sclass GazelleContextCache_v2 {
  transient Lock lock = lock();
  transient GazelleEvalContext cachedCtx;
  DynModule module;
  bool debug = true;
  
  *(DynModule *module) {}
  
  void fill {
    lock lock;
    cachedCtx = dm_gazelle_stdEvalContext(dm_gazelle_allRulesWithComment("discord")); 
    gazelle_addHelpers(cachedCtx);
  }
  
  
  GazelleEvalContext get() {
    lock lock;
    ret gazelle_cloneCtx(cachedCtx);
  }

  AutoCloseable listenToMessages() {
    ret combineAutoCloseables(
      vmBus_onMessage('gazelleRuleChanged, voidfunc(O ruleObj) {
        fS ruleID = getString globalID(ruleObj);
        dm_q(r {
          lock lock;
          if (cachedCtx == null) ret;
          print("GazelleContextCache_v2: processing rule update " + ruleID);
          RuleEngine2 engine = cachedCtx.engine;
          RuleEngine2.Rule rule = engine.getRule(ruleID);
          if (rule == null) print("GazelleContextCache_v2: rule not found, assuming it's new");
          else engine.rules.remove(rule);
          PairS p = dm_textAndCommentForRule(ruleID);
          if (p == null) ret with print("GazelleContextCache_v2: no text found for rule");
          engine.addRules2(ll(t3(p.a, p.b, ruleID)));
          rule = cachedCtx.engine.getRule(ruleID);
          if (rule == null) ret with print("GazelleContextCache_v2: rule not properly added");
          gazelle_addHelpers(nu(GazelleEvalContext, engine := gazelle_dummyEngineWithRule(rule)));
          print("GazelleContextCache_v2: rule update complete");
        })
      }),
      vmBus_onMessage('gazelleRuleDeleted, voidfunc(O rule) {
        S ruleID = getString globalID(rule);
        dm_q(r {
          lock lock;
          if (cachedCtx == null) ret;
          cachedCtx.engine.deleteRule(ruleID);
          print("GazelleContextCache_v2: rule " + ruleID + " deleted");
        })
      }));
  }
}