# Development History

This document records the historical development phases of `dance-lessons-coach`. Extracted from the original `AGENTS.md` (Tâche 6 restructure) for lazy-loading compatibility with Mistral Vibe (128k context).

All phases below are **completed** ✅. They are kept here for traceability and onboarding context — refer to ADRs (`adr/`) for the technical decisions behind each phase.

## Phase 1: Foundation

- Go 1.26.1 environment setup
- Project structure with `cmd/` and `pkg/` directories
- Core Greet service implementation
- CLI interface
- Unit tests

## Phase 2: Web API

- Chi router integration
- Versioned API endpoints (`/api/v1`)
- Health endpoint (`/api/health`)
- JSON responses with proper headers

## Phase 3: Logging & Architecture

- Zerolog integration with Trace level
- Context-aware logging
- Interface-based design patterns
- Dependency injection

## Phase 4: Documentation & Testing

- Comprehensive `AGENTS.md`
- `README.md` with usage instructions
- Server management guide
- API endpoint documentation

## Phase 5: Configuration Management

- Viper integration for configuration
- Environment variable support with `DLC_` prefix
- Customizable server host/port
- Configurable shutdown timeout
- Configuration validation and logging
- Example configuration file

## Phase 6: Graceful Shutdown

- Context-aware server initialization
- Signal-based termination (`SIGINT`, `SIGTERM`)
- Configurable shutdown timeout
- Readiness endpoint for Kubernetes/service mesh integration
- Proper resource cleanup during shutdown
- Health endpoint remains healthy during graceful shutdown

## Phase 7: OpenTelemetry Integration

- OpenTelemetry Go libraries integration
- Jaeger compatibility for distributed tracing
- Middleware-only approach using `otelhttp.NewHandler`
- Configurable sampling strategies
- Graceful shutdown of tracer provider
- OTLP exporter with gRPC support

## Phase 8: Build System & Documentation

- Build script for binary compilation
- Binary output to `bin/` directory
- Comprehensive commit conventions with gitmoji reference
- Updated documentation with Jaeger integration guide
- Cleaned up configuration files
- Enhanced logging configuration with file output support

## Phase 9: Final Refinements

- Removed unnecessary `time.Sleep` for log flushing
- Changed server operational logs from Info to Trace level
- Moved all logging setup logic to config package
- Simplified server entrypoint to 27 lines
- Verified all functionality with comprehensive testing
- Updated documentation to reflect final architecture

## Beyond Phase 9

Subsequent work (CI/CD, BDD scenarios, ADR audit, JWT, config hot-reloading) is tracked in the [Changelog](../CHANGELOG.md) and the corresponding [ADRs](../adr/).