figure_out_kt1.ml

(* In the tezos codebase: Use ["dune utop src/lib_base figure_out_kt1.ml"] *)

open Tezos_crypto

let enc =
  (* src/proto_alpha/lib_protocol/contract_repr.ml *)
  let open Data_encoding in
  obj2 (req "operation" Operation_hash.encoding) (dft "index" int32 0l)

(* src/proto_alpha/lib_protocol/contract_hash.ml *)

let contract_hash = "\002\090\121" (* KT1(36) *)

module H =
  Blake2B.Make
    (Base58)
    (struct
      let name = "Contract_hash"

      let title = "A contract ID"

      let b58check_prefix = contract_hash

      let size = Some 20
    end)

let input =
  [
    ("ooLC2QykF5NGiugdTyXJwsn2MEPMdRYJ4TeUoPMx8s38NzFximC", 0l);
    (* let expected = "KT1B94zMXzBr5nLuGXxx1GF7r6uSK6Sfz7pn" *)
    ("opCCqC2xtPgXHdoYynQF4WajE3BvAJwr2uJN4jS54ziweKCiUgw", 0l);
    ("opCCqC2xtPgXHdoYynQF4WajE3BvAJwr2uJN4jS54ziweKCiUgw", 1l);
    ("opCCqC2xtPgXHdoYynQF4WajE3BvAJwr2uJN4jS54ziweKCiUgw", 1023l);
    ("opCCqC2xtPgXHdoYynQF4WajE3BvAJwr2uJN4jS54ziweKCiUgw", 0xdeadbeefl);
  ]

let op op58 = Operation_hash.of_b58check_exn op58

let data op index = Data_encoding.Binary.to_bytes_exn enc (op, index)

let () =
  Fmt.pr "[\n" ;
  ListLabels.iter input ~f:(fun (op58, index) ->
      let kt1 = H.hash_bytes [data (op op58) index] |> H.to_b58check in
      Fmt.pr "  (%S, 0x%lxl, %S);\n" op58 index kt1) ;
  Fmt.pr "]\n"