/*******************************************************************************
 * Copyright (c) 2014-2015 IBM Corp.
 * All rights reserved. This program and the accompanying materials
 * are made available under the terms of the Eclipse Public License v1.0
 * which accompanies this distribution, and is available at
 * http://www.eclipse.org/legal/epl-v10.html
 *
 * Contributors:
 *    Allan Stockdill-Mander - initial API and implementation
 *******************************************************************************/

package packets

import (
	"io"
)

type RegisterMessage struct {
	Header
	TopicId   uint16
	MessageId uint16
	TopicName []byte
}

func NewRegisterMessage(TopicId, MessageId uint16, TopicName []byte) *RegisterMessage {
	return &RegisterMessage{
		TopicId:   TopicId,
		MessageId: MessageId,
		TopicName: TopicName,
	}
}

func (r *RegisterMessage) MessageType() byte {
	return REGISTER
}

func (r *RegisterMessage) Write(w io.Writer) error {
	r.Header.Length = uint16(len(r.TopicName) + 6)
	packet := r.Header.pack()
	packet.WriteByte(REGISTER)
	packet.Write(encodeUint16(r.TopicId))
	packet.Write(encodeUint16(r.MessageId))
	packet.Write(r.TopicName)
	_, err := packet.WriteTo(w)

	return err
}

func (r *RegisterMessage) Unpack(b io.Reader) {
	r.TopicId = readUint16(b)
	r.MessageId = readUint16(b)
	r.TopicName = make([]byte, r.Header.Length-6)
	b.Read(r.TopicName)
}