UnPoller - Cursor AI Rules

# UnPoller - Cursor AI Rules

## Project Overview
UnPoller is a Go application that collects metrics from UniFi network controllers and exports them to various backends (InfluxDB, Prometheus, Loki, DataDog). The architecture is plugin-based with input and output plugins.

## Architecture

### Core Components
- **main.go**: Entry point, loads plugins via blank imports
- **pkg/poller/**: Core library providing input/output interfaces and plugin management
- **pkg/inputunifi/**: Input plugin for UniFi controller data collection
- **pkg/influxunifi/**: Output plugin for InfluxDB
- **pkg/promunifi/**: Output plugin for Prometheus
- **pkg/lokiunifi/**: Output plugin for Loki
- **pkg/datadogunifi/**: Output plugin for DataDog
- **pkg/webserver/**: Web server for health checks and metrics
- **pkg/mysqlunifi/**: MySQL output plugin

### Plugin System
- Plugins are loaded via blank imports (`_ "github.com/unpoller/unpoller/pkg/inputunifi"`)
- Input plugins implement the `Input` interface from `pkg/poller/inputs.go`
- Output plugins implement the `Output` interface from `pkg/poller/outputs.go`
- The poller core automatically discovers and initializes imported plugins
- Configuration is automatically unmarshaled from config files (TOML/JSON/YAML) and environment variables

## Code Style & Conventions

### Go Standards
- Use Go 1.25.5+ features
- Follow standard Go formatting (gofmt)
- Use `golangci-lint` with the project's `.golangci.yaml` configuration
- Enable linters: `nlreturn`, `revive`, `tagalign`, `testpackage`, `wsl_v5`
- Use `//nolint:gci` for import ordering when needed

### Naming Conventions
- Package names should be lowercase, single word
- Exported types/functions use PascalCase
- Unexported types/functions use camelCase
- Constants use PascalCase with descriptive names
- Error variables should be named `err` and checked immediately

### Error Handling
- Always check errors, don't ignore them
- Use `github.com/pkg/errors` for error wrapping when appropriate
- Return errors from functions, don't log and continue
- Use descriptive error messages

### Configuration
- Configuration uses `golift.io/cnfg` and `golift.io/cnfgfile`
- Environment variables use `UP_` prefix (defined in `ENVConfigPrefix`)
- Support TOML (default), JSON, and YAML formats
- Config structs should have tags: `json`, `toml`, `xml`, `yaml`

### Testing
- Use `testpackage` linter - tests should be in separate `_test` packages
- Use `github.com/stretchr/testify` for assertions
- Integration tests use `integration_test_expectations.yaml` files

### Logging
- Use structured logging via logger interfaces
- Log levels: ERROR, WARN, INFO, DEBUG
- Prefix log messages with `[LEVEL]` when using standard log package

## Dependencies

### Key Libraries
- `github.com/unpoller/unifi/v5` - UniFi API client (local replace: `/Users/briangates/unifi`)
- `golift.io/cnfg` - Configuration management
- `golift.io/cnfgfile` - Config file parsing
- `github.com/spf13/pflag` - CLI flag parsing
- `github.com/gorilla/mux` - HTTP router
- `github.com/prometheus/client_golang` - Prometheus metrics

### Output Backends
- InfluxDB: `github.com/influxdata/influxdb1-client` and `github.com/influxdata/influxdb-client-go/v2`
- Prometheus: `github.com/prometheus/client_golang`
- Loki: Custom HTTP client
- DataDog: `github.com/DataDog/datadog-go/v5`

## Project Structure

```
unpoller/
├── main.go                 # Entry point
├── pkg/
│   ├── poller/             # Core plugin system
│   ├── inputunifi/         # UniFi input plugin
│   ├── influxunifi/        # InfluxDB output
│   ├── promunifi/          # Prometheus output
│   ├── lokiunifi/          # Loki output
│   ├── datadogunifi/       # DataDog output
│   ├── mysqlunifi/         # MySQL output
│   └── webserver/          # Web server
├── examples/               # Configuration examples
├── init/                   # Init scripts (systemd, docker, etc.)
└── scripts/                # Build/deployment scripts
```

## Common Patterns

### Adding a New Output Plugin
1. Create new package in `pkg/` (e.g., `pkg/myoutput/`)
2. Implement `Output` interface from `pkg/poller/outputs.go`
3. Register plugin in `init()` function
4. Add blank import to `main.go`
5. Add configuration struct with proper tags
6. Create README.md in package directory

### Adding a New Input Plugin
1. Create new package in `pkg/` (e.g., `pkg/myinput/`)
2. Implement `Input` interface from `pkg/poller/inputs.go`
3. Register plugin in `init()` function
4. Add blank import to `main.go`
5. Add configuration struct with proper tags

### Device Type Reporting
- Device types: UAP, USG, USW, UDM, UBB, UCI, UXG, PDU
- Each output plugin has device-specific reporting functions (e.g., `uap.go`, `usg.go`)
- Follow existing patterns in `pkg/promunifi/` or `pkg/influxunifi/`

## Important Notes

- The `pkg/poller` library is generic and has no knowledge of UniFi, Influx, Prometheus, etc.
- It provides interfaces for any type of input/output plugin
- Use `[]any` types for flexibility in the core library
- Configuration is automatically loaded from files and environment variables
- The application supports multiple UniFi controllers via configuration
- Timezone can be set via `TZ` environment variable

## Build & Deployment

- Uses GitHub Actions for CI/CD
- Uses `goreleaser` for multi-platform builds
- Supports: Linux, macOS, Windows, FreeBSD
- Docker images built automatically
- Homebrew formula for macOS
- Configuration examples in `examples/` directory

## When Writing Code

- Keep functions focused and single-purpose
- Use interfaces for testability
- Follow the existing plugin patterns
- Document exported functions and types
- Add appropriate error handling
- Consider cross-platform compatibility (Windows, macOS, Linux, BSD)
- Use context.Context for cancellable operations
- Respect timeouts and deadlines