autocomplete_item_search_live_3.ex

def handle_event("select", %{"id" => id}, socket) do
  item = Items.get_item(id)
  selected = Enum.uniq_by([item] ++ socket.assigns.selected, & &1.id)
  suggestions = filter_selected(socket.assigns.suggestions, selected)

  socket =
    assign(socket,
      selected: selected,
      suggestions: suggestions
    )

  {:noreply, socket}
end

defp filter_selected(items, selected) do
  Enum.filter(items, fn i -> !Enum.any?(selected, fn s -> i.id == s.id end) end)
end