// Copyright(c) 2019, NVIDIA CORPORATION. All rights reserved.
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
//     http://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.
//
// VulkanHpp Samples : OcclusionQuery
//                     Use occlusion query to determine if drawing renders any samples.

#include "../utils/geometries.hpp"
#include "../utils/math.hpp"
#include "../utils/shaders.hpp"
#include "../utils/utils.hpp"
#include "SPIRV/GlslangToSpv.h"
#include "vulkan/vulkan.hpp"

#include <iostream>
#include <thread>

static char const * AppName    = "OcclusionQuery";
static char const * EngineName = "Vulkan.hpp";

int main( int /*argc*/, char ** /*argv*/ )
{
  try
  {
    vk::UniqueInstance instance = vk::su::createInstance( AppName, EngineName, {}, vk::su::getInstanceExtensions() );
#if !defined( NDEBUG )
    vk::UniqueDebugUtilsMessengerEXT debugUtilsMessenger = vk::su::createDebugUtilsMessenger( instance );
#endif

    vk::PhysicalDevice physicalDevice = instance->enumeratePhysicalDevices().front();

    vk::su::SurfaceData surfaceData( instance, AppName, vk::Extent2D( 500, 500 ) );

    std::pair<uint32_t, uint32_t> graphicsAndPresentQueueFamilyIndex =
      vk::su::findGraphicsAndPresentQueueFamilyIndex( physicalDevice, *surfaceData.surface );
    vk::UniqueDevice device =
      vk::su::createDevice( physicalDevice, graphicsAndPresentQueueFamilyIndex.first, vk::su::getDeviceExtensions() );

    vk::UniqueCommandPool   commandPool = vk::su::createCommandPool( device, graphicsAndPresentQueueFamilyIndex.first );
    vk::UniqueCommandBuffer commandBuffer = std::move( device
                                                         ->allocateCommandBuffersUnique( vk::CommandBufferAllocateInfo(
                                                           commandPool.get(), vk::CommandBufferLevel::ePrimary, 1 ) )
                                                         .front() );

    vk::Queue graphicsQueue = device->getQueue( graphicsAndPresentQueueFamilyIndex.first, 0 );
    vk::Queue presentQueue  = device->getQueue( graphicsAndPresentQueueFamilyIndex.second, 0 );

    vk::su::SwapChainData swapChainData( physicalDevice,
                                         device,
                                         *surfaceData.surface,
                                         surfaceData.extent,
                                         vk::ImageUsageFlagBits::eColorAttachment |
                                           vk::ImageUsageFlagBits::eTransferSrc,
                                         vk::UniqueSwapchainKHR(),
                                         graphicsAndPresentQueueFamilyIndex.first,
                                         graphicsAndPresentQueueFamilyIndex.second );

    vk::su::DepthBufferData depthBufferData( physicalDevice, device, vk::Format::eD16Unorm, surfaceData.extent );

    vk::su::BufferData uniformBufferData(
      physicalDevice, device, sizeof( glm::mat4x4 ), vk::BufferUsageFlagBits::eUniformBuffer );
    vk::su::copyToDevice(
      device, uniformBufferData.deviceMemory, vk::su::createModelViewProjectionClipMatrix( surfaceData.extent ) );

    vk::UniqueDescriptorSetLayout descriptorSetLayout = vk::su::createDescriptorSetLayout(
      device, { { vk::DescriptorType::eUniformBuffer, 1, vk::ShaderStageFlagBits::eVertex } } );
    vk::UniquePipelineLayout pipelineLayout = device->createPipelineLayoutUnique(
      vk::PipelineLayoutCreateInfo( vk::PipelineLayoutCreateFlags(), *descriptorSetLayout ) );

    vk::UniqueRenderPass renderPass = vk::su::createRenderPass(
      device,
      vk::su::pickSurfaceFormat( physicalDevice.getSurfaceFormatsKHR( surfaceData.surface.get() ) ).format,
      depthBufferData.format );

    glslang::InitializeProcess();
    vk::UniqueShaderModule vertexShaderModule =
      vk::su::createShaderModule( device, vk::ShaderStageFlagBits::eVertex, vertexShaderText_PC_C );
    vk::UniqueShaderModule fragmentShaderModule =
      vk::su::createShaderModule( device, vk::ShaderStageFlagBits::eFragment, fragmentShaderText_C_C );
    glslang::FinalizeProcess();

    std::vector<vk::UniqueFramebuffer> framebuffers = vk::su::createFramebuffers(
      device, renderPass, swapChainData.imageViews, depthBufferData.imageView, surfaceData.extent );

    vk::su::BufferData vertexBufferData(
      physicalDevice, device, sizeof( coloredCubeData ), vk::BufferUsageFlagBits::eVertexBuffer );
    vk::su::copyToDevice( device,
                          vertexBufferData.deviceMemory,
                          coloredCubeData,
                          sizeof( coloredCubeData ) / sizeof( coloredCubeData[0] ) );

    vk::UniqueDescriptorPool descriptorPool =
      vk::su::createDescriptorPool( device, { { vk::DescriptorType::eUniformBuffer, 1 } } );
    vk::UniqueDescriptorSet descriptorSet = std::move(
      device->allocateDescriptorSetsUnique( vk::DescriptorSetAllocateInfo( *descriptorPool, *descriptorSetLayout ) )
        .front() );

    vk::su::updateDescriptorSets(
      device, descriptorSet, { { vk::DescriptorType::eUniformBuffer, uniformBufferData.buffer, {} } }, {} );

    vk::UniquePipelineCache pipelineCache    = device->createPipelineCacheUnique( vk::PipelineCacheCreateInfo() );
    vk::UniquePipeline      graphicsPipeline = vk::su::createGraphicsPipeline(
      device,
      pipelineCache,
      std::make_pair( *vertexShaderModule, nullptr ),
      std::make_pair( *fragmentShaderModule, nullptr ),
      sizeof( coloredCubeData[0] ),
      { { vk::Format::eR32G32B32A32Sfloat, 0 }, { vk::Format::eR32G32B32A32Sfloat, 16 } },
      vk::FrontFace::eClockwise,
      true,
      pipelineLayout,
      renderPass );

    /* VULKAN_KEY_START */

    vk::UniqueSemaphore imageAcquiredSemaphore =
      device->createSemaphoreUnique( vk::SemaphoreCreateInfo( vk::SemaphoreCreateFlags() ) );

    // Get the index of the next available swapchain image:
    vk::ResultValue<uint32_t> currentBuffer =
      device->acquireNextImageKHR( swapChainData.swapChain.get(), UINT64_MAX, imageAcquiredSemaphore.get(), nullptr );
    assert( currentBuffer.result == vk::Result::eSuccess );
    assert( currentBuffer.value < framebuffers.size() );

    /* Allocate a uniform buffer that will take query results. */
    vk::UniqueBuffer queryResultBuffer = device->createBufferUnique(
      vk::BufferCreateInfo( vk::BufferCreateFlags(),
                            4 * sizeof( uint64_t ),
                            vk::BufferUsageFlagBits::eUniformBuffer | vk::BufferUsageFlagBits::eTransferDst ) );

    vk::MemoryRequirements memoryRequirements = device->getBufferMemoryRequirements( queryResultBuffer.get() );
    uint32_t               memoryTypeIndex =
      vk::su::findMemoryType( physicalDevice.getMemoryProperties(),
                              memoryRequirements.memoryTypeBits,
                              vk::MemoryPropertyFlagBits::eHostVisible | vk::MemoryPropertyFlagBits::eHostCoherent );
    vk::UniqueDeviceMemory queryResultMemory =
      device->allocateMemoryUnique( vk::MemoryAllocateInfo( memoryRequirements.size, memoryTypeIndex ) );

    device->bindBufferMemory( queryResultBuffer.get(), queryResultMemory.get(), 0 );

    vk::UniqueQueryPool queryPool = device->createQueryPoolUnique( vk::QueryPoolCreateInfo(
      vk::QueryPoolCreateFlags(), vk::QueryType::eOcclusion, 2, vk::QueryPipelineStatisticFlags() ) );

    commandBuffer->begin( vk::CommandBufferBeginInfo( vk::CommandBufferUsageFlags() ) );
    commandBuffer->resetQueryPool( queryPool.get(), 0, 2 );

    std::array<vk::ClearValue, 2> clearValues;
    clearValues[0].color        = vk::ClearColorValue( std::array<float, 4>( { { 0.2f, 0.2f, 0.2f, 0.2f } } ) );
    clearValues[1].depthStencil = vk::ClearDepthStencilValue( 1.0f, 0 );
    commandBuffer->beginRenderPass( vk::RenderPassBeginInfo( renderPass.get(),
                                                             framebuffers[currentBuffer.value].get(),
                                                             vk::Rect2D( vk::Offset2D(), surfaceData.extent ),
                                                             clearValues ),
                                    vk::SubpassContents::eInline );

    commandBuffer->bindPipeline( vk::PipelineBindPoint::eGraphics, graphicsPipeline.get() );
    commandBuffer->bindDescriptorSets(
      vk::PipelineBindPoint::eGraphics, pipelineLayout.get(), 0, descriptorSet.get(), {} );

    commandBuffer->bindVertexBuffers( 0, *vertexBufferData.buffer, { 0 } );
    commandBuffer->setViewport( 0,
                                vk::Viewport( 0.0f,
                                              0.0f,
                                              static_cast<float>( surfaceData.extent.width ),
                                              static_cast<float>( surfaceData.extent.height ),
                                              0.0f,
                                              1.0f ) );
    commandBuffer->setScissor( 0, vk::Rect2D( vk::Offset2D( 0, 0 ), surfaceData.extent ) );

    commandBuffer->beginQuery( queryPool.get(), 0, vk::QueryControlFlags() );
    commandBuffer->endQuery( queryPool.get(), 0 );

    commandBuffer->beginQuery( queryPool.get(), 1, vk::QueryControlFlags() );
    commandBuffer->draw( 12 * 3, 1, 0, 0 );
    commandBuffer->endRenderPass();
    commandBuffer->endQuery( queryPool.get(), 1 );

    commandBuffer->copyQueryPoolResults( queryPool.get(),
                                         0,
                                         2,
                                         queryResultBuffer.get(),
                                         0,
                                         sizeof( uint64_t ),
                                         vk::QueryResultFlagBits::e64 | vk::QueryResultFlagBits::eWait );
    commandBuffer->end();

    vk::UniqueFence drawFence = device->createFenceUnique( vk::FenceCreateInfo() );

    vk::PipelineStageFlags waitDestinationStageMask( vk::PipelineStageFlagBits::eColorAttachmentOutput );
    vk::SubmitInfo         submitInfo( *imageAcquiredSemaphore, waitDestinationStageMask, *commandBuffer );
    graphicsQueue.submit( submitInfo, drawFence.get() );

    graphicsQueue.waitIdle();

    vk::ResultValue<std::vector<uint64_t>> rv =
      device->getQueryPoolResults<uint64_t>( *queryPool,
                                   0,
                                   2,
                                   2 * sizeof( uint64_t ),
                                   sizeof( uint64_t ),
                                   vk::QueryResultFlagBits::e64 | vk::QueryResultFlagBits::eWait );
   switch ( rv.result )
    {
      case vk::Result::eSuccess: break;
      case vk::Result::eNotReady: std::cout << "vk::Device::getQueryPoolResults returned vk::Result::eNotReady !\n";
      default: assert( false );  // an unexpected result is returned !
    }

    std::cout << "vkGetQueryPoolResults data\n";
    std::cout << "samples_passed[0] = " << rv.value[0] << "\n";
    std::cout << "samples_passed[1] = " << rv.value[1] << "\n";

    /* Read back query result from buffer */
    uint64_t * samplesPassedPtr = static_cast<uint64_t *>(
      device->mapMemory( queryResultMemory.get(), 0, memoryRequirements.size, vk::MemoryMapFlags() ) );

    std::cout << "vkCmdCopyQueryPoolResults data\n";
    std::cout << "samples_passed[0] = " << samplesPassedPtr[0] << "\n";
    std::cout << "samples_passed[1] = " << samplesPassedPtr[1] << "\n";

    device->unmapMemory( queryResultMemory.get() );

    while ( vk::Result::eTimeout == device->waitForFences( drawFence.get(), VK_TRUE, vk::su::FenceTimeout ) )
      ;

    vk::Result result = presentQueue.presentKHR( vk::PresentInfoKHR( {}, *swapChainData.swapChain, currentBuffer.value ) );
    switch ( result )
    {
      case vk::Result::eSuccess: break;
      case vk::Result::eSuboptimalKHR: std::cout << "vk::Queue::presentKHR returned vk::Result::eSuboptimalKHR !\n";
      default: assert( false );  // an unexpected result is returned !
    }
    std::this_thread::sleep_for( std::chrono::milliseconds( 1000 ) );

    /* VULKAN_KEY_END */
  }
  catch ( vk::SystemError & err )
  {
    std::cout << "vk::SystemError: " << err.what() << std::endl;
    exit( -1 );
  }
  catch ( std::exception & err )
  {
    std::cout << "std::exception: " << err.what() << std::endl;
    exit( -1 );
  }
  catch ( ... )
  {
    std::cout << "unknown error\n";
    exit( -1 );
  }
  return 0;
}