/**
 * Copyright (c) 2002-2010 "Neo Technology,"
 * Network Engine for Objects in Lund AB [http://neotechnology.com]
 *
 * This file is part of Neo4j.
 *
 * Neo4j is free software: you can redistribute it and/or modify
 * it under the terms of the GNU Affero General Public License as
 * published by the Free Software Foundation, either version 3 of the
 * License, or (at your option) any later version.
 *
 * This program 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 Affero General Public License for more details.
 *
 * You should have received a copy of the GNU Affero General Public License
 * along with this program. If not, see <http://www.gnu.org/licenses/>.
 */

package org.neo4j.shell.impl;

import java.rmi.RemoteException;
import java.util.List;

import jline.Completor;
import jline.SimpleCompletor;

import org.neo4j.shell.ShellClient;
import org.neo4j.shell.ShellException;
import org.neo4j.shell.TabCompletion;

class ShellTabCompletor implements Completor
{
    private final ShellClient client;
    
    private long timeWhenCached;
    private Completor appNameCompletor;

    public ShellTabCompletor( ShellClient client )
    {
        this.client = client;
    }
    
    public int complete( String buffer, int cursor, List candidates )
    {
        if ( buffer == null || buffer.length() == 0 )
        {
            return cursor;
        }
        
        try
        {
            if ( buffer.contains( " " ) )
            {
                TabCompletion completion = client.getServer().tabComplete( buffer.trim(),
                        client.session() );
                cursor = completion.getCursor();
                candidates.addAll( completion.getCandidates() );
            }
            else
            {
                // Complete the app name
                return getAppNameCompletor().complete( buffer, cursor, candidates );
            }
        }
        catch ( RemoteException e )
        {
            // TODO Throw something?
            e.printStackTrace();
        }
        catch ( ShellException e )
        {
            // TODO Throw something?
            e.printStackTrace();
        }
        return cursor;
    }
    
    private Completor getAppNameCompletor() throws RemoteException
    {
        if ( timeWhenCached != client.timeForMostRecentConnection() )
        {
            timeWhenCached = client.timeForMostRecentConnection();
            appNameCompletor = new SimpleCompletor( client.getServer().getAllAvailableCommands() );
        }
        return this.appNameCompletor;
    }
}