/*
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 *  * 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
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package org.deeplearning4j.earlystopping.scorecalc;

import org.deeplearning4j.earlystopping.scorecalc.base.BaseIEvaluationScoreCalculator;
import org.deeplearning4j.nn.api.Model;
import org.nd4j.evaluation.IEvaluation;
import org.nd4j.evaluation.classification.ROC;
import org.nd4j.evaluation.classification.ROCBinary;
import org.nd4j.evaluation.classification.ROCMultiClass;
import org.nd4j.linalg.dataset.api.iterator.DataSetIterator;
import org.nd4j.linalg.dataset.api.iterator.MultiDataSetIterator;

public class ROCScoreCalculator extends BaseIEvaluationScoreCalculator<Model, IEvaluation> {

    public enum ROCType {ROC, BINARY, MULTICLASS}
    public enum Metric {AUC, AUPRC};

    protected final ROCType type;
    protected final Metric metric;

    public ROCScoreCalculator(ROCType type, DataSetIterator iterator) {
        this(type, Metric.AUC, iterator);
    }

    public ROCScoreCalculator(ROCType type, MultiDataSetIterator iterator){
        this(type, Metric.AUC, iterator);
    }

    public ROCScoreCalculator(ROCType type, Metric metric, DataSetIterator iterator){
        super(iterator);
        this.type = type;
        this.metric = metric;
    }

    public ROCScoreCalculator(ROCType type, Metric metric, MultiDataSetIterator iterator){
        super(iterator);
        this.type = type;
        this.metric = metric;
    }


    @Override
    protected IEvaluation newEval() {
        switch (type){
            case ROC:
                return new ROC();
            case BINARY:
                return new ROCBinary();
            case MULTICLASS:
                return new ROCMultiClass();
            default:
                throw new IllegalStateException("Unknown type: " + type);
        }
    }

    @Override
    protected double finalScore(IEvaluation eval) {
        switch (type){
            case ROC:
                ROC r = (ROC)eval;
                return metric == Metric.AUC ? r.calculateAUC() : r.calculateAUCPR();
            case BINARY:
                ROCBinary r2 = (ROCBinary) eval;
                return metric == Metric.AUC ? r2.calculateAverageAuc() : r2.calculateAverageAUCPR();
            case MULTICLASS:
                ROCMultiClass r3 = (ROCMultiClass)eval;
                return metric == Metric.AUC ? r3.calculateAverageAUC() : r3.calculateAverageAUCPR();
            default:
                throw new IllegalStateException("Unknown type: " + type);
        }
    }

    @Override
    public boolean minimizeScore() {
        return false;   //Maximize AUC, AUPRC
    }
}
