/*
 * Copyright (c) 2007, 2011, Oracle and/or its affiliates.  All rights reserved. 
 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. 
 *
 * This code is free software; you can redistribute it and/or modify it
 * under the terms of the GNU General Public License version 2 only, as
 * published by the Free Software Foundation.   Oracle designates this
 * particular file as subject to the "Classpath" exception as provided
 * by Oracle in the LICENSE file that accompanied this code. 
 *
 * This code is distributed in the hope that it will be useful, but WITHOUT
 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
 * FITNESS FOR A PARTICULAR PURPOSE.   See the GNU General Public License
 * version 2 for more details (a copy is included in the LICENSE file that
 * accompanied this code). 
 *
 * You should have received a copy of the GNU General Public License version
 * 2 along with this work; if not, write to the Free Software Foundation,
 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. 
 *
 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
 * or visit www.oracle.com if you need additional information or have any
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 */

package org.graalvm.visualvm.core.snapshot;

import org.graalvm.visualvm.core.datasource. DataSource;
import org.graalvm.visualvm.core.datasource.descriptor. DataSourceDescriptor;
import org.graalvm.visualvm.core.datasource.descriptor. DataSourceDescriptorFactory;
import java.awt. Component;
import java.awt.event. ActionEvent;
import java.util. ArrayList;
import java.util. Comparator;
import java.util. List;
import java.util.prefs. Preferences;
import javax.swing. JMenu;
import javax.swing. JMenuItem;
import javax.swing. JRadioButtonMenuItem;
import org.openide.awt. Mnemonics;
import org.openide.util. NbBundle;
import org.openide.util. NbPreferences;
import org.openide.util.actions. Presenter;

/**
 *
 * @author Jiri Sedlacek
 */
final class SnapshotsSorting implements Presenter. Menu {

    private static final String PROP_SNAPSHOTS_SORTING = "Snapshots.sorting"; // NOI18N

    private static SnapshotsSorting instance;
    
    private static final Comparator<DataSource> BY_TIME_COMPARATOR = byTimeComparator();
    private static final Comparator<DataSource> BY_NAME_COMPARATOR = byNameComparator();
    private static final List<Comparator<DataSource>> COMPARATORS = new ArrayList();
    static { COMPARATORS.add(BY_TIME_COMPARATOR); COMPARATORS.add(BY_NAME_COMPARATOR); }

    private final Preferences prefs;

    private JMenuItem presenter;
    private final Sorter sorter;


    public static synchronized SnapshotsSorting instance() {
        if (instance == null) instance = new SnapshotsSorting();
        return instance;
    }

    public JMenuItem getMenuPresenter() {
        if (presenter == null) presenter = createPresenter();
        return presenter;
    }


    Comparator<DataSource> getInitialSorting() {
        return COMPARATORS.get(prefs.getInt(PROP_SNAPSHOTS_SORTING, COMPARATORS. 
                                            indexOf(BY_TIME_COMPARATOR)));
    }


    private JMenuItem createPresenter() {
        final JMenu menu = new JMenu() {
            protected void fireMenuSelected() {
                Component[] items = getMenuComponents();
                for (Component item : items)
                    if (item instanceof SortAction)
                        ((SortAction)item).updateAction();
            }
        };
        Mnemonics.setLocalizedText(menu, NbBundle.getMessage(SnapshotsSorting.class,
                                   "ACT_SortSnapshots")); // NOI18N

        menu.add(new SortAction(NbBundle.getMessage(SnapshotsSorting.class,
                                "ACT_TimeAdded"), BY_TIME_COMPARATOR, sorter)); // NOI18N
        menu.add(new SortAction(NbBundle.getMessage(SnapshotsSorting.class,
                                "ACT_DisplayName"), BY_NAME_COMPARATOR, sorter)); // NOI18N

        return menu;
    }
    
    private static Comparator<DataSource> byTimeComparator() {
        return null;
    }

    private static Comparator<DataSource> byNameComparator() {
        return new Comparator<DataSource>() {
            public int compare(DataSource d1, DataSource d2) {
                DataSourceDescriptor dd1 = DataSourceDescriptorFactory.getDescriptor(d1);
                DataSourceDescriptor dd2 = DataSourceDescriptorFactory.getDescriptor(d2);

                return dd1.getName().compareTo(dd2.getName());
            }
        };
    }

    private SnapshotsSorting() {
        prefs = NbPreferences.forModule(SnapshotsSorting.class);

        sorter = new Sorter() {
            public void sort(Comparator<DataSource> comparator) {
                DataSourceDescriptor d = DataSourceDescriptorFactory.getDescriptor(
                                         SnapshotsContainer.sharedInstance());
                if (d instanceof SnapshotsContainerDescriptor) {
                    ((SnapshotsContainerDescriptor)d).setChildrenComparator(comparator);
                    prefs.putInt(PROP_SNAPSHOTS_SORTING, COMPARATORS.indexOf(comparator));
                }
            }
        };
    }


    private static class SortAction extends JRadioButtonMenuItem {

        private final Sorter sorter;
        private final Comparator<DataSource> comparator;
        private boolean currentlySelected;

        SortAction(String name, Comparator<DataSource> comparator, Sorter sorter) {
            Mnemonics.setLocalizedText(this, name);
            this.comparator = comparator;
            this.sorter = sorter;
        }

        void updateAction() {
            DataSourceDescriptor d = DataSourceDescriptorFactory.getDescriptor(
                                     SnapshotsContainer.sharedInstance());
            setEnabled(d instanceof SnapshotsContainerDescriptor);
            currentlySelected = d.getChildrenComparator() == comparator;
            setSelected(currentlySelected);
        }

        protected void fireActionPerformed(ActionEvent e) {
            if (! currentlySelected) sorter.sort(comparator);
        }

    }

    private static interface Sorter {

        void sort(Comparator<DataSource> comparator);

    }

}
