defmodule OrgGarden.Resolvers.DOI do
  @moduledoc """
  Last-resort citation resolver — always succeeds.

  If the citation key looks like a DOI (starts with "10."), returns a
  `https://doi.org/...` link. Otherwise returns the key itself as a
  plain label with no URL.
  """

  @spec resolve(String.t()) :: {:ok, map()}
  def resolve(key) do
    if String.starts_with?(key, "10.") do
      {:ok, %{label: key, url: "https://doi.org/#{key}"}}
    else
      {:ok, %{label: key, url: nil}}
    end
  end
end