/*
 * Copyright 2022-2023 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 "static_model.hpp"

#include "../core.hpp"
#include "uniform_data_object.hpp"

namespace
{

void
load_uniform_buffers(void *obj)
{
  auto self = static_cast<VK::StaticModel*>(obj);

  try
  {
    self->uniform_buffers.reserve(cg_core.vk_swapchain->images_count);
    for(auto i{0}; i < cg_core.vk_swapchain->images_count; i++)
      self->uniform_buffers.emplace_back(
	cg_core.vk_device_with_swapchain, sizeof(VK::UDOStaticModel));
  }
  catch(const std::exception& e)
  {
    throw CommandError{e.what()};
  }
}

void
unload_uniform_buffers(void *obj)
{
  auto self = static_cast<VK::StaticModel*>(obj);

  self->uniform_buffers.clear();
}

void
load_descriptor_set_pool(void *obj)
{
  auto self = static_cast<VK::StaticModel*>(obj);

  std::array<VkDescriptorPoolSize, 2> descriptor_pool_sizes{};
  descriptor_pool_sizes[0].type = VK_DESCRIPTOR_TYPE_UNIFORM_BUFFER;
  descriptor_pool_sizes[0].descriptorCount =
    self->uniform_buffers.size();
  descriptor_pool_sizes[1].type = VK_DESCRIPTOR_TYPE_COMBINED_IMAGE_SAMPLER;
  descriptor_pool_sizes[1].descriptorCount =
    cg_core.vk_swapchain->images_count;

  VkDescriptorPoolCreateInfo pool_info{};
  pool_info.sType = VK_STRUCTURE_TYPE_DESCRIPTOR_POOL_CREATE_INFO;
  pool_info.pNext = nullptr;
  pool_info.flags = 0;
  pool_info.maxSets = self->uniform_buffers.size();
  pool_info.poolSizeCount = descriptor_pool_sizes.size();
  pool_info.pPoolSizes = descriptor_pool_sizes.data();

  if(vkCreateDescriptorPool(
       self->static_mesh->queue_family->device->device, &pool_info, nullptr,
       &self->descriptor_pool) != VK_SUCCESS)
    throw CommandError{"Failed to create a Vulkan descriptor pool."};
}

void
unload_descriptor_set_pool(void *obj)
{
  auto self = static_cast<VK::StaticModel*>(obj);

  vkDestroyDescriptorPool(
    self->static_mesh->queue_family->device->device, self->descriptor_pool,
    nullptr);
}

void
load_descriptor_sets(void *obj)
{
  auto self = static_cast<VK::StaticModel*>(obj);

  std::vector<VkDescriptorSetLayout> layouts(
    cg_core.vk_swapchain->images_count,
    cg_core.vk_graphics_pipeline_3d_layout->descriptor_set_model);

  VkDescriptorSetAllocateInfo alloc_info{};
  alloc_info.sType = VK_STRUCTURE_TYPE_DESCRIPTOR_SET_ALLOCATE_INFO;
  alloc_info.descriptorPool = self->descriptor_pool;
  alloc_info.descriptorSetCount = layouts.size();
  alloc_info.pSetLayouts = layouts.data();

  self->descriptor_sets.resize(layouts.size());
  if(vkAllocateDescriptorSets(
       self->static_mesh->queue_family->device->device, &alloc_info,
       self->descriptor_sets.data()) != VK_SUCCESS)
    CommandError{"Failed to create Vulkan descriptor set."};
}

void
load_buffers_to_descriptor_sets(void *obj)
{
  auto self = static_cast<VK::StaticModel*>(obj);

  for(auto i{0}; i < self->uniform_buffers.size(); i++)
  {
    VkDescriptorBufferInfo buffer_info{};
    buffer_info.buffer = self->uniform_buffers[i].buffer;
    buffer_info.offset = 0;
    buffer_info.range = sizeof(VK::UDOStaticModel);

    VkDescriptorImageInfo image_info{};
    image_info.imageLayout = VK_IMAGE_LAYOUT_SHADER_READ_ONLY_OPTIMAL;
    image_info.imageView = self->texture->view;
    image_info.sampler = self->texture->sampler;

    std::array<VkWriteDescriptorSet, 2> write_descriptors{};
    write_descriptors[0].sType = VK_STRUCTURE_TYPE_WRITE_DESCRIPTOR_SET;
    write_descriptors[0].dstSet = self->descriptor_sets[i];
    write_descriptors[0].dstBinding = 0;
    write_descriptors[0].dstArrayElement = 0;
    write_descriptors[0].descriptorCount = 1;
    write_descriptors[0].descriptorType = VK_DESCRIPTOR_TYPE_UNIFORM_BUFFER;
    write_descriptors[0].pBufferInfo = &buffer_info;
    write_descriptors[0].pImageInfo = nullptr;
    write_descriptors[0].pTexelBufferView = nullptr;
    write_descriptors[1].sType = VK_STRUCTURE_TYPE_WRITE_DESCRIPTOR_SET;
    write_descriptors[1].dstSet = self->descriptor_sets[i];
    write_descriptors[1].dstBinding = 1;
    write_descriptors[1].dstArrayElement = 0;
    write_descriptors[1].descriptorCount = 1;
    write_descriptors[1].descriptorType =
      VK_DESCRIPTOR_TYPE_COMBINED_IMAGE_SAMPLER;
    write_descriptors[1].pBufferInfo = nullptr;
    write_descriptors[1].pImageInfo = &image_info;
    write_descriptors[1].pTexelBufferView = nullptr;

    vkUpdateDescriptorSets(
      cg_core.vk_device_with_swapchain->device, write_descriptors.size(),
      write_descriptors.data(), 0, nullptr);
  }
}

static const CommandChain loader{
  {&load_uniform_buffers, &unload_uniform_buffers},
  {&load_descriptor_set_pool, &unload_descriptor_set_pool},
  {&load_descriptor_sets, nullptr},
  {&load_buffers_to_descriptor_sets, nullptr}
};

}

namespace VK
{

StaticModel::StaticModel(
  std::shared_ptr<StaticMesh> static_mesh,
  std::shared_ptr<Texture> texture, std::shared_ptr<glm::vec3> position,
  std::shared_ptr<glm::vec3> rotation):
  static_mesh{static_mesh},
  texture{texture},
  position{position},
  rotation{rotation}
{
  loader.execute(this);
}

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

}