/*
 * Copyright 2022-2024 Frederico de Oliveira Linhares
 *
 * 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.
 */

#include "render_pass.hpp"

#include <array>

#include "../core.hpp"

namespace
{

void
load_3d(void *obj)
{
  auto self = static_cast<BluCat::RenderPass*>(obj);

  std::array<VkAttachmentDescription, 2> attachments{};
  // Color attachment.
  attachments[0].flags = 0;
  attachments[0].format = cg_core.vk_swapchain->image_format;
  attachments[0].samples = VK_SAMPLE_COUNT_1_BIT;
  attachments[0].loadOp = VK_ATTACHMENT_LOAD_OP_CLEAR;
  attachments[0].storeOp = VK_ATTACHMENT_STORE_OP_STORE;
  attachments[0].stencilLoadOp = VK_ATTACHMENT_LOAD_OP_DONT_CARE;
  attachments[0].stencilStoreOp = VK_ATTACHMENT_STORE_OP_DONT_CARE;
  attachments[0].initialLayout = VK_IMAGE_LAYOUT_UNDEFINED;
  attachments[0].finalLayout = VK_IMAGE_LAYOUT_COLOR_ATTACHMENT_OPTIMAL;
  // Depth attachment.
  attachments[1].flags = 0;
  attachments[1].format = VK_FORMAT_D32_SFLOAT;
  attachments[1].samples = VK_SAMPLE_COUNT_1_BIT;
  attachments[1].loadOp = VK_ATTACHMENT_LOAD_OP_CLEAR;
  attachments[1].storeOp = VK_ATTACHMENT_STORE_OP_DONT_CARE;
  attachments[1].stencilLoadOp = VK_ATTACHMENT_LOAD_OP_DONT_CARE;
  attachments[1].stencilStoreOp = VK_ATTACHMENT_STORE_OP_DONT_CARE;
  attachments[1].initialLayout = VK_IMAGE_LAYOUT_UNDEFINED;
  attachments[1].finalLayout =
      VK_IMAGE_LAYOUT_DEPTH_STENCIL_ATTACHMENT_OPTIMAL;

  VkAttachmentReference color_attachment_ref{};
  color_attachment_ref.attachment = 0;
  color_attachment_ref.layout = VK_IMAGE_LAYOUT_COLOR_ATTACHMENT_OPTIMAL;
  VkAttachmentReference depth_attachment_ref{};
  depth_attachment_ref.attachment = 1;
  depth_attachment_ref.layout =
    VK_IMAGE_LAYOUT_DEPTH_STENCIL_ATTACHMENT_OPTIMAL;

  VkSubpassDescription subpass = {};
  subpass.flags = 0;
  subpass.pipelineBindPoint = VK_PIPELINE_BIND_POINT_GRAPHICS;
  subpass.inputAttachmentCount = 0;
  subpass.pInputAttachments = nullptr;
  subpass.colorAttachmentCount = 1;
  subpass.pColorAttachments = &color_attachment_ref;
  subpass.pResolveAttachments = nullptr;
  subpass.pDepthStencilAttachment = &depth_attachment_ref;
  subpass.preserveAttachmentCount = 0;
  subpass.pPreserveAttachments = nullptr;

  VkSubpassDependency dependency = {};
  dependency.srcSubpass = VK_SUBPASS_EXTERNAL;
  dependency.dstSubpass = 0;
  dependency.srcStageMask = VK_PIPELINE_STAGE_COLOR_ATTACHMENT_OUTPUT_BIT |
    VK_PIPELINE_STAGE_EARLY_FRAGMENT_TESTS_BIT;
  dependency.srcAccessMask = 0;
  dependency.dstStageMask = VK_PIPELINE_STAGE_COLOR_ATTACHMENT_OUTPUT_BIT |
    VK_PIPELINE_STAGE_EARLY_FRAGMENT_TESTS_BIT;
  dependency.dstAccessMask = VK_ACCESS_COLOR_ATTACHMENT_READ_BIT |
    VK_ACCESS_DEPTH_STENCIL_ATTACHMENT_WRITE_BIT |
    VK_ACCESS_COLOR_ATTACHMENT_WRITE_BIT;

  VkRenderPassCreateInfo render_pass_info{};
  render_pass_info.sType = VK_STRUCTURE_TYPE_RENDER_PASS_CREATE_INFO;
  render_pass_info.pNext = nullptr;
  render_pass_info.flags = 0;
  render_pass_info.attachmentCount = attachments.size();
  render_pass_info.pAttachments = attachments.data();
  render_pass_info.subpassCount = 1;
  render_pass_info.pSubpasses = &subpass;
  render_pass_info.dependencyCount = 1;
  render_pass_info.pDependencies = &dependency;

  if(vkCreateRenderPass(
       cg_core.vk_device_with_swapchain->device, &render_pass_info, nullptr,
       &self->pipeline_3d) != VK_SUCCESS)
    throw CommandError{"Failed to create Vulkan Render Pass 3D."};
}

void
unload_3d(void *obj)
{
  auto self = static_cast<BluCat::RenderPass*>(obj);

  vkDestroyRenderPass(
    cg_core.vk_device_with_swapchain->device, self->pipeline_3d, nullptr);
}

void
load_2d(void *obj)
{
  auto self = static_cast<BluCat::RenderPass*>(obj);

  std::array<VkAttachmentDescription, 1> attachments{};
  // Color attachment.
  attachments[0].flags = 0;
  attachments[0].format = cg_core.vk_swapchain->image_format;
  attachments[0].samples = VK_SAMPLE_COUNT_1_BIT;
  attachments[0].loadOp = VK_ATTACHMENT_LOAD_OP_LOAD;
  attachments[0].storeOp = VK_ATTACHMENT_STORE_OP_STORE;
  attachments[0].stencilLoadOp = VK_ATTACHMENT_LOAD_OP_DONT_CARE;
  attachments[0].stencilStoreOp = VK_ATTACHMENT_STORE_OP_DONT_CARE;
  attachments[0].initialLayout = VK_IMAGE_LAYOUT_COLOR_ATTACHMENT_OPTIMAL;
  attachments[0].finalLayout = VK_IMAGE_LAYOUT_PRESENT_SRC_KHR;

  VkAttachmentReference color_attachment_ref{};
  color_attachment_ref.attachment = 0;
  color_attachment_ref.layout = VK_IMAGE_LAYOUT_COLOR_ATTACHMENT_OPTIMAL;

  VkSubpassDescription subpass{};
  subpass.flags = 0;
  subpass.pipelineBindPoint = VK_PIPELINE_BIND_POINT_GRAPHICS;
  subpass.inputAttachmentCount = 0;
  subpass.pInputAttachments = nullptr;
  subpass.colorAttachmentCount = 1;
  subpass.pColorAttachments = &color_attachment_ref;
  subpass.pResolveAttachments = nullptr;
  subpass.pDepthStencilAttachment = nullptr;
  subpass.preserveAttachmentCount = 0;
  subpass.pPreserveAttachments = nullptr;

  VkSubpassDependency dependency{};
  dependency.srcSubpass = VK_SUBPASS_EXTERNAL;
  dependency.dstSubpass = 0;
  dependency.srcStageMask = VK_PIPELINE_STAGE_COLOR_ATTACHMENT_OUTPUT_BIT |
    VK_PIPELINE_STAGE_EARLY_FRAGMENT_TESTS_BIT;
  dependency.srcAccessMask = 0;
  dependency.dstStageMask = VK_PIPELINE_STAGE_COLOR_ATTACHMENT_OUTPUT_BIT |
    VK_PIPELINE_STAGE_EARLY_FRAGMENT_TESTS_BIT;
  dependency.dstAccessMask = VK_ACCESS_COLOR_ATTACHMENT_READ_BIT |
    VK_ACCESS_DEPTH_STENCIL_ATTACHMENT_WRITE_BIT |
    VK_ACCESS_COLOR_ATTACHMENT_WRITE_BIT;

  VkRenderPassCreateInfo render_pass_info{};
  render_pass_info.sType = VK_STRUCTURE_TYPE_RENDER_PASS_CREATE_INFO;
  render_pass_info.pNext = nullptr;
  render_pass_info.flags = 0;
  render_pass_info.attachmentCount = attachments.size();
  render_pass_info.pAttachments = attachments.data();
  render_pass_info.subpassCount = 1;
  render_pass_info.pSubpasses = &subpass;
  render_pass_info.dependencyCount = 1;
  render_pass_info.pDependencies = &dependency;

  if(vkCreateRenderPass(
       cg_core.vk_device_with_swapchain->device, &render_pass_info,
       nullptr, &self->pipeline_2d) != VK_SUCCESS)
    throw CommandError{"Failed to create Vulkan Render Pass 2D."};
}

void
unload_2d(void *obj)
{
  auto self = static_cast<BluCat::RenderPass*>(obj);

  vkDestroyRenderPass(
    cg_core.vk_device_with_swapchain->device, self->pipeline_2d, nullptr);
}

const CommandChain loader{
  {&load_3d, &unload_3d},
  {&load_2d, &unload_2d}
};

}

namespace BluCat
{

RenderPass::RenderPass()
{
  loader.execute(this);
}

RenderPass::~RenderPass()
{
  loader.revert(this);
}

}