timer/lua/timer.lua

local TOML = require("toml")

local augroup = vim.api.nvim_create_augroup("Timer", { clear = true })
local focus_events = {}
local clean_to = 1

function trim(s)
  return (s:gsub("^%s*(.-)%s*$", "%1"))
end

local function clean_from(from, events)
  local to = 1
  local clean_events = {}

  -- coppy until from
  for i = 1, from - 1, 1 do
    table.insert(clean_events, events[i])
  end

  local last = {}
  for i = from, #events, 1
  do
    local event = events[i]
    local next_event = events[i + 1]


    if next_event == nil then
      --do nothing
    elseif next_event.event == "gain" and event.event == "lose" then
      if os.difftime(next_event.time, event.time) > 5 * 60 then
        table.insert(clean_events, event)
      end
    end
    if last == nil then
      -- do nothing
    elseif last.event == "lose" and event.event == "gain" then
      if os.difftime(event.time, last.time) > 5 * 60 then
        table.insert(clean_events, event)
      end
    end

    last = event
  end

  return clean_events
end

local function time()
  focus_events = clean_from(clean_to + 1, focus_events)
  clean_to = #focus_events

  local t = 0

  local start = os.time()
  for _, fe in pairs(focus_events) do
    if fe.event == "gain" then
      start = fe.time
    else
      t = t + os.difftime(fe.time, start)
    end
    if focus_events[#focus_events].event == "gain" then
      t = t + os.difftime(os.time(), focus_events[#focus_events].time)
    end
  end
  return t
end

local function log_time()
  print(time())
end

local function log_time_table()
  for i, e in pairs(focus_events) do
    print(i, e.event, os.date("%H:%M:%S", e.time))
  end
end

local function focus_gained()
  print("Huiii Fokus")

  table.insert(focus_events, {
    time = os.time(),
    event = "gain",
  })
end

local function focus_lost()
  print("Hokus pokus fort ist der fokus")

  table.insert(focus_events, {
    time = os.time(),
    event = "lose",
  })
end

local function persist()
  local filename = ".timer.toml"
  local username = trim(os.getenv("USER")) .. "_at_" .. trim(io.popen("hostname -s"):read("*a"))
  local today = os.date("%y-%m-%d", os.time())
  local table = {}

  local file = io.open(filename, "r")

  -- if file exists read
  if file ~= nil then
    table = TOML.parse(file:read("*a"))
    file:close()
  end

  -- write time to table
  if table[today] ~= nil and table[today][username] ~= nil then
    table[today][username] = table[today][username] + time()
  else
    if table[today] == nil then
      table[today] = {}
    end
    table[today][username] = time()
  end

  -- write table to file
  file = io.open(filename, "w")
  if file == nil then
    error("can't write to .timer file")
    return
  end

  file:write("## dates and their corresponding seconds been here :)\n", TOML.encode(table), "\n")
  file.close()

  --reset timer
  clean_to = 1
  focus_events = {}
  focus_gained()
end

local function setup()
  vim.api.nvim_create_autocmd("VimEnter",
    { group = augroup, desc = "Start Timer", once = true, callback = focus_gained })
  vim.api.nvim_create_autocmd("ExitPre",
    { group = augroup, desc = "Persist timer", once = true, callback = persist })
  vim.api.nvim_create_autocmd("FocusGained", { group = augroup, callback = focus_gained })
  vim.api.nvim_create_autocmd("FocusLost", { group = augroup, callback = focus_lost })

  vim.api.nvim_create_user_command(
    'Timer',      -- The name of the command (accessible via :TimerStart)
    log_time,
    { nargs = 0 } -- No arguments for this command (you can configure this later)
  )
  vim.api.nvim_create_user_command(
    'TimerLog',   -- The name of the command (accessible via :TimerStart)
    log_time_table,
    { nargs = 0 } -- No arguments for this command (you can configure this later)
  )
  vim.api.nvim_create_user_command(
    'TimerSave',  -- The name of the command (accessible via :TimerStart)
    persist,
    { nargs = 0 } -- No arguments for this command (you can configure this later)
  )
end

return { setup = setup }