@type activity() ::
  Exercise.t()
  | Cardio.t()
  | Nutrition.t()
  | Meditation.t()
  | Recovery.t()
  | Habit.t()
  | SimpleActivity.t()
  | SubPlan.t()

@type block_structure() ::
  :circuit | :straight_sets | :superset | :emom | :amrap | :tabata | nil

@type block_type() ::
  :warmup
  | :main
  | :cooldown
  | :nutrition
  | :meditation
  | :education
  | :assessment

@type t() :: %WplAi.AST.Block{
  activities: [activity()],
  meta: map(),
  rest_between_rounds: Duration.t() | nil,
  rounds: integer() | nil,
  structure: block_structure(),
  type: block_type()
}