refactor_instructions.md

Refactoring Requirements

Objectives:

1. Reduce cyclomatic complexity to < 5 per function
2. Extract nested conditionals into separate functions
3. Use strategy pattern for discount calculations
4. Improve readability and maintainability
5. Preserve all existing functionality

Constraints:

• Do not change function signatures
• Maintain backward compatibility
• Add type hints
• Add docstrings

Approach:

1. Extract discount calculation logic into separate functions
2. Create discount strategy classes
3. Simplify conditional logic
4. Use early returns to reduce nesting