From 886d57faf9a6736cf8a4829599cdb1210efb094e Mon Sep 17 00:00:00 2001
From: tmadlener <thomas.madlener@desy.de>
Date: Tue, 3 Sep 2024 11:30:38 +0200
Subject: [PATCH] Configure the cmake config for downstream consumption

- Make sure all required dependencies are also detected in downstream
  users
- Add some legacy variables
---
 CMakeLists.txt                   |  6 ++----
 cmake/k4FWCoreConfig.cmake       | 11 -----------
 cmake/k4FWCoreConfig.cmake.in    | 34 ++++++++++++++++++++++++++++++++
 cmake/k4FWCoreCreateConfig.cmake |  6 ++++++
 4 files changed, 42 insertions(+), 15 deletions(-)
 delete mode 100644 cmake/k4FWCoreConfig.cmake
 create mode 100644 cmake/k4FWCoreConfig.cmake.in
 create mode 100644 cmake/k4FWCoreCreateConfig.cmake

diff --git a/CMakeLists.txt b/CMakeLists.txt
index 08401d48..866abe63 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -95,14 +95,12 @@ if(ENABLE_CPACK)
   include(cmake/${PROJECT_NAME}CPack.cmake)
 endif()
 
-
-
-
 install(EXPORT ${PROJECT_NAME}Targets
   NAMESPACE ${PROJECT_NAME}::
   FILE "${PROJECT_NAME}Targets.cmake"
   DESTINATION "${CMAKE_INSTALL_LIBDIR}/cmake/${PROJECT_NAME}/"
   )
 
-gaudi_install(CMAKE cmake/${PROJECT_NAME}Config.cmake)
+include(cmake/k4FWCoreCreateConfig.cmake)
 
+gaudi_install(CMAKE ${PROJECT_BINARY_DIR}/k4FWCoreConfig.cmake)
diff --git a/cmake/k4FWCoreConfig.cmake b/cmake/k4FWCoreConfig.cmake
deleted file mode 100644
index 50a30cc7..00000000
--- a/cmake/k4FWCoreConfig.cmake
+++ /dev/null
@@ -1,11 +0,0 @@
-
-include(CMakeFindDependencyMacro)
-find_dependency(podio REQUIRED)
-find_dependency(Gaudi REQUIRED)
-
-# - Include the targets file to create the imported targets that a client can
-# link to (libraries) or execute (programs)
-include("${CMAKE_CURRENT_LIST_DIR}/k4FWCoreTargets.cmake")
-
-get_property(TEST_K4FWCORE_LIBRARY TARGET k4FWCore::k4FWCore PROPERTY LOCATION)
-find_package_handle_standard_args(k4FWCore  DEFAULT_MSG CMAKE_CURRENT_LIST_FILE TEST_K4FWCORE_LIBRARY)
diff --git a/cmake/k4FWCoreConfig.cmake.in b/cmake/k4FWCoreConfig.cmake.in
new file mode 100644
index 00000000..3478680f
--- /dev/null
+++ b/cmake/k4FWCoreConfig.cmake.in
@@ -0,0 +1,34 @@
+###############################################################################
+# k4FWCore CMake Config
+#
+# Exported Targets
+#  - k4FWCore::k4FWCore         The core library containing the PodioDataSvc
+#                               and the KeepDropSwitch
+#  - k4FWCore::k4FWCorePlugins  The plugin library for the core plugins
+#                               provided by k4FWCore. Includes all major
+#                               services for I/O and as well as some utility
+#                               algorithms
+#  - k4FWCore::k4Interface      The (header-only) target containing all
+#                               interface definitions
+#
+###############################################################################
+@PACKAGE_INIT@
+
+set_and_check(k4FWCore_INCLUDE_DIR "@PACKAGE_CMAKE_INSTALL_INCLUDEDIR@")
+set_and_check(k4FWCore_LIBRARY_DIR "@PACKAGE_CMAKE_INSTALL_LIBDIR@")
+
+include(CMakeFindDependencyMacro)
+find_dependency(podio @podio_VERSION@)
+find_dependency(Gaudi @Gaudi_VERSION@)
+find_dependency(EDM4HEP @EDM4HEP_VERSION@)
+find_dependency(ROOT @ROOT_VERSION@ COMPONENTS RIO Tree)
+
+if(NOT TARGET k4FWCore::k4FWCore)
+  include("${CMAKE_CURRENT_LIST_DIR}/k4FWCoreTargets.cmake")
+endif()
+
+check_required_components(k4FWCore)
+
+include(FindPackageHandleStandardArgs)
+get_property(TEST_K4FWCORE_LIBRARY TARGET k4FWCore::k4FWCore PROPERTY LOCATION)
+find_package_handle_standard_args(k4FWCore DEFAULT_MSG CMAKE_CURRENT_LIST_FILE TEST_K4FWCORE_LIBRARY)
diff --git a/cmake/k4FWCoreCreateConfig.cmake b/cmake/k4FWCoreCreateConfig.cmake
new file mode 100644
index 00000000..a80ae942
--- /dev/null
+++ b/cmake/k4FWCoreCreateConfig.cmake
@@ -0,0 +1,6 @@
+include(CMakePackageConfigHelpers)
+
+configure_package_config_file(${PROJECT_SOURCE_DIR}/cmake/k4FWCoreConfig.cmake.in
+                              ${PROJECT_BINARY_DIR}/k4FWCoreConfig.cmake
+                              INSTALL_DESTINATION ${CMAKE_INSTALL_LIBDIR}/cmake/k4FWCore
+                              PATH_VARS CMAKE_INSTALL_INCLUDEDIR CMAKE_INSTALL_LIBDIR)