service-finder/docs/verified_service_reviews_implementation.md

Verified Service Reviews Implementation

Overview

This document describes the implementation of verified service reviews (Social 3 module) as specified in logic_spec_66_verified_service_reviews.md. The implementation adds transaction-based verification to service reviews, ensuring that only users who have completed a financial transaction with a service provider can leave verified reviews.

Changes Made

1. Model Updates

backend/app/models/identity/social.py - ServiceReview Model

• Added foreign key constraint from transaction_id to audit.financial_ledger.transaction_id
• Added ForeignKey("audit.financial_ledger.transaction_id", ondelete="RESTRICT") to the transaction_id field
• Added relationship financial_transaction to FinancialLedger model
• The foreign key ensures that service reviews can only reference valid financial transactions

backend/app/models/system/audit.py - FinancialLedger Model

• Added unique=True constraint to transaction_id field
• This ensures transaction_id has a unique constraint required for foreign key reference
• Changed from index=True to unique=True, index=True

2. Database Schema Impact

• Foreign Key: identity.service_reviews.transaction_id → audit.financial_ledger.transaction_id
• Unique Constraint: Added unique constraint on audit.financial_ledger.transaction_id
• Relationship: ServiceReview now has a financial_transaction relationship to FinancialLedger

3. Business Logic Implementation

The implementation follows the logic spec requirements:

• Service reviews are linked to financial transactions via transaction_id
• Only users who have completed transactions can leave verified reviews
• The foreign key uses ondelete="RESTRICT" to prevent deletion of financial ledger entries that have associated reviews
• The relationship allows easy access to transaction details from service reviews

4. Migration Status

• Model changes have been implemented in Python code
• Database schema changes require manual migration due to project constraints on Alembic usage
• The sync_engine.py script confirms the models are properly defined but database synchronization needs to be performed

Technical Details

Foreign Key Constraint

transaction_id: Mapped[uuid.UUID] = mapped_column(
    PG_UUID(as_uuid=True), 
    ForeignKey("audit.financial_ledger.transaction_id", ondelete="RESTRICT"),
    nullable=False, 
    index=True
)

Unique Constraint on FinancialLedger

transaction_id: Mapped[uuid.UUID] = mapped_column(
    PG_UUID(as_uuid=True), default=uuid.uuid4, nullable=False, unique=True, index=True
)

Relationship

financial_transaction: Mapped["FinancialLedger"] = relationship(
    "FinancialLedger", 
    foreign_keys=[transaction_id]
)

Next Steps Required

1. Database Migration

The following SQL commands need to be executed to apply the schema changes:

-- 1. Add unique constraint to audit.financial_ledger.transaction_id
ALTER TABLE audit.financial_ledger 
ADD CONSTRAINT uq_financial_ledger_transaction_id 
UNIQUE (transaction_id);

-- 2. Add foreign key constraint to identity.service_reviews.transaction_id
ALTER TABLE identity.service_reviews 
ADD CONSTRAINT fk_service_reviews_transaction_id 
FOREIGN KEY (transaction_id) 
REFERENCES audit.financial_ledger(transaction_id) 
ON DELETE RESTRICT;

2. API Endpoints

According to the logic spec, the following API endpoints need to be implemented:

• POST /marketplace/service-reviews - Create a new service review
• GET /marketplace/service-reviews/{service_id} - Get reviews for a service
• GET /marketplace/service-reviews/user/{user_id} - Get user's reviews

3. Service Layer

The service layer (marketplace_service.py) needs to be updated to:

• Validate that users have completed transactions before allowing verified reviews
• Calculate aggregated ratings for service profiles
• Implement the trust score influence factor logic

Testing Considerations

Test Scenarios

1. Valid Review: User with completed transaction can leave verified review
2. Invalid Review: User without transaction cannot leave verified review
3. Transaction Deletion Attempt: Attempt to delete financial ledger entry with associated reviews should be restricted
4. Aggregated Ratings: Service profile ratings should update when new verified reviews are added

Data Validation

• transaction_id must reference an existing audit.financial_ledger entry
• Review window validation (based on REVIEW_WINDOW_DAYS system parameter)
• Trust score influence factor application

Dependencies

Input Dependencies

• Financial Ledger: Requires audit.financial_ledger table with unique transaction_id
• Service Profiles: Requires marketplace.service_profiles table for aggregated ratings
• System Parameters: Requires REVIEW_WINDOW_DAYS and TRUST_SCORE_INFLUENCE_FACTOR parameters

Output Dependencies

• Service Finder Algorithm: Verified reviews influence service ranking
• User Trust System: Review verification contributes to user trust scores
• Analytics: Aggregated ratings used in business intelligence reports

Risk Mitigation

Schema Changes

• Added ondelete="RESTRICT" to prevent accidental data loss
• Unique constraint on transaction_id ensures data integrity
• Foreign key maintains referential integrity between reviews and transactions

Performance Considerations

• Index on transaction_id in both tables ensures efficient joins
• Aggregated ratings in service_profiles table prevent expensive calculations at query time
• Proper indexing strategy for review queries by service and user

Conclusion

The verified service reviews implementation provides a robust foundation for transaction-based review verification. The model changes ensure data integrity and proper relationships between financial transactions and service reviews. The implementation follows the Masterbook 2.0 architecture and prepares the system for the complete Social 3 module implementation.

Status: Model implementation complete, database migration pending, API endpoints to be implemented.