;; Heavy-duty wallet for mass transfers (e.g., for cryptocurrency exchanges)
;; accepts orders for up to 254 internal messages (transfers) in one external message

() recv_internal(slice in_msg) impure {
  ;; do nothing for internal messages
}

() recv_external(slice in_msg) impure {
  var signature = in_msg~load_bits(512);
  var cs = in_msg;
  var (subwallet_id, valid_until, msg_seqno) = (cs~load_uint(32), cs~load_uint(32), cs~load_uint(32));
  throw_if(35, valid_until <= now());
  var ds = get_data().begin_parse();
  var (stored_seqno, stored_subwallet, public_key) = (ds~load_uint(32), ds~load_uint(32), ds~load_uint(256));
  ds.end_parse();
  throw_unless(33, msg_seqno == stored_seqno);
  throw_unless(34, subwallet_id == stored_subwallet);
  throw_unless(35, check_signature(slice_hash(in_msg), signature, public_key));
  var dict = cs~load_dict();
  cs.end_parse();
  accept_message();
  int i = -1;
  do {
    (i, var cs, var f) = dict.idict_get_next?(16, i);
    if (f) {
      var mode = cs~load_uint(8);
      send_raw_message(cs~load_ref(), mode);
    }
  } until (~ f);
  set_data(begin_cell()
    .store_uint(stored_seqno + 1, 32)
    .store_uint(stored_subwallet, 32)
    .store_uint(public_key, 256)
    .end_cell());
}

;; Get methods

int seqno() method_id {
  return get_data().begin_parse().preload_uint(32);
}