// VulkanTutorial.cpp: 定义应用程序的入口点。
//

#include "VulkanTutorial.h"

const int Width = 800;
const int Height = 600;

const std::vector<const char*> validationLayers = {
	"VK_LAYER_KHRONOS_validation"

};

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

//window init
GLFWwindow* HelloTriangleApplication::initWindow(int Width, int Height) {
	glfwInit();
	glfwWindowHint(GLFW_CLIENT_API, GLFW_NO_API);
	glfwWindowHint(GLFW_RESIZABLE, GLFW_FALSE);
	window = glfwCreateWindow(Width, Height, "vulkan", nullptr, nullptr);
	return window;
}
// vulkan instace create
void HelloTriangleApplication::createInstance() {

	// check validation layers
	if (enableValidationLayers && ! checkValidationLayerSupport())
	{
		throw std::runtime_error("validation layers requsted,but not available");
	}

	//setup appliaction info
	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;

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

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

	/* enable glfw extension in creatInfo
	uint32_t glfwExtentionCount = 0;
	const char** glfwExtensions;
	glfwExtensions = glfwGetRequiredInstanceExtensions(&glfwExtentionCount);
	createInfo.enabledExtensionCount = glfwExtentionCount;
	createInfo.ppEnabledExtensionNames = glfwExtensions;
	*/

	// enable validation layer if available in createInfo
	VkDebugUtilsMessengerCreateInfoEXT debugCreateInfo{};
	if (enableValidationLayers)
	{
		createInfo.enabledLayerCount = static_cast<uint32_t>(validationLayers.size());
		createInfo.ppEnabledLayerNames = validationLayers.data();

		populateDebugMessengerCreateInfo(debugCreateInfo);
		createInfo.pNext = (VkDebugUtilsMessengerCreateInfoEXT*) &debugCreateInfo;
	}
	else
	{
		createInfo.enabledLayerCount = 0;
		
		createInfo.pNext = nullptr;
	}

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

	// show available extensions
	
	uint32_t availableExtensionCount = 0;
	vkEnumerateInstanceExtensionProperties(nullptr, &availableExtensionCount, nullptr);
	std::vector<VkExtensionProperties> availableExtensions(availableExtensionCount);
	vkEnumerateInstanceExtensionProperties(nullptr, &availableExtensionCount, availableExtensions.data());
	std::cout << "available extensions :" << std::endl;
	for (const auto& extension : availableExtensions)
	{
		std::cout << "\t" << extension.extensionName << " ver:" << extension.specVersion << std::endl;
	}

}



void HelloTriangleApplication::initVulkan() {

	createInstance();

	setupDebugMessenger();

}



void HelloTriangleApplication::mainLoop(GLFWwindow* window){

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

}



void HelloTriangleApplication::cleanup(GLFWwindow* window) {

	if (enableValidationLayers)
	{
		DestroyDebugUtilsMessengerEXT(instance, debugMessenger, nullptr);
	}

	vkDestroyInstance(instance, nullptr);
	
	glfwDestroyWindow(window);

	glfwTerminate();
}

std::vector<const char*> HelloTriangleApplication::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_UTILS_EXTENSION_NAME);
		
	}

	return extensions;

}

VKAPI_ATTR VkBool32 VKAPI_CALL HelloTriangleApplication::debugCallback(
	VkDebugUtilsMessageSeverityFlagBitsEXT messageSeverity,
	VkDebugUtilsMessageTypeFlagsEXT messageTypes,
	const VkDebugUtilsMessengerCallbackDataEXT* pCallbackData,
	void* pUserData)
{
	std::cerr << "validation layer: " << pCallbackData->pMessage << std::endl;

	return VK_FALSE;
}

void HelloTriangleApplication::setupDebugMessenger()
{
	if (! enableValidationLayers)
	{
		return;
	}

	VkDebugUtilsMessengerCreateInfoEXT createInfo{};
	populateDebugMessengerCreateInfo(createInfo);


	if (CreateDebugUtilsMessengerEXT(instance,&createInfo,nullptr,&debugMessenger)!= VK_SUCCESS)
	{
		throw std::runtime_error("failed to set up debug messenger in setupDebugMessenger");
	}

}

void HelloTriangleApplication::populateDebugMessengerCreateInfo(VkDebugUtilsMessengerCreateInfoEXT& createInfo)
{
	
	createInfo.sType = VK_STRUCTURE_TYPE_DEBUG_UTILS_MESSENGER_CREATE_INFO_EXT;
	createInfo.messageSeverity = VK_DEBUG_UTILS_MESSAGE_SEVERITY_VERBOSE_BIT_EXT |
								 VK_DEBUG_UTILS_MESSAGE_SEVERITY_WARNING_BIT_EXT |
								 VK_DEBUG_UTILS_MESSAGE_SEVERITY_ERROR_BIT_EXT;
	createInfo.messageType = VK_DEBUG_UTILS_MESSAGE_TYPE_GENERAL_BIT_EXT |
							 VK_DEBUG_UTILS_MESSAGE_TYPE_VALIDATION_BIT_EXT |
							 VK_DEBUG_UTILS_MESSAGE_TYPE_PERFORMANCE_BIT_EXT;
	createInfo.pfnUserCallback = &debugCallback;
	createInfo.pUserData = nullptr;

}

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

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

	// check if validationLayers can be found in availableLayers
	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;
}


VkResult CreateDebugUtilsMessengerEXT(VkInstance instance, const VkDebugUtilsMessengerCreateInfoEXT* pCreateInfo, const VkAllocationCallbacks* pAllocator, VkDebugUtilsMessengerEXT* pDebugMessenger)
{
	auto func = (PFN_vkCreateDebugUtilsMessengerEXT) vkGetInstanceProcAddr(instance, "vkCreateDebugUtilsMessengerEXT");

	if (func != nullptr)
	{
		return func(instance, pCreateInfo, pAllocator, pDebugMessenger);

	}
	else
	{
		return VK_ERROR_EXTENSION_NOT_PRESENT;
	}

}

void DestroyDebugUtilsMessengerEXT(VkInstance instance, VkDebugUtilsMessengerEXT debugMessenger, const VkAllocationCallbacks* pAllocator)
{
	auto func = (PFN_vkDestroyDebugUtilsMessengerEXT)vkGetInstanceProcAddr(instance, "vkDestroyDebugUtilsMessengerEXT");

		if (func!=nullptr)
		{
			func(instance, debugMessenger, pAllocator);
		}
}


int main()
{
	HelloTriangleApplication app;

	try
	{
		app.run(Width,Height);
	}
	catch (const std::exception& e)
	{
		std::cerr << e.what() << std::endl;
		return EXIT_FAILURE;
	}
	return EXIT_SUCCESS;
}