# Project Readme Hints

## v3.0 Transformation Progress

### Completed Components

**Phase 1: Foundation (100%)** - Complete

- Error handling with typed hierarchy
- Observability (logging, metrics, tracing)
- Configuration management with fluent builder
- Connection management with health checks and circuit breaker

**Phase 2: Domain APIs (100%)** - Complete! 🎉

- **Document API (100%)** - Complete fluent CRUD operations with sessions, iteration, snapshots
- **Query Builder (100%)** - Type-safe query construction with aggregations
- **Logging API (100%)** - Enterprise structured logging with:
  - Batched bulk indexing with auto-flush
  - Log enrichment pipeline (host, environment, service, sanitization)
  - Sampling strategies (all, errors-only, percentage, rate-limit)
  - ILM (Index Lifecycle Management) integration
  - Metric extraction from logs
  - Dynamic tagging based on content
  - Queue overflow protection
  - Example at `ts/examples/logging/logging-example.ts`
- **Bulk Indexer (100%)** - High-throughput document ingestion with:
  - Fixed, adaptive, and size-based batching strategies
  - Parallel workers for concurrent processing
  - Backpressure handling with queue management
  - Dead-letter queue for failed operations
  - Progress callbacks with ETA estimation
  - Automatic retries with exponential backoff
  - Mixed operations (index, update, delete)
  - Comprehensive statistics tracking
  - Example at `ts/examples/bulk/bulk-indexer-example.ts`
- **KV Store (100%)** - Distributed key-value storage with:
  - Time-to-live (TTL) support with automatic expiration
  - In-memory caching layer with multiple eviction policies (LRU, LFU, FIFO, TTL)
  - Batch operations (mget, mset, mdelete)
  - Scan/cursor support for large keyspaces with wildcard patterns
  - Automatic compression for large values
  - Optimistic concurrency control
  - Cache hit/miss statistics
  - Example at `ts/examples/kv/kv-store-example.ts`

**Phase 3: Advanced Features (100%)** - Complete!

- **Plugin Architecture (100%)** - Extensible request/response middleware:
  - Plugin lifecycle hooks (beforeRequest, afterResponse, onError)
  - Plugin priority and execution ordering
  - Plugin statistics and monitoring
  - Built-in plugins:
    - Logging plugin - automatic request/response logging
    - Metrics plugin - automatic metrics collection
    - Cache plugin - response caching for GET requests
    - Retry plugin - automatic retry with exponential backoff
    - Rate limit plugin - token bucket rate limiting
  - Custom plugin creation with factories
  - Dynamic plugin registration/unregistration
  - Shared context between plugins
  - Timeout protection for plugin hooks
  - Example at `ts/examples/plugins/plugin-example.ts`
- **Transaction Support (100%)** - ACID-like distributed transactions:
  - Optimistic concurrency control (seq_no/primary_term)
  - Automatic rollback with compensation operations
  - Savepoints for partial rollback
  - Conflict detection and configurable resolution (retry, abort, skip, force)
  - Multi-document atomic operations
  - Isolation levels (read_uncommitted, read_committed, repeatable_read)
  - Transaction callbacks (onBegin, onCommit, onRollback, onConflict)
  - Transaction statistics and monitoring
  - Timeout with automatic cleanup
  - Example at `ts/examples/transactions/transaction-example.ts`
- **Schema Management (100%)** - Index mapping management and migrations:
  - Index creation with mappings, settings, and aliases
  - Schema validation before apply
  - Versioned migrations with history tracking
  - Schema diff and comparison (added/removed/modified fields)
  - Breaking change detection
  - Index templates (composable and legacy)
  - Component templates
  - Alias management with filters
  - Dynamic settings updates
  - Migration rollback support
  - Dry run mode for testing
  - Example at `ts/examples/schema/schema-example.ts`

### Query Builder Usage

```typescript
import { createQuery } from './ts';

// Simple query
const results = await createQuery<Product>('products')
  .match('name', 'laptop')
  .range('price', { gte: 100, lte: 1000 })
  .sort('price', 'asc')
  .execute();

// With aggregations
const stats = await createQuery<Product>('products')
  .matchAll()
  .aggregations((agg) => {
    agg
      .terms('brands', 'brand.keyword')
      .subAggregation('avg_price', (sub) => sub.avg('avg_price', 'price'));
  })
  .execute();
```

### Next Priorities (Phase 4)

1. **Comprehensive Test Suite** - Full test coverage for all modules
2. **Migration Guide** - Guide from v2 to v3 API
3. **README Update** - Update main README with new v3 API documentation

### Structure

- Single `ts/` directory (no parallel structures)
- Single `tsconfig.json` with strict mode enabled
- All v3.0 code lives in `ts/` directory

### Known Issues

- Minor TypeScript strict mode import issues documented in `ts/QUICK_FIXES.md`
- Need to apply `import type` fixes for verbatimModuleSyntax compliance