/*
 * dnssecjava - a DNSSEC validating stub resolver for Java
 * Copyright (c) 2013-2015 Ingo Bauersachs
 *
 * 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
 */

package org.jitsi.dnssec;

import java.io.BufferedReader;
import java.io.ByteArrayInputStream;
import java.io.IOException;
import java.io.Reader;

import org.xbill.DNS.DClass;
import org.xbill.DNS.Master;
import org.xbill.DNS.Message;
import org.xbill.DNS.Name;
import org.xbill.DNS.Rcode;
import org.xbill.DNS.Record;
import org.xbill.DNS.Section;
import org.xbill.DNS.Type;

public class MessageReader {
    public Message readMessage(Reader in) throws IOException {
        BufferedReader r;
        if (in instanceof BufferedReader) {
            r = (BufferedReader)in;
        }
        else {
            r = new BufferedReader(in);
        }

        Message m = null;
        String line = null;
        int section = 103;
        while ((line = r.readLine()) != null) {
            String[] data;
            if (line.startsWith(";; ->>HEADER<<- ")) {
                section = 101;
                m = new Message();
            }
            else if (line.startsWith(";; QUESTIONS:")) {
                section = 102;
            }
            else if (line.startsWith(";; ANSWERS:")) {
                section = Section.ANSWER;
                line = r.readLine();
            }
            else if (line.startsWith(";; AUTHORITY RECORDS:")) {
                section = Section.AUTHORITY;
                line = r.readLine();
            }
            else if (line.startsWith(";; ADDITIONAL RECORDS:")) {
                section = 100;
            }
            else if (line.startsWith("####")) {
                return m;
            }
            else if (line.startsWith("#")) {
                continue;
            }

            switch (section) {
                case 100: // ignore
                    break;

                case 101: // header
                    section = 100;
                    data = line.substring(";; ->>HEADER<<- ".length()).split(",");
                    m.getHeader().setRcode(Rcode.value(data[1].split(":\\s*")[1]));
                    m.getHeader().setID(Integer.parseInt(data[2].split(":\\s*")[1]));
                    break;

                case 102: // question
                    line = r.readLine();
                    data = line.split(",");
                    Record q = Record.newRecord(
                            Name.fromString(data[0].replaceAll(";;\\s*", "")),
                            Type.value(data[1].split("\\s*=\\s*")[1]),
                            DClass.value(data[2].split("\\s*=\\s*")[1]));
                    m.addRecord(q, Section.QUESTION);
                    section = 100;
                    break;

                default:
                    if (line != null && !"".equals(line)) {
                        Master ma = new Master(new ByteArrayInputStream(line.getBytes()));
                        Record record = ma.nextRecord();
                        if (record != null) {
                            m.addRecord(record, section);
                        }
                    }
            }
        }

        r.close();
        return m;
    }
}