# Checkout Flow Central Index

This document centralizes all documentation, findings, and tasks related to the checkout flow, including race conditions, seat holds, timeouts, and related bug fixes.

## Key Documentation

- [Race Condition Solution Summary](_CONTEXT/RACE-CONDITION-SOLUTION-COMPLETE.md)
- [Race Condition Test Findings](test-results/race-condition-test-findings.md)
- [E2E Testing Framework](_CONTEXT/E2E-TESTING-FRAMEWORK.md)
- [Operations Runbook](_CONTEXT/OPERATIONS-RUNBOOK.md)
- [Seating System Architecture](_CONTEXT/seating-system-architecture.md)
- [Final Security Checklist](_CONTEXT/FINAL-SECURITY-CHECKLIST.md)
- [Build Status Report](_CONTEXT/build-status-report.md)

## Task Tracker

### Completed Tasks

- Race condition eliminated with atomic seat operations ([RACE-CONDITION-SOLUTION-COMPLETE.md], [API/FIXLIST.md])
  - confirmed with test-improved-seat-management.js
- Database-level hardening: unique constraints, hold expiry, idempotency ([E2E-IMPLEMENTATION-COMPLETE.md])
- E2E test suite implemented: happy paths, race conditions, data integrity ([E2E-IMPLEMENTATION-COMPLETE.md], [E2E-TESTING-FRAMEWORK.md])
- UI testability features: ARIA, countdown, visual states ([E2E-IMPLEMENTATION-COMPLETE.md])
- Smoke test complete, core API fix validated ([API/RUNLOG.md])
- Multi-seat selection reliability: 100% success ([API/FIXLIST.md])
- Payment failure handling, idempotent checkout ([E2E-TESTING-FRAMEWORK.md])
- Server-side instrumentation: structured logging, DB write path trace ([API/RUNLOG.md], [API/PHASE-1-COMPLETE.md])
- Data & identity integrity checks: seat identity normalization, DB constraints/indexes ([API/RUNLOG.md], [API/PHASE-1-COMPLETE.md])
- Anti-spam throttle precision bug resolved (`time()` → `microtime(true)`) ([API/PHASE-1-COMPLETE.md])
- API parallel holds working perfectly ([API/PHASE-1-COMPLETE.md])
- Regression test created for parallel holds ([API/PHASE-1-COMPLETE.md])
- Complete server-side observability added ([API/PHASE-1-COMPLETE.md])
- Documentation created for identity consistency and DB design ([API/PHASE-1-COMPLETE.md])

### Open Tasks (Consolidated)

**Monitoring & Observability**

- Monitor key metrics post-deployment (seat selection, errors, API times, DB impact)
- Integrate and monitor performance metrics (API response times, conflict rates, booking conversion rates)
- Set up and validate Prometheus/Grafana observability stack and alert manager
- Monitor baseline performance and establish gates for regression
- Add/verify monitoring and alerting for stale holds, conflict rates, and response times

**Load Testing & Performance**

- Expand load testing for high concurrency (k6, Playwright matrix)
- Add analytics integration for booking flow

**User Experience & Accessibility**

- Validate user experience (multi-seat selection, error handling, feedback)
- Ensure accessibility compliance (ARIA, keyboard nav) and expand coverage
- Expand accessibility and notification coverage in E2E tests

**Code/Test Maintenance**

- Remove old race-condition-prone code and archive outdated test files
- Review and update test fixtures and seeded data for new edge cases
- Continue to maintain and expand Page Object Model for E2E tests
- Template/test alignment and client-side flow analysis (FIXLIST items #7, #13)
- Regularly review and update documentation and test coverage for new features
- Expand and automate reporting and artifact collection for CI/CD
- Maintain path-aware CI/CD integration and artifact collection (videos, screenshots, traces)

**Business Logic & Data Integrity**

- Stock integrity fix: add row locks/atomic decrements in EventController.php
- Settlement system: build MBS settlement workflow
- Payment idempotency: prevent double-processing in StripeNotificationController.php
- Cart expiry logic: session-based cart cleanup
- Admin order management: refund/resend functionality
- Door audit logging: enhance BoxOfficeController.php check-in logs
- DOM/state update determinism: verify class/data attributes per seat
- Add distributed seat locking during cart-to-booking
- Concurrency protection: row-level locks for seat allocation
- Validate business rules at API level
- Stock management: enforce category-wise ticket limits
- Implement check-in state machine
- Additional FIXLIST items as needed

**Payment & Webhook Integration**

- Implement webhook → seat confirmation integration and payment flow success tracking
- Add webhook processing metrics and operational alerting
- Document complete payment architecture and create troubleshooting runbooks

**Operational Readiness**

- Train operations team on runbook and emergency procedures
- Schedule cleanup job for expired seat holds
- Fix database cleanup/session isolation (blocking all other progress)

**Feature Enhancements**

- Move to production SVG booking system
- Implement and validate real-time sync (WebSocket integration, polling)
- Add/verify group booking, dynamic pricing, smart seat recommendations (optional enhancements)
- Test and monitor price snapshot drift (mid-hold price changes)
- Test seatmap mutability (seat renaming with active holds)
- Add load testing for high concurrency and analytics integration
- Plan Vite migration for build modernization (optional)
- GDPR/data export utilities, banner/content page setup, email deliverability, dry run, go-live

**Testing & Acceptance**

- Ensure all 8/14 acceptance test scenarios remain passing before deployment

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_Last updated: September 10, 2025_