/*
 * Licensed to "Neo Technology," Network Engine for Objects in Lund AB
 * (http://neotechnology.com) under one or more contributor license agreements.
 * See the NOTICE file distributed with this work for additional information
 * regarding copyright ownership. Neo Technology licenses this file to you 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.neo4j.neoclipse.search;

import org.eclipse.jface.viewers.DoubleClickEvent;
import org.eclipse.jface.viewers.IDoubleClickListener;
import org.eclipse.jface.viewers.StructuredSelection;
import org.eclipse.jface.viewers.TreeViewer;
import org.eclipse.search.ui.ISearchResult;
import org.eclipse.search.ui.ISearchResultListener;
import org.eclipse.search.ui.ISearchResultPage;
import org.eclipse.search.ui.ISearchResultViewPart;
import org.eclipse.search.ui.SearchResultEvent;
import org.eclipse.swt.SWT;
import org.eclipse.swt.widgets.Composite;
import org.eclipse.swt.widgets.Control;
import org.eclipse.ui.IMemento;
import org.eclipse.ui.PlatformUI;
import org.eclipse.ui.part.Page;
import org.neo4j.graphdb.Node;
import org.neo4j.neoclipse.view.NeoGraphLabelProviderWrapper;
import org.neo4j.neoclipse.view.NeoGraphViewPart;

/**
 * This class represents a page in the search view that displays Neo search
 * results, e.g. lists of Neo nodes matching a search criteria.
 * @author Peter Hänsgen
 */
public class NeoSearchResultPage extends Page implements ISearchResultPage
{
    /**
     * The id of this page.
     */
    private String id;
    /**
     * The list of found nodes.
     */
    private TreeViewer viewer;

    /**
     * Creates the control
     */
    @Override
    public void createControl( final Composite parent )
    {
        viewer = new TreeViewer( parent, SWT.NONE );
        viewer.setContentProvider( new NeoSearchResultContentProvider() );
        // TODO keep search result labels and graph labels separated?
        // no, keep them together to get consistency in the GUI.
        viewer.setLabelProvider( NeoGraphLabelProviderWrapper.getInstance() );
        viewer
            .addDoubleClickListener( new NeoSearchResultDoubleClickListener() );
    }

    /**
     * Returns the control.
     */
    @Override
    public Control getControl()
    {
        return viewer.getControl();
    }

    /**
     * Sets the focus.
     */
    @Override
    public void setFocus()
    {
        if ( viewer != null )
        {
            viewer.getControl().setFocus();
        }
    }

    /**
     * Returns the id.
     */
    public String getID()
    {
        return id;
    }

    /**
     * Sets the id.
     */
    public void setID( final String id )
    {
        this.id = id;
    }

    /**
     * Returns the label of the page.
     */
    public String getLabel()
    {
        NeoSearchResult result = (NeoSearchResult) viewer.getInput();
        if ( result != null )
        {
            return "Neo4j - Matches for '"
                + ((NeoSearchQuery) result.getQuery()).getExpression() + "'";
        }
        else
        {
            return "Neo4j";
        }
    }

    /**
     * Sets the search result for a Neo search.
     */
    public void setInput( final ISearchResult result, final Object uiState )
    {
        setInput( result );
        if ( result != null )
        {
            // observe changes in the result and update the view accordingly
            result.addListener( new ISearchResultListener()
            {
                public void searchResultChanged( final SearchResultEvent e )
                {
                    PlatformUI.getWorkbench().getDisplay().syncExec(
                        new Runnable()
                        {
                            public void run()
                            {
                                setInput( e.getSearchResult() );
                            }
                        } );
                }
            } );
        }
    }

    /**
     * Sets the input of the viewer.
     */
    protected void setInput( final ISearchResult result )
    {
        viewer.setInput( result );
    }

    /**
     * Sets the view.
     */
    public void setViewPart( final ISearchResultViewPart part )
    {
        // does nothing
    }

    /**
     * Not supported.
     */
    public Object getUIState()
    {
        return null;
    }

    /**
     * Not supported.
     */
    public void restoreState( final IMemento memento )
    {
        // not supported
    }

    /**
     * Not supported.
     */
    public void saveState( final IMemento memento )
    {
        // not supported
    }

    /**
     * The handler for double clicks on search result list entries.
     */
    static class NeoSearchResultDoubleClickListener implements
        IDoubleClickListener
    {
        /**
         * Sets the selected node as input for the graph viewer.
         */
        public void doubleClick( final DoubleClickEvent event )
        {
            StructuredSelection sel = (StructuredSelection) event
                .getSelection();
            Object s = sel.getFirstElement();
            if ( s instanceof Node )
            {
                // get the graph viewer
                NeoGraphViewPart gv = (NeoGraphViewPart) PlatformUI
                    .getWorkbench().getActiveWorkbenchWindow().getActivePage()
                    .findView( NeoGraphViewPart.ID );
                // TODO if it does not exist yet - create one? how?
                if ( gv != null )
                {
                    gv.showNode( (Node) s );
                }
            }
        }
    }
}