config/modules/neovim/commands/SmartQuit.lua

vim.api.nvim_create_user_command("SmartQuit", function(opts)
  -- scan all buffers for unsaved buffers
	local unsaved = {}
	local saved = {}
	for _, buf in ipairs(vim.api.nvim_list_bufs()) do
		if vim.api.nvim_buf_is_loaded(buf) and vim.api.nvim_buf_get_option(buf, "buflisted") then
			if vim.api.nvim_buf_get_option(buf, "modified") then
				table.insert(unsaved, buf)
			else
				table.insert(saved, buf)
			end
		end
	end

	if #unsaved == 0 then
		vim.cmd("qa")
		return
	end

	-- gui for resolving unsaved files
	local lines = {}
	for _, buf in ipairs(unsaved) do
		local full_path = vim.api.nvim_buf_get_name(buf)
		local name = full_path == "" and ("[No Name] #" .. buf) or vim.fn.fnamemodify(full_path, ":~:.")
		table.insert(lines, " • " .. name)
	end
	table.insert(lines, "")
	table.insert(lines, " s - Save all and quit")
	table.insert(lines, " c - Close saved; leave unsaved open")
	table.insert(lines, " d - DISCARD ALL")

	local buf = vim.api.nvim_create_buf(false, true)
	vim.api.nvim_buf_set_lines(buf, 0, -1, false, lines)
  vim.api.nvim_buf_set_option(buf, "readonly", true)
	local width = math.max(unpack(vim.tbl_map(function(l) return #l end, lines)))
	local height = #lines
	local win = vim.api.nvim_open_win(buf, true, {
		relative = "editor",
		width = width + 1,
		height = height,
		row = (vim.o.lines - height) / 2 - 1,
		col = (vim.o.columns - width) / 2,
		style = "minimal",
		border = "rounded",
		title = {
			{ #unsaved .. " Unsaved Buffer" .. (#unsaved ~= 1 and "s" or "") .. "!", "ErrorMsg" },
		},
		title_pos = "center",
	})

	vim.wo[win].winhighlight = "Normal:Normal,FloatBorder:ErrorMsg"
	vim.api.nvim_win_set_option(win, "cursorline", false)

  local hl = vim.api.nvim_get_hl_by_name('Cursor', true)
  hl.blend = 100
  vim.api.nvim_set_hl(0, 'Cursor', hl)
  vim.opt.guicursor:append('a:Cursor/lCursor')

  function close()
    local hl = vim.api.nvim_get_hl_by_name('Cursor', true)
    hl.blend = 0
    vim.api.nvim_set_hl(0, 'Cursor', hl)
    vim.opt.guicursor:remove('a:Cursor/lCursor')
    vim.api.nvim_win_close(win, true)
  end

	-- keyboard event handlers
	vim.keymap.set("n", "s", function()
		for _, buf in ipairs(unsaved) do
			vim.api.nvim_buf_call(buf, function()
				vim.cmd("write")
			end)
		end
    close()
		vim.cmd("qa")
	end, { buffer = buf })
	vim.keymap.set("n", "c", function()
		for _, buf in ipairs(saved) do
			vim.api.nvim_buf_delete(buf, {})
		end
    close()
	end, { buffer = buf })
	vim.keymap.set("n", "d", function()
		vim.cmd("qa!")
	end, { buffer = buf })
	vim.keymap.set("n", "<esc>", function()
    close()
	end, { buffer = buf })
 
  vim.api.nvim_create_autocmd({ 'WinLeave' }, {
    buffer = buf,
    callback = close,
  })
end, { nargs = 0 })

vim.api.nvim_set_hl(0, "QuitPopUpBorder", { fg = "red" })