// Blaze.cpp : This file contains the 'main' function. Program execution begins and ends there.
//

#include <array>
#include <cassert>
#include <limits>
#include <span>

#include <volk.h>

#define SDL_MAIN_USE_CALLBACKS 1
#include <SDL3/SDL.h>
#include <SDL3/SDL_filesystem.h>
#include <SDL3/SDL_main.h>
#include <SDL3/SDL_vulkan.h>

#include "AppState.h"
#include "Frame.h"
#include "GlobalMemory.h"
#include "MacroUtils.h"
#include "MathUtil.h"
#include "MiscData.h"
#include "RenderDevice.h"

constexpr uint32_t WIDTH      = 1280;
constexpr uint32_t HEIGHT     = 720;
constexpr uint32_t NUM_FRAMES = 3;

namespace Blaze::Global
{
GlobalMemory g_Memory;
}

SDL_AppResult SDL_AppInit( void** appstate, int, char** )
{
  SDL_Init( SDL_INIT_VIDEO | SDL_INIT_EVENTS );

  Blaze::Global::g_Memory.init( 128_MiB );

  *appstate = AppState_Create( &Blaze::Global::g_Memory, WIDTH, HEIGHT );
  if ( !*appstate ) return SDL_APP_FAILURE;

  return SDL_APP_CONTINUE;
}

SDL_AppResult SDL_AppIterate( void* appstate )
{
  AppState&     appState     = *static_cast<AppState*>( appstate );
  RenderDevice& renderDevice = *appState.renderDevice;
  MiscData&     misc         = *appState.miscData;
  Frame&        currentFrame = renderDevice.frames[renderDevice.frameIndex];

  VK_CHECK( vkWaitForFences(
      renderDevice.device, 1, &currentFrame.frameReadyToReuse, VK_TRUE, std::numeric_limits<uint32_t>::max() ) );
  // All resources of frame 'frameIndex' are free.

  // time calc
  uint64_t const previousCounter = misc.previousCounter;
  uint64_t const currentCounter  = SDL_GetPerformanceCounter();
  uint64_t const deltaCount      = currentCounter - previousCounter;
  uint64_t const perfFreq        = SDL_GetPerformanceFrequency();
  double const   deltaTime       = static_cast<double>( deltaCount ) / static_cast<double>( perfFreq );
  misc.previousCounter           = currentCounter;

  {
    double deltaTimeMs = deltaTime * 1000.0;
    double fps         = 1.0 / deltaTime;
    ( void )sprintf_s<256>(
        appState.sprintfBuffer, "%.2f fps %.5fms %llu -> %llu", fps, deltaTimeMs, previousCounter, currentCounter );
    SDL_SetWindowTitle( appState.window, appState.sprintfBuffer );
  }

  for ( Transform& transform : misc.modelTransform )
  {
    transform.rotation = DirectX::XMQuaternionMultiply(
        DirectX::XMQuaternionRotationAxis(
            DirectX::XMVectorSet( 0.0f, 1.0f, 0.0f, 0.0f ),
            DirectX::XMConvertToRadians( 60.0f ) * static_cast<float>( deltaTime ) ),
        transform.rotation );
  }

  uint32_t currentImageIndex;
  VK_CHECK( vkAcquireNextImageKHR(
      renderDevice.device,
      renderDevice.swapchain,
      std::numeric_limits<uint32_t>::max(),
      currentFrame.imageAcquiredSemaphore,
      nullptr,
      &currentImageIndex ) );

  VK_CHECK( vkResetFences( renderDevice.device, 1, &currentFrame.frameReadyToReuse ) );
  VK_CHECK( vkResetCommandPool( renderDevice.device, currentFrame.commandPool, 0 ) );

  misc.acquireToRenderBarrier.image            = renderDevice.swapchainImages[currentImageIndex];
  misc.renderToPresentBarrier.image            = renderDevice.swapchainImages[currentImageIndex];

  VkCommandBuffer cmd                          = currentFrame.commandBuffer;

  VkCommandBufferBeginInfo constexpr beginInfo = {
    .sType            = VK_STRUCTURE_TYPE_COMMAND_BUFFER_BEGIN_INFO,
    .pNext            = nullptr,
    .flags            = 0,
    .pInheritanceInfo = nullptr,
  };

  VkClearColorValue constexpr static BLACK_CLEAR = {
    .float32 = { 0.0f, 0.0f, 0.0f, 1.0f },
  };

  VK_CHECK( vkBeginCommandBuffer( cmd, &beginInfo ) );
  {
    VkRenderingAttachmentInfo const attachmentInfo = {
      .sType              = VK_STRUCTURE_TYPE_RENDERING_ATTACHMENT_INFO,
      .pNext              = nullptr,
      .imageView          = renderDevice.swapchainViews[currentImageIndex],
      .imageLayout        = VK_IMAGE_LAYOUT_COLOR_ATTACHMENT_OPTIMAL,
      .resolveMode        = VK_RESOLVE_MODE_NONE,
      .resolveImageView   = nullptr,
      .resolveImageLayout = VK_IMAGE_LAYOUT_UNDEFINED,
      .loadOp             = VK_ATTACHMENT_LOAD_OP_CLEAR,
      .storeOp            = VK_ATTACHMENT_STORE_OP_STORE,
      .clearValue         = { .color = BLACK_CLEAR },
    };

    VkRenderingInfo renderingInfo = {
      .sType                = VK_STRUCTURE_TYPE_RENDERING_INFO,
      .pNext                = nullptr,
      .flags                = 0,
      .renderArea           = { .offset = { 0, 0 }, .extent = renderDevice.swapchainExtent },
      .layerCount           = 1,
      .viewMask             = 0,
      .colorAttachmentCount = 1,
      .pColorAttachments    = &attachmentInfo,
      .pDepthAttachment     = nullptr,
      .pStencilAttachment   = nullptr,
    };

    vkCmdPipelineBarrier2( cmd, &misc.acquireToRenderDependency );
    vkCmdBeginRendering( cmd, &renderingInfo );
    {
      VkViewport viewport = {
        .x        = 0,
        .y        = static_cast<float>( renderDevice.swapchainExtent.height ),
        .width    = static_cast<float>( renderDevice.swapchainExtent.width ),
        .height   = -static_cast<float>( renderDevice.swapchainExtent.height ),
        .minDepth = 0.0f,
        .maxDepth = 1.0f,
      };
      vkCmdSetViewport( cmd, 0, 1, &viewport );
      VkRect2D scissor = {
        .offset = { 0, 0 },
        .extent = renderDevice.swapchainExtent,
      };
      vkCmdSetScissor( cmd, 0, 1, &scissor );

      // Render Something?
      vkCmdBindPipeline( cmd, VK_PIPELINE_BIND_POINT_GRAPHICS, misc.meshPipeline );
      VkDeviceSize constexpr offset = 0;
      vkCmdBindVertexBuffers( cmd, 0, 1, &misc.vertexBuffer, &offset );
      vkCmdBindDescriptorSets(
          cmd, VK_PIPELINE_BIND_POINT_GRAPHICS, misc.pipelineLayout, 0, 1, &misc.descriptorSet, 0, nullptr );
      for ( Transform& localTransform : misc.modelTransform )
      {
        DirectX::XMMATRIX worldTransform;
        {
          auto [x, y, z] = localTransform.position;
          auto scale     = localTransform.scale;
          worldTransform = DirectX::XMMatrixScaling( scale, scale, scale ) *
                           DirectX::XMMatrixRotationQuaternion( localTransform.rotation ) *
                           DirectX::XMMatrixTranslation( x, y, z );
        }
        vkCmdPushConstants(
            cmd, misc.pipelineLayout, VK_SHADER_STAGE_ALL_GRAPHICS, 0, sizeof worldTransform, &worldTransform );
        vkCmdDraw( cmd, static_cast<uint32_t>( misc.vertices.size() ), 1, 0, 0 );
      }
    }
    vkCmdEndRendering( cmd );
    vkCmdPipelineBarrier2( cmd, &misc.renderToPresentDependency );
  }
  VK_CHECK( vkEndCommandBuffer( cmd ) );

  VkPipelineStageFlags stageMask  = VK_PIPELINE_STAGE_COLOR_ATTACHMENT_OUTPUT_BIT;
  VkSubmitInfo const   submitInfo = {
      .sType                = VK_STRUCTURE_TYPE_SUBMIT_INFO,
      .pNext                = nullptr,
      .waitSemaphoreCount   = 1,
      .pWaitSemaphores      = &currentFrame.imageAcquiredSemaphore,
      .pWaitDstStageMask    = &stageMask,
      .commandBufferCount   = 1,
      .pCommandBuffers      = &cmd,
      .signalSemaphoreCount = 1,
      .pSignalSemaphores    = &currentFrame.renderFinishedSemaphore,
  };
  VK_CHECK( vkQueueSubmit( renderDevice.directQueue, 1, &submitInfo, currentFrame.frameReadyToReuse ) );

  VkPresentInfoKHR const presentInfo = {
    .sType              = VK_STRUCTURE_TYPE_PRESENT_INFO_KHR,
    .pNext              = nullptr,
    .waitSemaphoreCount = 1,
    .pWaitSemaphores    = &currentFrame.renderFinishedSemaphore,
    .swapchainCount     = 1,
    .pSwapchains        = &renderDevice.swapchain,
    .pImageIndices      = &currentImageIndex,
    .pResults           = nullptr,
  };

  VK_CHECK( vkQueuePresentKHR( renderDevice.directQueue, &presentInfo ) );

  renderDevice.frameIndex = ( renderDevice.frameIndex + 1 ) % NUM_FRAMES;

  return SDL_APP_CONTINUE;
}

SDL_AppResult SDL_AppEvent( void*, SDL_Event* event )
{
  if ( event->type == SDL_EVENT_QUIT )
  {
    return SDL_APP_SUCCESS;
  }

  return SDL_APP_CONTINUE;
}

void SDL_AppQuit( void* appstate, SDL_AppResult )
{
  AppState* appState = static_cast<AppState*>( appstate );

  if ( appState ) appState->destroy();

  Blaze::Global::g_Memory.destroy();
}