package main

import (
	"encoding/json"
	"errors"
	"net"
)

// IP is the net.IP with a version string to allow storing the version
type IP struct {
	net.IP
	version string
}

// NewIP returns a new instance of an IP address
func NewIP(addr string) (*IP, error) {
	parsedIP := net.ParseIP(addr)
	if parsedIP == nil {
		return nil, errors.New("Could not parse address " + addr)
	}

	result := &IP{parsedIP, ""}
	if result.isV6() {
		result.version = "v6"
	} else {
		result.version = "v4"
	}

	return result, nil
}

// MarshalJSON for marshalling ip to json for response
func (ip *IP) MarshalJSON() ([]byte, error) {
	return json.Marshal(&struct {
		IP      string `json:"ip"`
		Version string `json:"version"`
	}{
		IP:      ip.String(),
		Version: ip.version,
	})
}

func (ip *IP) isV6() bool {
	return ip.To4() == nil
}