/*
 * 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
 */

/*
 * @(#)InterestStore.java	1.35 08/28/07
 */

package com.sun.messaging.jmq.jmsserver.persist.file;

import com.sun.messaging.jmq.jmsserver.core.ConsumerUID;
import com.sun.messaging.jmq.jmsserver.core.Consumer;
import com.sun.messaging.jmq.util.log.Logger;
import com.sun.messaging.jmq.util.SizeString;
import com.sun.messaging.jmq.jmsserver.util.*;
import com.sun.messaging.jmq.jmsserver.Globals;
import com.sun.messaging.jmq.jmsserver.Broker;
import com.sun.messaging.jmq.jmsserver.config.*;
import com.sun.messaging.jmq.jmsserver.resources.*;
import com.sun.messaging.jmq.jmsserver.persist.api.Store;
import com.sun.messaging.jmq.jmsserver.persist.api.LoadException;
import com.sun.messaging.jmq.io.disk.PHashMap;
import com.sun.messaging.jmq.io.disk.PHashMapLoadException;
import com.sun.messaging.jmq.io.disk.VRFileWarning;

import java.io.*;
import java.util.*;

/**
 * Keep track of all persisted Interest objects
 */
class InterestStore {

    Logger logger = Globals.getLogger();
    BrokerResources br = Globals.getBrokerResources();
    BrokerConfig config = Globals.getConfig();

    // initial size of backing file
    static final String INTEREST_FILE_SIZE_PROP = FileStore.FILE_PROP_PREFIX + "interest.file.size";

    static final long DEFAULT_INTEREST_FILE_SIZE = 1024; // 1024k = 1M

    static final String BASENAME = "interest"; // data file

    private File backingFile = null;

    // cache of all stored interests; maps interest id -> interest
    private PHashMap interestMap = null;

    private LoadException loadException = null;

    /**
     * When instantiated, all interests are loaded.
     */
    InterestStore(FileStore p, File topDir, boolean clear) throws BrokerException {

        SizeString filesize = config.getSizeProperty(INTEREST_FILE_SIZE_PROP, DEFAULT_INTEREST_FILE_SIZE);

        backingFile = new File(topDir, BASENAME);
        try {
            // safe=false; data synchronization is controlled by caller
            interestMap = new PHashMap(backingFile, filesize.getBytes(), false, clear, Globals.isMinimumWritesFileStore(), Broker.isInProcess());
        } catch (IOException e) {
            throw new BrokerException(br.getString(br.X_LOAD_INTERESTS_FAILED), e);
        }

        try {
            interestMap.load(p);
        } catch (IOException | ClassNotFoundException e) {
            throw new BrokerException(br.getString(br.X_LOAD_INTERESTS_FAILED), e);
        } catch (PHashMapLoadException le) {

            while (le != null) {
                logger.log(Logger.WARNING, br.X_FAILED_TO_LOAD_A_CONSUMER, le);

                // save info in LoadException
                LoadException e = new LoadException(le.getMessage(), le.getCause());
                e.setKey(le.getKey());
                e.setValue(le.getValue());
                e.setKeyCause(le.getKeyCause());
                e.setValueCause(le.getValueCause());
                e.setNextException(loadException);
                loadException = e;

                // get the chained exception
                le = le.getNextException();
            }
        }

        VRFileWarning w = interestMap.getWarning();
        if (w != null) {
            logger.log(logger.WARNING, "possible loss of consumer data", w);
        }

        if (clear && Store.getDEBUG()) {
            logger.log(logger.DEBUGHIGH, "InterestStore initialized with clear option");
        }

        if (Store.getDEBUG()) {
            logger.log(logger.DEBUG, "LOADED " + (interestMap.size()) + " INTERESTS");
        }
    }

    /**
     * When instantiated, upgrade data from old store if clear is true, just remove all data in old store
     */
    InterestStore(FileStore p, File topDir, File oldDir, boolean clear) throws BrokerException {

        File oldFile = new File(oldDir, BASENAME);
        PHashMap olddata = null;

        backingFile = new File(topDir, BASENAME);
        try {
            // safe=false; reset=clear
            olddata = new PHashMap(oldFile, false, clear, Globals.isMinimumWritesFileStore(), Broker.isInProcess());
        } catch (IOException e) {
            logger.log(logger.ERROR, br.X_UPGRADE_INTERESTS_FAILED, oldFile, backingFile, e);
            throw new BrokerException(br.getString(br.X_UPGRADE_INTERESTS_FAILED, oldFile, backingFile), e);
        }

        try {
            olddata.load(p);
        } catch (IOException | ClassNotFoundException e) {
            logger.log(logger.ERROR, br.X_UPGRADE_INTERESTS_FAILED, oldFile, backingFile, e);
            throw new BrokerException(br.getString(br.X_UPGRADE_INTERESTS_FAILED, oldFile, backingFile), e);
        } catch (PHashMapLoadException le) {

            while (le != null) {
                logger.log(Logger.WARNING, br.X_FAILED_TO_LOAD_A_CONSUMER_FROM_OLDSTORE, le);

                // save info in LoadException
                LoadException e = new LoadException(le.getMessage(), le.getCause());
                e.setKey(le.getKey());
                e.setValue(le.getValue());
                e.setKeyCause(le.getKeyCause());
                e.setValueCause(le.getValueCause());
                e.setNextException(loadException);
                loadException = e;

                // get the chained exception
                le = le.getNextException();
            }
        }

        VRFileWarning w = olddata.getWarning();
        if (w != null) {
            logger.log(logger.WARNING, "possible loss of consumer data in old store", w);
        }

        try {
            // safe=false; reset=false
            interestMap = new PHashMap(backingFile, oldFile.length(), false, false, Globals.isMinimumWritesFileStore(), Broker.isInProcess());
        } catch (IOException e) {
            logger.log(logger.ERROR, br.X_UPGRADE_INTERESTS_FAILED, oldFile, backingFile, e);
            throw new BrokerException(br.getString(br.X_UPGRADE_INTERESTS_FAILED, oldFile, backingFile), e);
        }

        try {
            interestMap.load(p);
        } catch (IOException | ClassNotFoundException | PHashMapLoadException e) {
            // should not happen so throw exception
            logger.log(logger.ERROR, br.X_UPGRADE_INTERESTS_FAILED, oldFile, backingFile, e);
            throw new BrokerException(br.getString(br.X_UPGRADE_INTERESTS_FAILED, oldFile, backingFile), e);
        }

        w = interestMap.getWarning();
        if (w != null) {
            logger.log(logger.WARNING, "possible loss of consumer data", w);
        }

        Iterator itr = olddata.entrySet().iterator();
        while (itr.hasNext()) {
            Map.Entry entry = (Map.Entry) itr.next();
            Object key = entry.getKey();
            Object value = entry.getValue();
            interestMap.put(key, value);
        }
        olddata.close();

        if (Store.getDEBUG()) {
            logger.log(logger.DEBUG, "UPGRADED " + (interestMap.size()) + " INTERESTS");
        }

        // if upgradeNoBackup, remove oldfile
        if (p.upgradeNoBackup()) {
            if (!oldFile.delete()) {
                logger.log(logger.ERROR, br.I_DELETE_FILE_FAILED, oldFile);
            }
        }
    }

    LoadException getLoadException() {
        return loadException;
    }

    private void sync() throws BrokerException {
        try {
            if (Store.getDEBUG_SYNC()) {
                String msg = "InterestStore sync()";
                logger.log(Logger.DEBUG, msg);
            }
            interestMap.force();
        } catch (IOException e) {
            throw new BrokerException("Failed to synchronize file: " + backingFile, e);
        }
    }

    /**
     * Get debug information about the store.
     *
     * @return A Hashtable of name value pair of information
     */
    Hashtable getDebugState() {
        Hashtable t = new Hashtable();
        t.put("Consumers", String.valueOf(interestMap.size()));
        return t;
    }

    /**
     * Print out usage info in the interest directory.
     */
    public void printInfo(PrintStream out) {
        out.println("\nInterests");
        out.println("---------");
        out.println("backing file: " + backingFile);
        out.println("number of interests:   " + interestMap.size());
    }

    /**
     * Store an interest which is uniquely identified by it's interest id.
     *
     * @param interest interest to be persisted
     * @exception IOException if an error occurs while persisting the interest
     * @exception BrokerException if an interest with the same id exists in the store already
     */
    void storeInterest(Consumer interest, boolean sync) throws IOException, BrokerException {

        ConsumerUID id = interest.getConsumerUID();

        try {
            Object oldValue = interestMap.putIfAbsent(id, interest);
            if (oldValue != null) {
                logger.log(logger.ERROR, br.E_INTEREST_EXISTS_IN_STORE, id, interest.getDestinationUID().getLongString());
                throw new BrokerException(br.getString(br.E_INTEREST_EXISTS_IN_STORE, id, interest.getDestinationUID().getLongString()));
            }

            if (sync) {
                sync();
            }
        } catch (RuntimeException e) {
            logger.log(logger.ERROR, br.X_PERSIST_INTEREST_FAILED, id, e);
            throw e;
        }
    }

    /**
     * Remove the interest from the persistent store.
     *
     * @param interest the interest to be removed
     * @exception IOException if an error occurs while removing the interest
     * @exception BrokerException if the interest is not found in the store
     */
    void removeInterest(Consumer interest, boolean sync) throws IOException, BrokerException {

        Object oldinterest = null;
        ConsumerUID id = interest.getConsumerUID();

        try {
            oldinterest = interestMap.remove(id);

            if (oldinterest == null) {
                logger.log(logger.ERROR, br.E_INTEREST_NOT_FOUND_IN_STORE, id, interest.getDestinationUID().getLongString());
                throw new BrokerException(br.getString(br.E_INTEREST_NOT_FOUND_IN_STORE, id, interest.getDestinationUID().getLongString()));
            }

            if (sync) {
                sync();
            }
        } catch (RuntimeException e) {
            logger.log(logger.ERROR, br.X_REMOVE_INTEREST_FAILED, id);
            throw new BrokerException(br.getString(br.X_REMOVE_INTEREST_FAILED, id), e);
        }
    }

    /**
     * Retrieve all interests in the store. Will return as many interests as we can read. Any interests that are retrieved
     * unsuccessfully will be logged as a warning.
     *
     * @return an array of Interest objects; a zero length array is returned if no interests exist in the store
     * @exception IOException if an error occurs while getting the data
     */
    Consumer[] getAllInterests() throws IOException {

        return (Consumer[]) interestMap.values().toArray(new Consumer[0]);
    }

    // clear the store; when this method returns, the store has a state
    // that is the same as an empty store (same as when InterestStore
    // is instantiated with the clear argument set to true
    void clearAll(boolean sync) {

        if (Store.getDEBUG()) {
            logger.log(logger.DEBUGHIGH, "InterestStore.clearAll() called");
        }

        interestMap.clear();

        if (sync) {
            try {
                sync();
            } catch (BrokerException e) {
                logger.log(logger.ERROR, "Got exception while synchronizing data to disk", e);
            }
        }
    }

    void close(boolean cleanup) {
        if (Store.getDEBUG()) {
            logger.log(logger.DEBUGHIGH, "InterestStore: closing, " + interestMap.size() + " persisted interests");
        }

        interestMap.close();
    }

}
