// ------------------- DTREE ensemble term ------------------
  var dtreeTerm(int i, int* outTopEq, var* outTopW){
    int j;
    int tid_i = dt.safeTreeIndexFromEq((int)net.EqTreeId[i], dt.TreeN);
    Node* ti = dt.treeAt(tid_i);
    int di = ti->d; var ri=ti->r;
    var predI = dt.predByTid(tid_i);

    var alpha = (var)net.TAlpha[i];
    var beta  = (var)net.TBeta[i];

    var sumw=0, acc=0, bestW=-1; int bestJ=-1;

    for(j=0;j<net.N;j++){
      if(j==i) continue;

      int tid_j = dt.safeTreeIndexFromEq((int)net.EqTreeId[j], dt.TreeN);
      Node* tj=dt.treeAt(tid_j);
      int dj=tj->d; var rj=tj->r;
      var predJ = dt.predByTid(tid_j);

      var w = exp(-alpha*abs(di-dj)) * exp(-beta*abs(ri-rj));
      var predBoost = 0.5 + 0.5*(predI*predJ);
      var propBoost = 0.5 + 0.5*( (net.Prop[i] + net.Prop[j]) );
      w *= predBoost * propBoost;

      var pairAdv = scorePairSafe(i,j,0,0,0,0);
      var pairBoost = 0.75 + 0.25*(0.5*(pairAdv+1.0));
      w *= pairBoost;

      sumw += w;
      acc  += w*net.State[j];
      if(w>bestW){ bestW=w; bestJ=j; }
    }

    if(outTopEq) *outTopEq = bestJ;
    if(outTopW)  *outTopW  = ifelse(sumw>0, bestW/sumw, 0);
    if(sumw>0) return acc/sumw;
    return 0;
  }

  // ------------------- expression builder (optional) --------------------
  void buildSymbolicExpr(int i, int n1, int n2){
    if(!LOG_EXPR_TEXT) return;
    if(!net.Sym) return;

    string s = net.Sym[i];
    s[0]=0;

    string a1 = strf("(%.3f*x[%i] + %.3f*lam + %.3f*mean + %.5f*E + %.3f*P + %.3f*i + %.3f)",
      (var)net.A1x[i], n1, (var)net.A1lam[i], (var)net.A1mean[i], (var)net.A1E[i], (var)net.A1P[i], (var)net.A1i[i], (var)net.A1c[i]);
    string a2 = strf("(%.3f*x[%i] + %.3f*lam + %.3f*mean + %.5f*E + %.3f*P + %.3f*i + %.3f)",
      (var)net.A2x[i], n2, (var)net.A2lam[i], (var)net.A2mean[i], (var)net.A2E[i], (var)net.A2P[i], (var)net.A2i[i], (var)net.A2c[i]);

    Alpha12Logger::strlcat_safe(s, "x[i]_next = ", EXPR_MAXLEN);
    Alpha12Logger::strlcat_safe(s, strf("%.3f*x[i] + ", (var)net.WSelf[i]), EXPR_MAXLEN);

    if(net.Mode[i]==1){
      Alpha12Logger::strlcat_safe(s, strf("%.3f*tanh%s + ", (var)net.WN1[i], a1), EXPR_MAXLEN);
      Alpha12Logger::strlcat_safe(s, strf("%.3f*sin%s + ",  (var)net.WN2[i], a2), EXPR_MAXLEN);
    } else if(net.Mode[i]==2){
      Alpha12Logger::strlcat_safe(s, strf("%.3f*cos%s + ",  (var)net.WN1[i], a1), EXPR_MAXLEN);
      Alpha12Logger::strlcat_safe(s, strf("%.3f*tanh%s + ", (var)net.WN2[i], a2), EXPR_MAXLEN);
    } else {
      Alpha12Logger::strlcat_safe(s, strf("%.3f*sin%s + ",  (var)net.WN1[i], a1), EXPR_MAXLEN);
      Alpha12Logger::strlcat_safe(s, strf("%.3f*cos%s + ",  (var)net.WN2[i], a2), EXPR_MAXLEN);
    }

    Alpha12Logger::strlcat_safe(s, strf("%.3f*tanh(%.3f*mean + %.5f*E) + ",
      (var)net.WGlob1[i], (var)net.G1mean[i], (var)net.G1E[i]), EXPR_MAXLEN);
    Alpha12Logger::strlcat_safe(s, strf("%.3f*sin(%.3f*P + %.3f*lam) + ",
      (var)net.WGlob2[i], (var)net.G2P[i], (var)net.G2lam[i]), EXPR_MAXLEN);
    Alpha12Logger::strlcat_safe(s, strf("%.3f*(x[i]-x_prev[i]) + ", (var)net.WMom[i]), EXPR_MAXLEN);
    Alpha12Logger::strlcat_safe(s, strf("Prop[i]=%.4f; ", (var)net.Prop[i]), EXPR_MAXLEN);
    Alpha12Logger::strlcat_safe(s, strf("%.3f*DT(i) + ", (var)net.WTree[i]), EXPR_MAXLEN);
    Alpha12Logger::strlcat_safe(s, strf("%.3f*DTREE(i)", (var)net.WAdv[i]), EXPR_MAXLEN);
  }

  void buildSymbolicExpr_range(int i0,int i1){
    if(!LOG_EXPR_TEXT) return;
    if(i0<0) i0=0; if(i1>net.N) i1=net.N;
    int i;
    for(i=i0;i<i1;i++){
      int n1 = net.adjSafe(i,0);
      int n2 = ifelse(net.D>=2, net.adjSafe(i,1), n1);
      buildSymbolicExpr(i,n1,n2);
    }
  }

  // ------------------- chunked rewire orchestrator ----------------------
  int rewireEpochChunk(var lambda, var mean, var energy, var power, int batch){
    if(net.N <= 0) return 0;
    if(batch < REWIRE_MIN_BATCH) batch = REWIRE_MIN_BATCH;

    if(RewirePos >= net.N) RewirePos = 0;
    int i0 = RewirePos;
    int i1 = i0 + batch; if(i1 > net.N) i1 = net.N;

    CandNeigh = ifelse(MH.Entropy < 0.45, CAND_NEIGH+4, CAND_NEIGH);

    rewireAdjacency_DTREE_range(i0,i1, lambda,mean,energy,power);
    net.sanitizeAdjacency();
    synthesizeEquation_range(i0,i1, lambda,mean,energy,power);
    buildSymbolicExpr_range(i0,i1);

    RewirePos = i1;
    if(RewirePos >= net.N){
      RewirePos = 0;
      RewirePasses++;
      return 1;
    }
    return 0;
  }

  void rewireEpoch(var lambda, var mean, var energy, var power){
    int done=0;
    while(!done){
      done = rewireEpochChunk(lambda,mean,energy,power, REWIRE_BATCH_EQ_H1);
    }
    net.normalizeProportions();

    {
      int D = net.D, i, total = net.N*D;
      unsigned int h = 2166136261u;
      for(i=0;i<total;i++){
        unsigned int x = (unsigned int)net.Adj[i];
        h ^= x + 0x9e3779b9u + (h<<6) + (h>>2);
      }
      CtxID = (int)((h ^ ((unsigned int)Epoch<<8)) & 0x7fffffff);
    }
  }

  // ------------------- coarse net projection -> gamma -------------------
  var projectNet(){
    int i;
    var sum=0,sumsq=0,cross=0;
    for(i=0;i<net.N;i++){
      sum += net.State[i];
      sumsq += net.State[i]*net.State[i];
      if(i+1<net.N) cross += net.State[i]*net.State[i+1];
    }
    var mean = sum/net.N;
    var corr = cross/(net.N-1);
    return 0.6*tanh(mean + 0.001*sumsq) + 0.4*sin(corr);
  }

  // ------------------- heavy update chunk (OpenCL-batched) --------------
  var nonlin1(int i, int n1, var lam, var mean, var E, var P){
    var x = net.State[n1];
    var arg = (var)net.A1x[i]*x + (var)net.A1lam[i]*lam + (var)net.A1mean[i]*mean + (var)net.A1E[i]*E + (var)net.A1P[i]*P + (var)net.A1i[i]*i + (var)net.A1c[i];
    return arg;
  }
  var nonlin2(int i, int n2, var lam, var mean, var E, var P){
    var x = net.State[n2];
    var arg = (var)net.A2x[i]*x + (var)net.A2lam[i]*lam + (var)net.A2mean[i]*mean + (var)net.A2E[i]*E + (var)net.A2P[i]*P + (var)net.A2i[i]*i + (var)net.A2c[i];
    return arg;
  }

  int heavyUpdateChunk(var lambda, var mean, var energy, var power, int batch){
    if(net.N <= 0) return 0;
    if(batch < UPDATE_MIN_BATCH) batch = UPDATE_MIN_BATCH;

    if(UpdatePos >= net.N) UpdatePos = 0;
    int i0 = UpdatePos;
    int i1 = i0 + batch; if(i1 > net.N) i1 = net.N;

    net.computeProjection();

    if(OclReady) {
      computeAdviceBatchRange(i0, i1, lambda, mean, energy, power);
    } else {
      resetAdvCacheForBar();
    }

    for(int i=i0;i<i1;i++){
      int n1 = net.adjSafe(i,0);
      int n2 = ifelse(net.D>=2, net.adjSafe(i,1), n1);

      int topEq=-1; var topW=0;
      var treeT = dtreeTerm(i, &topEq, &topW);
      net.TreeTerm[i] = (fvar)treeT;
      net.TopEq[i]    = (i16)topEq;
      net.TopW[i]     = (fvar)topW;

      var adv = adviseEq(i, lambda, mean, energy, power);

      var a1 = nonlin1(i,n1,lambda,mean,energy,power);
      var a2 = nonlin2(i,n2,lambda,mean,energy,power);
      var t1,t2;
      if(net.Mode[i]==1){ t1=tanh(a1); t2=sin(a2); }
      else if(net.Mode[i]==2){ t1=cos(a1); t2=tanh(a2); }
      else { t1=sin(a1); t2=cos(a2); }

      var glob1 = tanh((var)net.G1mean[i]*mean + (var)net.G1E[i]*energy);
      var glob2 = sin ((var)net.G2P[i]*power + (var)net.G2lam[i]*lambda);
      var mom = (net.State[i] - net.Prev[i]);

      var xnext =
          (var)net.WSelf[i]*net.State[i]
        + (var)net.WN1[i]*t1
        + (var)net.WN2[i]*t2
        + (var)net.WGlob1[i]*glob1
        + (var)net.WGlob2[i]*glob2
        + (var)net.WMom[i]*mom
        + (var)net.WTree[i]*treeT
        + (var)net.WAdv[i]*adv;

      xnext = clamp(xnext, -10., 10.);
      net.Prev[i]    = net.State[i];
      net.State[i]   = xnext;
      net.StateSq[i] = xnext*xnext;

      net.AdvPrev[i] = (fvar)adv;

      if(!rt.LogsOff && (Bar % LOG_EVERY)==0 && (i < LOG_EQ_SAMPLE)){
        int tid = dt.safeTreeIndexFromEq((int)net.EqTreeId[i], dt.TreeN);
        Node* tnode = dt.treeAt(tid);
        int nodeDepth = (tnode ? tnode->d : 0);
        var rate = (var)net.TBeta[i];
        var pred = dt.predByTid(tid);

        string expr = 0;
        if(LOG_EXPR_TEXT && net.Sym) expr = net.Sym[i];

        log.appendEqMetaLine(Bar, Epoch, CtxID,
          i, n1, n2, tid, nodeDepth, rate, pred, adv, net.Prop[i], (int)net.Mode[i],
          (var)net.WAdv[i], (var)net.WTree[i], MH.PBullNext, MH.Entropy, (int)MH.Cur,
          expr);
      }
    }

    UpdatePos = i1;
    if(UpdatePos >= net.N){
      UpdatePos = 0;
      UpdatePasses++;
      return 1;
    }
    return 0;
  }

  // ------------------- hit-rate scorer ----------------------
  void updateHitRates(){
    if(is(INITRUN)) return;
    if(Bar <= LookBack) return;

    var r = net.Ret1;
    var sgnR = sign(r);

    for(int i=0;i<net.N;i++){
      var a = (var)net.AdvPrev[i];
      var sgnA = ifelse(a > 0.0001, 1, ifelse(a < -0.0001, -1, 0));
      var hit = ifelse(sgnR == 0, 0.5, ifelse(sgnA == sgnR, 1.0, 0.0));
      net.HitEW[i] = (fvar)((1.0 - 0.02)*(var)net.HitEW[i] + 0.02*hit);
      net.HitN[i] += 1;
    }
  }

  // ------------------- blend lambda/gamma & accuracy --------------------
  var blendLambdaGamma(var lambda_raw, var gamma_raw){
    var w = clamp(FB_W + 0.15*(0.5 - MH.Entropy), 0.4, 0.9);
    var x = w*lambda_raw + (1.0 - w)*gamma_raw;
    rt.acc_update(lambda_raw, gamma_raw);
    return x;
  }

  // ------------------- rewire scheduler ----------------
  void maybeRewireNow(var lambda, var mean, var energy, var power){
    int mb = mem_mb_est();
    if(mb >= UPDATE_MEM_HARD) return;

    int batch = ifelse(is_H1_close(), REWIRE_BATCH_EQ_H1, REWIRE_BATCH_EQ_5M);
    if(mb >= REWIRE_MEM_SOFT) batch = (batch>>1);
    if(batch < REWIRE_MIN_BATCH) batch = REWIRE_MIN_BATCH;

    int finished = rewireEpochChunk(lambda,mean,energy,power,batch);

    if(finished && (RewirePasses % REWIRE_NORM_EVERY) == 0){
      net.normalizeProportions();
      log.writeEqHeaderOnce();
      if((RewirePasses % META_EVERY) == 0){
        int D = net.D, i, total = net.N*D;
        unsigned int h = 2166136261u;
        for(i=0;i<total;i++){
          unsigned int x = (unsigned int)net.Adj[i];
          h ^= x + 0x9e3779b9u + (h<<6) + (h>>2);
        }
        CtxID = (int)((h ^ ((unsigned int)Epoch<<8)) & 0x7fffffff);
      }
    }
  }

  // ------------------- heavy update scheduler ----------------
  void runHeavyUpdates(var lambda, var mean, var energy, var power){
    int mb = mem_mb_est();
    if(mb >= UPDATE_MEM_HARD) return;

    int batch = ifelse(is_H1_close(), UPDATE_BATCH_EQ_H1, UPDATE_BATCH_EQ_5M);
    if(mb >= UPDATE_MEM_SOFT) batch = (batch>>1);
    if(batch < UPDATE_MIN_BATCH) batch = UPDATE_MIN_BATCH;

    heavyUpdateChunk(lambda,mean,energy,power,batch);
  }

  // ------------------- main engine step ---------------------
  void alpha12_step(var ret1_now){
    if(!ready) return;

    updateAllMarkov();

    if(Bar < LookBack){
      net.computeProjection();
      net.Ret1 = ret1_now;

      var h=0;
      for(int i=0;i<net.N;i++) h += (var)net.HitEW[i];
      if(net.N > 0) h /= (var)net.N; else h=0.5;

      var target = MC_ACT + 0.15*(0.55 - h) + 0.10*(MH.Entropy - 0.5);
      target = clamp(target, 0.20, 0.50);
      MC_ACT_dyn = 0.95*MC_ACT_dyn + 0.05*target;
      return;
    }

    net.computeProjection();
    int Keff = net.keffClamped();
    var e=0, pwr=0;
    for(int k=0;k<Keff;k++){ var z=(var)net.Z[k]; e+=z; pwr+=z*z; }
    var mean=0, power=0;
    if(Keff > 0){ mean = e/(var)Keff; power = pwr/(var)Keff; }
    var energy = pwr;

    var lambda = 0.7*tanh(mean) + 0.3*tanh(0.05*power);

    maybeRewireNow(lambda,mean,energy,power);
    runHeavyUpdates(lambda,mean,energy,power);

    var gamma = projectNet();
    var x = blendLambdaGamma(lambda,gamma);
    (void)x;

    dt.updateEquationCycle(net.Prop, net.N);

    net.Ret1 = ret1_now;
    updateHitRates();

    int beforeDepth = rt.RT_TreeMaxDepth;
    rt.depth_manager_runtime(dt);
    if(rt.RT_TreeMaxDepth != beforeDepth){
      reindexTreeAndMap();
    }

    {
      var h=0;
      for(int i=0;i<net.N;i++) h += (var)net.HitEW[i];
      if(net.N > 0) h /= (var)net.N; else h=0.5;

      var target = MC_ACT + 0.15*(0.55 - h) + 0.10*(MH.Entropy - 0.5);
      target = clamp(target, 0.20, 0.50);
      MC_ACT_dyn = 0.9*MC_ACT_dyn + 0.1*target;
    }
  }

  // ------------------- realized 1-bar return ----------------
  var realizedRet1(){
    vars C = series(priceClose(0));
    if(Bar <= LookBack) return 0;
    return C[0] - C[1];
  }

  // ------------------- trading signal -----------------------
  var tradeSignal(){
    if(!ready) return 0;
    if(!net.RP || !net.Z || !net.StateSq) return 0;

    net.computeProjection();

    int Keff = net.keffClamped();
    if(Keff <= 0) return 0;

    var e=0, pwr=0;
    for(int k=0;k<Keff;k++){ var z=(var)net.Z[k]; e+=z; pwr+=z*z; }
    var mean=0, power=0;
    if(Keff > 0){ mean = e/(var)Keff; power = pwr/(var)Keff; }

    var lambda = 0.7*tanh(mean) + 0.3*tanh(0.05*power);
    var gamma  = projectNet();
    var x = blendLambdaGamma(lambda,gamma);
    LastSig = x;

    var gLong=0, gShort=0;
    if(MH.PBullNext >= PBULL_LONG_TH)  gLong = 1.0;
    if(MH.PBullNext <= PBULL_SHORT_TH) gShort= 1.0;

    var s=0;
    if(x > 0) s = x*gLong;
    else      s = x*gShort;

    var conf = 1.0 - 0.5*(MR.Entropy);
    s *= conf;

    return clamp(s,-1.,1.);
  }

  // ------------------- position sizing & orders -------------
  var posSizeFromSignal(var s){
    var base = 1;
    var scale = 2.0*abs(s);
    return base * (0.5 + 0.5*scale);
  }

  void placeOrders(var s){
    if(s > 0){
      if(NumOpenShort) exitShort();
      if(!NumOpenLong){
        Lots = posSizeFromSignal(s);
        enterLong();
      }
    } else if(s < 0){
      if(NumOpenLong) exitLong();
      if(!NumOpenShort){
        Lots = posSizeFromSignal(s);
        enterShort();
      }
    }
  }

  void plotSafe(string name, var v){
    if(ENABLE_PLOTS && !rt.ChartsOff) plot(name, v, NEW|LINE, 0);
  }

  void onBar(){
    var r1 = realizedRet1();
    alpha12_step(r1);
    var s = tradeSignal();
    placeOrders(s);

    plotSafe("PBull(1H)",   100*(MH.PBullNext-0.5));
    plotSafe("PBull(5M)",   100*(ML.PBullNext-0.5));
    plotSafe("PBull(Rel)",  100*(MR.PBullNext-0.5));
    plotSafe("Entropy(1H)", 100*(MH.Entropy));
    plotSafe("Sig",         100*LastSig);
  }

  // ----------------------- init/cleanup ----------------------
  void init() {
    if(ready) return;

    BarPeriod = BAR_PERIOD;
    LookBack  = max(300, NWIN);

    set(PLOTNOW);
    asset(ASSET_SYMBOL);

    net.Keff = KPROJ;
    if(net.Keff < 1) net.Keff = 1;
    if(net.Keff > net.K) net.Keff = net.K;

    net.allocate();

    MH.alloc(); ML.alloc(); MR.alloc();
    MH.Alpha = MC_Alpha; ML.Alpha = MC_Alpha; MR.Alpha = MC_Alpha;

    dt.allocDepthLUT();
    dt.DTreeExp = 0;
    dt.Root = dt.createNode(MAX_DEPTH);
    rt.RT_TreeMaxDepth = MAX_DEPTH;
    dt.refreshDepthW();

    reindexTreeAndMap();

    net.randomizeRP();
    net.computeProjection();

    rewireEpoch(0,0,0,0);

    log.writeEqHeaderOnce();

    RewirePos=0; RewirePasses=0;
    UpdatePos=0; UpdatePasses=0;

    seedBar = -1;
    memset(haveSeed,0,sizeof(haveSeed));

    // ---- OpenCL advisor init ----
    OclReady = 0;
    if(ocl.init(ADV_EQ_NF, NET_EQNS)) {
      OclReady = 1;
    }

    AdvCacheBar = -999999;
    memset(AdvHave,0,sizeof(AdvHave));
    memset(AdvCache,0,sizeof(AdvCache));

    ready = 1;

    printf("\n[Alpha12] init done: N=%i D=%i K=%i (Keff=%i) Depth=%i est=%i MB OpenCL=%i",
      net.N, net.D, net.K, net.Keff, rt.RT_TreeMaxDepth, mem_mb_est(), OclReady);
  }

  void cleanup() {
    if(!ready) return;

    if(OclReady) {
      ocl.shutdown();
      OclReady = 0;
    }

    MH.freeMem(); ML.freeMem(); MR.freeMem();

    dt.freeAll();
    pool.freeAll();
    net.freeAll();

    ready = 0;
  }
};

// ======================================================================
// ========================= Zorro DLL entry (bridge) ====================

DLLFUNC void run()
{
  if(is(INITRUN)) {
    if(!gAlpha12) gAlpha12 = new Alpha12Strategy();
    gAlpha12->init();
  }

  if(!gAlpha12 || !gAlpha12->ready)
    return;

  if(is(LOOKBACK) || Bar < LookBack) {
    gAlpha12->updateAllMarkov();
    gAlpha12->net.computeProjection();
    return;
  }

  gAlpha12->onBar();

  if(is(EXITRUN)) {
    gAlpha12->cleanup();
    delete gAlpha12;
    gAlpha12 = nullptr;
  }
}