/*
 * Copyright (c) 2000, 2017 Oracle and/or its affiliates. All rights reserved.
 * Copyright (c) 2021 Contributors to the Eclipse Foundation
 *
 * This program and the accompanying materials are made available under the
 * terms of the Eclipse Public License v. 2.0, which is available at
 * http://www.eclipse.org/legal/epl-2.0.
 *
 * This Source Code may also be made available under the following Secondary
 * Licenses when the conditions for such availability set forth in the
 * Eclipse Public License v. 2.0 are satisfied: GNU General Public License,
 * version 2 with the GNU Classpath Exception, which is available at
 * https://www.gnu.org/software/classpath/license.html.
 *
 * SPDX-License-Identifier: EPL-2.0 OR GPL-2.0 WITH Classpath-exception-2.0
 */

/*
 * @(#)RedeliverHandler.java	1.47 06/28/07
 */

package com.sun.messaging.jmq.jmsserver.data.handlers;

import java.io.*;
import java.util.*;
import com.sun.messaging.jmq.jmsserver.resources.BrokerResources;
import com.sun.messaging.jmq.jmsserver.data.PacketHandler;
import com.sun.messaging.jmq.jmsserver.data.TransactionUID;
import com.sun.messaging.jmq.jmsserver.data.TransactionList;
import com.sun.messaging.jmq.jmsserver.data.TransactionState;
import com.sun.messaging.jmq.jmsserver.core.PacketReference;
import com.sun.messaging.jmq.jmsserver.core.DestinationList;
import com.sun.messaging.jmq.jmsserver.util.BrokerException;
import com.sun.messaging.jmq.jmsserver.core.ConsumerUID;
import com.sun.messaging.jmq.jmsserver.core.Session;
import com.sun.messaging.jmq.jmsserver.core.Consumer;
import com.sun.messaging.jmq.io.*;
import com.sun.messaging.jmq.util.log.Logger;
import com.sun.messaging.jmq.jmsserver.Globals;

import com.sun.messaging.jmq.jmsserver.service.imq.IMQConnection;

/**
 * Handler class which deals with requests delivering messages
 */
public class RedeliverHandler extends PacketHandler {

    private static boolean DEBUG_CLUSTER_TXN = Globals.getConfig().getBooleanProperty(Globals.IMQ + ".cluster.debug.txn");

    // An Ack block is a 4 byte interest ID and a SysMessageID
    static final int REDELIVER_BLOCK_SIZE = 8 + SysMessageID.ID_SIZE;

    private Logger logger = Globals.getLogger();
    private static boolean DEBUG = false;
    private DestinationList DL = Globals.getDestinationList();

    /**
     * Method to handle DELIVER messages
     */
    @Override
    public boolean handle(IMQConnection con, Packet msg) throws BrokerException {
        Hashtable props = null;
        try {
            props = msg.getProperties();
        } catch (Exception ex) {
            logger.logStack(Logger.INFO, "Unable to retrieve " + " properties from redeliver message " + msg, ex);
            props = new Hashtable();
        }

        boolean redeliver = false;
        TransactionUID tid = null;

        if (props != null) {
            Boolean bool = (Boolean) props.get("JMQSetRedelivered");
            if (bool != null) {
                redeliver = bool.booleanValue();
            }

            Object txnid = props.get("JMQTransactionID");
            if (txnid != null) {
                if (txnid instanceof Integer) {
                    tid = new TransactionUID(((Integer) txnid).intValue());
                } else {
                    tid = new TransactionUID(((Long) txnid).longValue());
                }
            }
            if (tid == null) { // for client < 4.1
                long id = msg.getTransactionID();
                if (id != 0) {
                    tid = new TransactionUID(id);
                }
            }
        }

        int size = msg.getMessageBodySize();
        int ackcount = size / REDELIVER_BLOCK_SIZE;
        int mod = size % REDELIVER_BLOCK_SIZE;

        if (ackcount == 0) {
            return true;
        }
        if (mod != 0) {
            throw new BrokerException(Globals.getBrokerResources().getString(BrokerResources.X_INTERNAL_EXCEPTION,
                    "Invalid Redeliver Message Size: " + size + ". Not multiple of " + REDELIVER_BLOCK_SIZE));
        }

        if (DEBUG) {
            logger.log(Logger.DEBUG, "RedeliverMessage: processing message {0} {1}", msg.toString(), con.getConnectionUID().toString());
        }
        DataInputStream is = new DataInputStream(msg.getMessageBodyStream());

        ConsumerUID ids[] = new ConsumerUID[ackcount];
        SysMessageID sysids[] = new SysMessageID[ackcount];
        try {
            for (int i = 0; i < ackcount; i++) {
                ids[i] = new ConsumerUID(is.readLong());
                sysids[i] = new SysMessageID();
                sysids[i].readID(is);
            }

            redeliver(ids, sysids, con, tid, redeliver);
        } catch (Exception ex) {
            throw new BrokerException(Globals.getBrokerResources().getString(BrokerResources.X_INTERNAL_EXCEPTION, "Invalid Redeliver Packet", ex), ex);
        }
        return true;
    }

    public void redeliver(ConsumerUID ids[], SysMessageID sysids[], IMQConnection con, TransactionUID tid, boolean redeliver)
            throws BrokerException, IOException {
        SysMessageID sysid = null;
        Set sessions = new HashSet(); // really should only have one
        // but client to broker protocol doesnt specify
        HashMap cToM = new HashMap();

        HashMap noConsumerMap = new HashMap();
        HashMap storedIDToConsumerUIDMap = new HashMap();

        for (int i = 0; i < ids.length; i++) {
            ConsumerUID id = ids[i];
            id.setConnectionUID(con.getConnectionUID());
            sysid = sysids[i];

            PacketReference ref = DL.get(null, sysid, false);

            if (ref == null || ref.isInvalid()) {
                continue;
            }
            Session s = Session.getSession(id);
            Consumer c = null;
            if (s != null) {
                if (!sessions.contains(s)) {
                    s.pause("redeliver");
                    sessions.add(s);
                }
                c = (Consumer) s.getConsumerOnSession(id);
            }

            if (c == null) {
                // ok, make sure the consumer has really gone away
                // if not, something is really wrong
                // otherwise ...
                // consumer has gone away but session is still
                // valid ->
                c = Consumer.getConsumer(id);

                if (c != null) {
                    logger.log(Logger.WARNING,
                            "Internal Error " + " consumer with id of " + id + " is unavailable " + " on session " + s + "[conuid,sess conuid] =" + "["
                                    + con.getConnectionUID().longValue() + "," + (s == null ? 0 : s.getConnectionUID().longValue()) + "] consumer session is : "
                                    + c.getSessionUID());
                    continue;
                } else {
                    if (s != null && s.isClientAck(id) && !s.isTransacted() && redeliver && tid == null) {

                        ConsumerUID storedID = s.getStoredIDForDetatchedConsumer(id);
                        if (storedID != null && !storedID.equals(id)) {
                            storedIDToConsumerUIDMap.put(id, storedID);
                            SortedSet refset = (SortedSet) noConsumerMap.get(id);
                            if (refset == null) {
                                refset = new TreeSet(new RefCompare());
                                noConsumerMap.put(id, refset);
                            }
                            ref.removeInDelivery(storedID);
                            refset.add(ref);
                        }
                    }
                    // the consumer for this message has been
                    // closed before the redeliver was requested
                    // (this means the message has not been acked and
                    // the session is open)
                    // we dont need to deliver this message, ignore it
                    logger.log(Logger.DEBUG, " consumer with id of " + id + " is unavailable " + " on session " + s + "[conuid,sess conuid] =" + "["
                            + con.getConnectionUID().longValue() + "," + (s == null ? 0 : s.getConnectionUID().longValue()) + "] it has been closed");
                    continue;
                }
            }

            // for client < 4.1, need check 'redeliver' as well
            if (redeliver && (tid != null || s.isTransacted())) {
                if (tid == null) {
                    tid = s.getCurrentTransactionID();
                }
                TransactionList[] tls = Globals.getDestinationList().getTransactionList(con.getPartitionedStore());
                TransactionList translist = tls[0];
                if (translist != null) {
                    if (checkRemovedConsumedMessage(ref, id, tid, translist, true)) {
                        if (DEBUG_CLUSTER_TXN) {
                            logger.log(logger.INFO, "Ignore redeliver request for [" + sysid + ":" + id + "], removed with transaction (rerouted)" + tid);
                        }
                        continue;
                    }
                    if (checkRemovedConsumedMessage(ref, id, tid, translist, false)) {
                        if (DEBUG_CLUSTER_TXN) {
                            logger.log(logger.INFO, "Ignore redeliver request for [" + sysid + ":" + id + "], removed with transaction " + tid);
                        }
                        continue;
                    }
                }
            }

            Set set = (Set) cToM.get(c);
            if (set == null) {
                set = new LinkedHashSet();
                cToM.put(c, set);
            }
            if (!set.contains(ref)) {
                ref.removeInDelivery((c.getStoredConsumerUID() == null ? c.getConsumerUID() : c.getStoredConsumerUID()));
                set.add(ref);
            } else if (DEBUG_CLUSTER_TXN) {
                logger.log(logger.INFO, "Ignore duplicated redeliver request [" + sysid + ":" + id + "]");
            }
            if (redeliver) {
                ref.consumed(c.getStoredConsumerUID(), s.isDupsOK(c.getConsumerUID()), false);
            } else {
                ref.removeDelivered(c.getStoredConsumerUID(), false);
            }
        }
        Iterator itr = cToM.entrySet().iterator();
        while (itr.hasNext()) {
            Map.Entry entry = (Map.Entry) itr.next();
            Consumer c = (Consumer) entry.getKey();
            Set msgs = (Set) entry.getValue();
            c.pause("start redeliver");
            c.routeMessages(msgs, true);
            c.resume("end redeliver");
        }
        cToM.clear(); // help gc

        if (noConsumerMap.size() > 0) {
            try {
                logger.log(logger.DEBUG, "REDELIVER unacked for closed consumers: " + noConsumerMap);

                TransactionHandler.redeliverUnackedNoConsumer(noConsumerMap, storedIDToConsumerUIDMap, redeliver, null, null);

            } catch (Exception e) {
                logger.logStack(logger.WARNING, "Exception in redelivering unacked messages for closed consumers", e);
            }
        }

        itr = sessions.iterator();
        while (itr.hasNext()) {
            Session s = (Session) itr.next();
            s.resume("redeliver");
        }
    }

    private boolean checkRemovedConsumedMessage(PacketReference ref, ConsumerUID id, TransactionUID tid, TransactionList translist, boolean rerouted)
            throws BrokerException {

        SysMessageID sysid = ref.getSysMessageID();

        HashMap cmap = translist.retrieveRemovedConsumedMessages(tid, rerouted);
        if (cmap != null && cmap.size() > 0) {
            List interests = (List) cmap.get(sysid);
            if (interests == null || interests.size() == 0) {
                return false;
            }
            for (int j = 0; j < interests.size(); j++) {
                ConsumerUID intid = (ConsumerUID) interests.get(j);
                if (intid.equals(id)) {
                    TransactionState ts = translist.retrieveState(tid);
                    if (ts != null && ts.getState() == TransactionState.FAILED) {
                        if (!rerouted) {
                            TransactionHandler.releaseRemoteForActiveConsumer(ref, id, tid, translist);
                        }
                        return true;
                    }
                }
            }
        }
        return false;
    }
}
