package org.handwerkszeug.dns.server;

import static org.handwerkszeug.util.Validation.notNull;

import org.handwerkszeug.dns.*;
import org.handwerkszeug.dns.record.SingleNameRecord;

public
class DNAMEResponse extends DefaultResponse {

    final SingleNameRecord dname;
    final Name qname;
    final RRType qtype;

    public
    DNAMEResponse(ResourceRecord dname, Name qname, RRType qtype) {
        super(RCode.NoError);
        notNull(dname, "dname");
        notNull(qname, "qname");
        notNull(qtype, "qtype");
        this.dname = SingleNameRecord.class.cast(dname);
        this.qname = qname;
        this.qtype = qtype;
    }

    @Override
    public
    void postProcess(ResolveContext context) {
        DNSMessage res = context.response();
        res.answer()
           .add(this.dname);
        Name name = this.qname.replace(this.dname.name(), this.dname.oneName());
        if (name == null) {
            context.response()
                   .header()
                   .rcode(RCode.YXDomain);
        }
        else {
            SingleNameRecord cname = new SingleNameRecord(RRType.CNAME, name);
            cname.name(this.qname);
            res.answer()
               .add(cname);
            res.header()
               .aa(true);
            Response r = context.resolve(name, this.qtype);
            r.postProcess(context);
        }
    }

}