/*
 * 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 "texture.hpp"

#include <SDL2/SDL.h>
#include <SDL2/SDL_image.h>

#include "../command.hpp"
#include "../core.hpp"
#include "image.hpp"
#include "source_buffer.hpp"

namespace
{

struct TextureBuilder
{
  VK::Texture *texture;
  std::string texture_path;

  TextureBuilder(VK::Texture *t, std::string tp);
  TextureBuilder(VK::Texture *t, const char* tp);
};

TextureBuilder::TextureBuilder(VK::Texture *t, std::string tp):
  texture{t},
  texture_path{tp}
{
}

TextureBuilder::TextureBuilder(VK::Texture *t, const char* tp):
  TextureBuilder{t, std::string(tp)}
{
}

void move_image_state(
    VkCommandBuffer vk_command_buffer, VkImage vk_image, VkFormat format,
    VkAccessFlags src_access_mask, VkAccessFlags dst_access_mask,
    VkImageLayout old_layout, VkImageLayout new_layout,
    VkPipelineStageFlags source_stage, VkPipelineStageFlags destination_stage)
{
  VkImageMemoryBarrier barrier{};
  barrier.sType = VK_STRUCTURE_TYPE_IMAGE_MEMORY_BARRIER;
  barrier.pNext = nullptr;
  barrier.srcAccessMask = src_access_mask;
  barrier.dstAccessMask = dst_access_mask;
  barrier.oldLayout = old_layout;
  barrier.newLayout = new_layout;
  barrier.srcQueueFamilyIndex = VK_QUEUE_FAMILY_IGNORED;
  barrier.dstQueueFamilyIndex = VK_QUEUE_FAMILY_IGNORED;
  barrier.image = vk_image;
  barrier.subresourceRange.aspectMask = VK_IMAGE_ASPECT_COLOR_BIT;
  barrier.subresourceRange.baseMipLevel = 0;
  barrier.subresourceRange.levelCount = 1;
  barrier.subresourceRange.baseArrayLayer = 0;
  barrier.subresourceRange.layerCount = 1;

  vkCmdPipelineBarrier(
      vk_command_buffer, source_stage, destination_stage, 0, 0, nullptr,
      0, nullptr, 1, &barrier);
}

void
load_image(void *obj)
{
  auto self = static_cast<TextureBuilder*>(obj);

  SDL_Surface *image{nullptr};

  // Load file image from file.
  {
    SDL_Surface *raw_surface{nullptr};
    raw_surface = IMG_Load(self->texture_path.c_str());
    if(raw_surface == nullptr)
    {
      std::string error{"Failed to load image. SDL2_image Error: "};
      error += IMG_GetError();
      throw CommandError{error};
    }

    image = SDL_ConvertSurfaceFormat(raw_surface, SDL_PIXELFORMAT_ARGB8888, 0);
    if(image == nullptr)
    {
      std::string error{"Failed to convert image. SDL2 Error: "};
      error += SDL_GetError();
      throw CommandError{error};
    }

    self->texture->width = static_cast<uint32_t>(image->w);
    self->texture->height = static_cast<uint32_t>(image->h);
    self->texture->mip_levels = 1;

    SDL_FreeSurface(raw_surface);
  }

  // Load file image into a vulkan buffer.
  size_t image_size{static_cast<size_t>(
      image->format->BytesPerPixel * image->w * image->h)};
  VK::SourceBuffer source_image_buffer{
    cg_core.vk_device_with_swapchain, image->pixels, image_size};

  // Create vulkan image.
  {
    try
    {
      VkExtent3D vk_extent3d{};
      vk_extent3d.width = self->texture->width;
      vk_extent3d.height = self->texture->height;
      vk_extent3d.depth = 1;

      VK::Image::create(
	cg_core.vk_device_with_swapchain,
	&self->texture->image,
	&self->texture->device_memory,
	VK_FORMAT_R8G8B8A8_UNORM,
	vk_extent3d,
	self->texture->mip_levels,
	VK_IMAGE_TILING_OPTIMAL,
	VK_IMAGE_USAGE_TRANSFER_DST_BIT | VK_IMAGE_USAGE_SAMPLED_BIT);
    }
    catch(VK::Image::Error error)
    {
      throw CommandError{error.what()};
    }
  }

  // Copy image from vulkan buffer into vulkan image.
  {
    auto queue_family{
      cg_core.vk_device_with_swapchain->get_queue_family_with_presentation()};
    auto queue{queue_family->get_queue()};
    VK::CommandPool command_pool{queue_family, 1};
    VkCommandBuffer vk_command_buffer{command_pool.command_buffers[0]};

    queue.submit_one_time_command(vk_command_buffer, [&](){
      move_image_state(
	vk_command_buffer, self->texture->image, VK_FORMAT_R8G8B8A8_UNORM,
	0, VK_ACCESS_TRANSFER_WRITE_BIT,
	VK_IMAGE_LAYOUT_UNDEFINED, VK_IMAGE_LAYOUT_TRANSFER_DST_OPTIMAL,
	VK_PIPELINE_STAGE_HOST_BIT, VK_PIPELINE_STAGE_TRANSFER_BIT);

      VkBufferImageCopy image_copy{};
      image_copy.bufferOffset = 0;
      image_copy.bufferRowLength = 0;
      image_copy.bufferImageHeight = 0;
      image_copy.imageSubresource.aspectMask = VK_IMAGE_ASPECT_COLOR_BIT;
      image_copy.imageSubresource.mipLevel = 0;
      image_copy.imageSubresource.baseArrayLayer = 0;
      image_copy.imageSubresource.layerCount = 1;
      image_copy.imageOffset = {0, 0, 0};
      image_copy.imageExtent = {self->texture->width, self->texture->height, 1};

      vkCmdCopyBufferToImage(
	vk_command_buffer, source_image_buffer.buffer, self->texture->image,
	VK_IMAGE_LAYOUT_TRANSFER_DST_OPTIMAL, 1, &image_copy);

      move_image_state(
	vk_command_buffer, self->texture->image, VK_FORMAT_R8G8B8A8_UNORM,
	VK_ACCESS_TRANSFER_WRITE_BIT, VK_ACCESS_SHADER_READ_BIT,
	VK_IMAGE_LAYOUT_TRANSFER_DST_OPTIMAL,
	VK_IMAGE_LAYOUT_SHADER_READ_ONLY_OPTIMAL,
	VK_PIPELINE_STAGE_TRANSFER_BIT,
	VK_PIPELINE_STAGE_FRAGMENT_SHADER_BIT);
    });
  }

  // Free resources.
  SDL_FreeSurface(image);
}

void
unload_image(void *obj)
{
  auto self = static_cast<TextureBuilder*>(obj);

  vkDestroyImage(
    cg_core.vk_device_with_swapchain->device, self->texture->image, nullptr);
  vkFreeMemory(
    cg_core.vk_device_with_swapchain->device, self->texture->device_memory,
    nullptr);
}

void
load_sampler(void *obj)
{
  auto self = static_cast<TextureBuilder*>(obj);

  VkSamplerCreateInfo sampler_info{};
  sampler_info.sType = VK_STRUCTURE_TYPE_SAMPLER_CREATE_INFO;
  sampler_info.pNext = nullptr;
  sampler_info.flags = 0;
  sampler_info.magFilter = VK_FILTER_LINEAR;
  sampler_info.minFilter = VK_FILTER_LINEAR;
  sampler_info.mipmapMode = VK_SAMPLER_MIPMAP_MODE_LINEAR;
  sampler_info.addressModeU = VK_SAMPLER_ADDRESS_MODE_REPEAT;
  sampler_info.addressModeV = VK_SAMPLER_ADDRESS_MODE_REPEAT;
  sampler_info.addressModeW = VK_SAMPLER_ADDRESS_MODE_REPEAT;
  sampler_info.mipLodBias = 0.0f;
  sampler_info.anisotropyEnable = VK_TRUE;
  sampler_info.maxAnisotropy = 16;
  sampler_info.compareEnable = VK_FALSE;
  sampler_info.compareOp = VK_COMPARE_OP_NEVER;
  sampler_info.minLod = 0.0f;
  sampler_info.maxLod = 0.0f;
  sampler_info.borderColor = VK_BORDER_COLOR_FLOAT_OPAQUE_WHITE;
  sampler_info.unnormalizedCoordinates = VK_FALSE;

  if(vkCreateSampler(
       cg_core.vk_device_with_swapchain->device, &sampler_info, nullptr,
       &self->texture->sampler) != VK_SUCCESS)
    throw CommandError{"Failed to create texture sampler."};
}

void
unload_sampler(void *obj)
{
  auto self = static_cast<TextureBuilder*>(obj);

  vkDestroySampler(
    cg_core.vk_device_with_swapchain->device, self->texture->sampler, nullptr);
}

void
load_view(void *obj)
{
  auto self = static_cast<TextureBuilder*>(obj);

  try
  {
    VK::Image::create_view(
      cg_core.vk_device_with_swapchain, &self->texture->view,
      self->texture->image,
      VK_FORMAT_R8G8B8A8_UNORM, VK_IMAGE_ASPECT_COLOR_BIT);
  }
  catch(VK::Image::Error error)
  {
    throw CommandError{error.what()};
  }
}

void
unload_view(void *obj)
{
  auto self = static_cast<TextureBuilder*>(obj);

  vkDestroyImageView(
    cg_core.vk_device_with_swapchain->device, self->texture->view, nullptr);
}

const CommandChain loader{
  {&load_image, &unload_image},
  {&load_sampler, &unload_sampler},
  {&load_view, &unload_view}
};

}

namespace VK
{

Texture::Texture(std::string texture_path)
{
  TextureBuilder texture_builder(this, texture_path);
  loader.execute(&texture_builder);
}

Texture::Texture(const char* texture_path):
  Texture{std::string(texture_path)}
{
}

Texture::~Texture()
{
  TextureBuilder texture_builder(this, "");
  loader.revert(&texture_builder);
}

}