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(* Open Source License                                                       *)
(* Copyright (c) 2018 Dynamic Ledger Solutions, Inc. <contact@tezos.com>     *)
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open Client_keys
open Signer_messages

let tcp_scheme = "tcp"

let unix_scheme = "unix"

module Make (P : sig
  val authenticate :
    Signature.Public_key_hash.t list -> Bytes.t -> Signature.t tzresult Lwt.t
end) =
struct
  type request_type =
    | Sign_request
    | Deterministic_nonce_request
    | Deterministic_nonce_hash_request

  let build_request pkh data signature = function
    | Sign_request ->
        Request.Sign {Sign.Request.pkh; data; signature}
    | Deterministic_nonce_request ->
        Request.Deterministic_nonce
          {Deterministic_nonce.Request.pkh; data; signature}
    | Deterministic_nonce_hash_request ->
        Request.Deterministic_nonce_hash
          {Deterministic_nonce_hash.Request.pkh; data; signature}

  let signer_operation path pkh msg request_type =
    Lwt_utils_unix.Socket.connect path
    >>=? (fun conn ->
           Lwt_utils_unix.Socket.send
             conn
             Request.encoding
             Request.Authorized_keys
           >>=? fun () ->
           Lwt_utils_unix.Socket.recv
             conn
             (result_encoding Authorized_keys.Response.encoding)
           >>=? fun authorized_keys ->
           Lwt.return authorized_keys
           >>=? fun authorized_keys ->
           Lwt_unix.close conn
           >>= fun () ->
           match authorized_keys with
           | No_authentication ->
               return_none
           | Authorized_keys authorized_keys ->
               P.authenticate
                 authorized_keys
                 (Sign.Request.to_sign ~pkh ~data:msg)
               >>=? fun signature -> return_some signature)
    >>=? fun signature ->
    Lwt_utils_unix.Socket.connect path
    >>=? fun conn ->
    let req = build_request pkh msg signature request_type in
    Lwt_utils_unix.Socket.send conn Request.encoding req
    >>=? fun () -> return conn

  let sign ?watermark path pkh msg =
    let msg =
      match watermark with
      | None ->
          msg
      | Some watermark ->
          Bytes.cat (Signature.bytes_of_watermark watermark) msg
    in
    signer_operation path pkh msg Sign_request
    >>=? fun conn ->
    Lwt_utils_unix.Socket.recv conn (result_encoding Sign.Response.encoding)
    >>=? fun res -> Lwt_unix.close conn >>= fun () -> Lwt.return res

  let deterministic_nonce path pkh msg =
    signer_operation path pkh msg Deterministic_nonce_request
    >>=? fun conn ->
    Lwt_utils_unix.Socket.recv
      conn
      (result_encoding Deterministic_nonce.Response.encoding)
    >>=? fun res -> Lwt_unix.close conn >>= fun () -> Lwt.return res

  let deterministic_nonce_hash path pkh msg =
    signer_operation path pkh msg Deterministic_nonce_hash_request
    >>=? fun conn ->
    Lwt_utils_unix.Socket.recv
      conn
      (result_encoding Deterministic_nonce_hash.Response.encoding)
    >>=? fun res -> Lwt_unix.close conn >>= fun () -> Lwt.return res

  let supports_deterministic_nonces path pkh =
    Lwt_utils_unix.Socket.connect path
    >>=? fun conn ->
    Lwt_utils_unix.Socket.send
      conn
      Request.encoding
      (Request.Supports_deterministic_nonces pkh)
    >>=? fun () ->
    Lwt_utils_unix.Socket.recv
      conn
      (result_encoding Supports_deterministic_nonces.Response.encoding)
    >>=? fun res -> Lwt_unix.close conn >>= fun () -> Lwt.return res

  let public_key path pkh =
    Lwt_utils_unix.Socket.connect path
    >>=? fun conn ->
    Lwt_utils_unix.Socket.send conn Request.encoding (Request.Public_key pkh)
    >>=? fun () ->
    let encoding = result_encoding Public_key.Response.encoding in
    Lwt_utils_unix.Socket.recv conn encoding
    >>=? fun res -> Lwt_unix.close conn >>= fun () -> Lwt.return res

  module Unix = struct
    let scheme = unix_scheme

    let title =
      "Built-in tezos-signer using remote signer through hardcoded unix socket."

    let description =
      "Valid locators are of the form\n - unix:/path/to/socket?pkh=tz1..."

    let parse uri =
      assert (Uri.scheme uri = Some scheme) ;
      trace (Invalid_uri uri)
      @@
      match Uri.get_query_param uri "pkh" with
      | None ->
          failwith "Missing the query parameter: 'pkh=tz1...'"
      | Some key ->
          Lwt.return (Signature.Public_key_hash.of_b58check key)
          >>=? fun key ->
          return (Lwt_utils_unix.Socket.Unix (Uri.path uri), key)

    let public_key uri =
      parse (uri : pk_uri :> Uri.t) >>=? fun (path, pkh) -> public_key path pkh

    let neuterize uri =
      return (Client_keys.make_pk_uri (uri : sk_uri :> Uri.t))

    let public_key_hash uri =
      public_key uri
      >>=? fun pk -> return (Signature.Public_key.hash pk, Some pk)

    let import_secret_key ~io:_ = public_key_hash

    let sign ?watermark uri msg =
      parse (uri : sk_uri :> Uri.t)
      >>=? fun (path, pkh) -> sign ?watermark path pkh msg

    let deterministic_nonce uri msg =
      parse (uri : sk_uri :> Uri.t)
      >>=? fun (path, pkh) -> deterministic_nonce path pkh msg

    let deterministic_nonce_hash uri msg =
      parse (uri : sk_uri :> Uri.t)
      >>=? fun (path, pkh) -> deterministic_nonce_hash path pkh msg

    let supports_deterministic_nonces uri =
      parse (uri : sk_uri :> Uri.t)
      >>=? fun (path, pkh) -> supports_deterministic_nonces path pkh
  end

  module Tcp = struct
    let scheme = tcp_scheme

    let title =
      "Built-in tezos-signer using remote signer through hardcoded tcp socket."

    let description =
      "Valid locators are of the form\n - tcp://host:port/tz1..."

    let parse uri =
      assert (Uri.scheme uri = Some scheme) ;
      trace (Invalid_uri uri)
      @@
      match (Uri.host uri, Uri.port uri) with
      | (None, _) ->
          failwith "Missing host address"
      | (_, None) ->
          failwith "Missing host port"
      | (Some path, Some port) ->
          let pkh = Uri.path uri in
          let pkh = try String.(sub pkh 1 (length pkh - 1)) with _ -> "" in
          Lwt.return (Signature.Public_key_hash.of_b58check pkh)
          >>=? fun pkh ->
          return
            ( Lwt_utils_unix.Socket.Tcp
                (path, string_of_int port, [Lwt_unix.AI_SOCKTYPE SOCK_STREAM]),
              pkh )

    let public_key uri =
      parse (uri : pk_uri :> Uri.t) >>=? fun (path, pkh) -> public_key path pkh

    let neuterize uri =
      return (Client_keys.make_pk_uri (uri : sk_uri :> Uri.t))

    let public_key_hash uri =
      public_key uri
      >>=? fun pk -> return (Signature.Public_key.hash pk, Some pk)

    let import_secret_key ~io:_ = public_key_hash

    let sign ?watermark uri msg =
      parse (uri : sk_uri :> Uri.t)
      >>=? fun (path, pkh) -> sign ?watermark path pkh msg

    let deterministic_nonce uri msg =
      parse (uri : sk_uri :> Uri.t)
      >>=? fun (path, pkh) -> deterministic_nonce path pkh msg

    let deterministic_nonce_hash uri msg =
      parse (uri : sk_uri :> Uri.t)
      >>=? fun (path, pkh) -> deterministic_nonce_hash path pkh msg

    let supports_deterministic_nonces uri =
      parse (uri : sk_uri :> Uri.t)
      >>=? fun (path, pkh) -> supports_deterministic_nonces path pkh
  end
end

let make_unix_base path = Uri.make ~scheme:unix_scheme ~path ()

let make_tcp_base host port = Uri.make ~scheme:tcp_scheme ~host ~port ()