/*
 * Copyright 2022 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 "sprite.hpp"

#include <array>

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

namespace
{

struct SpriteBuilder
{
  VK::Sprite *sprite;
  glm::vec4 rect;

  SpriteBuilder(VK::Sprite *sprite, glm::vec4 rect);
};

SpriteBuilder::SpriteBuilder(VK::Sprite *sprite, glm::vec4 rect):
  sprite{sprite},
  rect{rect}
{
}

void
load_mesh(void *obj)
{
  auto self = static_cast<SpriteBuilder*>(obj);

  self->sprite->queue_family =
    cg_core.vk_device_with_swapchain->get_queue_family_with_graphics();

  glm::vec2 rect[VK::Sprite::vertex_count]{
    glm::vec2{self->rect.x, self->rect.y},
    glm::vec2{self->rect.x, self->rect.w},
    glm::vec2{self->rect.z, self->rect.y},
    glm::vec2{self->rect.z, self->rect.w}
  };

  void *vertexes_data{&rect};
  static const size_t vertexes_size =
    sizeof(glm::vec2) * VK::Sprite::vertex_count;
  self->sprite->source_buffer = new VK::SourceBuffer{
    self->sprite->queue_family->device, vertexes_data, vertexes_size};
  self->sprite->vertex_buffer = new VK::DestinationBuffer{
    self->sprite->queue_family, self->sprite->source_buffer,
    VK_BUFFER_USAGE_VERTEX_BUFFER_BIT};
}

void
unload_mesh(void *obj)
{
  auto self = static_cast<SpriteBuilder*>(obj);

  delete self->sprite->vertex_buffer;
  delete self->sprite->source_buffer;
}

void
load_descriptor_set_pool(void *obj)
{
  auto self = static_cast<SpriteBuilder*>(obj);

  std::array<VkDescriptorPoolSize, 1> descriptor_pool_sizes{};
  descriptor_pool_sizes[0].type = VK_DESCRIPTOR_TYPE_COMBINED_IMAGE_SAMPLER;
  descriptor_pool_sizes[0].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 = cg_core.vk_swapchain->images_count;
  pool_info.poolSizeCount = descriptor_pool_sizes.size();
  pool_info.pPoolSizes = descriptor_pool_sizes.data();

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

}

void
unload_descriptor_set_pool(void *obj)
{
  auto self = static_cast<SpriteBuilder*>(obj);

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

void
load_descriptor_sets(void *obj)
{
  auto self = static_cast<SpriteBuilder*>(obj);

  std::vector<VkDescriptorSetLayout> layouts(
    cg_core.vk_swapchain->images_count,
    cg_core.vk_graphics_pipeline_2d_solid_layout->descriptor_set_sprite);

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

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

void
load_buffers_to_descriptor_sets(void *obj)
{
  auto self = static_cast<SpriteBuilder*>(obj);

  for(auto i{0}; i < cg_core.vk_swapchain->images_count; i++)
  {
    VkDescriptorImageInfo image_info{};
    image_info.imageLayout = VK_IMAGE_LAYOUT_SHADER_READ_ONLY_OPTIMAL;
    image_info.imageView = self->sprite->texture->view;
    image_info.sampler = self->sprite->texture->sampler;

    std::array<VkWriteDescriptorSet, 1> write_descriptors{};
    write_descriptors[0].sType = VK_STRUCTURE_TYPE_WRITE_DESCRIPTOR_SET;
    write_descriptors[0].dstSet = self->sprite->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_COMBINED_IMAGE_SAMPLER;
    write_descriptors[0].pBufferInfo = nullptr;
    write_descriptors[0].pImageInfo = &image_info;
    write_descriptors[0].pTexelBufferView = nullptr;

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

static const CommandChain loader{
  {&load_mesh, &unload_mesh},
  {&load_descriptor_set_pool, &unload_descriptor_set_pool},
  {&load_descriptor_sets, nullptr},
  {&load_buffers_to_descriptor_sets, nullptr},
};

}

namespace VK
{

Sprite::Sprite(std::shared_ptr<Texture> texture, glm::vec4 rect):
  texture{texture}
{
  SpriteBuilder sprite_builder(this, rect);
  loader.execute(&sprite_builder);
}

Sprite::~Sprite()
{
  SpriteBuilder sprite_builder(this, glm::vec4());
  loader.revert(&sprite_builder);
}

}