feat: reorganize source code + cleanup

src/IO/file_manager.cpp

@@ -0,0 +1,33 @@
+#include "IO/file_manager.h"
+
+#include <fstream>
+#include <iostream>
+#include <sstream>
+
+FileManager::FileManager()
+{
+}
+
+FileManager::~FileManager()
+{
+}
+
+std::string FileManager::read(const std::string &filename)
+{
+    std::ifstream file;
+    file.exceptions(std::ifstream::failbit | std::ifstream::badbit);
+
+    std::stringstream fileStream;
+    try
+    {
+        file.open(filename.c_str());
+        fileStream << file.rdbuf();
+        file.close();
+    }
+    catch (std::ifstream::failure e)
+    {
+        std::cout << "FileManager: error reading file: " << filename << std::endl;
+    }
+
+    return fileStream.str();
+}