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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.
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 *  *  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.nn.params;

import org.deeplearning4j.nn.api.ParamInitializer;
import org.deeplearning4j.nn.conf.NeuralNetConfiguration;
import org.deeplearning4j.nn.conf.layers.Layer;
import org.deeplearning4j.nn.conf.layers.misc.FrozenLayer;
import org.deeplearning4j.nn.conf.layers.misc.FrozenLayerWithBackprop;
import org.nd4j.linalg.api.ndarray.INDArray;

import java.util.Collections;
import java.util.List;
import java.util.Map;

public class FrozenLayerWithBackpropParamInitializer implements ParamInitializer {

    private static final FrozenLayerWithBackpropParamInitializer INSTANCE = new FrozenLayerWithBackpropParamInitializer();

    public static FrozenLayerWithBackpropParamInitializer getInstance() {
        return INSTANCE;
    }

    @Override
    public long numParams(NeuralNetConfiguration conf) {
        return numParams(conf.getLayer());
    }

    @Override
    public long numParams(Layer layer) {
        FrozenLayerWithBackprop fl = (FrozenLayerWithBackprop) layer;
        ParamInitializer initializer = fl.getUnderlying().initializer();
        return initializer.numParams(fl.getUnderlying());
    }

    @Override
    public List<String> paramKeys(Layer layer) {
        return Collections.emptyList();
    }

    @Override
    public List<String> weightKeys(Layer layer) {
        return Collections.emptyList();
    }

    @Override
    public List<String> biasKeys(Layer layer) {
        return Collections.emptyList();
    }

    @Override
    public boolean isWeightParam(Layer layer, String key) {
        return false;
    }

    @Override
    public boolean isBiasParam(Layer layer, String key) {
        return false;
    }

    @Override
    public Map<String, INDArray> init(NeuralNetConfiguration conf, INDArray paramsView, boolean initializeParams) {
        FrozenLayerWithBackprop fl = (FrozenLayerWithBackprop) conf.getLayer();
        Layer innerLayer = fl.getUnderlying();
        ParamInitializer initializer = innerLayer.initializer();
        conf.setLayer(innerLayer);
        Map<String, INDArray> m = initializer.init(conf, paramsView, initializeParams);
        conf.setLayer(fl);

        return m;
    }

    @Override
    public Map<String, INDArray> getGradientsFromFlattened(NeuralNetConfiguration conf, INDArray gradientView) {
        FrozenLayerWithBackprop fl = (FrozenLayerWithBackprop) conf.getLayer();
        Layer innerLayer = fl.getUnderlying();
        ParamInitializer initializer = innerLayer.initializer();
        conf.setLayer(innerLayer);
        Map<String, INDArray> m = initializer.getGradientsFromFlattened(conf, gradientView);
        conf.setLayer(fl);
        return m;
    }
}
