/*
 * Copyright (c) 2017-2020 Arm Limited.
 *
 * SPDX-License-Identifier: MIT
 *
 * Permission is hereby granted, free of charge, to any person obtaining a copy
 * of this software and associated documentation files (the "Software"), to
 * deal in the Software without restriction, including without limitation the
 * rights to use, copy, modify, merge, publish, distribute, sublicense, and/or
 * sell copies of the Software, and to permit persons to whom the Software is
 * furnished to do so, subject to the following conditions:
 *
 * The above copyright notice and this permission notice shall be included in all
 * copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
 * SOFTWARE.
 */
#include "arm_compute/core/GLES_COMPUTE/kernels/GCAbsoluteDifferenceKernel.h"

#include "arm_compute/core/Error.h"
#include "arm_compute/core/GLES_COMPUTE/GCHelpers.h"
#include "arm_compute/core/GLES_COMPUTE/GCKernelLibrary.h"
#include "arm_compute/core/GLES_COMPUTE/IGCTensor.h"
#include "arm_compute/core/GLES_COMPUTE/OpenGLES.h"
#include "arm_compute/core/Helpers.h"
#include "arm_compute/core/Types.h"
#include "arm_compute/core/Validate.h"
#include "arm_compute/core/Window.h"
#include "support/StringSupport.h"

#include <set>
#include <string>

using namespace arm_compute;

GCAbsoluteDifferenceKernel::GCAbsoluteDifferenceKernel()
    : _input1(nullptr), _input2(nullptr), _output(nullptr)
{
}

void GCAbsoluteDifferenceKernel::configure(const IGCTensor *input1, const IGCTensor *input2, IGCTensor *output)
{
    ARM_COMPUTE_ERROR_ON_DATA_TYPE_CHANNEL_NOT_IN(input1, 1, DataType::U8);
    ARM_COMPUTE_ERROR_ON_DATA_TYPE_CHANNEL_NOT_IN(input2, 1, DataType::U8);
    ARM_COMPUTE_ERROR_ON_DATA_TYPE_CHANNEL_NOT_IN(output, 1, DataType::U8);
    ARM_COMPUTE_ERROR_ON_MISMATCHING_DATA_TYPES(input1, input2, output);

    _input1 = input1;
    _input2 = input2;
    _output = output;

    constexpr unsigned int num_elems_processed_per_iteration = 4;

    // Set kernel build options
    std::set<std::string> build_opts;
    build_opts.emplace("#define LOCAL_SIZE_X " + support::cpp11::to_string(1));
    build_opts.emplace("#define LOCAL_SIZE_Y " + support::cpp11::to_string(1));
    build_opts.emplace("#define LOCAL_SIZE_Z " + support::cpp11::to_string(1));

    // Create kernel
    _kernel = static_cast<GCKernel>(GCKernelLibrary::get().create_kernel("absdiff", build_opts));

    // Configure kernel window
    Window win = calculate_max_window(*input1->info(), Steps(num_elems_processed_per_iteration));

    AccessWindowRectangle input1_access(input1->info(), 0, 0, 4, 1);
    AccessWindowRectangle input2_access(input2->info(), 0, 0, 4, 1);
    AccessWindowRectangle output_access(output->info(), 0, 0, 4, 1);

    update_window_and_padding(win, input1_access, input2_access, output_access);

    ValidRegion valid_region = intersect_valid_regions(input1->info()->valid_region(),
                                                       input2->info()->valid_region());

    output_access.set_valid_region(win, valid_region);

    IGCKernel::configure(win);
}

void GCAbsoluteDifferenceKernel::run(const Window &window)
{
    ARM_COMPUTE_ERROR_ON_UNCONFIGURED_KERNEL(this);
    ARM_COMPUTE_ERROR_ON_INVALID_SUBWINDOW(IGCKernel::window(), window);

    _kernel.use();

    Window slice = window.first_slice_window_2D();
    do
    {
        unsigned int idx     = 0;
        unsigned int binding = 1; // SSBO binding starts from 1.
        add_2D_tensor_argument(idx, _input1, binding++, slice);
        add_2D_tensor_argument(idx, _input2, binding++, slice);
        add_2D_tensor_argument(idx, _output, binding++, slice);

        _kernel.update_shader_params();

        enqueue(*this, slice);
    }
    while(window.slide_window_slice_2D(slice));
}