/*
 * Licensed to the Apache Software Foundation (ASF) under one
 * or more contributor license agreements.  See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership.  The ASF 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.apache.felix.cm.impl;


import java.io.IOException;

import org.osgi.framework.Bundle;
import org.osgi.framework.InvalidSyntaxException;
import org.osgi.service.cm.Configuration;
import org.osgi.service.cm.ConfigurationAdmin;
import org.osgi.service.cm.ConfigurationPermission;


/**
 * The <code>ConfigurationAdminImpl</code> is the per-bundle frontend to the
 * configuration manager. Instances of this class are created on-demand for
 * each bundle trying to get hold of the <code>ConfigurationAdmin</code>
 * service.
 *
 * @author fmeschbe
 */
public class ConfigurationAdminImpl implements ConfigurationAdmin
{

    // The configuration manager to which most of the tasks are delegated
    private ConfigurationManager configurationManager;

    // The bundle for which this instance has been created
    private Bundle bundle;


    ConfigurationAdminImpl( ConfigurationManager configurationManager, Bundle bundle )
    {
        this.configurationManager = configurationManager;
        this.bundle = bundle;
    }


    void dispose()
    {
        bundle = null;
        configurationManager = null;
    }


    Bundle getBundle()
    {
        return bundle;
    }


    //---------- ConfigurationAdmin interface ---------------------------------

    /* (non-Javadoc)
     * @see org.osgi.service.cm.ConfigurationAdmin#createFactoryConfiguration(java.lang.String)
     */
    public Configuration createFactoryConfiguration( String factoryPid ) throws IOException
    {
        return this.wrap( configurationManager.createFactoryConfiguration( this, factoryPid ) );
    }


    /* (non-Javadoc)
     * @see org.osgi.service.cm.ConfigurationAdmin#createFactoryConfiguration(java.lang.String, java.lang.String)
     */
    public Configuration createFactoryConfiguration( String factoryPid, String location ) throws IOException
    {
        this.checkPermission();

        return this.wrap( configurationManager.createFactoryConfiguration( factoryPid, location ) );
    }


    /* (non-Javadoc)
     * @see org.osgi.service.cm.ConfigurationAdmin#getConfiguration(java.lang.String)
     */
    public Configuration getConfiguration( String pid ) throws IOException
    {
        ConfigurationImpl config = configurationManager.getConfiguration( pid, getBundle().getLocation() );

        if ( config.getBundleLocation() == null )
        {
            config.setBundleLocation( this.getBundle().getLocation() );
        }
        else if ( !config.getBundleLocation().equals( this.getBundle().getLocation() ) )
        {
            this.checkPermission();
        }

        return this.wrap( config );
    }


    /* (non-Javadoc)
     * @see org.osgi.service.cm.ConfigurationAdmin#getConfiguration(java.lang.String, java.lang.String)
     */
    public Configuration getConfiguration( String pid, String location ) throws IOException
    {
        this.checkPermission();

        return this.wrap( configurationManager.getConfiguration( pid, location ) );
    }


    /* (non-Javadoc)
     * @see org.osgi.service.cm.ConfigurationAdmin#listConfigurations(java.lang.String)
     */
    public Configuration[] listConfigurations( String filter ) throws IOException, InvalidSyntaxException
    {
        ConfigurationImpl ci[] = configurationManager.listConfigurations( this, filter );
        if ( ci == null )
        {
            return null;
        }

        Configuration[] cfgs = new Configuration[ci.length];
        for ( int i = 0; i < cfgs.length; i++ )
        {
            cfgs[i] = this.wrap( ci[i] );
        }

        return cfgs;
    }


    //---------- Security checks ----------------------------------------------

    private Configuration wrap( ConfigurationImpl configuration )
    {
        return new ConfigurationAdapter( this, configuration );
    }


    /**
     * Checks whether the bundle to which this instance has been given has the
     * <code>CONFIGURE</code> permission and returns <code>true</code> in this
     * case.
     */
    boolean hasPermission()
    {
        return bundle.hasPermission( new ConfigurationPermission( "*", ConfigurationPermission.CONFIGURE ) );
    }


    /**
     * Checks whether the bundle to which this instance has been given has the
     * <code>CONFIGURE</code> permission and throws a <code>SecurityException</code>
     * if this is not the case.
     *
     * @throws SecurityException if the bundle to which this instance belongs
     *      does not have the <code>CONFIGURE</code> permission.
     */
    void checkPermission()
    {
        if ( !this.hasPermission() )
        {
            throw new SecurityException( "Bundle " + bundle.getSymbolicName()
                + " not permitted for Configuration Tasks" );
        }
    }

}