/*
 *  ******************************************************************************
 *  *
 *  *
 *  * 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.datavec.api.writable;

import org.datavec.api.transform.metadata.NDArrayMetaData;
import org.junit.jupiter.api.Tag;
import org.junit.jupiter.api.Test;
import org.nd4j.common.tests.BaseND4JTest;
import org.nd4j.common.tests.tags.TagNames;
import org.nd4j.linalg.api.buffer.DataType;
import org.nd4j.linalg.api.ndarray.INDArray;
import org.nd4j.linalg.factory.Nd4j;

import java.io.*;

import static org.junit.jupiter.api.Assertions.*;
@Tag(TagNames.JAVA_ONLY)
@Tag(TagNames.FILE_IO)
public class TestNDArrayWritableAndSerialization extends BaseND4JTest {

    @Test
    public void testIsValid() {

        NDArrayMetaData meta = new NDArrayMetaData("col", new long[] {1, 10});

        NDArrayWritable valid = new NDArrayWritable(Nd4j.create(1, 10));
        NDArrayWritable invalid = new NDArrayWritable(Nd4j.create(1, 5));
        NDArrayWritable invalid2 = new NDArrayWritable(null);


        assertTrue(meta.isValid(valid));
        assertFalse(meta.isValid(invalid));
        assertFalse(meta.isValid(invalid2));

        assertTrue(meta.isValid(valid.get()));
        assertFalse(meta.isValid(invalid.get()));
        assertFalse(meta.isValid(invalid2.get()));
    }

    @Test
    public void testWritableSerializationSingle() throws Exception {

        INDArray arrC = Nd4j.rand(DataType.DOUBLE,'c',new long[] {1, 10});

        ByteArrayOutputStream baos = new ByteArrayOutputStream();
        DataOutput da = new DataOutputStream(baos);

        NDArrayWritable wC = new NDArrayWritable(arrC);
        wC.write(da);

        byte[] b = baos.toByteArray();

        NDArrayWritable w2C = new NDArrayWritable();

        ByteArrayInputStream bais = new ByteArrayInputStream(b);
        DataInput din = new DataInputStream(bais);

        w2C.readFields(din);


        assertEquals(arrC, w2C.get());
    }

    @Test
    public void testWritableSerialization() throws Exception {

        INDArray arrC = Nd4j.rand(DataType.DOUBLE,'c',new long[] {10, 20});
        INDArray arrF = Nd4j.rand(DataType.DOUBLE, 'f',new long[] {10, 20});


        ByteArrayOutputStream baos = new ByteArrayOutputStream();
        DataOutput da = new DataOutputStream(baos);

        NDArrayWritable wC = new NDArrayWritable(arrC);
        NDArrayWritable wF = new NDArrayWritable(arrF);

        wC.write(da);
        wF.write(da);

        byte[] b = baos.toByteArray();

        NDArrayWritable w2C = new NDArrayWritable();
        NDArrayWritable w2F = new NDArrayWritable();

        ByteArrayInputStream bais = new ByteArrayInputStream(b);
        DataInput din = new DataInputStream(bais);

        w2C.readFields(din);
        w2F.readFields(din);


        assertEquals(arrC, w2C.get());
        assertEquals(arrF, w2F.get());
    }

    @Test
    public void testWritableEqualsHashCodeOrdering() throws Exception {
        //NDArrayWritable implements WritableComparable - we need to make sure this operates as expected...

        //First: check C vs. F order, same contents
        INDArray arrC = Nd4j.rand(DataType.DOUBLE,'c',new long[] {10, 20});
        INDArray arrF = arrC.dup('f');

        NDArrayWritable wC = new NDArrayWritable(arrC);
        NDArrayWritable wF = new NDArrayWritable(arrF);

        assertEquals(wC, wF);
        assertEquals(wC.hashCode(), wF.hashCode());

        int compare = wC.compareTo(wF);
        assertEquals(0, compare);


        //Check order conventions:
        //Null first
        //Then smallest rank first
        //Then smallest length first
        //Then sort by shape
        //Then sort by contents, element-wise

        assertEquals(-1, new NDArrayWritable(null).compareTo(new NDArrayWritable(Nd4j.create(1))));
        assertEquals(-1, new NDArrayWritable(Nd4j.create(1, 1)).compareTo(new NDArrayWritable(Nd4j.create(1, 1, 1))));
        assertEquals(-1, new NDArrayWritable(Nd4j.create(1, 1)).compareTo(new NDArrayWritable(Nd4j.create(1, 2))));
        assertEquals(-1, new NDArrayWritable(Nd4j.create(1, 3)).compareTo(new NDArrayWritable(Nd4j.create(3, 1))));
        assertEquals(-1, new NDArrayWritable(Nd4j.create(new double[] {1.0, 2.0, 3.0}))
                        .compareTo(new NDArrayWritable(Nd4j.create(new double[] {1.0, 2.0, 3.1}))));

        assertEquals(1, new NDArrayWritable(Nd4j.create(1)).compareTo(new NDArrayWritable(null)));
        assertEquals(1, new NDArrayWritable(Nd4j.create(1, 1, 1)).compareTo(new NDArrayWritable(Nd4j.create(1, 1))));
        assertEquals(1, new NDArrayWritable(Nd4j.create(1, 2)).compareTo(new NDArrayWritable(Nd4j.create(1, 1))));
        assertEquals(1, new NDArrayWritable(Nd4j.create(3, 1)).compareTo(new NDArrayWritable(Nd4j.create(1, 3))));
        assertEquals(1, new NDArrayWritable(Nd4j.create(new double[] {1.0, 2.0, 3.1}))
                        .compareTo(new NDArrayWritable(Nd4j.create(new double[] {1.0, 2.0, 3.0}))));
    }

}
