#include "xe_image.hpp"

#include <vulkan/vulkan.h>
#include <stdexcept>
#include <memory>
#include <cstring>

#define STB_IMAGE_IMPLEMENTATION
#include "stb_image.h"

namespace xe {

XeImage::XeImage(XeDevice &xeDevice, const std::string &filename) : xeDevice{xeDevice} {
  createTextureImage(filename);
  createTextureImageView();
}

XeImage::~XeImage() {
  vkDestroyImage(xeDevice.device(), textureImage, nullptr);
  vkFreeMemory(xeDevice.device(), textureImageMemory, nullptr);
  vkDestroyImageView(xeDevice.device(), textureImageView, nullptr);
}

void XeImage::createTextureImage(const std::string &filename) {
  int texWidth, texHeight, texChannels;
  stbi_uc* pixels = stbi_load(filename.c_str(), &texWidth, &texHeight, &texChannels, STBI_rgb_alpha);
  VkDeviceSize imageSize = texWidth * texHeight * 4;

  if (!pixels) {
      throw std::runtime_error("failed to load texture: " + filename);
  }

  VkBuffer stagingBuffer;
  VkDeviceMemory stagingBufferMemory;

  xeDevice.createBuffer(
    imageSize, 
    VK_BUFFER_USAGE_TRANSFER_SRC_BIT, 
    VK_MEMORY_PROPERTY_HOST_VISIBLE_BIT | VK_MEMORY_PROPERTY_HOST_COHERENT_BIT, 
    stagingBuffer, 
    stagingBufferMemory
  );

  void* data;
  vkMapMemory(xeDevice.device(), stagingBufferMemory, 0, imageSize, 0, &data);
  memcpy(data, pixels, static_cast<size_t>(imageSize));
  vkUnmapMemory(xeDevice.device(), stagingBufferMemory);

  stbi_image_free(pixels);

  createImage(texWidth, texHeight, VK_FORMAT_R8G8B8A8_SRGB, VK_IMAGE_TILING_OPTIMAL, VK_IMAGE_USAGE_TRANSFER_DST_BIT | VK_IMAGE_USAGE_SAMPLED_BIT, VK_MEMORY_PROPERTY_DEVICE_LOCAL_BIT, textureImage, textureImageMemory);

  transitionImageLayout(textureImage, VK_FORMAT_R8G8B8A8_SRGB, VK_IMAGE_LAYOUT_UNDEFINED, VK_IMAGE_LAYOUT_TRANSFER_DST_OPTIMAL);
  copyBufferToImage(stagingBuffer, textureImage, static_cast<uint32_t>(texWidth), static_cast<uint32_t>(texHeight));
  transitionImageLayout(textureImage, VK_FORMAT_R8G8B8A8_SRGB, VK_IMAGE_LAYOUT_TRANSFER_DST_OPTIMAL, VK_IMAGE_LAYOUT_SHADER_READ_ONLY_OPTIMAL);

  vkDestroyBuffer(xeDevice.device(), stagingBuffer, nullptr);
  vkFreeMemory(xeDevice.device(), stagingBufferMemory, nullptr);

}

void XeImage::createImage(uint32_t width, uint32_t height, VkFormat format, VkImageTiling tiling, VkImageUsageFlags usage, VkMemoryPropertyFlags properties, VkImage& image, VkDeviceMemory& imageMemory) {
    
    VkImageCreateInfo imageInfo{};
    imageInfo.sType = VK_STRUCTURE_TYPE_IMAGE_CREATE_INFO;
    imageInfo.imageType = VK_IMAGE_TYPE_2D;
    imageInfo.extent.width = width;
    imageInfo.extent.height = height;
    imageInfo.extent.depth = 1;
    imageInfo.mipLevels = 1;
    imageInfo.arrayLayers = 1;
    imageInfo.format = format;
    imageInfo.tiling = tiling;
    imageInfo.initialLayout = VK_IMAGE_LAYOUT_UNDEFINED;
    imageInfo.usage = usage;
    imageInfo.samples = VK_SAMPLE_COUNT_1_BIT;
    imageInfo.sharingMode = VK_SHARING_MODE_EXCLUSIVE;

    if (vkCreateImage(xeDevice.device(), &imageInfo, nullptr, &image) != VK_SUCCESS) {
        throw std::runtime_error("failed to create image!");
    }

    VkMemoryRequirements memRequirements;
    vkGetImageMemoryRequirements(xeDevice.device(), image, &memRequirements);

    VkMemoryAllocateInfo allocInfo{};
    allocInfo.sType = VK_STRUCTURE_TYPE_MEMORY_ALLOCATE_INFO;
    allocInfo.allocationSize = memRequirements.size;
    allocInfo.memoryTypeIndex = xeDevice.findMemoryType(memRequirements.memoryTypeBits, properties);

    if (vkAllocateMemory(xeDevice.device(), &allocInfo, nullptr, &imageMemory) != VK_SUCCESS) {
        throw std::runtime_error("failed to allocate image memory!");
    }

    vkBindImageMemory(xeDevice.device(), image, imageMemory, 0);
}

void XeImage::transitionImageLayout(VkImage image, VkFormat format, VkImageLayout oldLayout, VkImageLayout newLayout) {
    VkCommandBuffer commandBuffer = xeDevice.beginSingleTimeCommands();

    VkImageMemoryBarrier barrier{};
    barrier.sType = VK_STRUCTURE_TYPE_IMAGE_MEMORY_BARRIER;
    barrier.oldLayout = oldLayout;
    barrier.newLayout = newLayout;
    barrier.srcQueueFamilyIndex = VK_QUEUE_FAMILY_IGNORED;
    barrier.dstQueueFamilyIndex = VK_QUEUE_FAMILY_IGNORED;
    barrier.image = 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;

    VkPipelineStageFlags sourceStage;
    VkPipelineStageFlags destinationStage;

    if (oldLayout == VK_IMAGE_LAYOUT_UNDEFINED && newLayout == VK_IMAGE_LAYOUT_TRANSFER_DST_OPTIMAL) {
        barrier.srcAccessMask = 0;
        barrier.dstAccessMask = VK_ACCESS_TRANSFER_WRITE_BIT;

        sourceStage = VK_PIPELINE_STAGE_TOP_OF_PIPE_BIT;
        destinationStage = VK_PIPELINE_STAGE_TRANSFER_BIT;
    } else if (oldLayout == VK_IMAGE_LAYOUT_TRANSFER_DST_OPTIMAL && newLayout == VK_IMAGE_LAYOUT_SHADER_READ_ONLY_OPTIMAL) {
        barrier.srcAccessMask = VK_ACCESS_TRANSFER_WRITE_BIT;
        barrier.dstAccessMask = VK_ACCESS_SHADER_READ_BIT;

        sourceStage = VK_PIPELINE_STAGE_TRANSFER_BIT;
        destinationStage = VK_PIPELINE_STAGE_FRAGMENT_SHADER_BIT;
    } else {
        throw std::invalid_argument("unsupported layout transition!");
    }

    vkCmdPipelineBarrier(
        commandBuffer,
        sourceStage, destinationStage,
        0,
        0, nullptr,
        0, nullptr,
        1, &barrier
    );

    xeDevice.endSingleTimeCommands(commandBuffer);
}

void XeImage::copyBufferToImage(VkBuffer buffer, VkImage image, uint32_t width, uint32_t height) {
  VkCommandBuffer commandBuffer = xeDevice.beginSingleTimeCommands();
  
  VkBufferImageCopy region{};
  region.bufferOffset = 0;
  region.bufferRowLength = 0;
  region.bufferImageHeight = 0;
  region.imageSubresource.aspectMask = VK_IMAGE_ASPECT_COLOR_BIT;
  region.imageSubresource.mipLevel = 0;
  region.imageSubresource.baseArrayLayer = 0;
  region.imageSubresource.layerCount = 1;
  region.imageOffset = {0, 0, 0};
  region.imageExtent = {
    width,
    height,
    1
  };

  vkCmdCopyBufferToImage(commandBuffer, buffer, image, VK_IMAGE_LAYOUT_TRANSFER_DST_OPTIMAL, 1, &region);

  xeDevice.endSingleTimeCommands(commandBuffer);
}

void XeImage::createTextureImageView() {
    VkImageViewCreateInfo viewInfo{};
    viewInfo.sType = VK_STRUCTURE_TYPE_IMAGE_VIEW_CREATE_INFO;
    viewInfo.image = textureImage;
    viewInfo.viewType = VK_IMAGE_VIEW_TYPE_2D;
    viewInfo.format = VK_FORMAT_R8G8B8A8_SRGB;
    viewInfo.subresourceRange.aspectMask = VK_IMAGE_ASPECT_COLOR_BIT;
    viewInfo.subresourceRange.baseMipLevel = 0;
    viewInfo.subresourceRange.levelCount = 1;
    viewInfo.subresourceRange.baseArrayLayer = 0;
    viewInfo.subresourceRange.layerCount = 1;

    if (vkCreateImageView(xeDevice.device(), &viewInfo, nullptr, &textureImageView) != VK_SUCCESS) {
    throw std::runtime_error("failed to create texture image view!");
    }
}

}