(*****************************************************************************)
(*                                                                           *)
(* 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"),*)
(* to deal in the Software without restriction, including without limitation *)
(* the rights to use, copy, modify, merge, publish, distribute, sublicense,  *)
(* and/or sell copies of the Software, and to permit persons to whom the     *)
(* Software is furnished to do so, subject to the following conditions:      *)
(*                                                                           *)
(* The above copyright notice and this permission notice shall be included   *)
(* in all copies or substantial portions of the Software.                    *)
(*                                                                           *)
(* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR*)
(* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,  *)
(* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL   *)
(* THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER*)
(* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING   *)
(* FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER       *)
(* DEALINGS IN THE SOFTWARE.                                                 *)
(*                                                                           *)
(*****************************************************************************)

type t =
  | Implicit of Signature.Public_key_hash.t
  | Originated of Contract_hash.t

include Compare.Make (struct
  type nonrec t = t

  let compare l1 l2 =
    match (l1, l2) with
    | (Implicit pkh1, Implicit pkh2) ->
        Signature.Public_key_hash.compare pkh1 pkh2
    | (Originated h1, Originated h2) ->
        Contract_hash.compare h1 h2
    | (Implicit _, Originated _) ->
        -1
    | (Originated _, Implicit _) ->
        1
end)

type contract = t

type error += Invalid_contract_notation of string (* `Permanent *)

let to_b58check = function
  | Implicit pbk ->
      Signature.Public_key_hash.to_b58check pbk
  | Originated h ->
      Contract_hash.to_b58check h

let of_b58check s =
  match Base58.decode s with
  | Some (Ed25519.Public_key_hash.Data h) ->
      ok (Implicit (Signature.Ed25519 h))
  | Some (Secp256k1.Public_key_hash.Data h) ->
      ok (Implicit (Signature.Secp256k1 h))
  | Some (P256.Public_key_hash.Data h) ->
      ok (Implicit (Signature.P256 h))
  | Some (Contract_hash.Data h) ->
      ok (Originated h)
  | _ ->
      error (Invalid_contract_notation s)

let pp ppf = function
  | Implicit pbk ->
      Signature.Public_key_hash.pp ppf pbk
  | Originated h ->
      Contract_hash.pp ppf h

let pp_short ppf = function
  | Implicit pbk ->
      Signature.Public_key_hash.pp_short ppf pbk
  | Originated h ->
      Contract_hash.pp_short ppf h

let encoding =
  let open Data_encoding in
  def
    "contract_id"
    ~title:"A contract handle"
    ~description:
      "A contract notation as given to an RPC or inside scripts. Can be a \
       base58 implicit contract hash or a base58 originated contract hash."
  @@ splitted
       ~binary:
         (union
            ~tag_size:`Uint8
            [ case
                (Tag 0)
                ~title:"Implicit"
                Signature.Public_key_hash.encoding
                (function Implicit k -> Some k | _ -> None)
                (fun k -> Implicit k);
              case
                (Tag 1)
                (Fixed.add_padding Contract_hash.encoding 1)
                ~title:"Originated"
                (function Originated k -> Some k | _ -> None)
                (fun k -> Originated k) ])
       ~json:
         (conv
            to_b58check
            (fun s ->
              match of_b58check s with
              | Ok s ->
                  s
              | Error _ ->
                  Json.cannot_destruct "Invalid contract notation.")
            string)

let () =
  let open Data_encoding in
  register_error_kind
    `Permanent
    ~id:"contract.invalid_contract_notation"
    ~title:"Invalid contract notation"
    ~pp:(fun ppf x -> Format.fprintf ppf "Invalid contract notation %S" x)
    ~description:
      "A malformed contract notation was given to an RPC or in a script."
    (obj1 (req "notation" string))
    (function Invalid_contract_notation loc -> Some loc | _ -> None)
    (fun loc -> Invalid_contract_notation loc)

let implicit_contract id = Implicit id

let is_implicit = function Implicit m -> Some m | Originated _ -> None

let is_originated = function Implicit _ -> None | Originated h -> Some h

type origination_nonce = {
  operation_hash : Operation_hash.t;
  origination_index : int32;
}

let origination_nonce_encoding =
  let open Data_encoding in
  conv
    (fun {operation_hash; origination_index} ->
      (operation_hash, origination_index))
    (fun (operation_hash, origination_index) ->
      {operation_hash; origination_index})
  @@ obj2 (req "operation" Operation_hash.encoding) (dft "index" int32 0l)

let originated_contract nonce =
  let data =
    Data_encoding.Binary.to_bytes_exn origination_nonce_encoding nonce
  in
  Originated (Contract_hash.hash_bytes [data])

let originated_contracts
    ~since:{origination_index = first; operation_hash = first_hash}
    ~until:( {origination_index = last; operation_hash = last_hash} as
           origination_nonce ) =
  assert (Operation_hash.equal first_hash last_hash) ;
  let rec contracts acc origination_index =
    if Compare.Int32.(origination_index < first) then acc
    else
      let origination_nonce = {origination_nonce with origination_index} in
      let acc = originated_contract origination_nonce :: acc in
      contracts acc (Int32.pred origination_index)
  in
  contracts [] (Int32.pred last)

let initial_origination_nonce operation_hash =
  {operation_hash; origination_index = 0l}

let incr_origination_nonce nonce =
  let origination_index = Int32.succ nonce.origination_index in
  {nonce with origination_index}

let rpc_arg =
  let construct = to_b58check in
  let destruct hash =
    match of_b58check hash with
    | Error _ ->
        Error "Cannot parse contract id"
    | Ok contract ->
        Ok contract
  in
  RPC_arg.make
    ~descr:"A contract identifier encoded in b58check."
    ~name:"contract_id"
    ~construct
    ~destruct
    ()

module Index = struct
  type t = contract

  let path_length = 7

  let to_path c l =
    let raw_key = Data_encoding.Binary.to_bytes_exn encoding c in
    let (`Hex key) = Hex.of_bytes raw_key in
    let (`Hex index_key) = Hex.of_bytes (Raw_hashes.blake2b raw_key) in
    String.sub index_key 0 2 :: String.sub index_key 2 2
    :: String.sub index_key 4 2 :: String.sub index_key 6 2
    :: String.sub index_key 8 2 :: String.sub index_key 10 2 :: key :: l

  let of_path = function
    | []
    | [_]
    | [_; _]
    | [_; _; _]
    | [_; _; _; _]
    | [_; _; _; _; _]
    | [_; _; _; _; _; _]
    | _ :: _ :: _ :: _ :: _ :: _ :: _ :: _ :: _ ->
        None
    | [index1; index2; index3; index4; index5; index6; key] ->
        let raw_key = Hex.to_bytes (`Hex key) in
        let (`Hex index_key) = Hex.of_bytes (Raw_hashes.blake2b raw_key) in
        assert (Compare.String.(String.sub index_key 0 2 = index1)) ;
        assert (Compare.String.(String.sub index_key 2 2 = index2)) ;
        assert (Compare.String.(String.sub index_key 4 2 = index3)) ;
        assert (Compare.String.(String.sub index_key 6 2 = index4)) ;
        assert (Compare.String.(String.sub index_key 8 2 = index5)) ;
        assert (Compare.String.(String.sub index_key 10 2 = index6)) ;
        Data_encoding.Binary.of_bytes encoding raw_key

  let rpc_arg = rpc_arg

  let encoding = encoding

  let compare = compare
end