open Bos.OS
open Syntax
open Crypto

let read fname =
  let* b = File.exists fname in
  match b with
  | false -> Ok None
  | true ->
      let+ content = File.read fname in
      Some content

let read_eddsa fname =
  let+ content_opt = read fname in
  Option.map EddsaPrivateKey.of_octets content_opt

let read_rsa fname =
  let+ content_opt = read fname in
  Option.map RsaPrivateKey.of_octets content_opt

let write_eddsa fname priv = EddsaPrivateKey.to_octets priv |> File.write fname
let write_rsa fname priv = RsaPrivateKey.to_octets priv |> File.write fname

let load_signkey conn fname =
  let* opt = read_eddsa fname in
  match opt with
  | None -> Ok None
  | Some priv -> (
      let pub = EddsaPrivateKey.pub_of_priv priv in
      let* opt = Pg.lookup_signing_key conn pub in
      match opt with
      | None ->
          Fmt.error_msg
            "load_signkey error no associated metadata found in database for \
             signkey `%s`."
            (Fpath.to_string fname)
      | Some (stamp_start, stamp_expire, stamp_end) ->
          (* TODO master_sig *)
          let master_sig = None in
          let v =
            Signkey.
              { pub; priv; stamp_start; stamp_expire; stamp_end; master_sig }
          in
          Ok (Some v))

let load_denom conn ~section_name fname =
  let* opt = read_rsa fname in
  match opt with
  | None -> Ok None
  | Some priv -> (
      let pub = RsaPrivateKey.pub_of_priv priv in
      let h_pub = Bin_type.DenominationHash.hash (RsaPublicKey.to_octets pub) in
      let* opt = Pg.lookup_denomination_key conn h_pub in
      match opt with
      | None ->
          Fmt.error_msg
            "load_denom error no associated metadata found in database for \
             denom `%s`."
            (Fpath.to_string fname)
      | Some
          ( stamp_start,
            stamp_expire_withdraw,
            stamp_expire_deposit,
            stamp_expire_legal,
            value,
            fee_withdraw,
            fee_deposit,
            fee_refresh,
            fee_refund,
            age_mask ) ->
          (* TODO master_sig *)
          let master_sig = None in
          let v =
            Denomination.
              {
                pub;
                priv;
                section_name;
                value;
                stamp_start;
                stamp_expire_withdraw;
                stamp_expire_deposit;
                stamp_expire_legal;
                fee_withdraw;
                fee_deposit;
                fee_refresh;
                fee_refund;
                age_mask;
                h_pub;
                master_sig;
              }
          in
          Ok (Some v))