pragma language_version >= 0.23;
import CompactStandardLibrary;

export ledger startedAt: Uint<64>;
export ledger authenticated: Boolean;

constructor() {
  startedAt = 0;
  authenticated = false;
}

export circuit authenticate(expectedTimeWindow: Uint<64>): [] {
  assert(blockTimeGte(disclose(expectedTimeWindow)), "future window");
  assert(disclose(expectedTimeWindow >= startedAt), "window");
  startedAt = disclose(expectedTimeWindow);
  authenticated = true;
}