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(* Copyright (c) 2018 Dynamic Ledger Solutions, Inc. <contact@tezos.com>     *)
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type t = private {
  level : Raw_level_repr.t;
      (** The level of the block relative to genesis. This
                              is also the Shell's notion of level. *)
  level_position : int32;
      (** The level of the block relative to the block that starts the
     alpha family of protocols.  *)
  cycle : Cycle_repr.t;
      (** The current cycle's number. Note that cycles are a protocol-specific
     notion. As a result, the cycle number starts at 0 with the first block of
     the first version of protocol alpha. *)
  cycle_position : int32;
      (** The current level of the block relative to the first block of the current
     cycle. *)
  expected_commitment : bool;
}

type level = t

include Compare.S with type t := level

val encoding : level Data_encoding.t

val pp : Format.formatter -> level -> unit

val pp_full : Format.formatter -> level -> unit

val diff : level -> level -> int32

(** A cycle era is a chunk of cycles having the same number of levels
   per cycle and the same number of blocks per commitment. *)
type cycle_era = {
  first_level : Raw_level_repr.t;  (** The first level of a cycle era. *)
  first_cycle : Cycle_repr.t;  (** The first cycle of a cycle era. *)
  blocks_per_cycle : int32;
      (** The value of the blocks_per_cycle constant used during the cycle
       era starting with first_level. *)
  blocks_per_commitment : int32;
      (** The value of the blocks_per_commitment constant used during the
       cycle era starting with first_level. *)
}

(** Stores the cycles eras of the Alpha family of protocols *)
type cycle_eras

val cycle_eras_encoding : cycle_eras Data_encoding.t

(** Preconditions on the input list of cycle eras:
   - the list is not empty
   - the first levels and the first cycles are decreasing, meaning that the
     first era in the list is the current era, and the last era in the list
     is the oldest era
   Invariants: 
   - the first era therefore contains the same constants as in Constants
   - the first level of an era is the first level of a cycle
*)
val create_cycle_eras : cycle_era list -> cycle_eras tzresult

(** Returns the current era *)
val current_era : cycle_eras -> cycle_era

(** Returns the first level of the oldest era *)
val root_level : cycle_eras -> level

(** Returns the annotated level corresponding to a raw level and an
   offset. A positive offset corresponds to a higher level. *)
val from_raw :
  cycle_eras:cycle_eras -> ?offset:int32 -> Raw_level_repr.t -> level

(** Returns the first level of the given cycle. *)
val first_level_in_cycle : cycle_eras:cycle_eras -> Cycle_repr.t -> level

(** Returns true if the given level is the last of a cycle. *)
val last_of_cycle : cycle_eras:cycle_eras -> level -> bool

(**/**)

(* exported for unit testing only *)
type error += Invalid_cycle_eras