/*
 * 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.binding.erlang.impl;

import org.apache.tuscany.sca.binding.erlang.ErlangBinding;
import org.apache.tuscany.sca.binding.erlang.impl.types.TypeHelpersProxy;
import org.apache.tuscany.sca.invocation.Invoker;
import org.apache.tuscany.sca.invocation.Message;
import org.apache.tuscany.sca.runtime.RuntimeComponentReference;

import com.ericsson.otp.erlang.OtpConnection;
import com.ericsson.otp.erlang.OtpEpmd;
import com.ericsson.otp.erlang.OtpErlangList;
import com.ericsson.otp.erlang.OtpErlangObject;
import com.ericsson.otp.erlang.OtpMbox;
import com.ericsson.otp.erlang.OtpMsg;
import com.ericsson.otp.erlang.OtpNode;
import com.ericsson.otp.erlang.OtpPeer;
import com.ericsson.otp.erlang.OtpSelf;

/**
 * @version $Rev: $ $Date: $
 */
public class ErlangInvoker implements Invoker {

    private RuntimeComponentReference reference;
    private ErlangBinding binding;
    private OtpNode node;

    public ErlangInvoker(RuntimeComponentReference reference, ErlangBinding binding) {
        this.reference = reference;
        this.binding = binding;
    }

    private Message sendMessage(Message msg) {
        OtpMbox tmpMbox = null;
        try {
            String nodeName = "_connector_to_" + binding.getNode();
            node = new OtpNode(nodeName);
            tmpMbox = node.createMbox();
            Object[] args = msg.getBody();
            OtpErlangObject msgPayload = TypeHelpersProxy.toErlang(args);
            tmpMbox.send(msg.getOperation().getName(), binding.getNode(), msgPayload);
            if (msg.getOperation().getOutputType() != null) {
                OtpMsg resultMsg = tmpMbox.receiveMsg();
                OtpErlangObject result = resultMsg.getMsg();
                msg.setBody(TypeHelpersProxy.toJava(result, msg.getOperation().getOutputType().getPhysical()));
            }
        } catch (Exception e) {
            msg.setFaultBody(e);
        } finally {
            if (tmpMbox != null) {
                tmpMbox.close();
            }
            if (node != null) {
                OtpEpmd.unPublishPort(node);
                node.close();
            }
        }
        return msg;
    }

    private Message invokeOperation(Message msg) {
        OtpSelf self = null;
        OtpPeer other = null;
        OtpConnection connection = null;
        try {
            String nodeName = "_connector_to_" + binding.getNode();
            self = new OtpSelf(nodeName);
            other = new OtpPeer(binding.getNode());
            connection = self.connect(other);
            OtpErlangList params = TypeHelpersProxy.toErlangAsList((Object[])msg.getBody());
            connection.sendRPC(binding.getModule(), msg.getOperation().getName(), params);
            if (msg.getOperation().getOutputType() != null) {
                OtpErlangObject result = connection.receiveRPC();
                msg.setBody(TypeHelpersProxy.toJava(result, msg.getOperation().getOutputType().getPhysical()));
            }
        } catch (Exception e) {
            msg.setFaultBody(e);
        } finally {
            if (connection != null) {
                connection.close();
            }
        }
        return msg;
    }

    /**
     * @see org.apache.tuscany.sca.invocation.Invoker#invoke(org.apache.tuscany.sca.invocation.Message)
     */
    public Message invoke(Message msg) {
        if (binding.isMbox()) {
            return sendMessage(msg);
        } else {
            return invokeOperation(msg);
        }

    }

}