[Feature]: Restructure application

### Describe the feature you'd like

There is a couple of structural problem with the entire application. We should be addressing these issues one by one as to not end up in development hell.

- It seems like an anemic architectural model, which is an anti-pattern
- There are no unit tests

Further sub-tasks will be created to address this issue one section at a time.

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### Why is this feature important?

Unit tests will ensure the application is working as expected and with a proper domain model, we can protect business rules from outside change.