fix(api): return proper json objects (#3544)

cmake/compile_definitions/common.cmake

@@ -149,6 +149,7 @@ list(APPEND SUNSHINE_EXTERNAL_LIBRARIES
         ${CMAKE_THREAD_LIBS_INIT}
         enet
         libdisplaydevice::display_device
+        nlohmann_json::nlohmann_json
         opus
         ${FFMPEG_LIBRARIES}
         ${Boost_LIBRARIES}

cmake/compile_definitions/windows.cmake

@@ -76,7 +76,6 @@ list(PREPEND PLATFORM_LIBRARIES
         libstdc++.a
         libwinpthread.a
         minhook::minhook
-        nlohmann_json::nlohmann_json
         ntdll
         setupapi
         shlwapi

cmake/dependencies/common.cmake

@@ -16,6 +16,7 @@ add_subdirectory("${CMAKE_SOURCE_DIR}/third-party/Simple-Web-Server")
 add_subdirectory("${CMAKE_SOURCE_DIR}/third-party/libdisplaydevice")
 
 # common dependencies
+include("${CMAKE_MODULE_PATH}/dependencies/nlohmann_json.cmake")
 find_package(OpenSSL REQUIRED)
 find_package(PkgConfig REQUIRED)
 find_package(Threads REQUIRED)

cmake/dependencies/nlohmann_json.cmake

@@ -0,0 +1,18 @@
+#
+# Loads the nlohmann_json library giving the priority to the system package first, with a fallback to FetchContent.
+#
+include_guard(GLOBAL)
+
+find_package(nlohmann_json 3.11 QUIET GLOBAL)
+if(NOT nlohmann_json_FOUND)
+    message(STATUS "nlohmann_json v3.11.x package not found in the system. Falling back to FetchContent.")
+    include(FetchContent)
+
+    FetchContent_Declare(
+            json
+            URL      https://github.com/nlohmann/json/releases/download/v3.11.3/json.tar.xz
+            URL_HASH MD5=c23a33f04786d85c29fda8d16b5f0efd
+            DOWNLOAD_EXTRACT_TIMESTAMP
+    )
+    FetchContent_MakeAvailable(json)
+endif()

cmake/dependencies/windows.cmake

@@ -1,8 +1,5 @@
 # windows specific dependencies
 
-# nlohmann_json
-find_package(nlohmann_json CONFIG 3.11 REQUIRED)
-
 # Make sure MinHook is installed
 find_library(MINHOOK_LIBRARY libMinHook.a REQUIRED)
 find_path(MINHOOK_INCLUDE_DIR MinHook.h PATH_SUFFIXES include REQUIRED)