/*
 *  ******************************************************************************
 *  *
 *  *
 *  * This program and the accompanying materials are made available under the
 *  * terms of the Apache License, Version 2.0 which is available at
 *  * https://www.apache.org/licenses/LICENSE-2.0.
 *  *
 *  *  See the NOTICE file distributed with this work for additional
 *  *  information regarding copyright ownership.
 *  * 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.
 *  *
 *  * SPDX-License-Identifier: Apache-2.0
 *  *****************************************************************************
 */

package org.nd4j.common.util;

import org.apache.commons.io.FileUtils;

import java.io.*;

public class SerializationUtils {

    protected SerializationUtils() {}

    @SuppressWarnings("unchecked")
    public static <T> T readObject(File file) {
        try {
            ObjectInputStream ois = new ObjectInputStream(FileUtils.openInputStream(file));
            T ret = (T) ois.readObject();
            ois.close();
            return ret;
        } catch (Exception e) {
            throw new RuntimeException(e);
        }

    }

    /**
     * Reads an object from the given input stream
     * @param is the input stream to read from
     * @return the read object
     */
    @SuppressWarnings("unchecked")
    public static <T> T readObject(InputStream is) {
        try {
            ObjectInputStream ois = new ObjectInputStream(is);
            T ret = (T) ois.readObject();
            ois.close();
            return ret;
        } catch (Exception e) {
            throw new RuntimeException(e);
        }

    }



    /**
     * Converts the given object to a byte array
     * @param toSave the object to save
     */
    public static byte[] toByteArray(Serializable toSave) {
        try {
            ByteArrayOutputStream bos = new ByteArrayOutputStream();
            ObjectOutputStream os = new ObjectOutputStream(bos);
            os.writeObject(toSave);
            byte[] ret = bos.toByteArray();
            os.close();
            return ret;
        } catch (Exception e) {
            throw new RuntimeException(e);
        }

    }

    /**
     * Deserializes object from byte array
     * @param bytes
     * @param <T>
     * @return
     */
    public static <T> T fromByteArray(byte[] bytes) {
        return readObject(new ByteArrayInputStream(bytes));
    }

    /**
     * Deserializes object from byte array
     * @param bytes
     * @param <T>
     * @return
     */
    public static <T> T deserialize(byte[] bytes) {
        return fromByteArray(bytes);
    }

    /**
     * Deserializes object from InputStream
     * @param bytes
     * @param <T>
     * @return
     */
    public static <T> T deserialize(InputStream is) {
        return readObject(is);
    }

    /**
     * Writes the object to the output stream
     * THIS DOES NOT FLUSH THE STREAM
     * @param toSave the object to save
     * @param writeTo the output stream to write to
     */
    public static void writeObject(Serializable toSave, OutputStream writeTo) {
        try {
            ObjectOutputStream os = new ObjectOutputStream(writeTo);
            os.writeObject(toSave);
        } catch (Exception e) {
            throw new RuntimeException(e);
        }
    }

    /**
     * Writes the object to the output stream
     * THIS DOES NOT FLUSH THE STREAM
     * @param toSave the object to save
     * @param writeTo the output stream to write to
     */
    public static void serialize(Serializable object, OutputStream os) {
        writeObject(object, os);
    }

    public static void saveObject(Object toSave, File saveTo) {
        try {
            OutputStream os1 = FileUtils.openOutputStream(saveTo);
            ObjectOutputStream os = new ObjectOutputStream(os1);
            os.writeObject(toSave);
            os.flush();
            os.close();
            os1.close();
        } catch (Exception e) {
            throw new RuntimeException(e);
        }

    }
}
