local fn = vim.fn

local M = {}

function M.executable(name)
  if fn.executable(name) > 0 then
    return true
  end

  return false
end

--- check whether a feature exists in Nvim
--- @feat: string
---   the feature name, like `nvim-0.7` or `unix`.
--- return: bool
M.has = function(feat)
  if fn.has(feat) == 1 then
    return true
  end

  return false
end

--- Create a dir if it does not exist
function M.may_create_dir(dir)
  local res = fn.isdirectory(dir)

  if res == 0 then
    fn.mkdir(dir, "p")
  end
end

M['unload_lua_namespace'] = function(prefix)
  local prefix_with_dot = prefix .. '.'
  for key, value in pairs(package.loaded) do
    if key == prefix or key:sub(1, #prefix_with_dot) == prefix_with_dot then
      package.loaded[key] = nil
    end
  end
end

-- toggle cmp completion
vim.g.cmp_toggle_flag = false -- initialize
local normal_buftype = function()
  return vim.api.nvim_buf_get_option(0, "buftype") ~= "prompt"
end
M.toggle_completion = function()
  local ok, cmp = pcall(require, "cmp")
  if ok then
    local next_cmp_toggle_flag = not vim.g.cmp_toggle_flag
    if next_cmp_toggle_flag then
      print("completion on")
    else
      print("completion off")
    end
    cmp.setup({
      enabled = function()
        vim.g.cmp_toggle_flag = next_cmp_toggle_flag
        if next_cmp_toggle_flag then
          return normal_buftype
        else
          return next_cmp_toggle_flag
        end
      end,
    })
  else
    print("completion not available")
  end
end

function M.get_nvim_version()
  local actual_ver = vim.version()

  local nvim_ver_str = string.format("%d.%d.%d", actual_ver.major, actual_ver.minor, actual_ver.patch)
  return nvim_ver_str
end

function M.add_pack(name)
  local status, error = pcall(vim.cmd, "packadd " .. name)

  return status
end

return M