chore/specs/archive/feat-dynamic-points/IMPLEMENTATION_SUMMARY.md

Tracking Feature Implementation Summary

✅ Implementation Complete

All acceptance criteria from feat-tracking.md have been implemented and tested.

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📦 What Was Delivered

Backend

1. Data Model (tracking_event.py)

   • TrackingEvent dataclass with full type safety
   • Factory method create_event() for server-side timestamp generation
   • Delta invariant validation (delta == points_after - points_before)

2. Database Layer (tracking.py)

   • New TinyDB table: tracking_events.json
   • Helper functions: insert_tracking_event, get_tracking_events_by_child, get_tracking_events_by_user, anonymize_tracking_events_for_user
   • Offset-based pagination with sorting by occurred_at (desc)

3. Audit Logging (tracking_logger.py)

   • Per-user rotating file handlers (logs/tracking_user_<user_id>.log)
   • 10MB max file size, 5 backups
   • Structured log format with all event metadata

4. API Integration (child_api.py)

   • Tracking added to:
     • POST /child/<id>/trigger-task → action: activated
     • POST /child/<id>/request-reward → action: requested
     • POST /child/<id>/trigger-reward → action: redeemed
     • POST /child/<id>/cancel-request-reward → action: cancelled

5. Admin API (tracking_api.py)

   • GET /admin/tracking with filters:
     • child_id (required if no user_id)
     • user_id (admin only)
     • entity_type (task|reward|penalty)
     • action (activated|requested|redeemed|cancelled)
     • limit (default 50, max 500)
     • offset (default 0)
   • Returns total count for future pagination UI

6. SSE Events (event_types.py, tracking_event_created.py)

   • New event type: TRACKING_EVENT_CREATED
   • Payload: tracking_event_id, child_id, entity_type, action
   • Emitted on every tracking event creation

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Frontend

1. TypeScript Models (models.ts)

   • TrackingEvent interface (1:1 parity with Python)
   • Type aliases: EntityType, ActionType
   • TrackingEventCreatedPayload for SSE events

2. API Helpers (api.ts)

   • getTrackingEventsForChild() function with all filter params

3. SSE Registration

   • Event type registered in type union
   • Ready for future UI components

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Tests

Backend Unit Tests (test_tracking.py):

• ✅ Tracking event creation with factory method
• ✅ Delta invariant validation
• ✅ Insert and query tracking events
• ✅ Filtering by entity_type and action
• ✅ Offset-based pagination
• ✅ User anonymization on deletion
• ✅ Points change correctness (positive/negative/zero delta)
• ✅ No points change for request/cancel actions

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🔑 Key Design Decisions

1. Append-only tracking table - No deletions, only anonymization on user deletion
2. Server timestamps - occurred_at always uses server time (UTC) to avoid client clock drift
3. Separate logging - Per-user audit logs independent of database
4. Offset pagination - Simpler than cursors, sufficient for expected scale
5. No UI (yet) - API/models/SSE only; UI deferred to future phase

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🚀 Usage Examples

Backend: Create a tracking event

from models.tracking_event import TrackingEvent
from db.tracking import insert_tracking_event
from utils.tracking_logger import log_tracking_event

event = TrackingEvent.create_event(
    user_id='user123',
    child_id='child456',
    entity_type='task',
    entity_id='task789',
    action='activated',
    points_before=50,
    points_after=60,
    metadata={'task_name': 'Homework'}
)

insert_tracking_event(event)
log_tracking_event(event)

Frontend: Query tracking events

import { getTrackingEventsForChild } from "@/common/api";

const res = await getTrackingEventsForChild({
  childId: "child456",
  entityType: "task",
  limit: 20,
  offset: 0,
});

const data = await res.json();
// { tracking_events: [...], total: 42, count: 20, limit: 20, offset: 0 }

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📋 Migration Notes

1. New database file: backend/data/db/tracking_events.json will be created automatically on first tracking event.
2. New log directory: backend/logs/tracking_user_<user_id>.log files will be created per user.
3. No breaking changes to existing APIs or data models.

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🔮 Future Enhancements (Not in This Phase)

• Admin/parent UI for viewing tracking history
• Badges and certificates based on tracking data
• Analytics and reporting dashboards
• Export tracking data (CSV, JSON)
• Time-based filters (date range queries)