feat: Complete DynamoDB Product Service Integration with Production-R…

[DamirSt]

feat: Complete DynamoDB Product Service Integration with Production-Ready Features

Summary

This PR implements complete DynamoDB integration for the Product Service, replacing mock data with persistent NoSQL database storage and adding production-ready features for robust error handling, logging, and data consistency.

What's New

Database Integration

• Replaced mock data with real DynamoDB tables (products & stock)
• Set up proper schema with UUID primary keys and relationships
• Created automated data population script with 8 vinyl record test products
• Frontend now displays live stock counts from the database

Complete API Implementation

• GET /products - Returns all products with joined stock information
• GET /products/{id} - Fetches individual products with stock data
• POST /products - Creates new products with automatic stock entries

Production-Ready Features

Robust Validation & Error Handling

• Comprehensive input validation with detailed error messages
• Proper HTTP status codes (400, 409, 500, 503)
• Structured error responses with timestamps
• Prevents invalid data from entering the database

Transaction-Based Operations

• Uses DynamoDB transactions for atomic product + stock creation
• Guarantees data consistency with no orphaned records
• Prevents overwrites with conditional expressions

Enhanced Logging

• Structured JSON logging for better observability
• Request tracking with unique IDs and metadata
• Error logging with stack traces for debugging
• Performance metrics for monitoring

API Details

Base URL: https://uf4ds80g46.execute-api.us-east-1.amazonaws.com/prod

Product Schema

{
  "id": "string (UUID)",
  "name": "string",
  "artist": "string", 
  "description": "string",
  "price": "number (USD)",
  "category": "string",
  "genre": "string",
  "year": "number",
  "count": "number (stock quantity)",
  "inStock": "boolean",
  "imageUrl": "string"
}

Example Usage

# Get all products
curl "https://uf4ds80g46.execute-api.us-east-1.amazonaws.com/prod/products"

# Create new product
curl -X POST "https://uf4ds80g46.execute-api.us-east-1.amazonaws.com/prod/products" \
  -H "Content-Type: application/json" \
  -d '{"title":"New Album","description":"Great music","price":29.99,"artist":"New Artist"}'

Technical Implementation

Key Files Modified

• infra/lib/product-service/product-service-stack.ts - Added DynamoDB tables and API Gateway setup
• infra/lib/product-service/handler.ts - Complete rewrite with production features
• infra/scripts/simple-populate.ts - Database seeding script
• FE/src/app/products/product.interface.ts - Added count field for stock

Database Design

• Products Table: Stores product information with UUID primary key
• Stock Table: Stores inventory counts linked by product_id
• Pay-per-request billing for cost efficiency
• Removal policy: DESTROY for development (change for production)

Testing Results

All endpoints are fully tested and working:

• Product listing with stock counts
• Individual product retrieval
• Product creation with validation
• Error handling for invalid requests
• Transaction integrity confirmed

Frontend Integration

The Angular frontend now displays real stock data:

• Product cards show actual inventory counts
• Cart controls respect stock availability
• No more hardcoded mock data