Refactor Main game logic into Modular Structure

## Description
Currently, main game logic code is written in single file, which makes the code difficult to maintain, extend and test. It needs modularizing To improve the structure, readability and reusability.

## Goals
1. Seperate the main game logic code into modules and classes.
2. Improve separation of concerns.
3. Prepare the code for easier features additions or fixing bugs.