From f797e8ab0ab3cac8d4163478342aaf6d0d19d23d Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Nicol=C3=B2=20Jacazio?= <nicolo.jacazio@cern.ch>
Date: Wed, 16 Sep 2026 21:15:55 +0200
Subject: [PATCH 1/3] Add DittoMC

---
 MC/config/ALICE3/ini/ditto_pp_136tev.ini     |  6 ++
 MC/config/ALICE3/pythia8/generator_DittoMC.C | 62 ++++++++++++++++++++
 2 files changed, 68 insertions(+)
 create mode 100644 MC/config/ALICE3/ini/ditto_pp_136tev.ini
 create mode 100644 MC/config/ALICE3/pythia8/generator_DittoMC.C

diff --git a/MC/config/ALICE3/ini/ditto_pp_136tev.ini b/MC/config/ALICE3/ini/ditto_pp_136tev.ini
new file mode 100644
index 000000000..cefe555d6
--- /dev/null
+++ b/MC/config/ALICE3/ini/ditto_pp_136tev.ini
@@ -0,0 +1,6 @@
+[Diamond]
+width[2]=6.0
+
+[GeneratorExternal]
+fileName=${O2DPG_MC_CONFIG_ROOT}/MC/config/ALICE3/pythia8/generator_DittoMC.C
+funcName=generator_DittoMC("Ditto_tune_pythia8_inel_136tev.root")
diff --git a/MC/config/ALICE3/pythia8/generator_DittoMC.C b/MC/config/ALICE3/pythia8/generator_DittoMC.C
new file mode 100644
index 000000000..d454a9383
--- /dev/null
+++ b/MC/config/ALICE3/pythia8/generator_DittoMC.C
@@ -0,0 +1,62 @@
+#include "Ditto.h"
+
+#include <algorithm>
+#include <cstdint>
+#include <cstdlib>
+#include <stdexcept>
+
+#if !defined(__CLING__) || defined(__ROOTCLING__)
+
+#include <SimulationDataFormat/MCGenProperties.h>
+
+#include <Generators/GeneratorPythia8.h>
+#include <Pythia8/Pythia.h>
+
+#include <FairGenerator.h>
+#include <FairPrimaryGenerator.h>
+
+#endif
+
+// Ditto event generator
+
+class GeneratorDittoMC : public o2::eventgen::GeneratorPythia8
+{
+ public:
+  /// Constructor
+  GeneratorDittoMC(const TString& tuneFile) : mGenerator(makeConfig(tuneFile))
+  {
+    mPythia.readString("ProcessLevel:all = off");
+  }
+
+  bool generateEvent() override
+  {
+    mGenerator.generate();
+    mGenerator.loadParticles(mPythia.event, true);
+    return true;
+  }
+
+  ///  Destructor
+  ~GeneratorDittoMC() = default;
+
+ private:
+  static Ditto::Config makeConfig(const TString& tuneFile)
+  {
+    Ditto::Config config;
+    if (tuneFile.IsNull()) {
+      throw std::runtime_error("DITTO_TUNE_FILE must point to a Ditto tune file");
+    }
+    config.tuneFile = tuneFile;
+
+    const char* alienProcId = std::getenv("ALIEN_PROC_ID");
+    config.seed = alienProcId ? static_cast<std::uint64_t>(std::atoll(alienProcId)) : 0;
+    Printf("Using Ditto tune: %s and seed: %lu\n", config.tuneFile.c_str(), config.seed);
+    return config;
+  }
+
+  Ditto::Generator mGenerator;
+};
+
+FairGenerator* generator_DittoMC(const TString& tuneFile)
+{
+  return new GeneratorDittoMC(tuneFile);
+}

From ac62decc6a1239fdf536191ef221213bb2699215 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Nicol=C3=B2=20Jacazio?= <njacazio@users.noreply.github.com>
Date: Mon, 21 Sep 2026 14:55:01 +0200
Subject: [PATCH 2/3] Update ditto_pp_136tev.ini

---
 MC/config/ALICE3/ini/ditto_pp_136tev.ini | 3 ---
 1 file changed, 3 deletions(-)

diff --git a/MC/config/ALICE3/ini/ditto_pp_136tev.ini b/MC/config/ALICE3/ini/ditto_pp_136tev.ini
index cefe555d6..eed87b70f 100644
--- a/MC/config/ALICE3/ini/ditto_pp_136tev.ini
+++ b/MC/config/ALICE3/ini/ditto_pp_136tev.ini
@@ -1,6 +1,3 @@
-[Diamond]
-width[2]=6.0
-
 [GeneratorExternal]
 fileName=${O2DPG_MC_CONFIG_ROOT}/MC/config/ALICE3/pythia8/generator_DittoMC.C
 funcName=generator_DittoMC("Ditto_tune_pythia8_inel_136tev.root")

From dc3262a7f33f130c5a17f008fe05f1c521bc6afa Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Nicol=C3=B2=20Jacazio?= <nicolo.jacazio@cern.ch>
Date: Tue, 22 Sep 2026 17:14:08 +0200
Subject: [PATCH 3/3] Add test

---
 MC/config/ALICE3/ini/tests/ditto_pp_136tev.C | 1 +
 1 file changed, 1 insertion(+)
 create mode 120000 MC/config/ALICE3/ini/tests/ditto_pp_136tev.C

diff --git a/MC/config/ALICE3/ini/tests/ditto_pp_136tev.C b/MC/config/ALICE3/ini/tests/ditto_pp_136tev.C
new file mode 120000
index 000000000..4103e578f
--- /dev/null
+++ b/MC/config/ALICE3/ini/tests/ditto_pp_136tev.C
@@ -0,0 +1 @@
+pythia8_pp_ropes.C
\ No newline at end of file