refactor: convert functions to methods

[GixoXYZ]

Description and Problem
Functions are scattered.

Proposed Changes
Convert functions to class methods where it makes sense.

Benefits
Cleaner, more unified code.

Tests

• Check the code under normal conditions.
• Check the code with problematic internet connection, unusual scenarios and repeatedly.
• Check the results and reportings to make sure they work as intended.

Checklist

• Proposed changes have been reviewed and approved.
• Code has been reviewed and has passed the tests.
• Documentation has been updated (if necessary).
• Code follows coding standards.