(*****************************************************************************)
(*                                                                           *)
(* Open Source License                                                       *)
(* Copyright (c) 2018 Nomadic Development. <contact@tezcore.com>             *)
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(* copy of this software and associated documentation files (the "Software"),*)
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module type FILTER = sig
  type config

  val config_encoding : config Data_encoding.t

  val default_config : config

  module Proto : Registered_protocol.T

  val pre_filter : config -> Proto.operation_data -> bool

  val post_filter :
    config ->
    validation_state_before:Proto.validation_state ->
    validation_state_after:Proto.validation_state ->
    Proto.operation_data * Proto.operation_receipt ->
    bool Lwt.t
end

module No_filter (Proto : Registered_protocol.T) = struct
  type config = unit

  let config_encoding = Data_encoding.empty

  let default_config = ()

  module Proto = Proto

  let pre_filter _ _ = true

  let post_filter _ ~validation_state_before:_ ~validation_state_after:_ _ =
    Lwt.return_true
end

let table : (module FILTER) Protocol_hash.Table.t =
  Protocol_hash.Table.create 5

let register (module Filter : FILTER) =
  assert (not (Protocol_hash.Table.mem table Filter.Proto.hash)) ;
  Protocol_hash.Table.add table Filter.Proto.hash (module Filter)

let find = Protocol_hash.Table.find_opt table