// 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 : InputAttachment
//                     Use an input attachment to draw a yellow triangle

#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    = "InputAttachment";
static char const * EngineName = "Vulkan.hpp";

static std::string vertexShaderText = R"(
#version 450

vec2 vertices[3];

void main()
{
  vertices[0] = vec2(-1.0f, -1.0f);
  vertices[1] = vec2( 1.0f, -1.0f);
  vertices[2] = vec2( 0.0f,  1.0f);

  gl_Position = vec4(vertices[gl_VertexIndex % 3], 0.0f, 1.0f);
}
)";

// Use subpassLoad to read from input attachment
static const char * fragmentShaderText = R"(
#version 450

layout (input_attachment_index = 0, set = 0, binding = 0) uniform subpassInput inputAttachment;

layout (location = 0) out vec4 outColor;

void main()
{
  outColor = subpassLoad(inputAttachment);
}
)";
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::FormatProperties formatProperties = physicalDevice.getFormatProperties( vk::Format::eR8G8B8A8Unorm );
    if ( !( formatProperties.optimalTilingFeatures & vk::FormatFeatureFlagBits::eColorAttachment ) )
    {
      std::cout << "vk::Format::eR8G8B8A8Unorm format unsupported for input attachment\n";
      exit( -1 );
    }

    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 );

    /* VULKAN_KEY_START */

    // Create a framebuffer with 2 attachments, one the color attachment the shaders render into, and the other an input
    // attachment which will be cleared to yellow, and then used by the shaders to color the drawn triangle. Final
    // result should be a yellow triangle

    // Create the image that will be used as the input attachment
    // The image for the color attachment is the presentable image already created as part of the SwapChainData
    vk::UniqueImage inputImage = device->createImageUnique(
      vk::ImageCreateInfo( vk::ImageCreateFlags(),
                           vk::ImageType::e2D,
                           swapChainData.colorFormat,
                           vk::Extent3D( surfaceData.extent, 1 ),
                           1,
                           1,
                           vk::SampleCountFlagBits::e1,
                           vk::ImageTiling::eOptimal,
                           vk::ImageUsageFlagBits::eInputAttachment | vk::ImageUsageFlagBits::eTransferDst ) );

    vk::MemoryRequirements memoryRequirements = device->getImageMemoryRequirements( inputImage.get() );
    uint32_t               memoryTypeIndex    = vk::su::findMemoryType(
      physicalDevice.getMemoryProperties(), memoryRequirements.memoryTypeBits, vk::MemoryPropertyFlags() );
    vk::UniqueDeviceMemory inputMemory =
      device->allocateMemoryUnique( vk::MemoryAllocateInfo( memoryRequirements.size, memoryTypeIndex ) );
    device->bindImageMemory( inputImage.get(), inputMemory.get(), 0 );

    // Set the image layout to TRANSFER_DST_OPTIMAL to be ready for clear
    commandBuffer->begin( vk::CommandBufferBeginInfo() );
    vk::su::setImageLayout( commandBuffer,
                            inputImage.get(),
                            swapChainData.colorFormat,
                            vk::ImageLayout::eUndefined,
                            vk::ImageLayout::eTransferDstOptimal );

    commandBuffer->clearColorImage(
      inputImage.get(),
      vk::ImageLayout::eTransferDstOptimal,
      vk::ClearColorValue( std::array<float, 4>( { { 1.0f, 1.0f, 0.0f, 0.0f } } ) ),
      vk::ImageSubresourceRange(
        vk::ImageAspectFlagBits::eColor, 0, VK_REMAINING_MIP_LEVELS, 0, VK_REMAINING_ARRAY_LAYERS ) );

    // Set the image layout to SHADER_READONLY_OPTIMAL for use by the shaders
    vk::su::setImageLayout( commandBuffer,
                            inputImage.get(),
                            swapChainData.colorFormat,
                            vk::ImageLayout::eTransferDstOptimal,
                            vk::ImageLayout::eShaderReadOnlyOptimal );

    vk::ComponentMapping componentMapping(
      vk::ComponentSwizzle::eR, vk::ComponentSwizzle::eG, vk::ComponentSwizzle::eB, vk::ComponentSwizzle::eA );
    vk::ImageViewCreateInfo imageViewCreateInfo(
      vk::ImageViewCreateFlags(),
      inputImage.get(),
      vk::ImageViewType::e2D,
      swapChainData.colorFormat,
      componentMapping,
      vk::ImageSubresourceRange( vk::ImageAspectFlagBits::eColor, 0, 1, 0, 1 ) );
    vk::UniqueImageView inputAttachmentView = device->createImageViewUnique( imageViewCreateInfo );

    vk::DescriptorSetLayoutBinding layoutBinding(
      0, vk::DescriptorType::eInputAttachment, 1, vk::ShaderStageFlagBits::eFragment );
    vk::UniqueDescriptorSetLayout descriptorSetLayout = device->createDescriptorSetLayoutUnique(
      vk::DescriptorSetLayoutCreateInfo( vk::DescriptorSetLayoutCreateFlags(), layoutBinding ) );

    vk::UniquePipelineLayout pipelineLayout = device->createPipelineLayoutUnique(
      vk::PipelineLayoutCreateInfo( vk::PipelineLayoutCreateFlags(), *descriptorSetLayout ) );

    std::array<vk::AttachmentDescription, 2> attachments = {
      // First attachment is the color attachment - clear at the beginning of the renderpass and transition layout to
      // PRESENT_SRC_KHR at the end of renderpass
      vk::AttachmentDescription( vk::AttachmentDescriptionFlags(),
                                 swapChainData.colorFormat,
                                 vk::SampleCountFlagBits::e1,
                                 vk::AttachmentLoadOp::eClear,
                                 vk::AttachmentStoreOp::eStore,
                                 vk::AttachmentLoadOp::eDontCare,
                                 vk::AttachmentStoreOp::eDontCare,
                                 vk::ImageLayout::eUndefined,
                                 vk::ImageLayout::ePresentSrcKHR ),
      // Second attachment is input attachment.  Once cleared it should have width*height yellow pixels.
      // Doing a subpassLoad in the fragment shader should give the shader the color at the fragments x,y location from
      // the input attachment
      vk::AttachmentDescription( vk::AttachmentDescriptionFlags(),
                                 swapChainData.colorFormat,
                                 vk::SampleCountFlagBits::e1,
                                 vk::AttachmentLoadOp::eLoad,
                                 vk::AttachmentStoreOp::eDontCare,
                                 vk::AttachmentLoadOp::eDontCare,
                                 vk::AttachmentStoreOp::eDontCare,
                                 vk::ImageLayout::eShaderReadOnlyOptimal,
                                 vk::ImageLayout::eShaderReadOnlyOptimal )
    };
    vk::AttachmentReference colorReference( 0, vk::ImageLayout::eColorAttachmentOptimal );
    vk::AttachmentReference inputReference( 1, vk::ImageLayout::eShaderReadOnlyOptimal );
    vk::SubpassDescription  subPass(
      vk::SubpassDescriptionFlags(), vk::PipelineBindPoint::eGraphics, inputReference, colorReference );
    vk::UniqueRenderPass renderPass =
      device->createRenderPassUnique( vk::RenderPassCreateInfo( vk::RenderPassCreateFlags(), attachments, subPass ) );

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

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

    vk::DescriptorPoolSize   poolSize( vk::DescriptorType::eInputAttachment, 1 );
    vk::UniqueDescriptorPool descriptorPool = device->createDescriptorPoolUnique(
      vk::DescriptorPoolCreateInfo( vk::DescriptorPoolCreateFlagBits::eFreeDescriptorSet, 1, poolSize ) );

    vk::UniqueDescriptorSet descriptorSet = std::move(
      device->allocateDescriptorSetsUnique( vk::DescriptorSetAllocateInfo( *descriptorPool, *descriptorSetLayout ) )
        .front() );

    vk::DescriptorImageInfo inputImageInfo(
      nullptr, inputAttachmentView.get(), vk::ImageLayout::eShaderReadOnlyOptimal );
    vk::WriteDescriptorSet writeDescriptorSet(
      descriptorSet.get(), 0, 0, vk::DescriptorType::eInputAttachment, inputImageInfo );
    device->updateDescriptorSets( vk::ArrayProxy<const vk::WriteDescriptorSet>( 1, &writeDescriptorSet ), nullptr );

    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 ),
                                      0,
                                      {},
                                      vk::FrontFace::eClockwise,
                                      false,
                                      pipelineLayout,
                                      renderPass );

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

    vk::ResultValue<uint32_t> nexImage = device->acquireNextImage2KHR(
      vk::AcquireNextImageInfoKHR( swapChainData.swapChain.get(), UINT64_MAX, imageAcquiredSemaphore.get(), {}, 1 ) );
    assert( nexImage.result == vk::Result::eSuccess );
    uint32_t currentBuffer = nexImage.value;

    vk::ClearValue clearValue;
    clearValue.color = vk::ClearColorValue( std::array<float, 4>( { { 0.2f, 0.2f, 0.2f, 0.2f } } ) );
    commandBuffer->beginRenderPass( vk::RenderPassBeginInfo( renderPass.get(),
                                                             framebuffers[currentBuffer].get(),
                                                             vk::Rect2D( vk::Offset2D( 0, 0 ), surfaceData.extent ),
                                                             clearValue ),
                                    vk::SubpassContents::eInline );
    commandBuffer->bindPipeline( vk::PipelineBindPoint::eGraphics, graphicsPipeline.get() );
    commandBuffer->bindDescriptorSets(
      vk::PipelineBindPoint::eGraphics, pipelineLayout.get(), 0, descriptorSet.get(), nullptr );

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

    /* VULKAN_KEY_END */

    vk::su::submitAndWait( device, graphicsQueue, commandBuffer );

    vk::Result result = presentQueue.presentKHR( vk::PresentInfoKHR( {}, *swapChainData.swapChain, currentBuffer ) );
    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 ) );
  }
  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;
}