/*
 * 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.tuscany.sca.host.rmi;

import java.rmi.AlreadyBoundException;
import java.rmi.NotBoundException;
import java.rmi.Remote;
import java.rmi.RemoteException;
import java.rmi.registry.LocateRegistry;
import java.rmi.registry.Registry;
import java.util.Map;
import java.util.concurrent.ConcurrentHashMap;

/**
 * Default implementation of a RMI host.
 * 
 * @version $Rev$ $Date$
 */
public class DefaultRMIHost implements RMIHost {

    //map of RMI registries started and running
    private Map<String, Registry> rmiRegistries;

    public DefaultRMIHost() {
        rmiRegistries = new ConcurrentHashMap<String, Registry>();
        /*
         * if (System.getSecurityManager() == null) { System.setSecurityManager(new RMISecurityManager()); }
         */
    }

    public void registerService(String serviceName, int port, Remote serviceObject) throws RMIHostException,
        RMIHostRuntimeException {
        Registry registry;
        try {
            registry = rmiRegistries.get(Integer.toString(port));
            if (registry == null) {
                try {
                    registry = LocateRegistry.getRegistry(port);
                    registry.list();
                } catch (RemoteException e) {
                    registry = LocateRegistry.createRegistry(port);
                }
                rmiRegistries.put(Integer.toString(port), registry);
            }
            registry.bind(serviceName, serviceObject);
        } catch (AlreadyBoundException e) {
            throw new RMIHostException(e);
        } catch (RemoteException e) {
            RMIHostRuntimeException rmiExec = new RMIHostRuntimeException(e.getMessage());
            rmiExec.setStackTrace(e.getStackTrace());
            throw rmiExec;
        }

    }

    public void registerService(String serviceName, Remote serviceObject) throws RMIHostException,
        RMIHostRuntimeException {
        registerService(serviceName, RMI_DEFAULT_PORT, serviceObject);
    }

    public void unregisterService(String serviceName, int port) throws RMIHostException, RMIHostRuntimeException {
        Registry registry;

        try {
            registry = rmiRegistries.get(Integer.toString(port));
            if (registry == null) {
                registry = LocateRegistry.getRegistry(port);
                rmiRegistries.put(Integer.toString(port), registry);
            }
            registry.unbind(serviceName);
        } catch (RemoteException e) {
            RMIHostRuntimeException rmiExec = new RMIHostRuntimeException(e.getMessage());
            rmiExec.setStackTrace(e.getStackTrace());
            throw rmiExec;
        } catch (NotBoundException e) {
            throw new RMIHostException(e.getMessage());
        }
    }

    public void unregisterService(String serviceName) throws RMIHostException, RMIHostRuntimeException {
        unregisterService(serviceName, RMI_DEFAULT_PORT);

    }

    public Remote findService(String host, String port, String svcName) throws RMIHostException,
        RMIHostRuntimeException {
        Registry registry;
        Remote remoteService = null;
        host = (host == null || host.length() <= 0) ? "localhost" : host;
        int portNumber = (port == null || port.length() <= 0) ? RMI_DEFAULT_PORT : Integer.decode(port);

        try {
            // Requires permission java.net.SocketPermission "host:port", "connect,accept,resolve"
            // in security policy.
            registry = LocateRegistry.getRegistry(host, portNumber);

            if (registry != null) {
                remoteService = registry.lookup(svcName);
            }
        } catch (RemoteException e) {
            RMIHostRuntimeException rmiExec = new RMIHostRuntimeException(e.getMessage());
            rmiExec.setStackTrace(e.getStackTrace());
            throw rmiExec;
        } catch (NotBoundException e) {
            throw new RMIHostException(e.getMessage());
        }
        return remoteService;
    }

}