Added Json item loader

Added Json item loader

dll/item_db_loader.cpp

@@ -0,0 +1,57 @@
+/* Copyright (C) 2019 Nemirtingas (Maxime P)
+   This file is part of the Goldberg Emulator
+
+   The Goldberg Emulator is free software; you can redistribute it and/or
+   modify it under the terms of the GNU Lesser General Public
+   License as published by the Free Software Foundation; either
+   version 3 of the License, or (at your option) any later version.
+
+   The Goldberg Emulator is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+   Lesser General Public License for more details.
+
+   You should have received a copy of the GNU Lesser General Public
+   License along with the Goldberg Emulator; if not, see
+   <http://www.gnu.org/licenses/>.  */
+#include "item_db_loader.h"
+
+#include <fstream>
+#include "json.hpp"
+
+std::map<SteamItemDef_t, std::map<std::string, std::string>> read_items_db(std::string const& items_db)
+{
+    std::map<SteamItemDef_t, std::map<std::string, std::string>> items;
+   
+    std::ifstream items_file(items_db);
+    items_file.seekg(0, std::ios::end);
+    size_t size = items_file.tellg();
+    std::string buffer(size, '\0');
+    items_file.seekg(0);
+    items_file.read(&buffer[0], size);
+    items_file.close();
+
+    try
+    {
+        std::map<SteamItemDef_t, std::map<std::string, std::string>> tmp;
+        nlohmann::json json = nlohmann::json::parse(buffer);
+
+        for (auto& i : json.items())
+        {
+            SteamItemDef_t key = std::stoi((*i).key());
+            nlohmann::json& value = (*i).value();
+            for( auto& j : value.items() )
+            {
+                tmp[key][(*j).key()] = (*j).value();
+            }
+        }
+
+        items.swap(tmp);
+    }
+    catch (std::exception& e)
+    {
+        PRINT_DEBUG("Error while parsing json: %s", e.what());
+    }
+
+    return items;
+}