// 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 : PipelineCache
//                     This sample tries to save and reuse pipeline cache data between runs.

#if defined( _MSC_VER )
// no need to ignore any warnings with MSVC
#elif defined( __clang__ )
#  pragma clang diagnostic ignored "-Wmissing-braces"
#elif defined( __GNUC__ )
#else
// unknow compiler... just ignore the warnings for yourselves ;)
#endif

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

#include <fstream>
#include <iomanip>
#include <thread>

// For timestamp code (getMilliseconds)
#ifdef WIN32
#  include <Windows.h>
#else
#  include <sys/time.h>
#endif

typedef unsigned long long timestamp_t;
timestamp_t                getMilliseconds()
{
#ifdef WIN32
  LARGE_INTEGER frequency;
  BOOL          useQPC = QueryPerformanceFrequency( &frequency );
  if ( useQPC )
  {
    LARGE_INTEGER now;
    QueryPerformanceCounter( &now );
    return ( 1000LL * now.QuadPart ) / frequency.QuadPart;
  }
  else
  {
    return GetTickCount();
  }
#else
  struct timeval now;
  gettimeofday( &now, NULL );
  return ( now.tv_usec / 1000 ) + (timestamp_t)now.tv_sec;
#endif
}

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

int main( int /*argc*/, char ** /*argv*/ )
{
  try
  {
    std::unique_ptr<vk::raii::Context>  context = vk::raii::su::make_unique<vk::raii::Context>();
    std::unique_ptr<vk::raii::Instance> instance =
      vk::raii::su::makeUniqueInstance( *context, AppName, EngineName, {}, vk::su::getInstanceExtensions() );
#if !defined( NDEBUG )
    std::unique_ptr<vk::raii::DebugUtilsMessengerEXT> debugUtilsMessenger =
      vk::raii::su::makeUniqueDebugUtilsMessengerEXT( *instance );
#endif

    std::unique_ptr<vk::raii::PhysicalDevice> physicalDevice = vk::raii::su::makeUniquePhysicalDevice( *instance );
    vk::PhysicalDeviceProperties              properties     = physicalDevice->getProperties();

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

    std::pair<uint32_t, uint32_t> graphicsAndPresentQueueFamilyIndex =
      vk::raii::su::findGraphicsAndPresentQueueFamilyIndex( *physicalDevice, *surfaceData.surface );
    std::unique_ptr<vk::raii::Device> device = vk::raii::su::makeUniqueDevice(
      *physicalDevice, graphicsAndPresentQueueFamilyIndex.first, vk::su::getDeviceExtensions() );

    std::unique_ptr<vk::raii::CommandPool> commandPool =
      vk::raii::su::makeUniqueCommandPool( *device, graphicsAndPresentQueueFamilyIndex.first );
    std::unique_ptr<vk::raii::CommandBuffer> commandBuffer =
      vk::raii::su::makeUniqueCommandBuffer( *device, *commandPool );

    std::unique_ptr<vk::raii::Queue> graphicsQueue =
      vk::raii::su::make_unique<vk::raii::Queue>( *device, graphicsAndPresentQueueFamilyIndex.first, 0 );
    std::unique_ptr<vk::raii::Queue> presentQueue =
      vk::raii::su::make_unique<vk::raii::Queue>( *device, graphicsAndPresentQueueFamilyIndex.second, 0 );

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

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

    vk::raii::su::TextureData textureData( *physicalDevice, *device );

    commandBuffer->begin( vk::CommandBufferBeginInfo() );
    textureData.setImage( *commandBuffer, vk::su::MonochromeImageGenerator( { 118, 185, 0 } ) );

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

    std::unique_ptr<vk::raii::DescriptorSetLayout> descriptorSetLayout = vk::raii::su::makeUniqueDescriptorSetLayout(
      *device,
      { { vk::DescriptorType::eUniformBuffer, 1, vk::ShaderStageFlagBits::eVertex },
        { vk::DescriptorType::eCombinedImageSampler, 1, vk::ShaderStageFlagBits::eFragment } } );
    std::unique_ptr<vk::raii::PipelineLayout> pipelineLayout =
      vk::raii::su::makeUniquePipelineLayout( *device, *descriptorSetLayout );

    vk::Format colorFormat =
      vk::su::pickSurfaceFormat( physicalDevice->getSurfaceFormatsKHR( **surfaceData.surface ) ).format;
    std::unique_ptr<vk::raii::RenderPass> renderPass =
      vk::raii::su::makeUniqueRenderPass( *device, colorFormat, depthBufferData.format );

    glslang::InitializeProcess();
    std::unique_ptr<vk::raii::ShaderModule> vertexShaderModule =
      vk::raii::su::makeUniqueShaderModule( *device, vk::ShaderStageFlagBits::eVertex, vertexShaderText_PT_T );
    std::unique_ptr<vk::raii::ShaderModule> fragmentShaderModule =
      vk::raii::su::makeUniqueShaderModule( *device, vk::ShaderStageFlagBits::eFragment, fragmentShaderText_T_C );
    glslang::FinalizeProcess();

    std::vector<std::unique_ptr<vk::raii::Framebuffer>> framebuffers = vk::raii::su::makeUniqueFramebuffers(
      *device, *renderPass, swapChainData.imageViews, depthBufferData.imageView, surfaceData.extent );

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

    std::unique_ptr<vk::raii::DescriptorPool> descriptorPool = vk::raii::su::makeUniqueDescriptorPool(
      *device, { { vk::DescriptorType::eUniformBuffer, 1 }, { vk::DescriptorType::eCombinedImageSampler, 1 } } );
    std::unique_ptr<vk::raii::DescriptorSet> descriptorSet =
      vk::raii::su::makeUniqueDescriptorSet( *device, *descriptorPool, *descriptorSetLayout );

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

    /* VULKAN_KEY_START */

    // Check disk for existing cache data
    size_t startCacheSize = 0;
    char * startCacheData = nullptr;

    std::string   cacheFileName = "pipeline_cache_data.bin";
    std::ifstream readCacheStream( cacheFileName, std::ios_base::in | std::ios_base::binary );
    if ( readCacheStream.good() )
    {
      // Determine cache size
      readCacheStream.seekg( 0, readCacheStream.end );
      startCacheSize = static_cast<size_t>( readCacheStream.tellg() );
      readCacheStream.seekg( 0, readCacheStream.beg );

      // Allocate memory to hold the initial cache data
      startCacheData = (char *)std::malloc( startCacheSize );

      // Read the data into our buffer
      readCacheStream.read( startCacheData, startCacheSize );

      // Clean up and print results
      readCacheStream.close();
      std::cout << "  Pipeline cache HIT!\n";
      std::cout << "  cacheData loaded from " << cacheFileName << "\n";
    }
    else
    {
      // No cache found on disk
      std::cout << "  Pipeline cache miss!\n";
    }

    if ( startCacheData != nullptr )
    {
      // Check for cache validity
      //
      // TODO: Update this as the spec evolves. The fields are not defined by the header.
      //
      // The code below supports SDK 0.10 Vulkan spec, which contains the following table:
      //
      // Offset	 Size            Meaning
      // ------    ------------    ------------------------------------------------------------------
      //      0               4    a device ID equal to VkPhysicalDeviceProperties::DeviceId written
      //                           as a stream of bytes, with the least significant byte first
      //
      //      4    VK_UUID_SIZE    a pipeline cache ID equal to VkPhysicalDeviceProperties::pipelineCacheUUID
      //
      //
      // The code must be updated for latest Vulkan spec, which contains the following table:
      //
      // Offset	 Size            Meaning
      // ------    ------------    ------------------------------------------------------------------
      //      0               4    length in bytes of the entire pipeline cache header written as a
      //                           stream of bytes, with the least significant byte first
      //      4               4    a VkPipelineCacheHeaderVersion value written as a stream of bytes,
      //                           with the least significant byte first
      //      8               4    a vendor ID equal to VkPhysicalDeviceProperties::vendorID written
      //                           as a stream of bytes, with the least significant byte first
      //     12               4    a device ID equal to VkPhysicalDeviceProperties::deviceID written
      //                           as a stream of bytes, with the least significant byte first
      //     16    VK_UUID_SIZE    a pipeline cache ID equal to VkPhysicalDeviceProperties::pipelineCacheUUID

      uint32_t headerLength                    = 0;
      uint32_t cacheHeaderVersion              = 0;
      uint32_t vendorID                        = 0;
      uint32_t deviceID                        = 0;
      uint8_t  pipelineCacheUUID[VK_UUID_SIZE] = {};

      memcpy( &headerLength, (uint8_t *)startCacheData + 0, 4 );
      memcpy( &cacheHeaderVersion, (uint8_t *)startCacheData + 4, 4 );
      memcpy( &vendorID, (uint8_t *)startCacheData + 8, 4 );
      memcpy( &deviceID, (uint8_t *)startCacheData + 12, 4 );
      memcpy( pipelineCacheUUID, (uint8_t *)startCacheData + 16, VK_UUID_SIZE );

      // Check each field and report bad values before freeing existing cache
      bool badCache = false;

      if ( headerLength <= 0 )
      {
        badCache = true;
        std::cout << "  Bad header length in " << cacheFileName << ".\n";
        std::cout << "    Cache contains: " << std::hex << std::setw( 8 ) << headerLength << "\n";
      }

      if ( cacheHeaderVersion != VK_PIPELINE_CACHE_HEADER_VERSION_ONE )
      {
        badCache = true;
        std::cout << "  Unsupported cache header version in " << cacheFileName << ".\n";
        std::cout << "    Cache contains: " << std::hex << std::setw( 8 ) << cacheHeaderVersion << "\n";
      }

      if ( vendorID != properties.vendorID )
      {
        badCache = true;
        std::cout << "  Vender ID mismatch in " << cacheFileName << ".\n";
        std::cout << "    Cache contains: " << std::hex << std::setw( 8 ) << vendorID << "\n";
        std::cout << "    Driver expects: " << std::hex << std::setw( 8 ) << properties.vendorID << "\n";
      }

      if ( deviceID != properties.deviceID )
      {
        badCache = true;
        std::cout << "  Device ID mismatch in " << cacheFileName << ".\n";
        std::cout << "    Cache contains: " << std::hex << std::setw( 8 ) << deviceID << "\n";
        std::cout << "    Driver expects: " << std::hex << std::setw( 8 ) << properties.deviceID << "\n";
      }

      if ( memcmp( pipelineCacheUUID, properties.pipelineCacheUUID, sizeof( pipelineCacheUUID ) ) != 0 )
      {
        badCache = true;
        std::cout << "  UUID mismatch in " << cacheFileName << ".\n";
        std::cout << "    Cache contains: " << vk::su::UUID( pipelineCacheUUID ) << "\n";
        std::cout << "    Driver expects: " << vk::su::UUID( properties.pipelineCacheUUID ) << "\n";
      }

      if ( badCache )
      {
        // Don't submit initial cache data if any version info is incorrect
        free( startCacheData );
        startCacheSize = 0;
        startCacheData = nullptr;

        // And clear out the old cache file for use in next run
        std::cout << "  Deleting cache entry " << cacheFileName << " to repopulate.\n";
        if ( remove( cacheFileName.c_str() ) != 0 )
        {
          std::cerr << "Reading error";
          exit( EXIT_FAILURE );
        }
      }
    }

    // Feed the initial cache data into cache creation
    vk::PipelineCacheCreateInfo              pipelineCacheCreateInfo( {}, startCacheSize, startCacheData );
    std::unique_ptr<vk::raii::PipelineCache> pipelineCache =
      vk::raii::su::make_unique<vk::raii::PipelineCache>( *device, pipelineCacheCreateInfo );

    // Free our initialData now that pipeline cache has been created
    free( startCacheData );
    startCacheData = NULL;

    // Time (roughly) taken to create the graphics pipeline
    timestamp_t                         start            = getMilliseconds();
    std::unique_ptr<vk::raii::Pipeline> graphicsPipeline = vk::raii::su::makeUniqueGraphicsPipeline(
      *device,
      *pipelineCache,
      *vertexShaderModule,
      nullptr,
      *fragmentShaderModule,
      nullptr,
      sizeof( texturedCubeData[0] ),
      { { vk::Format::eR32G32B32A32Sfloat, 0 }, { vk::Format::eR32G32Sfloat, 16 } },
      vk::FrontFace::eClockwise,
      true,
      *pipelineLayout,
      *renderPass );
    timestamp_t elapsed = getMilliseconds() - start;
    std::cout << "  vkCreateGraphicsPipeline time: " << (double)elapsed << " ms\n";

    std::unique_ptr<vk::raii::Semaphore> imageAcquiredSemaphore =
      vk::raii::su::make_unique<vk::raii::Semaphore>( *device, vk::SemaphoreCreateInfo() );

    // Get the index of the next available swapchain image:
    vk::Result result;
    uint32_t   imageIndex;
    std::tie( result, imageIndex ) =
      swapChainData.swapChain->acquireNextImage( vk::su::FenceTimeout, **imageAcquiredSemaphore );
    assert( result == vk::Result::eSuccess );
    assert( imageIndex < swapChainData.images.size() );

    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, **framebuffers[imageIndex], vk::Rect2D( vk::Offset2D(), surfaceData.extent ), clearValues ),
      vk::SubpassContents::eInline );
    commandBuffer->bindPipeline( vk::PipelineBindPoint::eGraphics, **graphicsPipeline );
    commandBuffer->bindDescriptorSets( vk::PipelineBindPoint::eGraphics, **pipelineLayout, 0, { **descriptorSet }, {} );

    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->draw( 12 * 3, 1, 0, 0 );
    commandBuffer->endRenderPass();
    commandBuffer->end();

    std::unique_ptr<vk::raii::Fence> drawFence = vk::raii::su::make_unique<vk::raii::Fence>( *device, vk::FenceCreateInfo() );

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

    while ( vk::Result::eTimeout == device->waitForFences( { **drawFence }, VK_TRUE, vk::su::FenceTimeout ) )
      ;

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

    // Store away the cache that we've populated.  This could conceivably happen
    // earlier, depends on when the pipeline cache stops being populated
    // internally.
    std::vector<uint8_t> endCacheData = pipelineCache->getData();

    // Write the file to disk, overwriting whatever was there
    std::ofstream writeCacheStream( cacheFileName, std::ios_base::out | std::ios_base::binary );
    if ( writeCacheStream.good() )
    {
      writeCacheStream.write( reinterpret_cast<char const *>( endCacheData.data() ), endCacheData.size() );
      writeCacheStream.close();
      std::cout << "  cacheData written to " << cacheFileName << "\n";
    }
    else
    {
      // Something bad happened
      std::cout << "  Unable to write cache data to disk!\n";
    }

    /* 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;
}