Find IDN instead of using default path

README.md

@@ -75,7 +75,7 @@ First you need the dependencies
 * C++20 capable compiler
   * Tested with GCC 12.1 and Clang 14.0
 * A installation of GNUnet 0.19 (or likely the latest version)
-* libidn2
+* libidn
 
 (For examples)
 * CLI11
@@ -95,7 +95,7 @@ This project aims to create a easy to use wapper for the commonly used part of G
   - [ ] Port to C++ modules when CMake supports it
 - CMake
   - [x] Locate GNUnet installation path (currently use the expected path)
-  - [ ] Find libidn2
+  - [x] Find libidn
 - DHT
   - [x] Basic operations (put/get)
   - [ ] Monitor

cmake/FindGNUnet.cmake

@@ -23,6 +23,9 @@ if (NOT all_libs_found)
     return()
 endif ()
 
+find_package(idn REQUIRED)
+list(APPEND GNUnet_LIBRARIES idn::idn)
+
 # HACK: CMake requires a library as the "target" of an imported library, so we
 # use a library we know will be present on the system.
 add_library(GNUnet::GNUnet IMPORTED UNKNOWN)

cmake/Findidn.cmake

@@ -0,0 +1,32 @@
+if(TARGET idn::idn)
+    return()
+endif ()
+
+find_library(IDN_LIBRARY NAMES idn)
+if(NOT IDN_LIBRARY)
+    set(IDN_FOUND FALSE)
+    return()
+endif()
+
+find_path(IDN_INCLUDE_DIR NAMES idna.h)
+if(NOT IDN_INCLUDE_DIR)
+    set(IDN_FOUND FALSE)
+    return()
+endif()
+
+set(IDN_FOUND TRUE)
+set(IDN_LIBRARIES ${IDN_LIBRARY})
+set(IDN_INCLUDE_DIRS ${IDN_INCLUDE_DIR})
+mark_as_advanced(IDN_INCLUDE_DIRS IDN_LIBRARIES)
+
+add_library(idn::idn IMPORTED UNKNOWN)
+set_target_properties(idn::idn PROPERTIES
+    INTERFACE_INCLUDE_DIRECTORIES "${IDN_INCLUDE_DIRS}"
+    IMPORTED_LOCATION ${IDN_LIBRARIES}
+)
+
+include(FindPackageHandleStandardArgs)
+find_package_handle_standard_args(
+    idn
+    REQUIRED_VARS IDN_LIBRARIES IDN_INCLUDE_DIRS
+)

gnunetpp/CMakeLists.txt

@@ -14,7 +14,7 @@ add_library(gnunetpp
     inner/Infra.cpp)
 target_include_directories(gnunetpp PUBLIC ${CMAKE_CURRENT_SOURCE_DIR})
 target_precompile_headers(gnunetpp PRIVATE pch.hpp)
-target_link_libraries(gnunetpp PUBLIC idn GNUnet::GNUnet)
+target_link_libraries(gnunetpp PUBLIC GNUnet::GNUnet)
 # workaround for libintl.h conflicts
 target_compile_definitions(gnunetpp PUBLIC -DENABLE_NLS)