move new protocol code into main repo

src/Config.cpp

@@ -0,0 +1,41 @@
+#include "Config.h"
+
+#include <boost/iostreams/device/mapped_file.hpp>
+#include <filesystem>
+#include <fstream>
+#include <nlohmann/json.hpp>
+
+Config::Config() {
+    if (std::filesystem::exists("Launcher.cfg")) {
+        boost::iostreams::mapped_file cfg("Launcher.cfg", boost::iostreams::mapped_file::mapmode::readonly);
+        nlohmann::json d = nlohmann::json::parse(cfg.const_data(), nullptr, false);
+        if (d.is_discarded()) {
+            is_valid = false;
+        }
+        // parse config
+        if (d["Port"].is_number()) {
+            port = d["Port"].get<int>();
+        }
+        if (d["Build"].is_string()) {
+            branch = d["Build"].get<std::string>();
+            for (char& c : branch) {
+                c = char(tolower(c));
+            }
+        }
+        if (d["GameDir"].is_string()) {
+            game_dir = d["GameDir"].get<std::string>();
+        }
+    } else {
+        write_to_file();
+    }
+}
+
+void Config::write_to_file() const {
+    nlohmann::json d {
+        { "Port", port },
+        { "Branch", branch },
+        { "GameDir", game_dir },
+    };
+    std::ofstream of("Launcher.cfg", std::ios::trunc);
+    of << d.dump(4);
+}