/*
 * Copyright 2010 JBoss Inc
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package org.drools.guvnor.client.explorer;

import java.util.Arrays;
import java.util.HashMap;
import java.util.Map;

import org.drools.guvnor.client.common.LoadingPopup;
import org.drools.guvnor.client.packages.PackageEditor;
import org.drools.guvnor.client.ruleeditor.GuvnorEditor;
import org.drools.guvnor.client.util.ScrollTabLayoutPanel;

import com.google.gwt.dom.client.Style.Unit;
import com.google.gwt.event.logical.shared.CloseEvent;
import com.google.gwt.event.logical.shared.CloseHandler;
import com.google.gwt.user.client.ui.Composite;
import com.google.gwt.user.client.ui.Panel;
import com.google.gwt.user.client.ui.ScrollPanel;
import com.google.gwt.user.client.ui.Widget;

/**
 * This is the tab panel manager.
 * @author Fernando Meyer, Michael Neale
 */
public class ExplorerViewCenterPanel extends Composite {

    private final ScrollTabLayoutPanel tabLayoutPanel;

    private MultiKeyMap<Panel>         openedTabs           = new MultiKeyMap<Panel>();
    private static int                 id                   = 0;

    /** to keep track of what is dirty, filthy */
    private Map<String, GuvnorEditor>  openedAssetEditors   = new HashMap<String, GuvnorEditor>();
    private Map<String, PackageEditor> openedPackageEditors = new HashMap<String, PackageEditor>();

    private Map<Panel, String[]>       itemWidgets          = new HashMap<Panel, String[]>();

    public ExplorerViewCenterPanel() {
        tabLayoutPanel = new ScrollTabLayoutPanel( 2,
                                                   Unit.EM );
        initWidget( tabLayoutPanel );
    }

    /**
     * Add a new tab. Should only do this if have checked showIfOpen to avoid dupes being opened.
     * @param tabname The displayed tab name.
     * @param widget The contents.
     * @param key A key which is unique.
     */
    public void addTab(final String tabname,
                       Widget widget,
                       final String key) {
        addTab( tabname,
                widget,
                new String[]{key} );
    }

    /**
     * Add a new tab. Should only do this if have checked showIfOpen to avoid dupes being opened.
     * @param tabname The displayed tab name.
     * @param widget The contents.
     * @param keys An array of keys which are unique.
     */
    public void addTab(final String tabname,
                       Widget widget,
                       final String[] keys) {
        final String panelId = (keys.length == 1 ? keys[0] + id++ : Arrays.toString( keys ) + id++);

        ScrollPanel localTP = new ScrollPanel();
        localTP.add( widget );
        tabLayoutPanel.add( localTP,
                            newClosableLabel( localTP,
                                              tabname ) );
        tabLayoutPanel.selectTab( localTP );

        //TODO: Dirtyable
        /*        localTP.ad( new PanelListenerAdapter() {
                    public void onDestroy(Component component) {
                        Panel p = openedTabs.remove( keys );
                        if ( p != null ) {
                            p.destroy();
                        }
                        openedAssetEditors.remove( panelId );
                        openedPackageEditors.remove( tabname );
                    }
                } );
        */
        if ( widget instanceof GuvnorEditor ) {
            this.openedAssetEditors.put( panelId,
                                         (GuvnorEditor) widget );
        } else if ( widget instanceof PackageEditor ) {
            this.getOpenedPackageEditors().put( tabname,
                                                (PackageEditor) widget );
        }

        openedTabs.put( keys,
                        localTP );
        itemWidgets.put( localTP,
                         keys );
    }

    private Widget newClosableLabel(final Panel panel,
                                    final String title) {
        ClosableLabel closableLabel = new ClosableLabel( title );

        closableLabel.addCloseHandler( new CloseHandler<ClosableLabel>() {
            public void onClose(CloseEvent<ClosableLabel> event) {
                int widgetIndex = tabLayoutPanel.getWidgetIndex( panel );
                if ( widgetIndex == tabLayoutPanel.getSelectedIndex() ) {
                    if ( isOnlyOneTabLeft() ) {
                        tabLayoutPanel.clear();
                    } else {
                        tabLayoutPanel.selectTab( widgetIndex - 1 );
                    }
                }
                tabLayoutPanel.remove( widgetIndex );
                String[] keys = itemWidgets.remove( panel );
                openedTabs.remove( keys );
            }

            private boolean isOnlyOneTabLeft() {
                return tabLayoutPanel.getWidgetCount() == 1;
            }
        } );

        return closableLabel;
    }

    /**
     * Will open if existing. If not it will return false;
     */
    public boolean showIfOpen(String key) {
        if ( openedTabs.containsKey( key ) ) {
            LoadingPopup.close();
            Panel tpi = (Panel) openedTabs.get( key );
            tabLayoutPanel.selectTab( tpi );
            return true;
        }
        return false;
    }

    public void close(String key) {
        Panel tpi = openedTabs.remove( key );

        int widgetIndex = tabLayoutPanel.getWidgetIndex( tpi );
        if ( widgetIndex == tabLayoutPanel.getSelectedIndex() ) {
            tabLayoutPanel.selectTab( widgetIndex - 1 );
        }

        tabLayoutPanel.remove( widgetIndex );
        itemWidgets.remove( tpi );
    }

    public Map<String, PackageEditor> getOpenedPackageEditors() {
        return openedPackageEditors;
    }

}