Code Refactoring Assistant

Refactor the following [LANGUAGE] code to improve readability, maintainability, and performance without changing its external behavior. Code to refactor: [CODE_BLOCK]. Apply these specific improvements: (1) eliminate duplicate logic using appropriate abstractions, (2) replace magic numbers and strings with named constants, (3) break functions longer than [MAX_FUNCTION_LINES] lines into smaller, single-responsibility functions, (4) rename variables and functions to clearly express intent, (5) add inline comments only where the "why" is non-obvious. Output the refactored code first, then provide a bulleted summary of every change made and the reason for each change. If you identify any bugs or edge cases in the original code, flag them separately under a "Potential Issues" heading but do not fix them unless instructed.