t
end

local function saveTodos(t)
  local f = fs.open(SAVE_FILE, "w")
  for _, item in ipairs(t) do
    f.writeLine((item.done and "1" or "0") .. "\t" .. item.text)
  end
  f.close()
end

local function wordWrap(str, width)
  if width <= 4 then return { str } end
  local lines, line = {}, ""
  for word in str:gmatch("%S+") do
    if #line == 0 then
      line = word
    elseif #line + 1 + #word <= width then
      line = line .. " " .. word
    else
      table.insert(lines, line)
      line = word
    end
  end
  if #line > 0 then table.insert(lines, line) end
  return lines
end

-- ---------- Peripherals ----------
local mon = peripheral.find("monitor")
local out = mon or term

local function setupSurface()
  if mon then
    -- Max out resolution for tiny monitors like 4x4 blocks
    pcall(function() mon.setTextScale(0.5) end)
    mon.setBackgroundColor(colors.black)
    mon.setTextColor(colors.white)
    mon.clear()
    mon.setCursorPos(1,1)
  else
    term.setBackgroundColor(colors.black)
    term.setTextColor(colors.white)
    term.clear()
    term.setCursorPos(1,1)
  end
end

local function size()
  return out.getSize()
end

local function clear() out.clear() end
local function setCursor(x,y) out.setCursorPos(x,y) end
local function writeAt(x,y,text)
  out.setCursorPos(x,y)
  out.write(text)
end

-- ---------- State ----------
local todos = loadTodos()
local scroll = 0
local selectedIdx = 1

-- ---------- Render ----------
local function render()
  local w,h = size()
  clear()
  -- Header
  local title = "TODO"
  local pad = math.max(0, math.floor((w - #title)/2))
  writeAt(1,1,(" "):rep(w))
  writeAt(pad+1, 1, title)

  -- Help (bottom line)
  local help = "↑/↓ scroll  a add  d del  ␣ toggle  q quit"
  if #help > w then help = help:sub(1, w) end
  writeAt(1, h, (" "):rep(w))
  writeAt(1, h, help)

  -- Items area
  local y = 2
  local areaH = math.max(0, h - 2)
  if areaH <= 0 then return end

  -- Build wrapped lines for each todo
  local lines = {}
  for i, it in ipairs(todos) do
    local prefix = (it.done and "[x] " or "[ ] ")
    local avail = math.max(1, w - #prefix)
    local wrapped = wordWrap(it.text, avail)
    if #wrapped == 0 then wrapped = { "" } end
    for j, ln in ipairs(wrapped) do
      table.insert(lines, { idx = i, first = (j==1), text = prefix .. ln })
      prefix = (" "):rep(4) -- indent continuation lines
    end
  end

  -- Clamp scroll
  local maxScroll = math.max(0, #lines - areaH)
  if scroll > maxScroll then scroll = maxScroll end
  if scroll < 0 then scroll = 0 end

  -- Draw visible window
  for i = 1, areaH do
    local row = i + scroll
    writeAt(1, y + i - 1, (" "):rep(w))
    local L = lines[row]
    if L then
      -- Highlight currently selected item’s first line
      if L.idx == selectedIdx and L.first then
        if out.setBackgroundColor then
          out.setBackgroundColor(colors.gray)
          out.setTextColor(colors.black)
          writeAt(1, y + i - 1, L.text .. (" "):rep(math.max(0, w - #L.text)))
          out.setBackgroundColor(colors.black)
          out.setTextColor(colors.white)
        else
          writeAt(1, y + i - 1, ">" .. L.text:sub(1, math.max(0, w-1)))
        end
      else
        writeAt(1, y + i - 1, L.text:sub(1, w))
      end
    end
  end
end

-- ---------- Actions ----------
local function moveSelection(delta)
  if #todos == 0 then return end
  selectedIdx = math.min(#todos, math.max(1, selectedIdx + delta))
end

local function ensureSelectedVisible()
  -- Find the first line index of selected item in the wrapped list
  local w,h = size()
  local areaH = math.max(0, h - 2)
  local prefixW = 4
  local lines = {}
  local targetTop = nil
  local targetBottom = nil
  for i, it in ipairs(todos) do
    local prefix = (it.done and "[x] " or "[ ] ")
    local avail = math.max(1, w - #prefix)
    local wrapped = wordWrap(it.text, avail)
    if #wrapped == 0 then wrapped = { "" } end
    for j, ln in ipairs(wrapped) do
      table.insert(lines, { idx = i, first = (j==1) })
      if i == selectedIdx and j == 1 then
        targetTop = #lines
        targetBottom = #lines + #wrapped - 1
      end
    end
  end
  if not targetTop then return end
  if scroll > targetTop - 2 then
    scroll = math.max(0, targetTop - 2)
  end
  if scroll + areaH < targetBottom then
    scroll = math.max(0, targetBottom - areaH)
  end
end

local function addItem()
  term.setCursorBlink(true)
  if mon then
    -- prompt on the computer terminal
    term.redirect(term.native())
    term.clear()
    term.setCursorPos(1,1)
    print("Add TODO (leave empty to cancel):")
    local t = trim(read())
    if #t > 0 then table.insert(todos, { done = false, text = t }); saveTodos(todos) end
    term.setCursorBlink(false)
  else
    term.setCursorPos(1,1); term.clear()
    print("Add TODO (leave empty to cancel):")
    local t = trim(read())
    if #t > 0 then table.insert(todos, { done = false, text = t }); saveTodos(todos) end
    term.setCursorBlink(false)
  end
end

local function deleteItem()
  if #todos == 0 then return end
  table.remove(todos, selectedIdx)
  if selectedIdx > #todos then selectedIdx = #todos end
  saveTodos(todos)
end

local function toggleItem(idx)
  if #todos == 0 then return end
  idx = idx or selectedIdx
  if not todos[idx] then return end
  todos[idx].done = not todos[idx].done
  saveTodos(todos)
end

-- Map a monitor touch y to an item idx
local function touchToIndex(tx, ty)
  local w,h = size()
  local areaTop = 2
  local areaH = math.max(0, h - 2)
  if ty < areaTop or ty >= areaTop + areaH then return nil end
  local lineRow = ty - areaTop + 1 + scroll

  -- Rebuild wrapped lines and find which idx sits on that row
  local lines = {}
  for i, it in ipairs(todos) do
    local prefix = (it.done and "[x] " or "[ ] ")
    local avail = math.max(1, w - #prefix)
    local wrapped = wordWrap(it.text, avail)
    if #wrapped == 0 then wrapped = { "" } end
    for j, _ in ipairs(wrapped) do
      table.insert(lines, { idx = i, first = (j==1) })
    end
  end
  local L = lines[lineRow]
  return L and L.idx or nil
end

-- ---------- Main ----------
setupSurface()
render()

-- If empty, create a starter note so the UI isn't blank
if #todos == 0 then
  table.insert(todos, { done = false, text = "Press 'a' to add items" })
end

ensureSelectedVisible()
render()

while true do
  local e, p1, p2, p3 = os.pullEvent()
  if e == "key" then
    local key = p1
    if key == keys.up then
      moveSelection(-1); ensureSelectedVisible(); render()
    elseif key == keys.down then
      moveSelection(1); ensureSelectedVisible(); render()
    elseif key == keys.pageUp then
      scroll = math.max(0, scroll - 5); ensureSelectedVisible(); render()
    elseif key == keys.pageDown then
      scroll = scroll + 5; ensureSelectedVisible(); render()
    elseif key == keys.q then
      break
    elseif key == keys.space then
      toggleItem(); render()
    elseif key == keys.a then
      addItem(); ensureSelectedVisible(); render()
    elseif key == keys.d then
      deleteItem(); ensureSelectedVisible(); render()
    end
  elseif e == "char" then
    if p1 == "q" then break
    elseif p1 == "a" then addItem(); ensureSelectedVisible(); render()
    elseif p1 == "d" then deleteItem(); ensureSelectedVisible(); render()
    elseif p1 == " " then toggleItem(); render()
    end
  elseif e == "monitor_touch" and mon then
    -- p1 = side, p2 = x, p3 = y
    local idx = touchToIndex(p2, p3)
    if idx then
      selectedIdx = idx
      toggleItem(idx)
      ensureSelectedVisible()
      render()
    end
  elseif e == "term_resize" then
    setupSurface(); ensureSelectedVisible(); render()
  end
end

-- Clean exit
clear()
setCursor(1,1)
if mon then
  print("todo.lua closed. Display cleared.")
else
  print("todo.lua closed.")
end