(*****************************************************************************)
(*                                                                           *)
(* Open Source License                                                       *)
(* Copyright (c) 2018 Dynamic Ledger Solutions, Inc. <contact@tezos.com>     *)
(*                                                                           *)
(* Permission is hereby granted, free of charge, to any person obtaining a   *)
(* copy of this software and associated documentation files (the "Software"),*)
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(* Software is furnished to do so, subject to the following conditions:      *)
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(* DEALINGS IN THE SOFTWARE.                                                 *)
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(** Places where tezzies can be found in the ledger's state. *)
type balance =
  | Contract of Contract_repr.t
  | Rewards of Signature.Public_key_hash.t * Cycle_repr.t
  | Fees of Signature.Public_key_hash.t * Cycle_repr.t
  | Deposits of Signature.Public_key_hash.t * Cycle_repr.t

(** A credit or debit of tezzies to a balance. *)
type balance_update =
  | Debited of Tez_repr.t
  | Credited of Tez_repr.t

(** A list of balance updates. Duplicates may happen. *)
type balance_updates = (balance * balance_update) list

val balance_updates_encoding : balance_updates Data_encoding.t

(** Remove zero-valued balances from a list of updates. *)
val cleanup_balance_updates : balance_updates -> balance_updates

type frozen_balance = {
  deposit : Tez_repr.t ;
  fees : Tez_repr.t ;
  rewards : Tez_repr.t ;
}

(** Is the contract eligible to delegation ? *)
val is_delegatable:
  Raw_context.t -> Contract_repr.t -> bool tzresult Lwt.t

(** Allow to register a delegate when creating an account. *)
val init:
  Raw_context.t -> Contract_repr.t -> Signature.Public_key_hash.t ->
  Raw_context.t tzresult Lwt.t

(** Cleanup delegation when deleting a contract. *)
val remove:
  Raw_context.t -> Contract_repr.t -> Raw_context.t tzresult Lwt.t

(** Reading the current delegate of a contract. *)
val get:
  Raw_context.t -> Contract_repr.t ->
  Signature.Public_key_hash.t option tzresult Lwt.t

val registered: Raw_context.t -> Signature.Public_key_hash.t -> bool Lwt.t

(** Updating the delegate of a contract.

    When calling this function on an "implicit contract" this function
    fails, unless when the registered delegate is the contract manager.
    In the that case, the manager is now registered as a delegate. One
    cannot unregister a delegate for now. The associate contract is
    now 'undeletable'. *)
val set:
  Raw_context.t -> Contract_repr.t -> Signature.Public_key_hash.t option ->
  Raw_context.t tzresult Lwt.t

(** Same as {!set} ignoring the [delegatable] flag. *)
val set_from_script:
  Raw_context.t -> Contract_repr.t -> Signature.Public_key_hash.t option ->
  Raw_context.t tzresult Lwt.t

type error +=
  | Non_delegatable_contract of Contract_repr.contract (* `Permanent *)
  | No_deletion of Signature.Public_key_hash.t (* `Permanent *)
  | Active_delegate (* `Temporary *)
  | Current_delegate (* `Temporary *)
  | Empty_delegate_account of Signature.Public_key_hash.t (* `Temporary *)
  | Balance_too_low_for_deposit of
      { delegate : Signature.Public_key_hash.t ;
        deposit : Tez_repr.t ;
        balance : Tez_repr.t } (* `Temporary *)

(** Iterate on all registered delegates. *)
val fold:
  Raw_context.t ->
  init:'a ->
  f:(Signature.Public_key_hash.t -> 'a -> 'a Lwt.t) -> 'a Lwt.t

(** List all registered delegates. *)
val list: Raw_context.t -> Signature.Public_key_hash.t list Lwt.t

(** Various functions to 'freeze' tokens.  A frozen 'deposit' keeps its
    associated rolls. When frozen, 'fees' may trigger new rolls
    allocation. Rewards won't trigger new rolls allocation until
    unfrozen. *)
val freeze_deposit:
  Raw_context.t -> Signature.Public_key_hash.t -> Tez_repr.t ->
  Raw_context.t tzresult Lwt.t

val freeze_fees:
  Raw_context.t -> Signature.Public_key_hash.t -> Tez_repr.t ->
  Raw_context.t tzresult Lwt.t

val freeze_rewards:
  Raw_context.t -> Signature.Public_key_hash.t -> Tez_repr.t ->
  Raw_context.t tzresult Lwt.t

(** Trigger the context maintenance at the end of cycle 'n', i.e.:
    unfreeze deposit/fees/rewards from 'n - preserved_cycle' ; punish the
    provided unrevealed seeds (tipically seed from cycle 'n - 1').
    Returns a list of account with the amount that was unfrozen for each
    and the list of deactivated delegates. *)
val cycle_end:
  Raw_context.t -> Cycle_repr.t -> Nonce_storage.unrevealed list ->
  (Raw_context.t * balance_updates * Signature.Public_key_hash.t list) tzresult Lwt.t

(** Burn all then frozen deposit/fees/rewards for a delegate at a given
    cycle. Returns the burned amounts. *)
val punish:
  Raw_context.t -> Signature.Public_key_hash.t -> Cycle_repr.t ->
  (Raw_context.t * frozen_balance) tzresult Lwt.t

(** Has the given key some frozen tokens in its implicit contract? *)
val has_frozen_balance:
  Raw_context.t -> Signature.Public_key_hash.t -> Cycle_repr.t ->
  bool tzresult Lwt.t

(** Returns the amount of frozen deposit, fees and rewards associated
    to a given delegate. *)
val frozen_balance:
  Raw_context.t -> Signature.Public_key_hash.t ->
  Tez_repr.t tzresult Lwt.t

val frozen_balance_encoding: frozen_balance Data_encoding.t
val frozen_balance_by_cycle_encoding:
  frozen_balance Cycle_repr.Map.t Data_encoding.t

(** Returns the amount of frozen deposit, fees and rewards associated
    to a given delegate, indexed by the cycle by which at the end the
    balance will be unfrozen. *)
val frozen_balance_by_cycle:
  Raw_context.t -> Signature.Public_key_hash.t ->
  frozen_balance Cycle_repr.Map.t Lwt.t

(** Returns the full 'balance' of the implicit contract associated to
    a given key, i.e. the sum of the spendable balance and of the
    frozen balance. *)
val full_balance:
  Raw_context.t -> Signature.Public_key_hash.t ->
  Tez_repr.t tzresult Lwt.t

val staking_balance:
  Raw_context.t -> Signature.Public_key_hash.t ->
  Tez_repr.t tzresult Lwt.t

(** Returns the list of contract that delegated towards a given delegate *)
val delegated_contracts:
  Raw_context.t -> Signature.Public_key_hash.t ->
  Contract_hash.t list Lwt.t

val delegated_balance:
  Raw_context.t -> Signature.Public_key_hash.t ->
  Tez_repr.t tzresult Lwt.t

val deactivated:
  Raw_context.t -> Signature.Public_key_hash.t ->
  bool tzresult Lwt.t

val grace_period:
  Raw_context.t -> Signature.Public_key_hash.t ->
  Cycle_repr.t tzresult Lwt.t