/*
 *  ******************************************************************************
 *  *
 *  *
 *  * 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.transform.transform.doubletransform;

import lombok.Data;
import org.datavec.api.writable.DoubleWritable;
import org.datavec.api.writable.Writable;
import com.fasterxml.jackson.annotation.JsonProperty;

@Data
public class StandardizeNormalizer extends BaseDoubleTransform {

    protected final double mean;
    protected final double stdev;

    public StandardizeNormalizer(@JsonProperty("columnName") String columnName, @JsonProperty("mean") double mean,
                    @JsonProperty("stdev") double stdev) {
        super(columnName);
        this.mean = mean;
        this.stdev = stdev;
    }


    @Override
    public Writable map(Writable writable) {
        double val = writable.toDouble();
        return new DoubleWritable((val - mean) / stdev);
    }

    @Override
    public String toString() {
        return "StandardizeNormalizer(mean=" + mean + ",stdev=" + stdev + ")";
    }

    /**
     * Transform an object
     * in to another object
     *
     * @param input the record to transform
     * @return the transformed writable
     */
    @Override
    public Object map(Object input) {
        Number n = (Number) input;
        double val = n.doubleValue();
        return new DoubleWritable((val - mean) / stdev);
    }
}
