/*******************************************************************************
 * 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
 ******************************************************************************/

//
// @author raver119@gmail.com
// @author Yurii Shyrma
//

#include <op_boilerplate.h>
#if NOT_EXCLUDED(OP_deconv2d)

#include <ops/declarable/CustomOperations.h>
#include <ops/declarable/helpers/convolutions.h>

namespace nd4j {
namespace ops  {

////////////////////////////////////////////////////////////////////////// 
CUSTOM_OP_IMPL(deconv2d_tf, 3, 1, false, 0, 9) {
    
    auto gradO      = INPUT_VARIABLE(2);                                                // [bS, oH, oW, oC] (NHWC) or [bS, oC, oH, oW] (NCHW), epsilon_next
    auto weights    = INPUT_VARIABLE(1);                                                // [kH, kW, iC, oC] always
    auto gradIShape = INPUT_VARIABLE(0);                                                // [4] - shape of input of conv2d (that is shape of gradI)
            
    auto gradI = OUTPUT_VARIABLE(0);                                                  // [bS, iH, iW, iC] (NHWC) or [bS, iC, iH, iW] (NCHW), epsilon

    int kH = INT_ARG(0) > 0 ? INT_ARG(0) : static_cast<int>(weights->sizeAt(0));// filter(kernel) height
    int kW = INT_ARG(1) > 0 ? INT_ARG(1) : static_cast<int>(weights->sizeAt(1));// filter(kernel) width
    int sH = INT_ARG(2);                                                        // strides height
    int sW = INT_ARG(3);                                                        // strides width
    int pH = INT_ARG(4);                                                        // paddings height
    int pW = INT_ARG(5);                                                        // paddings width
    int dH = INT_ARG(6);                                                        // dilations height
    int dW = INT_ARG(7);                                                        // dilations width
    int isSameMode = INT_ARG(8);                                                // 0-VALID, 1-SAME
    int isNCHW  = block.getIArguments()->size() > 9 ? !INT_ARG(9) : 1;          // INT_ARG(9): 1-NHWC, 0-NCHW

    const int rank = gradO->rankOf();

    REQUIRE_TRUE(weights->rankOf() == rank, 0, "CUSTOM DECONV2D_TF OP: rank of weights array must be equal to 4, but got %i instead !", weights->rankOf());
    REQUIRE_TRUE(gradIShape->rankOf() == 1, 0, "CUSTOM DECONV2D_TF OP: rank of array with output shape must be equal to 1, but got %i instead !", gradIShape->rankOf());
    REQUIRE_TRUE(gradIShape->lengthOf() == rank, 0, "CUSTOM DECONV2D_TF OP: length of array with output shape must be equal to 4, but got %i instead !", gradIShape->lengthOf());    

    // create empty conv2d input array
    NDArray input(gradO->ordering(), gradIShape->asVectorT<Nd4jLong>(), gradO->dataType(), block.launchContext());
    
                                     
    int bS, iC, iH, iW, oC, oH, oW;                             // batch size, input channels, input height/width, output channels, output height/width;
    int indIOioC, indIiH, indWoC, indWiC, indWkH, indOoH;       // corresponding indexes       
    ConvolutionUtils::getSizesAndIndexesConv2d(isNCHW, input, *gradO, bS, iC, iH, iW, oC, oH, oW, indIOioC, indIiH, indWiC, indWoC, indWkH, indOoH);
    
    int trueoH, trueoW;          // true output height, width
    ConvolutionUtils::calcOutSizePool2D(trueoH, trueoW, kH, kW, sH, sW, pH, pW, dH, dW, iH, iW, isSameMode);

    std::string expectedGradOShape   = ShapeUtils::shapeAsString(ShapeUtils::composeShapeUsingDimsAndIdx({bS,oC,trueoH,trueoW,  0,indIOioC,indOoH,indOoH+1}));
    std::string expectedWeightsShape = ShapeUtils::shapeAsString({kH, kW, iC, oC});
    REQUIRE_TRUE(expectedGradOShape == ShapeUtils::shapeAsString(gradO), 0,  "CUSTOM DECONV2D_TF OP: wrong shape of input array, basing on array with output shape expected is %s, but got %s instead !", expectedGradOShape.c_str(), ShapeUtils::shapeAsString(gradO).c_str());
    REQUIRE_TRUE(expectedWeightsShape == ShapeUtils::shapeAsString(weights), 0, "CUSTOM DECONV2D_TF OP: wrong shape of weights array, expected is %s, but got %s instead !", expectedWeightsShape.c_str(), ShapeUtils::shapeAsString(weights).c_str());

    ConvolutionUtils::conv2dBP(*block.launchContext(), &input, weights, nullptr, gradO, gradI, nullptr, nullptr, kH,kW,sH,sW,pH,pW,dH,dW,isSameMode,isNCHW);
    
    return Status::OK();
}

        DECLARE_TYPES(deconv2d_tf) {
            getOpDescriptor()
                    ->setAllowedInputTypes(nd4j::DataType::ANY)
                    ->setAllowedOutputTypes({ALL_FLOATS});
        }

DECLARE_SHAPE_FN(deconv2d_tf) {

    auto gradOShapeInfo   = inputShape->at(2);                                                // [bS, oH, oW, oC] (NHWC) or [bS, oC, oH, oW] (NCHW), epsilon_next
    auto weightsShapeInfo = inputShape->at(1);                                                // [kH, kW, iC, oC] always
    auto gradIShapeShapeInfo = inputShape->at(0);                                             // [4]

    const int rank = 4;
    
    REQUIRE_TRUE(weightsShapeInfo[0]  == rank, 0, "CUSTOM DECONV2D_TF OP: rank of weights array must be equal to %i, but got %i instead !", rank, weightsShapeInfo[0]);
    REQUIRE_TRUE(gradOShapeInfo[0]    == rank, 0, "CUSTOM DECONV2D_TF OP: rank of input array must be equal to %i, but got %i instead !", rank, gradOShapeInfo[0]);
    REQUIRE_TRUE(gradIShapeShapeInfo[0] == 1,    0, "CUSTOM DECONV2D_TF OP: rank of array with output shape must be equal to %i, but got %i instead !", 1, gradIShapeShapeInfo[0]);    
    

    const int kH = INT_ARG(0) > 0 ? INT_ARG(0) : static_cast<int>(shape::sizeAt(weightsShapeInfo, 0));// filter(kernel) height
    const int kW = INT_ARG(1) > 0 ? INT_ARG(1) : static_cast<int>(shape::sizeAt(weightsShapeInfo, 1));// filter(kernel) width
    const int sH = INT_ARG(2);                                                        // strides height
    const int sW = INT_ARG(3);                                                        // strides width
    const int pH = INT_ARG(4);                                                        // paddings height
    const int pW = INT_ARG(5);                                                        // paddings width
    const int dH = INT_ARG(6);                                                        // dilations height
    const int dW = INT_ARG(7);                                                        // dilations width
    const int isSameMode = INT_ARG(8);                                                // 0-VALID, 1-SAME
    const int isNCHW  = block.getIArguments()->size() > 9 ? !INT_ARG(9) : 1;          // INT_ARG(9): 1-NHWC, 0-NCHW

    int indIOioC, indIiH, indWoC(3), indOoH;
    if(!isNCHW) {
        indIOioC = 3; indIiH = 1; indOoH = 1;
    }
    else {        
        indIOioC = 1; indIiH = 2; indOoH = 2;
    }    

    std::vector<Nd4jLong> gradIShape = INPUT_VARIABLE(0)->template asVectorT<Nd4jLong>();

    const int bS = gradIShape[0];                          // batch size
    const int iH = gradIShape[indIiH];                     // input height
    const int iW = gradIShape[indIiH+1];                   // input width
    const int iC = gradIShape[indIOioC];                   // input channels        
    const int oC = weightsShapeInfo[indWoC+1];             // output channels
    const int oH = gradOShapeInfo[indOoH+1];               // input height
    const int oW = gradOShapeInfo[indOoH+2];               // input width

    int trueiH, trueiW;                                         // output height, width
    ConvolutionUtils::calcOutSizeDeconv2D(trueiH, trueiW, kH, kW, sH, sW, pH, pW, dH, dW, oH, oW, isSameMode);
    
    std::string expectedGradIShape = ShapeUtils::shapeAsString(ShapeUtils::composeShapeUsingDimsAndIdx({bS,iC,trueiH,trueiW,  0,indIOioC,indIiH,indIiH+1}));
    std::string expectedWeightsShape = ShapeUtils::shapeAsString({kH, kW, iC, oC});
    REQUIRE_TRUE(expectedGradIShape == ShapeUtils::shapeAsString(gradIShape), 0,  "CUSTOM DECONV2D_TF OP: wrong shape of array with output shape, expected is %s, but got %s instead !", expectedGradIShape.c_str(), ShapeUtils::shapeAsString(gradIShape).c_str());
    REQUIRE_TRUE(expectedWeightsShape == ShapeUtils::shapeAsString(weightsShapeInfo), 0, "CUSTOM DECONV2D_TF OP: wrong shape of weights array, expected is %s, but got %s instead !", expectedWeightsShape.c_str(), ShapeUtils::shapeAsString(weightsShapeInfo).c_str());
    
    Nd4jLong shape[4];
    shape[0] = bS;

    if (isNCHW) {
        shape[1] = iC;
        shape[2] = iH;
        shape[3] = iW;
    } else {
        shape[1] = iH;
        shape[2] = iW;
        shape[3] = iC;
    }

    return SHAPELIST(ConstantShapeHelper::getInstance()->createShapeInfo(ArrayOptions::dataType(weightsShapeInfo), shape::order(gradOShapeInfo), 4, shape));
}

}
}

#endif