From d9df3b45cb5208c36d84b30ca8a6a42ed8cfdaa4 Mon Sep 17 00:00:00 2001
From: Marco Giacalone <mgiacalo@gmail.com>
Date: Mon, 31 Aug 2026 16:41:49 +0200
Subject: [PATCH] Example Pythia8 for HY

---
 MC/config/examples/hybrid/examplehyp8.json    | 79 +++++++++++++++++++
 MC/config/examples/ini/GeneratorHYPythia8.ini |  4 +
 .../examples/ini/tests/GeneratorHYPythia8.C   | 38 +++++++++
 3 files changed, 121 insertions(+)
 create mode 100644 MC/config/examples/hybrid/examplehyp8.json
 create mode 100644 MC/config/examples/ini/GeneratorHYPythia8.ini
 create mode 100644 MC/config/examples/ini/tests/GeneratorHYPythia8.C

diff --git a/MC/config/examples/hybrid/examplehyp8.json b/MC/config/examples/hybrid/examplehyp8.json
new file mode 100644
index 000000000..b7d66de30
--- /dev/null
+++ b/MC/config/examples/hybrid/examplehyp8.json
@@ -0,0 +1,79 @@
+{
+  "mode": "parallel",
+  "generators": [
+    {
+      "name": "external",
+      "config": {
+        "fileName": "",
+        "funcName": "",
+        "iniFile": "${O2DPG_MC_CONFIG_ROOT}/MC/config/ALICE3/ini/pythia8_pp_136tev.ini"
+      }
+    },
+    {
+      "name": "external",
+      "config": {
+        "fileName": "",
+        "funcName": "",
+        "iniFile": "${O2DPG_MC_CONFIG_ROOT}/MC/config/ALICE3/ini/pythia8_pp_136tev.ini"
+      }
+    },
+    {
+      "name": "external",
+      "config": {
+        "fileName": "",
+        "funcName": "",
+        "iniFile": "${O2DPG_MC_CONFIG_ROOT}/MC/config/ALICE3/ini/pythia8_pp_136tev.ini"
+      }
+    },
+    {
+      "name": "external",
+      "config": {
+        "fileName": "",
+        "funcName": "",
+        "iniFile": "${O2DPG_MC_CONFIG_ROOT}/MC/config/ALICE3/ini/pythia8_pp_136tev.ini"
+      }
+    },
+    {
+      "name": "external",
+      "config": {
+        "fileName": "",
+        "funcName": "",
+        "iniFile": "${O2DPG_MC_CONFIG_ROOT}/MC/config/ALICE3/ini/pythia8_pp_136tev.ini"
+      }
+    },
+    {
+      "name": "external",
+      "config": {
+        "fileName": "",
+        "funcName": "",
+        "iniFile": "${O2DPG_MC_CONFIG_ROOT}/MC/config/ALICE3/ini/pythia8_pp_136tev.ini"
+      }
+    },
+    {
+      "name": "external",
+      "config": {
+        "fileName": "",
+        "funcName": "",
+        "iniFile": "${O2DPG_MC_CONFIG_ROOT}/MC/config/ALICE3/ini/pythia8_pp_136tev.ini"
+      }
+    },
+    {
+      "name": "external",
+      "config": {
+        "fileName": "",
+        "funcName":   "",
+        "iniFile": "${O2DPG_MC_CONFIG_ROOT}/MC/config/ALICE3/ini/pythia8_pp_136tev.ini"
+      }
+    }
+  ],
+  "fractions": [
+    1,
+    1,
+    1,
+    1,
+    1,
+    1,
+    1,
+    1
+  ]
+}
\ No newline at end of file
diff --git a/MC/config/examples/ini/GeneratorHYPythia8.ini b/MC/config/examples/ini/GeneratorHYPythia8.ini
new file mode 100644
index 000000000..da82b263d
--- /dev/null
+++ b/MC/config/examples/ini/GeneratorHYPythia8.ini
@@ -0,0 +1,4 @@
+[GeneratorHybrid]
+configFile = ${O2DPG_MC_CONFIG_ROOT}/MC/config/examples/hybrid/examplehyp8.json
+switchExtToHybrid = true
+num_workers = 8
diff --git a/MC/config/examples/ini/tests/GeneratorHYPythia8.C b/MC/config/examples/ini/tests/GeneratorHYPythia8.C
new file mode 100644
index 000000000..2694d57e4
--- /dev/null
+++ b/MC/config/examples/ini/tests/GeneratorHYPythia8.C
@@ -0,0 +1,38 @@
+int Hybrid()
+{
+  std::string path{"o2sim_Kine.root"};
+  // Check that file exists, can be opened and has the correct tree
+  TFile file(path.c_str(), "READ");
+  if (file.IsZombie())
+  {
+    std::cerr << "Cannot open ROOT file " << path << "\n";
+    return 1;
+  }
+  auto tree = (TTree *)file.Get("o2sim");
+  if (!tree)
+  {
+    std::cerr << "Cannot find tree o2sim in file " << path << "\n";
+    return 1;
+  }
+  std::vector<o2::MCTrack> *tracks{};
+  tree->SetBranchAddress("MCTrack", &tracks);
+
+  // Check if all events are filled
+  auto nEvents = tree->GetEntries();
+  for (Long64_t i = 0; i < nEvents; ++i)
+  {
+    tree->GetEntry(i);
+    if (tracks->empty())
+    {
+      std::cerr << "Empty entry found at event " << i << "\n";
+      return 1;
+    }
+  }
+  // Check if there are 100 events, as simulated in the o2dpg-test
+  if (nEvents != 100)
+  {
+    std::cerr << "Expected 100 events, got " << nEvents << "\n";
+    return 1;
+  }
+  return 0;
+}