/*
 * 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
 */

/*
 * @(#)ConsoleObjStoreManager.java	1.7 06/28/07
 */

package com.sun.messaging.jmq.admin.apps.console;

import java.util.Enumeration;

import com.sun.messaging.jmq.admin.objstore.ObjStoreAttrs;
import com.sun.messaging.jmq.admin.objstore.ObjStore;
import com.sun.messaging.jmq.admin.objstore.ObjStoreManager;
import com.sun.messaging.jmq.admin.objstore.ObjStoreException;
import com.sun.messaging.jmq.admin.util.UserPropertiesException;

/**
 * This class manages all the instances of the ObjStores that it creates. It also provides the default implementations
 * for the miscellaneous useful operations for the manager. The user should extend this class and overwrite methods if
 * he wishes to provide different implementations or add more operations.
 */
public class ConsoleObjStoreManager extends ObjStoreManager {

    /**
     * The reference to this class itself.
     */
    private static ConsoleObjStoreManager mgr = null;

    private String fileName = "objstorelist.properties";

    /**
     * Private constructor for this class. This is called only once.
     */
    protected ConsoleObjStoreManager() {
    }

    /**
     * If the ObjStoreManager was requested more than once, this will simply return the same instance.
     *
     * @return ConsoleObjStoreManager the only one instance of this class
     *
     * REVISIT: This allows two instances (ObjStoreManager and ConsoleObjStoreManager) to coexist, which is NO GOOD. We
     * should only have one instance of it - either ObjStoreManager OR ConsoleObjStoreManager OR a custom manager. This
     * needs to be fixed.
     */
    public static synchronized ConsoleObjStoreManager getConsoleObjStoreManager() {

        if (mgr == null) {
            mgr = new ConsoleObjStoreManager();
        }
        return mgr;
    }

    /**
     * Reads the files and populates objStores.
     *
     */
    public void readObjStoresFromFile() throws UserPropertiesException, ObjStoreException {

        ObjStoreListProperties oslProps = readFromFile();

        int count = oslProps.getObjStoreCount();

        for (int i = 0; i < count; ++i) {
            ObjStoreAttrs osa = oslProps.getObjStoreAttrs(i);

            createStore(osa);
        }
    }

    /**
     * Reads the files containing ObjStoreAttrs.
     *
     * @return Properties object containing list of ObjectStoreAttrs
     *
     */
    private ObjStoreListProperties readFromFile() throws UserPropertiesException {

        ObjStoreListProperties oslProps = new ObjStoreListProperties();

        oslProps.setFileName(fileName);
        oslProps.load();

        return (oslProps);
    }

    /**
     * Writes ObjStores to files.
     */
    public void writeObjStoresToFile() throws UserPropertiesException {

        // Must call ObjStoreAttrs.prepareToTerminate() prior to
        // storing

        Enumeration e = objStores.elements();
        ObjStoreListProperties oslProps = new ObjStoreListProperties();

        while (e.hasMoreElements()) {

            ObjStore os = (ObjStore) e.nextElement();
            ObjStoreAttrs osa = os.getObjStoreAttrs();
            osa.prepareToTerminate();

            oslProps.addObjStoreAttrs(osa);
        }

        writeToFile(oslProps);
    }

    /**
     * Writes ObjStoreAttrs to files.
     *
     */
    private void writeToFile(ObjStoreListProperties oslProps) throws UserPropertiesException {
        oslProps.setFileName(fileName);
        oslProps.save();
    }

    /**
     * Sets the name of the file where the objstore list is saved when writeObjStoresToFile() is called. This is also the
     * file that is read from when readObjStoresFromFile() is called.
     *
     * @param fileName The fileName where the object stores are read from and written to.
     */
    public void setFileName(String fileName) {
        this.fileName = fileName;
    }
}
