/*
 * Copyright 2012 JBoss by Red Hat.
 *
 * 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.jbpm.task.utils;

import com.google.protobuf.ExtensionRegistry;
import java.io.ByteArrayInputStream;
import java.io.ByteArrayOutputStream;
import java.io.IOException;
import java.util.HashMap;
import java.util.Map;

import org.drools.marshalling.ObjectMarshallingStrategy;
import org.drools.marshalling.ObjectMarshallingStrategyAcceptor;
import org.drools.marshalling.ObjectMarshallingStrategyStore;
import org.drools.marshalling.impl.*;
import org.drools.marshalling.impl.ProtobufMessages.Header;
import org.drools.runtime.Environment;
import org.drools.runtime.EnvironmentName;
import org.jbpm.marshalling.impl.JBPMMessages;
import org.jbpm.marshalling.impl.JBPMMessages.Variable;
import org.jbpm.marshalling.impl.ProtobufProcessMarshaller;
import org.jbpm.task.AccessType;
import org.jbpm.task.service.ContentData;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

public class ContentMarshallerHelper {

    private static final Logger logger = LoggerFactory.getLogger(ContentMarshallerHelper.class);

    public static ContentData marshal(Object o, Environment env) {
        MarshallerWriteContext context = null;
        ContentData content = null;
        try {
            MarshallingConfigurationImpl marshallingConfigurationImpl = null;
            if(env != null){
                 marshallingConfigurationImpl = new MarshallingConfigurationImpl((ObjectMarshallingStrategy[]) env.get(EnvironmentName.OBJECT_MARSHALLING_STRATEGIES), false, false);
            }else{
                marshallingConfigurationImpl = new MarshallingConfigurationImpl(new ObjectMarshallingStrategy[]{new SerializablePlaceholderResolverStrategy(ClassObjectMarshallingStrategyAcceptor.DEFAULT)}, false, false);
            }
            ObjectMarshallingStrategyStore objectMarshallingStrategyStore = marshallingConfigurationImpl.getObjectMarshallingStrategyStore();
            ByteArrayOutputStream stream = new ByteArrayOutputStream();
         
            context = new MarshallerWriteContext(stream, null, null, null, objectMarshallingStrategyStore, env);
            Variable marshallVariable = null;
            if(o instanceof Map){
                 marshallVariable = ProtobufProcessMarshaller.marshallVariablesMap(
                                                        context,
                                                        (Map<String, Object>)o);
            }else{
                 marshallVariable = ProtobufProcessMarshaller.marshallVariable(
                                                        context,
                                                        "results",
                                                        o);
            }
            PersisterHelper.writeToStreamWithHeader(
                    context,
                    marshallVariable);
            
            context.close();
            
            byte[] toByteArray = stream.toByteArray();

            content = new ContentData();
            content.setContent(toByteArray);
            content.setType(o.getClass().getCanonicalName());
            content.setAccessType(AccessType.Inline);

        } catch (IOException ex) {
            ex.printStackTrace();
        } 
        return content;
    }

    public static Object unmarshall(byte[] content, Environment env) {
        return unmarshall(content, env, null);
    }
    
    public static Object unmarshall(byte[] content, Environment env, ClassLoader classloader) {
        MarshallerReaderContext context = null;
        try {
            ByteArrayInputStream stream = new ByteArrayInputStream(content);
            MarshallingConfigurationImpl marshallingConfigurationImpl = null;
            if(env != null){
                 marshallingConfigurationImpl = new MarshallingConfigurationImpl((ObjectMarshallingStrategy[]) env.get(EnvironmentName.OBJECT_MARSHALLING_STRATEGIES), false, false);
            }else{
                marshallingConfigurationImpl = new MarshallingConfigurationImpl(new ObjectMarshallingStrategy[]{new SerializablePlaceholderResolverStrategy(ClassObjectMarshallingStrategyAcceptor.DEFAULT)}, false, false);
            }
            ObjectMarshallingStrategyStore objectMarshallingStrategyStore = marshallingConfigurationImpl.getObjectMarshallingStrategyStore();
            context = new MarshallerReaderContext(stream, null, null, objectMarshallingStrategyStore, null, env);
            if(classloader != null){
                context.classLoader = classloader;
            }else{
                context.classLoader = ContentMarshallerHelper.class.getClassLoader();
            }
            ExtensionRegistry registry = PersisterHelper.buildRegistry( context, null ); 
            Header _header = PersisterHelper.readFromStreamWithHeaderPreloaded(context, registry);
            Variable parseFrom = JBPMMessages.Variable.parseFrom(_header.getPayload(), registry);
            Object value = ProtobufProcessMarshaller.unmarshallVariableValue(context, parseFrom);
            
            if(value instanceof Map){
                Map result = new HashMap();
                Map<String, Variable> variablesMap = (Map<String, Variable>)value;
                for(String key: variablesMap.keySet()){
                    result.put(key, ProtobufProcessMarshaller.unmarshallVariableValue(context, variablesMap.get(key)));
                }
                return result;
            }
            return value;
        } catch (Exception ex) { 
            ex.printStackTrace();
        } 
        return null;
    }
}
