// 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.

#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 <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
  {
    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::PhysicalDeviceProperties properties     = physicalDevice.getProperties();

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

    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::DescriptorType::eCombinedImageSampler, 1, vk::ShaderStageFlagBits::eFragment } } );
    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_PT_T );
    vk::UniqueShaderModule fragmentShaderModule =
      vk::su::createShaderModule( device, vk::ShaderStageFlagBits::eFragment, fragmentShaderText_T_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( texturedCubeData ), vk::BufferUsageFlagBits::eVertexBuffer );
    vk::su::copyToDevice( device,
                          vertexBufferData.deviceMemory,
                          texturedCubeData,
                          sizeof( texturedCubeData ) / sizeof( texturedCubeData[0] ) );

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

    vk::su::updateDescriptorSets(
      device, descriptorSet, { { vk::DescriptorType::eUniformBuffer, uniformBufferData.buffer, {} } }, 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 = vk::su::checked_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::UniquePipelineCache pipelineCache = device->createPipelineCacheUnique(
      vk::PipelineCacheCreateInfo( vk::PipelineCacheCreateFlags(), startCacheSize, startCacheData ) );

    // 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();
    vk::UniquePipeline graphicsPipeline =
      vk::su::createGraphicsPipeline( device,
                                      pipelineCache,
                                      std::make_pair( *vertexShaderModule, nullptr ),
                                      std::make_pair( *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";

    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() );

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

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

    presentQueue.presentKHR( vk::PresentInfoKHR( {}, *swapChainData.swapChain, currentBuffer.value ) );
    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 = device->getPipelineCacheData( pipelineCache.get() );

    // 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;
}