-- Ensure that the binary spl file is up-to-date with the source add file
vim.api.nvim_create_autocmd("FocusGained", {
  pattern = "*",
  callback = function()
    local config_path = vim.fn.stdpath("config") -- Get Neovim's config path
    local add_file = config_path .. "/spell/en.utf-8.add"
    local spl_file = config_path .. "/spell/en.utf-8.add.spl"

    if vim.fn.filereadable(add_file) == 1 then
      local add_mtime = vim.fn.getftime(add_file) -- Get modification time of .add file
      local spl_mtime = vim.fn.getftime(spl_file) -- Get modification time of .add.spl file

      -- Run mkspell! only if .add is newer than .add.spl or .add.spl doesn't exist
      if add_mtime > spl_mtime or spl_mtime == -1 then
        vim.cmd("silent! mkspell! " .. spl_file .. " " .. add_file)
      end
    end
  end,
})