;; Restricted wallet initialized by a third party (a variant of restricted-wallet2-code.fc)
;; restricts access to parts of balance until certain dates

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

_ seconds_passed(int start_at, int utime) inline_ref {
  ifnot (start_at) {
    var p = config_param(-13);
    start_at = null?(p) ? 0 : begin_parse(p).preload_uint(32);
  }
  return start_at ? utime - start_at : -1;
}

() 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));
  throw_unless(33, msg_seqno == stored_seqno);
  throw_unless(34, subwallet_id == stored_subwallet);
  throw_unless(36, check_signature(slice_hash(in_msg), signature, public_key));
  ifnot (msg_seqno) {
    public_key = ds~load_uint(256);  ;; load "final" public key
    ds.end_parse();
    cs~touch();
    var (start_at, rdict) = (cs~load_uint(32), cs~load_dict());
    cs.end_parse();
    accept_message();
    set_data(begin_cell()
              .store_uint(stored_seqno + 1, 32)
              .store_uint(stored_subwallet, 32)
              .store_uint(public_key, 256)
              .store_uint(start_at, 32)
              .store_dict(rdict)
            .end_cell());
    return ();
  }
  var (start_at, rdict) = (ds~load_uint(32), ds~load_dict());
  ds.end_parse();
  accept_message();
  var ts = seconds_passed(start_at, now());
  var (_, value, found) = rdict.idict_get_preveq?(32, ts);
  if (found) {
    raw_reserve(value~load_grams(), 2);
  }
  cs~touch();
  while (cs.slice_refs()) {
    var mode = cs~load_uint(8);
    var msg = cs~load_ref();
    send_raw_message(msg, mode);
  }
  cs.end_parse();
  set_data(begin_cell()
            .store_uint(stored_seqno + 1, 32)
            .store_uint(stored_subwallet, 32)
            .store_uint(public_key, 256)
            .store_uint(start_at, 32)
            .store_dict(rdict)
          .end_cell());
}

;; Get methods

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

int wallet_id() method_id {
  var ds = get_data().begin_parse();
  ds~load_uint(32);
  return ds.preload_uint(32);
}

int get_public_key() method_id {
  var ds = get_data().begin_parse();
  ds~load_uint(32 + 32);
  return ds.preload_uint(256);
}

int compute_balance_at(int utime) inline_ref {
  var ds = get_data().begin_parse().skip_bits(32 + 32 + 256);
  var (start_at, rdict) = (ds~load_uint(32), ds~load_dict());
  ds.end_parse();
  var ts = seconds_passed(start_at, utime);
  var balance = get_balance().pair_first();
  var (_, value, found) = rdict.idict_get_preveq?(32, ts);
  if (found) {
    balance = max(balance - value~load_grams(), 0);
  }
  return balance;
}

int balance_at(int utime) method_id {
  return compute_balance_at(utime);
}

int balance() method_id {
  return compute_balance_at(now());
}