/*
 * Copyright 2020 Red Hat, Inc. and/or its affiliates.
 *
 * 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.drools.core.marshalling.impl;

import java.io.IOException;
import java.io.ObjectInputStream;
import java.io.ObjectOutputStream;
import java.util.ArrayList;
import java.util.List;

import org.kie.api.marshalling.ObjectMarshallingStrategyAcceptor;
import org.kie.kogito.internal.process.marshalling.KogitoObjectMarshallingStrategy;

public class KogitoSerializablePlaceholderResolverStrategy implements KogitoObjectMarshallingStrategy {

    private int index;

    private ObjectMarshallingStrategyAcceptor acceptor;

    public KogitoSerializablePlaceholderResolverStrategy(ObjectMarshallingStrategyAcceptor acceptor) {
        this.acceptor = acceptor;
    }

    public int getIndex() {
        return this.index;
    }

    public void setIndex(int index) {
        this.index = index;
    }

    public Object read(ObjectInputStream os) throws IOException,
            ClassNotFoundException {
        return os.readObject();
    }

    public void write(ObjectOutputStream os,
            Object object) throws IOException {
        os.writeObject(object);
    }

    public boolean accept(Object object) {
        return acceptor.accept(object);
    }

    public byte[] marshal(Context context,
            ObjectOutputStream os,
            Object object) throws IOException {

        SerializablePlaceholderStrategyContext ctx = (SerializablePlaceholderStrategyContext) context;
        int index = ctx.data.size();
        ctx.data.add(object);
        return MarshallingHelper.intToByteArray(index);
    }

    public Object unmarshal(String dataType,
            Context context,
            ObjectInputStream is,
            byte[] object,
            ClassLoader classloader) throws IOException, ClassNotFoundException {
        SerializablePlaceholderStrategyContext ctx = (SerializablePlaceholderStrategyContext) context;
        return ctx.data.get(MarshallingHelper.byteArrayToInt(object));
    }

    public Context createContext() {
        return new SerializablePlaceholderStrategyContext();
    }

    protected static class SerializablePlaceholderStrategyContext implements Context {
        // this data map is used when marshalling out objects in order
        // to preserve graph references without cloning objects all over
        // the place.
        public List<Object> data = new ArrayList<Object>();

        @SuppressWarnings("unchecked")
        public void read(ObjectInputStream ois) throws IOException,
                ClassNotFoundException {
            this.data = (List<Object>) ois.readObject();
        }

        public void write(ObjectOutputStream oos) throws IOException {
            oos.writeObject(this.data);
        }
    }

    @Override
    public String toString() {
        return "SerializablePlaceholderResolverStrategy{" +
                "acceptor=" + acceptor +
                '}';
    }
}