#define GLFW_INCLUDE_VULKAN
#include <GLFW/glfw3.h>

#include <iostream>
#include <stdexcept>
#include <vector>
#include <cstring>
#include <cstdlib>

const int WIDTH = 800;
const int HEIGHT = 600;

const std::vector<const char*> validationLayers = {
 "VK_LAYER_LUNARG_standard_validation"
};

#ifdef NDEBUG
const bool enableValidationLayers = false;
#else
const bool enableValidationLayers = true;
#endif

VkResult CreateDebugReportCallbackEXT(VkInstance instance, const VkDebugReportCallbackCreateInfoEXT* pCreateInfo, const VkAllocationCallbacks* pAllocator, VkDebugReportCallbackEXT* pCallback) {
 auto func = (PFN_vkCreateDebugReportCallbackEXT) vkGetInstanceProcAddr(instance, "vkCreateDebugReportCallbackEXT");
 if (func != nullptr) {
 return func(instance, pCreateInfo, pAllocator, pCallback);
 } else {
 return VK_ERROR_EXTENSION_NOT_PRESENT;
 }
}

void DestroyDebugReportCallbackEXT(VkInstance instance, VkDebugReportCallbackEXT callback, const VkAllocationCallbacks* pAllocator) {
 auto func = (PFN_vkDestroyDebugReportCallbackEXT) vkGetInstanceProcAddr(instance, "vkDestroyDebugReportCallbackEXT");
 if (func != nullptr) {
 func(instance, callback, pAllocator);
 }
}

struct QueueFamilyIndices {
 int graphicsFamily = -1;

 bool isComplete() {
 return graphicsFamily >= 0;
 }
};

class HelloTriangleApplication {
public:
 void run() {
 initWindow();
 initVulkan();
 mainLoop();
 cleanup();
 }

private:
 GLFWwindow* window;

 VkInstance instance;
 VkDebugReportCallbackEXT callback;

 VkPhysicalDevice physicalDevice = VK_NULL_HANDLE;
 VkDevice device;

 VkQueue graphicsQueue;

 void initWindow() {
 glfwInit();

 glfwWindowHint(GLFW_CLIENT_API, GLFW_NO_API);
 glfwWindowHint(GLFW_RESIZABLE, GLFW_FALSE);

 window = glfwCreateWindow(WIDTH, HEIGHT, "Vulkan", nullptr, nullptr);
 }

 void initVulkan() {
 createInstance();
 setupDebugCallback();
 pickPhysicalDevice();
 createLogicalDevice();
 }

 void mainLoop() {
 while (!glfwWindowShouldClose(window)) {
 glfwPollEvents();
 }
 }

 void cleanup() {
 vkDestroyDevice(device, nullptr);

 if (enableValidationLayers) {
 DestroyDebugReportCallbackEXT(instance, callback, nullptr);
 }

 vkDestroyInstance(instance, nullptr);

 glfwDestroyWindow(window);

 glfwTerminate();
 }

 void createInstance() {
 if (enableValidationLayers && !checkValidationLayerSupport()) {
 throw std::runtime_error("validation layers requested, but not available!");
 }

 VkApplicationInfo appInfo = {};
 appInfo.sType = VK_STRUCTURE_TYPE_APPLICATION_INFO;
 appInfo.pApplicationName = "Hello Triangle";
 appInfo.applicationVersion = VK_MAKE_VERSION(1, 0, 0);
 appInfo.pEngineName = "No Engine";
 appInfo.engineVersion = VK_MAKE_VERSION(1, 0, 0);
 appInfo.apiVersion = VK_API_VERSION_1_0;

 VkInstanceCreateInfo createInfo = {};
 createInfo.sType = VK_STRUCTURE_TYPE_INSTANCE_CREATE_INFO;
 createInfo.pApplicationInfo = &appInfo;

 auto extensions = getRequiredExtensions();
 createInfo.enabledExtensionCount = static_cast<uint32_t>(extensions.size());
 createInfo.ppEnabledExtensionNames = extensions.data();

 if (enableValidationLayers) {
 createInfo.enabledLayerCount = static_cast<uint32_t>(validationLayers.size());
 createInfo.ppEnabledLayerNames = validationLayers.data();
 } else {
 createInfo.enabledLayerCount = 0;
 }

 if (vkCreateInstance(&createInfo, nullptr, &instance) != VK_SUCCESS) {
 throw std::runtime_error("failed to create instance!");
 }
 }

 void setupDebugCallback() {
 if (!enableValidationLayers) return;

 VkDebugReportCallbackCreateInfoEXT createInfo = {};
 createInfo.sType = VK_STRUCTURE_TYPE_DEBUG_REPORT_CALLBACK_CREATE_INFO_EXT;
 createInfo.flags = VK_DEBUG_REPORT_ERROR_BIT_EXT | VK_DEBUG_REPORT_WARNING_BIT_EXT;
 createInfo.pfnCallback = debugCallback;

 if (CreateDebugReportCallbackEXT(instance, &createInfo, nullptr, &callback) != VK_SUCCESS) {
 throw std::runtime_error("failed to set up debug callback!");
 }
 }

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

 if (deviceCount == 0) {
 throw std::runtime_error("failed to find GPUs with Vulkan support!");
 }

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

 for (const auto& device : devices) {
 if (isDeviceSuitable(device)) {
 physicalDevice = device;
 break;
 }
 }

 if (physicalDevice == VK_NULL_HANDLE) {
 throw std::runtime_error("failed to find a suitable GPU!");
 }
 }

 void createLogicalDevice() {
 QueueFamilyIndices indices = findQueueFamilies(physicalDevice);

 VkDeviceQueueCreateInfo queueCreateInfo = {};
 queueCreateInfo.sType = VK_STRUCTURE_TYPE_DEVICE_QUEUE_CREATE_INFO;
 queueCreateInfo.queueFamilyIndex = indices.graphicsFamily;
 queueCreateInfo.queueCount = 1;

 float queuePriority = 1.0f;
 queueCreateInfo.pQueuePriorities = &queuePriority;

 VkPhysicalDeviceFeatures deviceFeatures = {};

 VkDeviceCreateInfo createInfo = {};
 createInfo.sType = VK_STRUCTURE_TYPE_DEVICE_CREATE_INFO;

 createInfo.pQueueCreateInfos = &queueCreateInfo;
 createInfo.queueCreateInfoCount = 1;

 createInfo.pEnabledFeatures = &deviceFeatures;

 createInfo.enabledExtensionCount = 0;

 if (enableValidationLayers) {
 createInfo.enabledLayerCount = static_cast<uint32_t>(validationLayers.size());
 createInfo.ppEnabledLayerNames = validationLayers.data();
 } else {
 createInfo.enabledLayerCount = 0;
 }

 if (vkCreateDevice(physicalDevice, &createInfo, nullptr, &device) != VK_SUCCESS) {
 throw std::runtime_error("failed to create logical device!");
 }

 vkGetDeviceQueue(device, indices.graphicsFamily, 0, &graphicsQueue);
 }

 bool isDeviceSuitable(VkPhysicalDevice device) {
 QueueFamilyIndices indices = findQueueFamilies(device);

 return indices.isComplete();
 }

 QueueFamilyIndices findQueueFamilies(VkPhysicalDevice device) {
 QueueFamilyIndices indices;

 uint32_t queueFamilyCount = 0;
 vkGetPhysicalDeviceQueueFamilyProperties(device, &queueFamilyCount, nullptr);

 std::vector<VkQueueFamilyProperties> queueFamilies(queueFamilyCount);
 vkGetPhysicalDeviceQueueFamilyProperties(device, &queueFamilyCount, queueFamilies.data());

 int i = 0;
 for (const auto& queueFamily : queueFamilies) {
 if (queueFamily.queueCount > 0 && queueFamily.queueFlags & VK_QUEUE_GRAPHICS_BIT) {
 indices.graphicsFamily = i;
 }

 if (indices.isComplete()) {
 break;
 }

 i++;
 }

 return indices;
 }

 std::vector<const char*> getRequiredExtensions() {
 uint32_t glfwExtensionCount = 0;
 const char** glfwExtensions;
 glfwExtensions = glfwGetRequiredInstanceExtensions(&glfwExtensionCount);

 std::vector<const char*> extensions(glfwExtensions, glfwExtensions + glfwExtensionCount);

 if (enableValidationLayers) {
 extensions.push_back(VK_EXT_DEBUG_REPORT_EXTENSION_NAME);
 }

 return extensions;
 }

 bool checkValidationLayerSupport() {
 uint32_t layerCount;
 vkEnumerateInstanceLayerProperties(&layerCount, nullptr);

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

 for (const char* layerName : validationLayers) {
 bool layerFound = false;

 for (const auto& layerProperties : availableLayers) {
 if (strcmp(layerName, layerProperties.layerName) == 0) {
 layerFound = true;
 break;
 }
 }

 if (!layerFound) {
 return false;
 }
 }

 return true;
 }

 static VKAPI_ATTR VkBool32 VKAPI_CALL debugCallback(VkDebugReportFlagsEXT flags, VkDebugReportObjectTypeEXT objType, uint64_t obj, size_t location, int32_t code, const char* layerPrefix, const char* msg, void* userData) {
 std::cerr << "validation layer: " << msg << std::endl;

 return VK_FALSE;
 }
};

int main() {
 HelloTriangleApplication app;

 try {
 app.run();
 } catch (const std::runtime_error& e) {
 std::cerr << e.what() << std::endl;
 return EXIT_FAILURE;
 }

 return EXIT_SUCCESS;
}