From 9247b8df8a9f685cb0e92a6dc800227244ff6083 Mon Sep 17 00:00:00 2001
From: freezarite <markus.roth2001@yahoo.de>
Date: Tue, 3 Dec 2024 18:17:31 +0100
Subject: [PATCH] started work on config-system added nlohmann_json library as
 submodule and to CMakeLists.txt created basic config.json file in root folder
 created ConfigLoader.h and added basic functionalities to it

---
 .gitmodules            |  3 +++
 CMakeLists.txt         |  6 +++++-
 config.json            |  3 +++
 extern/nlohmann_json   |  1 +
 include/ConfigLoader.h | 24 ++++++++++++++++++++++++
 src/ConfigLoader.cpp   | 41 +++++++++++++++++++++++++++++++++++++++++
 6 files changed, 77 insertions(+), 1 deletion(-)
 create mode 100644 config.json
 create mode 160000 extern/nlohmann_json
 create mode 100644 include/ConfigLoader.h
 create mode 100644 src/ConfigLoader.cpp

diff --git a/.gitmodules b/.gitmodules
index 6dd82fa..9f871ba 100644
--- a/.gitmodules
+++ b/.gitmodules
@@ -17,3 +17,6 @@
 	path = docs/doxygen-awesome-css
 	url = https://github.com/jothepro/doxygen-awesome-css.git
 
+[submodule "extern/nlohmann_json"]
+	path = extern/nlohmann_json
+	url = https://github.com/nlohmann/json.git
diff --git a/CMakeLists.txt b/CMakeLists.txt
index d38fa27..12d886d 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -24,10 +24,13 @@ add_subdirectory(extern/SDL_image EXCLUDE_FROM_ALL)
 add_subdirectory(extern/SDL_mixer EXCLUDE_FROM_ALL)
 add_subdirectory(extern/SDL_ttf EXCLUDE_FROM_ALL)
 add_subdirectory(extern/tmxlite/tmxlite EXCLUDE_FROM_ALL)
+add_subdirectory(extern/nlohmann_json EXCLUDE_FROM_ALL)
 
 
 file(GLOB_RECURSE SOURCES ${ENGINE_SOURCE_DIR}/src/*.cpp)
-add_library(${PROJECT_NAME} ${SOURCES})
+add_library(${PROJECT_NAME} ${SOURCES}
+        include/ConfigLoader.h
+        src/ConfigLoader.cpp)
 
 target_include_directories(${PROJECT_NAME} PUBLIC ${ENGINE_INCLUDE_DIR})
 
@@ -37,6 +40,7 @@ target_link_libraries(${PROJECT_NAME} PUBLIC # should be private when all SDL fu
     SDL3_mixer::SDL3_mixer-static
     SDL3_ttf::SDL3_ttf-static
     tmxlite
+    nlohmann_json::nlohmann_json
 )
 
 if(CMAKE_BUILD_TYPE MATCHES "Debug")
diff --git a/config.json b/config.json
new file mode 100644
index 0000000..2aff41b
--- /dev/null
+++ b/config.json
@@ -0,0 +1,3 @@
+{
+  "fullscreen": false
+}
\ No newline at end of file
diff --git a/extern/nlohmann_json b/extern/nlohmann_json
new file mode 160000
index 0000000..a006a7a
--- /dev/null
+++ b/extern/nlohmann_json
@@ -0,0 +1 @@
+Subproject commit a006a7a48bb30a247f0344b788c62c2806edd90b
diff --git a/include/ConfigLoader.h b/include/ConfigLoader.h
new file mode 100644
index 0000000..d0115a4
--- /dev/null
+++ b/include/ConfigLoader.h
@@ -0,0 +1,24 @@
+#pragma once
+
+#include <nlohmann/json.hpp>
+
+using json = nlohmann::json;
+
+class ConfigLoader {
+
+public:
+    ConfigLoader();
+    ~ConfigLoader();
+
+    void init();
+
+    void setCustomConfig(std::string path);
+
+private:
+    json baseConfig;
+    std::optional<json> customConfig;
+    json finalConfig;
+
+    json loadConfigFromJSON(const std::string& path);
+    json mergeConfigs(json baseConfig, json customConfig); //<! Merges 2 config.json files, prioritising the custom to the base one
+};
diff --git a/src/ConfigLoader.cpp b/src/ConfigLoader.cpp
new file mode 100644
index 0000000..4c8cb04
--- /dev/null
+++ b/src/ConfigLoader.cpp
@@ -0,0 +1,41 @@
+#include "ConfigLoader.h"
+
+#include <fstream>
+
+ConfigLoader::ConfigLoader() {
+    baseConfig = loadConfigFromJSON("config.json");
+}
+
+void ConfigLoader::init() {
+    if (!customConfig.has_value()) {
+        finalConfig = baseConfig;
+        return;
+    }
+    finalConfig = mergeConfigs(baseConfig, customConfig.value());
+}
+
+json ConfigLoader::loadConfigFromJSON(const std::string& path) {
+    std::ifstream config_file(path);
+    json config;
+
+    if (!config_file.is_open()) {
+        throw std::runtime_error(std::string("Could not load config file at: " + path));
+    }
+
+    config_file >> config;
+    return config;
+}
+
+
+void ConfigLoader::setCustomConfig(std::string path) {
+    customConfig.emplace(loadConfigFromJSON(path));
+}
+
+json ConfigLoader::mergeConfigs(json baseConfig, json customConfig) {
+    for (auto& entry : customConfig.items()) {
+        baseConfig[entry.key()] = entry.value();
+    }
+    return baseConfig;
+}
+
+