tests/test_fhir_validation_tdd.py

"""
TDD Tests for FHIR Validation
Focus on healthcare-grade FHIR R4 compliance
"""

import pytest
import json
from unittest.mock import Mock, patch
from typing import Dict, Any

# Will fail initially - TDD RED phase
try:
    from src.fhir_validator import FhirValidator
except ImportError:
    FhirValidator = None


class TestFhirValidatorTDD:
    """TDD tests for FHIR validation - healthcare grade"""
    
    def setup_method(self):
        """Setup test FHIR bundles"""
        self.valid_fhir_bundle = {
            "resourceType": "Bundle",
            "id": "test-bundle",
            "type": "document",
            "timestamp": "2025-06-03T00:00:00Z",
            "entry": [
                {
                    "resource": {
                        "resourceType": "Patient",
                        "id": "test-patient",
                        "identifier": [{"value": "123456789"}],
                        "name": [{"given": ["John"], "family": "Doe"}],
                        "birthDate": "1980-01-01"
                    }
                },
                {
                    "resource": {
                        "resourceType": "Observation",
                        "id": "test-observation",
                        "status": "final",
                        "code": {
                            "coding": [{
                                "system": "http://loinc.org",
                                "code": "85354-9",
                                "display": "Blood pressure"
                            }]
                        },
                        "subject": {"reference": "Patient/test-patient"},
                        "valueString": "140/90 mmHg"
                    }
                }
            ]
        }
        
        self.invalid_fhir_bundle = {
            "resourceType": "InvalidType",
            "entry": []
        }

    @pytest.mark.unit
    def test_fhir_validator_initialization(self):
        """Test: FHIR validator initializes correctly"""
        # Given: FHIR validator configuration
        # When: Creating validator
        validator = FhirValidator()
        
        # Then: Should initialize with healthcare-grade settings
        assert validator is not None
        assert validator.validation_level == 'healthcare_grade'
        assert validator.fhir_version == 'R4'

    @pytest.mark.unit
    def test_validate_valid_fhir_bundle(self):
        """Test: Valid FHIR bundle passes validation"""
        # Given: Valid FHIR bundle
        validator = FhirValidator()
        bundle = self.valid_fhir_bundle
        
        # When: Validating bundle
        result = validator.validate_bundle(bundle)
        
        # Then: Should pass validation
        assert result['is_valid'] is True
        assert result['compliance_score'] > 0.9
        assert len(result['errors']) == 0
        assert result['fhir_r4_compliant'] is True

    @pytest.mark.unit
    def test_validate_invalid_fhir_bundle(self):
        """Test: Invalid FHIR bundle fails validation"""
        # Given: Invalid FHIR bundle
        validator = FhirValidator()
        bundle = self.invalid_fhir_bundle
        
        # When: Validating bundle
        result = validator.validate_bundle(bundle)
        
        # Then: Should fail validation
        assert result['is_valid'] is False
        assert result['compliance_score'] < 0.5
        assert len(result['errors']) > 0
        assert result['fhir_r4_compliant'] is False

    @pytest.mark.unit
    def test_validate_fhir_structure(self):
        """Test: FHIR structure validation"""
        # Given: FHIR bundle with structure issues
        validator = FhirValidator()
        
        # When: Validating structure
        result = validator.validate_structure(self.valid_fhir_bundle)
        
        # Then: Should validate structure correctly
        assert result['structure_valid'] is True
        assert 'Bundle' in result['detected_resources']
        assert 'Patient' in result['detected_resources']
        assert 'Observation' in result['detected_resources']

    @pytest.mark.unit
    def test_validate_medical_terminology(self):
        """Test: Medical terminology validation (LOINC, SNOMED CT)"""
        # Given: FHIR bundle with medical codes
        validator = FhirValidator()
        bundle = self.valid_fhir_bundle
        
        # When: Validating terminology
        result = validator.validate_terminology(bundle)
        
        # Then: Should validate medical codes
        assert result['terminology_valid'] is True
        assert result['loinc_codes_valid'] is True
        assert 'validated_codes' in result
        assert len(result['validated_codes']) > 0

    @pytest.mark.unit
    def test_validate_hipaa_compliance(self):
        """Test: HIPAA compliance validation"""
        # Given: FHIR bundle
        validator = FhirValidator()
        bundle = self.valid_fhir_bundle
        
        # When: Checking HIPAA compliance
        result = validator.validate_hipaa_compliance(bundle)
        
        # Then: Should check HIPAA requirements
        assert result['hipaa_compliant'] is True
        assert result['phi_protection'] is True
        assert result['security_tags_present'] is False  # Test data has no security tags

    @pytest.mark.unit
    def test_calculate_compliance_score(self):
        """Test: Compliance score calculation"""
        # Given: Validation results
        validator = FhirValidator()
        validation_data = {
            'structure_valid': True,
            'terminology_valid': True,
            'hipaa_compliant': True,
            'fhir_r4_compliant': True
        }
        
        # When: Calculating compliance score
        score = validator.calculate_compliance_score(validation_data)
        
        # Then: Should return high compliance score
        assert score >= 0.95
        assert isinstance(score, float)
        assert 0.0 <= score <= 1.0

    @pytest.mark.unit
    def test_validate_with_healthcare_grade_level(self):
        """Test: Healthcare-grade validation level"""
        # Given: Validator with healthcare-grade settings
        validator = FhirValidator(validation_level='healthcare_grade')
        bundle = self.valid_fhir_bundle
        
        # When: Validating with strict healthcare standards
        result = validator.validate_bundle(bundle, validation_level='healthcare_grade')
        
        # Then: Should apply strict healthcare validation
        assert result['validation_level'] == 'healthcare_grade'
        assert result['strict_mode'] is True
        assert result['medical_coding_validated'] is True
        assert result['interoperability_score'] > 0.9