//  Copyright 2004 The Apache Software Foundation
//
// 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.apache.tapestry.util.io;

import java.io.IOException;

import org.apache.tapestry.Tapestry;
import org.apache.tapestry.util.ComponentAddress;

/**
 *  Squeezes a org.apache.tapestry.ComponentAddress.
 * 
 *  @author mindbridge
 *  @version $Id$
 *  @since 2.2
 * 
 **/

public class ComponentAddressAdaptor implements ISqueezeAdaptor
{
    private static final String PREFIX = "A";
    private static final char SEPARATOR = '/';
    
    public String squeeze(DataSqueezer squeezer, Object data) throws IOException
    {
        ComponentAddress address = (ComponentAddress) data;

        // a 'null' id path is encoded as an empty string
        String idPath = address.getIdPath();
        if (idPath == null)
        	idPath = "";

        return PREFIX + address.getPageName() + SEPARATOR + idPath;
    }

    public Object unsqueeze(DataSqueezer squeezer, String string) throws IOException
    {
        int separator = string.indexOf(SEPARATOR);
        if (separator < 0) 
            throw new IOException(Tapestry.getMessage("ComponentAddressAdaptor.no-separator"));

        String pageName = string.substring(1, separator);
        String idPath = string.substring(separator + 1);
        if (idPath.equals(""))
        	idPath = null;

        return new ComponentAddress(pageName, idPath);
    }

    public void register(DataSqueezer squeezer)
    {
        squeezer.register(PREFIX, ComponentAddress.class, this);
    }

}