Build Log – 2025-12-25

December 25, 2025

📅 Daily Log — December 25, 2025

🧠 Context / Focus for Today

Implement Phase 4 platform breadth features including Wahoo integration, enhanced Strava sync, brick workout builder, and taper wizard. Add comprehensive unit test coverage for core training logic modules. Fix critical bugs including Strava OAuth loop and compliance indicator display.

✔️ Things I Got Done Today

Phase 4: Platform Breadth Features

Wahoo Integration

Created comprehensive Wahoo Cloud API client (lib/wahoo/client.ts):
- Authenticated fetch with automatic token refresh
- Workout export to Wahoo devices
- Plan creation and management
- Error handling and retry logic
Implemented Wahoo OAuth flow (lib/wahoo/oauth.ts):
- Full OAuth 2.0 authorization flow
- Token refresh and expiration handling
- Secure token storage in wahoo_integrations table
Created Wahoo API endpoints:
- /api/wahoo/oauth - OAuth initiation
- /api/wahoo/callback - OAuth callback handler
- /api/wahoo/status - Integration status check
- /api/wahoo/export - Workout export to Wahoo
- /api/wahoo/disconnect - Integration removal
Created workout converter (lib/wahoo/workout-converter.ts):
- Converts internal workout format to Wahoo format
- Handles multi-sport workouts
- Supports structured workout steps
Created database migration (20251225000001_wahoo_integrations.sql):
- wahoo_integrations table for token storage
- RLS policies for user isolation
- Proper indexing for efficient queries

Strava Sync Improvements

Refactored Strava client (lib/strava/client.ts):
- Improved error handling and retry logic
- Better token management
- Enhanced API response handling
Created Strava activity converter (lib/strava/activity-converter.ts):
- Converts Strava activities to internal workout format
- Handles various activity types
- Preserves activity metadata
Enhanced Strava sync endpoint (app/api/strava/sync/route.ts):
- Improved sync logic with better error handling
- Activity fingerprinting for deduplication
- Better handling of existing workouts
Fixed Strava OAuth authorization loop:
- Resolved infinite redirect issue
- Improved error handling in OAuth flow
- Better state management

Brick Workout Builder

Created BrickWorkoutBuilder component (components/workouts/BrickWorkoutBuilder.tsx):
- Multi-sport segment management
- Transition timing between segments
- Template-based workout creation
- Per-segment step editing
- Total duration calculation across segments
Created brick workout templates (lib/training/brick-templates.ts):
- Sprint triathlon brick workouts
- Olympic distance brick workouts
- Half Ironman brick workouts
- Full Ironman brick workouts
- Custom brick workout creation
Supports various sport combinations:
- Bike→Run (duathlon)
- Swim→Bike→Run (triathlon)
- Custom multi-sport sequences

Taper Wizard

Created TaperWizard component (components/workouts/TaperWizard.tsx):
- Science-based taper protocol generation
- Race distance selection (Sprint, Olympic, Half, Full Ironman)
- Taper duration selection (1, 2, or 3 weeks)
- Day-by-day taper plan generation
Implemented taper protocols (lib/training/taper-protocols.ts):
- Evidence-based taper strategies
- Volume reduction (40-60% for peak weeks)
- Intensity maintenance
- Nutrition and mental preparation notes
- Race-specific protocols for each distance

Activity Fingerprinting

Created activity fingerprinting system (lib/activity-fingerprint.ts):
- Cross-source deduplication detection
- Fingerprint matching: date + duration + distance + sport
- Tolerance-based matching (5% default)
- Prevents duplicate activities from multiple sources
Integrated into Strava sync:
- Checks for existing workouts before importing
- Prevents Garmin→Strava duplicate imports
- Confidence scoring for matches

Comprehensive Unit Testing

Added 203 new unit tests across 5 test files:
- tests/training/adaptation.test.ts (816 lines):
  - Plan adaptation based on compliance
  - Intensity adjustments
  - Volume modifications
  - Rest day recommendations
- tests/training/compliance.test.ts (733 lines):
  - Compliance calculation
  - Duration compliance evaluation
  - Intensity compliance evaluation
  - Weekly compliance aggregation
- tests/training/duration-utils.test.ts (487 lines):
  - Duration parsing and formatting
  - Duration calculations
  - Time conversions
- tests/training/recovery.test.ts (689 lines):
  - Recovery status fetching
  - Training readiness recommendations
  - Body Battery integration
  - HRV and stress analysis
- tests/training/training-load.test.ts (534 lines):
  - Training load calculations
  - Load projection
  - TSB (Training Stress Balance) calculations
All tests passing with comprehensive coverage

Fixes & Improvements

Compliance Indicator Fix

Fixed compliance indicator to only show for matched imported workouts:
- Updated WorkoutCard.tsx with proper filtering
- Added match_status check
- Improved compliance calculation logic
Enhanced compliance calculation (lib/training/compliance.ts):
- Better handling of unmatched workouts
- Improved confidence scoring

Duration Validation

Implemented strict duration validation (lib/training/duration-utils.ts):
- Prevents silent data corruption
- Validates duration formats
- Better error messages
Enhanced FIT export with duration validation:
- Validates workout durations before export
- Prevents invalid FIT file generation
Updated garminAutoSync.ts with better duration handling

Logger Enhancements

Enhanced logger with namespacing support (lib/logger.ts):
- Namespace-based logging
- Better debugging capabilities
- Improved log organization
Updated AI coach route with namespaced logging:
- Better traceability
- Easier debugging

TypeScript Fixes

Fixed TypeScript errors in test files:
- Updated type assertions
- Fixed import issues
- Improved type safety
Added trailing newlines to test files for consistency

Database Migrations

Created Strava sync tracking migration (20251225000000_strava_sync_tracking.sql):
- Tracks sync status and errors
- Better sync history
Created Wahoo integrations migration (20251225000001_wahoo_integrations.sql):
- Token storage and management
- Integration status tracking

Settings Page Enhancements

Updated settings page (app/settings/page.tsx):
- Added Wahoo integration UI
- Enhanced Strava integration display
- Better integration management

🚧 In Progress

Testing Wahoo OAuth flow in staging environment
Validating brick workout export to Wahoo devices
Testing taper wizard with real race scenarios
Performance testing of activity fingerprinting

🎯 Targets for Tomorrow

Continue production readiness — monitoring, error tracking, performance optimization
Begin user acceptance testing with beta users for new integrations
Prepare documentation for Wahoo and Strava integrations
Monitor integration metrics and error rates

🤔 Notes / Observations

Wahoo integration expands platform reach beyond Garmin
Strava sync improvements significantly enhance reliability
Brick workout builder enables triathlon training support
Taper wizard provides science-based race preparation
Activity fingerprinting prevents duplicate imports across sources
Comprehensive test coverage ensures reliability of core training logic
All Phase 4 platform breadth features completed — application now supports multiple platforms

📈 Momentum Score: 9.6 / 10

Exceptional progress on Phase 4 platform breadth. Wahoo integration, enhanced Strava sync, brick workouts, and taper wizard significantly expand platform capabilities. Comprehensive test coverage (203 new tests) ensures reliability. Activity fingerprinting prevents data duplication. Application now supports multiple fitness platforms with robust integrations.