local M = {}

---Check whether file/directory exists.
---@param path string: file or directory path.
---@return string|boolean: type if path exists, false otherwise.
M.exists = function(path)
  ---@diagnostic disable-next-line: undefined-field
  local stat = vim.uv.fs_stat(path)
  return (stat and stat.type) or false
end

---Preserve register contents over function call.
---@param reg string: register to save, must be a valid register name.
---@param func function: function that may freely clobber the register.
---@return any: return value of calling `func`.
M.preserve_register = function(reg, func)
  local saved = vim.fn.getreg(reg)
  local result = func()
  vim.fn.setreg(reg, saved)
  return result
end

---Get selected text.
---@return string: selected text, or word under cursor if not in visual mode.
M.get_selected_text = function()
  if vim.fn.mode() ~= "v" then return vim.fn.expand("<cword>") end

  return M.preserve_register("v", function()
    vim.cmd([[noautocmd sil norm "vy]])
    return vim.fn.getreg("v")
  end)
end

M.keymap_decorator = function(opts)
  opts = opts or {}

  local decorate_key = function(key)
    return vim.tbl_extend("force", key, {
      (opts.lhs_prefix or "") .. key[1], -- lhs
      key[2], -- rhs
      desc = (opts.desc_prefix or "") .. key.desc .. (opts.desc_suffix or ""),
    })
  end

  return function(keys)
    if keys and type(keys[1]) == "table" then
      return vim.iter(keys):map(decorate_key):totable()
    else
      return decorate_key(keys)
    end
  end
end

-- M.test = function()
--   local key = {
--     "a",
--     "<cmd>DoA<cr>",
--     desc = "this does A",
--     mode = "v",
--   }

--   local keys = {
--     {
--       "a",
--       "<cmd>DoA<cr>",
--       desc = "this does A",
--       mode = "v",
--     },
--     {
--       "b",
--       "<cmd>DoB<cr>",
--       desc = "this does B",
--       mode = "n",
--     },
--   }

--   local do_it = M.keymap_decorator {
--     lhs_prefix = "<leader>!",
--     desc_prefix = "OK: ",
--   }

--   P(do_it(key))
--   P(do_it(keys))
-- end

return M