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(**
   Only delegates with at least one roll take part in the amendment procedure.
   It works as follows:
   - Proposal period: delegates can submit protocol amendment proposals using
     the proposal operation. At the end of a proposal period, the proposal with
     most supporters is selected and we move to a testing_vote period.
     If there are no proposals, or a tie between proposals, a new proposal
     period starts.
   - Testing_vote period: delegates can cast votes to test or not the winning
     proposal using the ballot operation.
     At the end of a testing_vote period if participation reaches the quorum
     and the proposal has a supermajority in favor, we proceed to a testing
     period. Otherwise we go back to a proposal period.
     In any case, if there is enough participation the quorum is updated.
   - Testing period: a test chain is forked for the lengh of the period.
     At the end of a testing period we move to a promotion_vote period.
   - Promotion_vote period: delegates can cast votes to promote or not the
     tested proposal using the ballot operation.
     At the end of a promotion_vote period if participation reaches the quorum
     and the tested proposal has a supermajority in favor, it is activated as
     the new protocol. Otherwise we go back to a proposal period.
     In any case, if there is enough participation the quorum is updated.
*)

open Alpha_context

(** If at the end of a voting period, moves to the next one following
    the state machine of the amendment procedure. *)
val may_start_new_voting_period : context -> context tzresult Lwt.t

type error +=
  | Unexpected_proposal
  | Unauthorized_proposal
  | Too_many_proposals
  | Empty_proposal

(** Records a list of proposals for a delegate.
    @raise Unexpected_proposal if [ctxt] is not in a proposal period.
    @raise Unauthorized_proposal if [delegate] is not in the listing. *)
val record_proposals :
  context -> public_key_hash -> Protocol_hash.t list -> context tzresult Lwt.t

type error += Invalid_proposal | Unexpected_ballot | Unauthorized_ballot

val record_ballot :
  context ->
  public_key_hash ->
  Protocol_hash.t ->
  Vote.ballot ->
  context tzresult Lwt.t
