jpictl/cmd/jpictl/dump.go

package main

import (
	"bytes"
	"encoding/json"
	"io"
	"os"

	"github.com/spf13/cobra"
	"gopkg.in/yaml.v3"
)

// Encoder represents an object that encodes another internally
type Encoder interface {
	Encode(any) error
}

// Encoding represents a type of [Encoder]
type Encoding int

const (
	// UndefinedEncoding implies the default encoding
	UndefinedEncoding Encoding = iota
	// JSONEncoding represents JSON encoding
	JSONEncoding
	// YAMLEncoding represents YAML encoding
	YAMLEncoding
)

// NewJSONEncoder returns a JSON [Encoder] to work on the given [io.Writer]
func NewJSONEncoder(w io.Writer) Encoder {
	enc := json.NewEncoder(w)
	enc.SetIndent(``, `  `)
	return enc
}

// NewYAMLEncoder returns a YAML [Encoder] to work on the given [io.Writer]
func NewYAMLEncoder(w io.Writer) Encoder {
	enc := yaml.NewEncoder(w)
	enc.SetIndent(2)
	return enc
}

const encoding = YAMLEncoding

// Command
var dumpCmd = &cobra.Command{
	Use:    "dump",
	Short:  "generates a text representation of the config",
	PreRun: setVerbosity,
	RunE: func(_ *cobra.Command, _ []string) error {
		var buf bytes.Buffer
		var enc Encoder

		m, err := cfg.LoadZones(true)
		if err != nil {
			return err
		}

		switch encoding {
		case JSONEncoding:
			enc = NewJSONEncoder(&buf)
		default:
			enc = NewYAMLEncoder(&buf)
		}

		if err = enc.Encode(m); err != nil {
			return err
		}

		if _, err = buf.WriteTo(os.Stdout); err != nil {
			return err
		}

		return nil
	},
}

func init() {
	rootCmd.AddCommand(dumpCmd)
}