/*******************************************************************************
 * Copyright (c) 2015-2018 Skymind, Inc.
 *
 * 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.
 *
 * 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.deeplearning4j.nn.conf.distribution;

import lombok.Data;
import lombok.EqualsAndHashCode;
import org.nd4j.shade.jackson.annotation.JsonCreator;
import org.nd4j.shade.jackson.annotation.JsonProperty;

/**
 * A normal (Gaussian) distribution, with two parameters: mean and standard deviation
 *
 */
@EqualsAndHashCode(callSuper = false)
@Data
public class NormalDistribution extends Distribution {

    private double mean, std;

    /**
     * Create a normal distribution
     * with the given mean and std
     *
     * @param mean the mean
     * @param std  the standard deviation
     */
    @JsonCreator
    public NormalDistribution(@JsonProperty("mean") double mean, @JsonProperty("std") double std) {
        this.mean = mean;
        this.std = std;
    }

    public double getMean() {
        return mean;
    }

    public void setMean(double mean) {
        this.mean = mean;
    }

    public double getStd() {
        return std;
    }

    public void setStd(double std) {
        this.std = std;
    }

    @Override
    public int hashCode() {
        final int prime = 31;
        int result = 1;
        long temp;
        temp = Double.doubleToLongBits(mean);
        result = prime * result + (int) (temp ^ (temp >>> 32));
        temp = Double.doubleToLongBits(std);
        result = prime * result + (int) (temp ^ (temp >>> 32));
        return result;
    }

    @Override
    public boolean equals(Object obj) {
        if (this == obj)
            return true;
        if (obj == null)
            return false;
        if (getClass() != obj.getClass())
            return false;
        NormalDistribution other = (NormalDistribution) obj;
        if (Double.doubleToLongBits(mean) != Double.doubleToLongBits(other.mean))
            return false;
        if (Double.doubleToLongBits(std) != Double.doubleToLongBits(other.std))
            return false;
        return true;
    }

    public String toString() {
        return "NormalDistribution(" + "mean=" + mean + ", std=" + std + ')';
    }
}
