HIPAA-Compliant Patient Data Anonymization API Middleware

Design a Laravel middleware that automatically anonymizes sensitive patient data during API responses while maintaining referential integrity. Create a solution that uses one-way hashing for patient identifiers, dynamically masks personally identifiable information (PII), and provides configurable anonymization levels compatible with HIPAA regulations. Include a mechanism to log anonymization events without storing original data, and develop unit tests that validate the anonymization process across different data types.