// Copyright (c) 1999-2004 Brian Wellington (bwelling@xbill.org)

package org.xbill.DNS;

import java.io.*;

/**
 * Server Selection Record  - finds hosts running services in a domain.  An
 * SRV record will normally be named _&lt;service&gt;._&lt;protocol&gt;.domain
 * - examples would be _sips._tcp.example.org (for the secure SIP protocol) and
 * _http._tcp.example.com (if HTTP used SRV records)
 *
 * @author Brian Wellington
 */

public class SRVRecord extends Record {

    private static final long serialVersionUID = -3886460132387522052L;

    private int priority, weight, port;
    private Name target;

    SRVRecord() {
    }

    Record
    getObject() {
        return new SRVRecord();
    }

    /**
     * Creates an SRV Record from the given data
     *
     * @param priority The priority of this SRV.  Records with lower priority
     *                 are preferred.
     * @param weight   The weight, used to select between records at the same
     *                 priority.
     * @param port     The TCP/UDP port that the service uses
     * @param target   The host running the service
     */
    public SRVRecord(Name name, int dclass, long ttl, int priority,
                     int weight, int port, Name target) {
        super(name, Type.SRV, dclass, ttl);
        this.priority = checkU16("priority", priority);
        this.weight = checkU16("weight", weight);
        this.port = checkU16("port", port);
        this.target = checkName("target", target);
    }

    void
    rrFromWire(DNSInput in) throws IOException {
        priority = in.readU16();
        weight = in.readU16();
        port = in.readU16();
        target = new Name(in);
    }

    void
    rdataFromString(Tokenizer st, Name origin) throws IOException {
        priority = st.getUInt16();
        weight = st.getUInt16();
        port = st.getUInt16();
        target = st.getName(origin);
    }

    /**
     * Converts rdata to a String
     */
    String
    rrToString() {
        StringBuffer sb = new StringBuffer();
        sb.append(priority + " ");
        sb.append(weight + " ");
        sb.append(port + " ");
        sb.append(target);
        return sb.toString();
    }

    /**
     * Returns the priority
     */
    public int
    getPriority() {
        return priority;
    }

    /**
     * Returns the weight
     */
    public int
    getWeight() {
        return weight;
    }

    /**
     * Returns the port that the service runs on
     */
    public int
    getPort() {
        return port;
    }

    /**
     * Returns the host running that the service
     */
    public Name
    getTarget() {
        return target;
    }

    void
    rrToWire(DNSOutput out, Compression c, boolean canonical) {
        out.writeU16(priority);
        out.writeU16(weight);
        out.writeU16(port);
        target.toWire(out, null, canonical);
    }

    public Name
    getAdditionalName() {
        return target;
    }

}
