#include "VulkanUtils.hpp"

#include <cstring>
#include <stdexcept>

bool checkValidationLayerSupport(const std::vector<const char *>& validationLayers) {
  uint32_t layerCount;
  vkEnumerateInstanceLayerProperties(&layerCount, nullptr);

  std::vector<VkLayerProperties> availableLayers(layerCount);
  vkEnumerateInstanceLayerProperties(&layerCount, availableLayers.data());

  for (const auto &requestedLayer: validationLayers) {
    bool presents = false;
    for (auto &layer: availableLayers) {
      if (strcmp(requestedLayer, layer.layerName) == 0) {
        presents = true;
        break;
      }
    }

    if (!presents) return false;
  }

  return true;
}

bool checkDeviceExtensions(VkPhysicalDevice device, const std::vector<const char *>& deviceExtensions) {
  uint32_t extensionsCount = 0;
  vkEnumerateDeviceExtensionProperties(device, nullptr, &extensionsCount, nullptr);

  std::vector<VkExtensionProperties> extensions(extensionsCount);
  vkEnumerateDeviceExtensionProperties(device, nullptr, &extensionsCount, extensions.data());

  for (const auto &requiredExtension: deviceExtensions) {
    bool found = false;
    for (const auto &extension: extensions) {
      if (strcmp(requiredExtension, extension.extensionName) == 0) {
        found = true;
        break;
      }
    }
    if (!found) return false;
  }

  return true;
}

VkInstance createInstance(const char ** instanceExtensions, uint32_t extensionsCount, uint32_t apiVersion) {
  VkInstance out = VK_NULL_HANDLE;

  std::vector<const char *> validationLayers;

#ifndef NDEBUG
  const std::vector<const char *> requestedLayers = {"VK_LAYER_KHRONOS_validation"};
  if (checkValidationLayerSupport(requestedLayers)) {
    validationLayers = requestedLayers;
  }
#endif

  VkApplicationInfo appInfo{
      .sType = VK_STRUCTURE_TYPE_APPLICATION_INFO,
      .pApplicationName = "App",
      .applicationVersion = VK_MAKE_VERSION(0, 0, 0),
      .pEngineName = "no",
      .engineVersion = VK_MAKE_VERSION(0, 0, 0),
      .apiVersion = apiVersion,
  };

  VkInstanceCreateInfo createInfo{
      .sType = VK_STRUCTURE_TYPE_INSTANCE_CREATE_INFO,
      .pApplicationInfo = &appInfo,
      .enabledLayerCount = (uint32_t) validationLayers.size(),
      .ppEnabledLayerNames = validationLayers.data(),
      .enabledExtensionCount = extensionsCount,
      .ppEnabledExtensionNames = instanceExtensions,
  };

  if (vkCreateInstance(&createInfo, nullptr, &out) != VK_SUCCESS) {
    return VK_NULL_HANDLE;
  }

  return out;
}

VkPhysicalDevice pickPhysicalDevice(VkInstance instance, const PhysicalDevicePickPolicy& pickPolicy) {
  VkPhysicalDevice out = VK_NULL_HANDLE;

  uint32_t deviceCount = 0;
  vkEnumeratePhysicalDevices(instance, &deviceCount, nullptr);

  if (deviceCount == 0) {
    throw std::runtime_error("no gpu with vulkan support");
  }

  std::vector<VkPhysicalDevice> devices(deviceCount);
  vkEnumeratePhysicalDevices(instance, &deviceCount, devices.data());

  for (auto device: devices) {
    if (pickPolicy(device)) {
      out = device;
      break;
    }
  }

  return out;
}

int findQueueFamilyIndex(VkPhysicalDevice physicalDevice, const QueuePickPolicy& pickPolicy) {
  int out = -1;

  uint32_t queuesCount = 0;
  vkGetPhysicalDeviceQueueFamilyProperties(physicalDevice, &queuesCount, nullptr);

  std::vector<VkQueueFamilyProperties> queueFamilyProperties(queuesCount);
  vkGetPhysicalDeviceQueueFamilyProperties(physicalDevice, &queuesCount, queueFamilyProperties.data());

  int index = 0;
  for (const auto &familyProperty: queueFamilyProperties) {
    if (pickPolicy(familyProperty, index)) {
      out = index;
    }
    index++;
  }

  return out;
}

uint32_t findMemoryType(VkPhysicalDevice physicalDevice, uint32_t typeFilter, VkMemoryPropertyFlags flags) {
  VkPhysicalDeviceMemoryProperties memoryProperties;
  vkGetPhysicalDeviceMemoryProperties(physicalDevice, &memoryProperties);

  for (uint32_t i = 0; i < memoryProperties.memoryTypeCount; i++) {
    if (typeFilter & (1 << i) && (memoryProperties.memoryTypes[i].propertyFlags & flags) == flags) {
      return i;
    }
  }

  throw std::runtime_error("no suitable memory for vertex buffer found");
}