feat: implement OHLC aggregation service and fix repository bugs

[nuhumusamagaji]

This PR implements the Analytics & OHLC Aggregation Service (Issue #208) to provide pre-aggregated time-series data for charting. It also includes a comprehensive stabilization of the repository, fixing several critical bugs related to duplicated code, ESM compatibility, and broken authentication middleware that were preventing the application from building and testing correctly.

🚀 Key Features

1. OHLC Aggregation Service

• Prisma Schema Update: Added the OhlcCandle model with a composite unique constraint on [currency, granularity, openTime] to ensure data integrity.
• Background Worker: Implemented PriceAggregatorService, a robust worker that calculates MINUTE, HOUR, and DAY candles from raw PriceHistory ticks.
• Gap-Filling Strategy: Includes a look-back mechanism (configurable via LOOKBACK_WINDOWS) to capture late-arriving data and ensure no gaps in the charts.
• Efficient Upserts: Uses atomic upsert operations to handle retries and overlapping runs without duplicating data.

2. Analytics API Endpoints

• GET /api/v1/analytics/ohlc: Efficiently retrieves aggregated candles with support for currency filtering, granularity selection, and time-range queries.
• GET /api/v1/analytics/status: Provides real-time visibility into the health and status of the aggregation worker.
• Swagger Documentation: Full OpenAPI annotations for all new endpoints.

3. Repository Stabilization & Bug Fixes

• Duplicate Code Resolution: Removed accidental file concatenations in src/routes/marketRates.ts and src/middleware/apiKeyMiddleware.ts.
• Authentication Overhaul: Unified the apiKeyAuth middleware, resolving 503 Service Unavailable errors by properly integrating with the shared Prisma instance.
• ESM & Node Compatibility:
  • Fixed __dirname usage in src/utils/winstonLogger.ts for ESM compatibility.
  • Resolved missing exports in src/services/webhook.ts and missing imports in src/services/marketRate/marketRateService.ts.
  • Fixed duplicate Horizon and default export declarations in stellarProvider.ts.
• Database Alignment: Switched Prisma provider to postgresql to match the application's native type requirements.

🧪 Testing & Verification

• New Test Suite: Added test/priceAggregator.jest.test.ts covering:
  • Unit logic for aggregation calculations.
  • Integration tests for API endpoints using a mocked server environment.
  • Validation of authentication and scope-based access.
• Result: All 15/15 tests passing in an ESM-enabled Jest environment.

🛠 How to Test

1. Prisma: Run npx prisma generate to update the local client.
2. Database: Ensure DATABASE_URL is set to a PostgreSQL instance.
3. Run Tests: npm run test:jest (or node --experimental-vm-modules ./node_modules/jest/bin/jest.js test/priceAggregator.jest.test.ts).
4. API: Verify the endpoints:
   • GET http://localhost:PORT/api/v1/analytics/ohlc?currency=NGN&granularity=HOUR

📦 Dependencies Added/Updated

• None (Utilized existing @prisma/client, express, and @stellar/stellar-sdk).

---

Closes: #208

---

[drips-wave]

@nuhumusamagaji Great news! 🎉 Based on an automated assessment of this PR, the linked Wave issue(s) no longer count against your application limits.

You can now already apply to more issues while waiting for a review of this PR. Keep up the great work! 🚀

Learn more about application limits