/*
 *  ******************************************************************************
 *  *
 *  *
 *  * 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
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 */

package org.eclipse.deeplearning4j.dl4jcore.datasets.iterator.tools;


import lombok.NonNull;
import org.nd4j.linalg.api.ndarray.INDArray;
import org.nd4j.linalg.dataset.api.MultiDataSet;
import org.nd4j.linalg.dataset.api.MultiDataSetPreProcessor;
import org.nd4j.linalg.dataset.api.iterator.MultiDataSetIterator;
import org.nd4j.linalg.factory.Nd4j;

import java.util.concurrent.atomic.AtomicLong;

public class MultiDataSetGenerator implements MultiDataSetIterator {

    protected final int[] shapeFeatures;
    protected final int[] shapeLabels;
    protected final long totalBatches;
    protected AtomicLong counter = new AtomicLong(0);

    public MultiDataSetGenerator(long numBatches, @NonNull int[] shapeFeatures, int[] shapeLabels) {
        this.shapeFeatures = shapeFeatures;
        this.shapeLabels = shapeLabels;
        this.totalBatches = numBatches;
    }

    public void shift() {
        counter.incrementAndGet();
    }

    @Override
    public MultiDataSet next(int num) {
        throw new UnsupportedOperationException();
    }

    @Override
    public void setPreProcessor(MultiDataSetPreProcessor preProcessor) {

    }

    @Override
    public MultiDataSetPreProcessor getPreProcessor() {
        return null;
    }

    @Override
    public boolean resetSupported() {
        return true;
    }

    @Override
    public boolean asyncSupported() {
        return true;
    }

    @Override
    public void reset() {
        counter.set(0);
    }

    @Override
    public boolean hasNext() {
        return counter.get() < totalBatches;
    }

    @Override
    public MultiDataSet next() {
        return new org.nd4j.linalg.dataset.MultiDataSet(new INDArray[]{Nd4j.create(shapeFeatures).assign(counter.get())}, new INDArray[]{Nd4j.create(shapeLabels).assign(counter.getAndIncrement())});
    }

    @Override
    public void remove() {
        throw new UnsupportedOperationException();
    }
}
