// 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 "vulkan/vulkan.hpp"
#include "SPIRV/GlslangToSpv.h"
#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(), 1, &descriptorSetLayout.get()));

    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, 1, &*descriptorSetLayout)).front());

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

    vk::ClearValue clearValues[2];
    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), 2, 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(1, &imageAcquiredSemaphore.get(), &waitDestinationStageMask, 1, &commandBuffer.get());
    graphicsQueue.submit(submitInfo, drawFence.get());

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

    presentQueue.presentKHR(vk::PresentInfoKHR(0, nullptr, 1, &swapChainData.swapChain.get(), &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::runtime_error& err)
  {
    std::cout << "std::runtime_error: " << err.what() << std::endl;
    exit(-1);
  }
  catch (...)
  {
    std::cout << "unknown error\n";
    exit(-1);
  }
  return 0;
}