dance-lessons-coach/README.md

# DanceLessonsCoach

A Go project demonstrating idiomatic package structure, CLI implementation, and JSON API with Chi router.

## Features

- Greet function with default behavior
- Command-line interface
- JSON API with versioned endpoints
- Chi router integration
- Zerolog for high-performance logging
- Viper for configuration management
- Graceful shutdown with context
- Readiness endpoint for Kubernetes/service mesh integration
- OpenTelemetry integration with Jaeger support
- OpenAPI/Swagger documentation
- Unit tests
- Go 1.26.1 compatible

## Installation

```bash
# Clone the repository
git clone https://github.com/yourusername/DanceLessonsCoach.git
cd DanceLessonsCoach

# Build and run
go run ./cmd/greet
```

## Configuration

Basic configuration options:

```bash
# Start with default configuration
./scripts/start-server.sh start

# Custom port
export DLC_SERVER_PORT=9090
./scripts/start-server.sh start

# JSON logging
export DLC_LOGGING_JSON=true
./scripts/start-server.sh start
```

**See [AGENTS.md](AGENTS.md#configuration-management) for comprehensive configuration guide including:**
- File-based configuration
- Environment variables
- Configuration priority rules
- OpenTelemetry setup
- Advanced scenarios

## Usage

### CLI

```bash
# Default greeting
go run ./cmd/greet
# Output: Hello world!

# Custom greeting
go run ./cmd/greet John
# Output: Hello John!
```

### Web Server

**Using the server control script (recommended):**

```bash
# Start the server
./scripts/start-server.sh start

# Test API endpoints
./scripts/start-server.sh test

# Access OpenAPI documentation
# Swagger UI: http://localhost:8080/swagger/
# OpenAPI spec: http://localhost:8080/swagger/doc.json

# Stop the server
./scripts/start-server.sh stop
```

**Manual server management:**

```bash
# Start the server
go run ./cmd/server

# Test API endpoints
curl http://localhost:8080/api/health
# Output: {"status":"healthy"}

curl http://localhost:8080/api/ready
# Output: {"ready":true}

curl http://localhost:8080/api/v1/greet
# Output: {"message":"Hello world!"}

curl http://localhost:8080/api/v1/greet/John
# Output: {"message":"Hello John!"}
```

## Testing

```bash
# Run all tests
go test ./...

# Run specific package tests
go test ./pkg/greet/
```

## Project Structure

```
DanceLessonsCoach/
├── adr/                    # Architecture Decision Records
├── cmd/                    # Entry points (greet CLI, server)
├── pkg/                    # Core packages (config, greet, server, telemetry)
│   └── server/docs/        # Generated OpenAPI documentation (gitignored)
├── config.yaml             # Configuration file
├── scripts/                # Management scripts
└── go.mod                   # Go module definition
```

**See [AGENTS.md](AGENTS.md#project-structure) for detailed structure and component explanations.**
```

## Development

### Generate OpenAPI Documentation

The project uses [swaggo/swag](https://github.com/swaggo/swag) to generate OpenAPI/Swagger documentation from code annotations:

```bash
# Generate documentation
go generate ./pkg/server/

# This creates:
# - pkg/server/docs/docs.go (swagger template)
# - pkg/server/docs/swagger.json (OpenAPI spec)
# - pkg/server/docs/swagger.yaml (YAML version)
```

**Note:** `pkg/server/docs/` is gitignored. Documentation is embedded in the binary at build time.

### Documentation Annotations

Add swagger annotations to handlers and models:

```go
// @Summary Get personalized greeting
// @Description Returns a greeting with the specified name
// @Tags greet
// @Accept json
// @Produce json
// @Param name path string true "Name to greet"
// @Success 200 {object} GreetResponse "Successful response"
// @Failure 400 {object} ErrorResponse "Invalid name parameter"
// @Router /v1/greet/{name} [get]
func (h *apiV1GreetHandler) handleGreetPath(w http.ResponseWriter, r *http.Request) {
    // handler implementation
}
```

## Architecture

This project uses Architecture Decision Records (ADRs) to document key technical choices. See [adr/](adr/) for complete documentation including decisions on Go 1.26.1, Chi router, Zerolog, OpenTelemetry, interface-based design, graceful shutdown, configuration management, testing strategies, and OpenAPI documentation.

**Adding new decisions?** See [adr/README.md](adr/README.md) for guidelines.

## License

MIT