// 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 : 11_InitShaders
//                     Initialize vertex and fragment shaders

#include <iostream>
#include "vulkan/vulkan.hpp"
#include "SPIRV/GlslangToSpv.h"

static char const* AppName = "11_InitShaders";
static char const* EngineName = "Vulkan.hpp";

static std::vector<char const*> getDeviceExtensions()
{
  std::vector<char const*> extensions;

  extensions.push_back(VK_KHR_SWAPCHAIN_EXTENSION_NAME);

  return extensions;
}

static std::vector<char const*> getInstanceExtensions()
{
  std::vector<char const*> extensions;

  extensions.push_back(VK_KHR_SURFACE_EXTENSION_NAME);
#if  defined(VK_USE_PLATFORM_ANDROID_KHR)
  extensions.push_back(VK_KHR_ANDROID_SURFACE_EXTENSION_NAME);
#elif defined(VK_USE_PLATFORM_IOS_MVK)
  extensions.push_back(VK_MVK_IOS_SURFACE_EXTENSION_NAME);
#elif defined(VK_USE_PLATFORM_MACOS_MVK)
  extensions.push_back(VK_MVK_MACOS_SURFACE_EXTENSION_NAME);
#elif defined(VK_USE_PLATFORM_MIR_KHR)
  extensions.push_back(VK_KHR_MIR_SURFACE_EXTENSION_NAME);
#elif defined(VK_USE_PLATFORM_VI_NN)
  extensions.push_back(VK_NN_VI_SURFACE_EXTENSION_NAME);
#elif defined(VK_USE_PLATFORM_WAYLAND_KHR)
  extensions.push_back(VK_KHR_WAYLAND_SURFACE_EXTENSION_NAME);
#elif defined(VK_USE_PLATFORM_WIN32_KHR)
  extensions.push_back(VK_KHR_WIN32_SURFACE_EXTENSION_NAME);
#elif defined(VK_USE_PLATFORM_XCB_KHR)
  extensions.push_back(VK_KHR_XCB_SURFACE_EXTENSION_NAME);
#elif defined(VK_USE_PLATFORM_XLIB_KHR)
  extensions.push_back(VK_KHR_XLIB_SURFACE_EXTENSION_NAME);
#elif defined(VK_USE_PLATFORM_XLIB_XRANDR_EXT)
  extensions.push_back(VK_EXT_ACQUIRE_XLIB_DISPLAY_EXTENSION_NAME);
#endif

  return extensions;
}

EShLanguage translateShaderStage(vk::ShaderStageFlagBits stage)
{
  switch (stage)
  {
    case vk::ShaderStageFlagBits::eVertex:                  return EShLangVertex;
    case vk::ShaderStageFlagBits::eTessellationControl:     return EShLangTessControl;
    case vk::ShaderStageFlagBits::eTessellationEvaluation:  return EShLangTessEvaluation;
    case vk::ShaderStageFlagBits::eGeometry:                return EShLangGeometry;
    case vk::ShaderStageFlagBits::eFragment:                return EShLangFragment;
    case vk::ShaderStageFlagBits::eCompute:                 return EShLangCompute;
    default:
      assert(false && "Unknown shader stage");
      return EShLangVertex;
  }
}

void init(TBuiltInResource & resource)
{
  resource.maxLights = 32;
  resource.maxClipPlanes = 6;
  resource.maxTextureUnits = 32;
  resource.maxTextureCoords = 32;
  resource.maxVertexAttribs = 64;
  resource.maxVertexUniformComponents = 4096;
  resource.maxVaryingFloats = 64;
  resource.maxVertexTextureImageUnits = 32;
  resource.maxCombinedTextureImageUnits = 80;
  resource.maxTextureImageUnits = 32;
  resource.maxFragmentUniformComponents = 4096;
  resource.maxDrawBuffers = 32;
  resource.maxVertexUniformVectors = 128;
  resource.maxVaryingVectors = 8;
  resource.maxFragmentUniformVectors = 16;
  resource.maxVertexOutputVectors = 16;
  resource.maxFragmentInputVectors = 15;
  resource.minProgramTexelOffset = -8;
  resource.maxProgramTexelOffset = 7;
  resource.maxClipDistances = 8;
  resource.maxComputeWorkGroupCountX = 65535;
  resource.maxComputeWorkGroupCountY = 65535;
  resource.maxComputeWorkGroupCountZ = 65535;
  resource.maxComputeWorkGroupSizeX = 1024;
  resource.maxComputeWorkGroupSizeY = 1024;
  resource.maxComputeWorkGroupSizeZ = 64;
  resource.maxComputeUniformComponents = 1024;
  resource.maxComputeTextureImageUnits = 16;
  resource.maxComputeImageUniforms = 8;
  resource.maxComputeAtomicCounters = 8;
  resource.maxComputeAtomicCounterBuffers = 1;
  resource.maxVaryingComponents = 60;
  resource.maxVertexOutputComponents = 64;
  resource.maxGeometryInputComponents = 64;
  resource.maxGeometryOutputComponents = 128;
  resource.maxFragmentInputComponents = 128;
  resource.maxImageUnits = 8;
  resource.maxCombinedImageUnitsAndFragmentOutputs = 8;
  resource.maxCombinedShaderOutputResources = 8;
  resource.maxImageSamples = 0;
  resource.maxVertexImageUniforms = 0;
  resource.maxTessControlImageUniforms = 0;
  resource.maxTessEvaluationImageUniforms = 0;
  resource.maxGeometryImageUniforms = 0;
  resource.maxFragmentImageUniforms = 8;
  resource.maxCombinedImageUniforms = 8;
  resource.maxGeometryTextureImageUnits = 16;
  resource.maxGeometryOutputVertices = 256;
  resource.maxGeometryTotalOutputComponents = 1024;
  resource.maxGeometryUniformComponents = 1024;
  resource.maxGeometryVaryingComponents = 64;
  resource.maxTessControlInputComponents = 128;
  resource.maxTessControlOutputComponents = 128;
  resource.maxTessControlTextureImageUnits = 16;
  resource.maxTessControlUniformComponents = 1024;
  resource.maxTessControlTotalOutputComponents = 4096;
  resource.maxTessEvaluationInputComponents = 128;
  resource.maxTessEvaluationOutputComponents = 128;
  resource.maxTessEvaluationTextureImageUnits = 16;
  resource.maxTessEvaluationUniformComponents = 1024;
  resource.maxTessPatchComponents = 120;
  resource.maxPatchVertices = 32;
  resource.maxTessGenLevel = 64;
  resource.maxViewports = 16;
  resource.maxVertexAtomicCounters = 0;
  resource.maxTessControlAtomicCounters = 0;
  resource.maxTessEvaluationAtomicCounters = 0;
  resource.maxGeometryAtomicCounters = 0;
  resource.maxFragmentAtomicCounters = 8;
  resource.maxCombinedAtomicCounters = 8;
  resource.maxAtomicCounterBindings = 1;
  resource.maxVertexAtomicCounterBuffers = 0;
  resource.maxTessControlAtomicCounterBuffers = 0;
  resource.maxTessEvaluationAtomicCounterBuffers = 0;
  resource.maxGeometryAtomicCounterBuffers = 0;
  resource.maxFragmentAtomicCounterBuffers = 1;
  resource.maxCombinedAtomicCounterBuffers = 1;
  resource.maxAtomicCounterBufferSize = 16384;
  resource.maxTransformFeedbackBuffers = 4;
  resource.maxTransformFeedbackInterleavedComponents = 64;
  resource.maxCullDistances = 8;
  resource.maxCombinedClipAndCullDistances = 8;
  resource.maxSamples = 4;
  resource.limits.nonInductiveForLoops = 1;
  resource.limits.whileLoops = 1;
  resource.limits.doWhileLoops = 1;
  resource.limits.generalUniformIndexing = 1;
  resource.limits.generalAttributeMatrixVectorIndexing = 1;
  resource.limits.generalVaryingIndexing = 1;
  resource.limits.generalSamplerIndexing = 1;
  resource.limits.generalVariableIndexing = 1;
  resource.limits.generalConstantMatrixVectorIndexing = 1;
}

bool GLSLtoSPV(const vk::ShaderStageFlagBits shaderType, std::string const& glslShader, std::vector<unsigned int> &spvShader)
{
  EShLanguage stage = translateShaderStage(shaderType);

  const char *shaderStrings[1];
  shaderStrings[0] = glslShader.data();

  glslang::TShader shader(stage);
  shader.setStrings(shaderStrings, 1);

  TBuiltInResource resource;
  init(resource);

  // Enable SPIR-V and Vulkan rules when parsing GLSL
  EShMessages messages = (EShMessages)(EShMsgSpvRules | EShMsgVulkanRules);

  if (!shader.parse(&resource, 100, false, messages))
  {
    puts(shader.getInfoLog());
    puts(shader.getInfoDebugLog());
    return false;  // something didn't work
  }

  glslang::TProgram program;
  program.addShader(&shader);

  //
  // Program-level processing...
  //

  if (!program.link(messages))
  {
    puts(shader.getInfoLog());
    puts(shader.getInfoDebugLog());
    fflush(stdout);
    return false;
  }

  glslang::GlslangToSpv(*program.getIntermediate(stage), spvShader);
  return true;
}

int main(int /*argc*/, char * /*argv[]*/)
{
  try
  {
    // create an instance
    vk::ApplicationInfo appInfo(AppName, 1, EngineName, 1, VK_API_VERSION_1_1);
    std::vector<char const*> instanceExtensions = getInstanceExtensions();
    vk::InstanceCreateInfo instanceCreateInfo({}, &appInfo, 0, nullptr, static_cast<uint32_t>(instanceExtensions.size()), instanceExtensions.data());
    vk::UniqueInstance instance = vk::createInstanceUnique(instanceCreateInfo);

    // get the physical devices
    std::vector<vk::PhysicalDevice> physicalDevices = instance->enumeratePhysicalDevices();
    assert(!physicalDevices.empty());

    // determine a queueFamilyIndex that supports graphics
    std::vector<vk::QueueFamilyProperties> queueFamilyProperties = physicalDevices[0].getQueueFamilyProperties();
    size_t graphicsQueueFamilyIndex = std::distance(queueFamilyProperties.begin(),
      std::find_if(queueFamilyProperties.begin(),
        queueFamilyProperties.end(),
        [](vk::QueueFamilyProperties const& qfp) { return qfp.queueFlags & vk::QueueFlagBits::eGraphics; }));

    // create a device
    float queuePriority = 0.0f;
    vk::DeviceQueueCreateInfo deviceQueueCreateInfo({}, static_cast<uint32_t>(graphicsQueueFamilyIndex), 1, &queuePriority);
    std::vector<char const*> deviceExtensionNames = getDeviceExtensions();
    vk::UniqueDevice device = physicalDevices[0].createDeviceUnique(vk::DeviceCreateInfo({}, 1, &deviceQueueCreateInfo, 0, nullptr, static_cast<uint32_t>(deviceExtensionNames.size()), deviceExtensionNames.data()));

    /* VULKAN_HPP_KEY_START */

    static const std::string vertexShaderText = R"(
#version 400
#extension GL_ARB_separate_shader_objects : enable
#extension GL_ARB_shading_language_420pack : enable

layout (std140, binding = 0) uniform bufferVals
{
    mat4 mvp;
} myBufferVals;

layout (location = 0) in vec4 pos;
layout (location = 1) in vec4 inColor;
layout (location = 0) out vec4 outColor;

void main()
{
    outColor = inColor;
    gl_Position = myBufferVals.mvp * pos;
}
)";

    static const std::string fragmentShaderText = R"(
#version 400
#extension GL_ARB_separate_shader_objects : enable
#extension GL_ARB_shading_language_420pack : enable

layout (location = 0) in vec4 color;
layout (location = 0) out vec4 outColor;

void main()
{
   outColor = color;
}
)";

    glslang::InitializeProcess();

    std::vector<unsigned int> vertexShaderSPV;
    bool ok = GLSLtoSPV(vk::ShaderStageFlagBits::eVertex, vertexShaderText, vertexShaderSPV);
    assert(ok);

    vk::ShaderModuleCreateInfo vertexShaderModuleCreateInfo(vk::ShaderModuleCreateFlags(), vertexShaderSPV.size() * sizeof(unsigned int), vertexShaderSPV.data());
    vk::UniqueShaderModule vertexShaderModule = device->createShaderModuleUnique(vertexShaderModuleCreateInfo);

    std::vector<unsigned int> fragmentShaderSPV;
    ok = GLSLtoSPV(vk::ShaderStageFlagBits::eFragment, fragmentShaderText, fragmentShaderSPV);
    assert(ok);

    vk::ShaderModuleCreateInfo fragmentShaderModuleCreateInfo(vk::ShaderModuleCreateFlags(), fragmentShaderSPV.size() * sizeof(unsigned int), fragmentShaderSPV.data());
    vk::UniqueShaderModule fragmentShaderModule = device->createShaderModuleUnique(fragmentShaderModuleCreateInfo);

    glslang::FinalizeProcess();

    // Note: No need to explicitly destroy the ShaderModules, as the corresponding destroy
    // functions are called by the destructor of the UniqueShaderModule on leaving this scope.

    /* VULKAN_HPP_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;
}