package dhcpv4

import (
	"fmt"
	"net"

	"github.com/u-root/u-root/pkg/uio"
)

// OptServerIdentifier represents an option encapsulating the server identifier.
//
// This option implements the server identifier option
// https://tools.ietf.org/html/rfc2132
type OptServerIdentifier struct {
	ServerID net.IP
}

// ParseOptServerIdentifier returns a new OptServerIdentifier from a byte
// stream, or error if any.
func ParseOptServerIdentifier(data []byte) (*OptServerIdentifier, error) {
	buf := uio.NewBigEndianBuffer(data)
	return &OptServerIdentifier{ServerID: net.IP(buf.CopyN(net.IPv4len))}, buf.FinError()
}

// Code returns the option code.
func (o *OptServerIdentifier) Code() OptionCode {
	return OptionServerIdentifier
}

// ToBytes returns a serialized stream of bytes for this option.
func (o *OptServerIdentifier) ToBytes() []byte {
	return o.ServerID.To4()
}

// String returns a human-readable string.
func (o *OptServerIdentifier) String() string {
	return fmt.Sprintf("Server Identifier -> %v", o.ServerID.String())
}