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

#include <iostream>
#include <stdexcept>
#include <cstdlib>
#include <vector>
#include <algorithm>
#include <string>
#include <sstream>

#include "Logger.h"

const uint32_t WIDTH = 800;
const uint32_t HEIGHT = 600;

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

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

class HelloTriangleApplication
{

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

		return VK_FALSE;
	}

private:
	GLFWwindow* window;

	VkInstance instance;

	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_UTILS_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;
	}

	// VkResult vkCreateInstance(
	//     const VkInstanceCreateInfo* pCreateInfo,
	//     const VkAllocationCallbacks* pAllocator,
	//     VkInstance* instance)
	//{
	//     if (pCreateInfo == nullptr || instance == nullptr) {
	//         log("Null pointer passed to required parameter!");
	//         return VK_ERROR_INITIALIZATION_FAILED;
	//     }

	//    return vkCreateInstance(pCreateInfo, pAllocator, instance);
	//}

public:
	void Run()
	{
		InitWindow();
		InitVulkan();
		MainLoop();
		Cleanup();
	}

private:
	void CheckExtensions(const char* requiredExtensions[], uint32_t requiredExtensionsCount)
	{
		uint32_t extensionCount = 0;
		vkEnumerateInstanceExtensionProperties(nullptr, &extensionCount, nullptr);

		std::vector<VkExtensionProperties> extensions(extensionCount);
		vkEnumerateInstanceExtensionProperties(nullptr, &extensionCount, extensions.data());

		std::string required;
		std::string available;

		required += "Required extensions:\n";

		bool found = false;
		for (uint32_t i = 0; i < requiredExtensionsCount; i++)
		{
			std::string requiredExtension = requiredExtensions[i];

			for (const auto& extension : extensions)
			{
				found = strcmp(extension.extensionName, requiredExtensions[i]);
				if (found)
				{
					break;
				}
			}

			std::string status = found ? "FOUND" : "NOT FOUND";
			required += "\t" + requiredExtension + " : " + status + "\n";
		}

		available += "available extensions:\n";

		for (const auto& extension : extensions)
		{
			std::string extensionName = extension.extensionName;
			available += "\t" + extensionName + "\n";
		}

		log(INFO, required);
		log(INFO, available);
	}

	void CreateInstance()
	{
		log(INFO, "Creating Vulkan instance");

		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;

		uint32_t	 glfwExtensionCount = 0;
		const char** glfwExtensions;
		glfwExtensions = glfwGetRequiredInstanceExtensions(&glfwExtensionCount);

		createInfo.enabledExtensionCount = glfwExtensionCount;
		createInfo.ppEnabledExtensionNames = glfwExtensions;

		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!");
		}

		CheckExtensions(glfwExtensions, glfwExtensionCount);

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

	void InitWindow()
	{
		log(INFO, "Initializing GLFW window...");

		glfwInit();

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

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

	void InitVulkan()
	{
		log(INFO, "Initializing Vulkan...");
		CreateInstance();
	}

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

	void Cleanup()
	{
		vkDestroyInstance(instance, nullptr);

		glfwDestroyWindow(window);

		glfwTerminate();
	}
};

int main()
{
	HelloTriangleApplication app;

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

	return EXIT_SUCCESS;
}