notes

local args = {...}
local opt = table.remove(args, 1)
local notes = {}
local path = shell.resolve '.notes-data'

local function loadNotes()
  local file = fs.open(path, 'r')
  if file then
    for line in file.readLine do
      table.insert(notes, line)
    end
    file.close()
  end
end

local function saveNotes()
  local file = fs.open(path, 'w')
  assert(file, 'Notes path is read-only')
  for i=1, #notes do
    file.writeLine(notes[i])
  end
  file.close()
end

if opt == 'add' then
  loadNotes()
  local newNote = table.concat(args, ' ')
  table.insert(notes, newNote)
  saveNotes()
  print('Added "'..newNote..'"')
elseif opt == 'remove'
or opt == 'delete' then
  loadNotes()
  local noteID = tonumber(args[1])
  assert(noteID, 'invalid note ID')
  local removed = table.remove(notes, noteID)
  saveNotes()
  print('Removed note '..noteID..': "'..removed..'"')
elseif opt == 'list' then
  loadNotes()
  for i=1, #notes do
    local space = string.rep(' ', 4 - #tostring(i))
    print(i..space..notes[i])
  end
else
  print [[
  Usage:
    notes add <note>
    notes remove <note #>
    notes delete <note #>
    notes list
  ]]
end