/*
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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
 *  * under the License.
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package org.nd4j.linalg.api.ops.impl.layers.convolution;

import lombok.Builder;
import lombok.extern.slf4j.Slf4j;
import org.nd4j.autodiff.samediff.SDVariable;
import org.nd4j.autodiff.samediff.SameDiff;
import org.nd4j.common.base.Preconditions;
import org.nd4j.imports.NoOpNameFoundException;
import org.nd4j.linalg.api.buffer.DataType;
import org.nd4j.linalg.api.ops.impl.layers.convolution.config.Conv3DConfig;

import java.util.ArrayList;
import java.util.List;


@Slf4j
public class Conv3DDerivative extends Conv3D {

    public Conv3DDerivative() {}

    @Builder(builderMethodName = "derivativeBuilder")
    public Conv3DDerivative(SameDiff sameDiff, SDVariable[] inputFunctions, Conv3DConfig conv3DConfig) {
        super(sameDiff, inputFunctions, conv3DConfig);
    }

    @Override
    public String opName() {
        return "conv3dnew_bp";
    }

    @Override
    public String tensorflowName() {
        throw new NoOpNameFoundException("No tensorflow op name found for conv3d derivative");
    }

    @Override
    public String[] tensorflowNames() {
        throw new NoOpNameFoundException("No tensorflow op name found for conv3d derivative");
    }

    @Override
    public String onnxName() {
        throw new NoOpNameFoundException("No onnx op name found for conv3d derivative");
    }

    @Override
    public String[] onnxNames() {
        throw new NoOpNameFoundException("No onnx op name found for conv3d derivative");
    }

    @Override
    public List<SDVariable> doDiff(List<SDVariable> f1) {
        throw new UnsupportedOperationException("Unable to differentiate from a derivative op");
    }

    @Override
    public int getNumOutputs(){
        //Fwd inputs: input, weight, optional bias
        //Bwd inputs: input, input grad, weight, optional bias
        if(args().length == 4){
            return 3;   //Includes bias
        } else {
            return 2;   //No bias - only input + weight grads
        }
    }

    @Override
    public List<DataType> calculateOutputDataTypes(List<DataType> inputDataTypes){
        int n = args().length;  //Original inputs + gradient at
        Preconditions.checkState(inputDataTypes != null && inputDataTypes.size() == n, "Expected %s input data types for %s, got %s", n, getClass(), inputDataTypes);
        List<DataType> out = new ArrayList<>(n-1);
        for( int i=0; i<n-1; i++ ){
            out.add(inputDataTypes.get(i));
        }
        return out;
    }
}
