Pocket Todo

-- pocket_todo.lua
-- A pocket computer todo list with notes, completed section, clickable buttons, and backup command

-- Data files
local TODO_FILE      = "todo.txt"
local NOTES_FILE     = "notes.txt"
local COMPLETED_FILE = "completed.txt"

-- Data tables
local items     = {}
local notes     = ""
local completed = {}

-- Utility: load list from file
local function loadList(file, tbl)
  if fs.exists(file) then
    local f = fs.open(file, "r")
    local line = f.readLine()
    while line do
      table.insert(tbl, line)
      line = f.readLine()
    end
    f.close()
  end
end

-- Initial load
loadList(TODO_FILE, items)
loadList(COMPLETED_FILE, completed)
if fs.exists(NOTES_FILE) then
  local f = fs.open(NOTES_FILE, "r")
  notes = f.readAll() or ""
  f.close()
end

-- Utility: save all data
local function save()
  local f = fs.open(TODO_FILE, "w")
  for _,v in ipairs(items) do f.writeLine(v) end
  f.close()
  local f2 = fs.open(COMPLETED_FILE, "w")
  for _,v in ipairs(completed) do f2.writeLine(v) end
  f2.close()
  local f3 = fs.open(NOTES_FILE, "w")
  f3.write(notes)
  f3.close()
end

-- Button mapping
local buttons = {}

-- Redraw UI to term
local function redraw()
  term.setBackgroundColor(colors.black)
  term.clear()
  term.setCursorPos(1,1)
  term.setTextColor(colors.white)
  local w,h = term.getSize()
  local y = 1
  buttons = {}

  -- Notes section
  if notes:match("%S") then
    term.setCursorPos(1,y)
    term.write("Notes:")
    y = y + 1
    local line = notes
    if #line > w then line = line:sub(1, w-3) .. "..." end
    term.setCursorPos(1, y)
    term.write(line)
    y = y + 1
    -- blank line after notes
    y = y + 1
  end

  -- To-Do List
  if y <= h then
    term.setCursorPos(1,y)
    term.write("To-Do List:")
    y = y + 1
    for i = 1, math.min(#items, h - y) do
      local text = string.format("%2d. %s", i, items[i])
      if #text > w-6 then text = text:sub(1, w-9) .. "..." end
      term.setCursorPos(1, y + i - 1)
      term.write(text)
      -- Done button
      local bx = w - 3
      term.setCursorPos(bx, y + i - 1)
      term.write("[D]")
      table.insert(buttons, {x1 = bx, x2 = bx + 2, y = y + i - 1, type = "done", idx = i})
    end
    y = y + math.min(#items, h - y) + 1
  end

  -- Completed Section
  if #completed > 0 and y <= h then
    term.setCursorPos(1,y)
    term.write("Completed:")
    y = y + 1
    for i = 1, math.min(#completed, h - y + 1) do
      local entry = completed[i]
      local text = "- " .. entry
      if #text > w-10 then text = text:sub(1, w-13) .. "..." end
      term.setCursorPos(1, y + i - 1)
      term.write(text)
      -- Restore button
      local rx = w - 7
      term.setCursorPos(rx, y + i - 1)
      term.write("[R]")
      table.insert(buttons, {x1 = rx, x2 = rx + 2, y = y + i - 1, type = "restore", idx = i})
      -- Delete button
      local dx = w - 3
      term.setCursorPos(dx, y + i - 1)
      term.write("[X]")
      table.insert(buttons, {x1 = dx, x2 = dx + 2, y = y + i - 1, type = "delete", idx = i})
    end
  end
end

-- Handle mouse clicks
local function handleClick(x,y)
  for _,b in ipairs(buttons) do
    if y == b.y and x >= b.x1 and x <= b.x2 then
      if b.type == "done" then
        table.insert(completed, items[b.idx])
        table.remove(items, b.idx)
      elseif b.type == "restore" then
        table.insert(items, completed[b.idx])
        table.remove(completed, b.idx)
      elseif b.type == "delete" then
        table.remove(completed, b.idx)
      end
      save()
      redraw()
      return
    end
  end
end

-- Initial draw
redraw()

-- Main loops: mouse and command
parallel.waitForAny(
  function()
    while true do
      local event, button, x, y = os.pullEvent("mouse_click")
      if button == 1 then handleClick(x,y) end
    end
  end,
  function()
    while true do
      term.setCursorPos(1,1)
      local input = read()
      local cmd, rest = input:match("^(%S+)%s*(.*)$")
      if not cmd then
        cmd = input
        rest = ""
      end
      if cmd=="add" and #rest>0 then
        table.insert(items,rest)
      elseif cmd=="remove" and tonumber(rest) and items[tonumber(rest)] then
        table.remove(items,tonumber(rest))
      elseif cmd=="done" and tonumber(rest) and items[tonumber(rest)] then
        table.insert(completed,items[tonumber(rest)]); table.remove(items,tonumber(rest))
      elseif cmd=="clear" then
        items = {}
      elseif cmd=="clearcompleted" then
        completed = {}
      elseif cmd=="backup" then
        -- delete existing backups to prevent file exists errors
        if fs.exists(BUP_TODO) then fs.delete(BUP_TODO) end
        if fs.exists(BUP_COMPLETED) then fs.delete(BUP_COMPLETED) end
        if fs.exists(BUP_NOTES) then fs.delete(BUP_NOTES) end
        -- perform backup
        if fs.exists(TODO_FILE) then fs.copy(TODO_FILE, BUP_TODO) end
        if fs.exists(COMPLETED_FILE) then fs.copy(COMPLETED_FILE, BUP_COMPLETED) end
        if fs.exists(NOTES_FILE) then fs.copy(NOTES_FILE, BUP_NOTES) end
        print("Backup complete.")
        os.sleep(0.5)
      elseif cmd=="sync" then
        -- delete existing files before sync
        if fs.exists(TODO_FILE) then fs.delete(TODO_FILE) end
        if fs.exists(COMPLETED_FILE) then fs.delete(COMPLETED_FILE) end
        if fs.exists(NOTES_FILE) then fs.delete(NOTES_FILE) end
        -- overwrite existing files from backup
        if fs.exists(BUP_TODO) then fs.copy(BUP_TODO, TODO_FILE) end
        if fs.exists(BUP_COMPLETED) then fs.copy(BUP_COMPLETED, COMPLETED_FILE) end
        if fs.exists(BUP_NOTES) then fs.copy(BUP_NOTES, NOTES_FILE) end
        -- reload data
        items = loadList(TODO_FILE)
        completed = loadList(COMPLETED_FILE)
        if fs.exists(NOTES_FILE) then local f = fs.open(NOTES_FILE, "r"); notes = f.readAll() or ""; f.close() else notes = "" end
        print("Sync complete.")
        os.sleep(0.5)
      elseif cmd=="note" then
        notes = rest or ""
      elseif cmd=="clearnote" then
        notes = ""
      elseif cmd=="exit" then
        print("Goodbye!") os.exit()
      else
        print("Invalid command. Press Enter to continue.") read()
      end
      save()
      redraw()
    end
  end
)