@type difficulty() :: :beginner | :intermediate | :advanced | :adaptive

@type plan_type() :: :workout | :nutrition | :meditation | :recovery | :hybrid

@type t() :: %WplAi.AST.Header{
  difficulty: difficulty() | nil,
  duration: Duration.t() | nil,
  language: String.t() | nil,
  meta: map(),
  min_app_version: String.t() | nil,
  name: String.t(),
  schema: String.t() | nil,
  tags: [String.t()] | nil,
  type: plan_type(),
  visibility: visibility() | nil
}

@type visibility() :: :private | :public | :template