From 36246bb62ae35932f46725154ad240e1d51d92c9 Mon Sep 17 00:00:00 2001
From: Thomas Madlener <thomas.madlener@desy.de>
Date: Thu, 19 Dec 2024 20:35:14 +0100
Subject: [PATCH] Add overloads for handling ParticleIDMeta

---
 k4FWCore/CMakeLists.txt                  |  2 +-
 k4FWCore/include/k4FWCore/IMetadataSvc.h | 34 +++++++++++++++++++-----
 2 files changed, 29 insertions(+), 7 deletions(-)

diff --git a/k4FWCore/CMakeLists.txt b/k4FWCore/CMakeLists.txt
index e9b8bc03..6797bb6a 100644
--- a/k4FWCore/CMakeLists.txt
+++ b/k4FWCore/CMakeLists.txt
@@ -31,7 +31,7 @@ gaudi_install(PYTHON)
 gaudi_add_library(k4FWCore
 		  SOURCES src/PodioDataSvc.cpp
               src/KeepDropSwitch.cpp
-                  LINK Gaudi::GaudiKernel podio::podioIO ROOT::Core ROOT::RIO ROOT::Tree
+                  LINK Gaudi::GaudiKernel podio::podioIO ROOT::Core ROOT::RIO ROOT::Tree EDM4HEP::utils
                   )
 target_include_directories(k4FWCore PUBLIC
   $<BUILD_INTERFACE:${CMAKE_CURRENT_LIST_DIR}/include>
diff --git a/k4FWCore/include/k4FWCore/IMetadataSvc.h b/k4FWCore/include/k4FWCore/IMetadataSvc.h
index 65748d6e..897581eb 100644
--- a/k4FWCore/include/k4FWCore/IMetadataSvc.h
+++ b/k4FWCore/include/k4FWCore/IMetadataSvc.h
@@ -21,6 +21,8 @@
 
 #include "GaudiKernel/IInterface.h"
 
+#include "edm4hep/utils/ParticleIDUtils.h"
+
 #include "podio/Frame.h"
 
 class IMetadataSvc : virtual public IInterface {
@@ -31,12 +33,7 @@ class IMetadataSvc : virtual public IInterface {
 
   virtual void setFrame(podio::Frame frame) = 0;
 
-  template <typename T> void put(const std::string& name, const T& obj) {
-    if (!getFrame()) {
-      setFrame(podio::Frame{});
-    }
-    getFrame()->putParameter(name, obj);
-  }
+  template <typename T> void put(const std::string& name, const T& obj) { getFrameForWrite()->putParameter(name, obj); }
 
   template <typename T> std::optional<T> get(const std::string& name) const {
     const auto* frame = getFrame();
@@ -49,6 +46,31 @@ class IMetadataSvc : virtual public IInterface {
 protected:
   virtual podio::Frame*       getFrame()       = 0;
   virtual const podio::Frame* getFrame() const = 0;
+
+private:
+  podio::Frame* getFrameForWrite() {
+    if (!getFrame()) {
+      setFrame(podio::Frame());
+    }
+    return getFrame();
+  }
 };
 
+template <>
+inline void IMetadataSvc::put<edm4hep::utils::ParticleIDMeta>(const std::string&                    collName,
+                                                              const edm4hep::utils::ParticleIDMeta& pidMetaInfo) {
+  edm4hep::utils::PIDHandler::setAlgoInfo(*getFrameForWrite(), collName, pidMetaInfo);
+}
+
+template <>
+inline std::optional<edm4hep::utils::ParticleIDMeta> IMetadataSvc::get<edm4hep::utils::ParticleIDMeta>(
+    const std::string& collName) const {
+  const auto* frame = getFrame();
+  if (!frame) {
+    return std::nullopt;
+  }
+
+  return edm4hep::utils::PIDHandler::getAlgoInfo(*frame, collName);
+}
+
 #endif