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

#define GLM_FORCE_RADIANS
#include <glm/glm.hpp>
#include <glm/gtc/matrix_transform.hpp>

#define STB_IMAGE_IMPLEMENTATION
#include <stb_image.h>

#include <iostream>
#include <fstream>
#include <stdexcept>
#include <algorithm>
#include <chrono>
#include <vector>
#include <cstring>
#include <array>
#include <set>

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

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

const std::vector<const char*> deviceExtensions = {
    VK_KHR_SWAPCHAIN_EXTENSION_NAME
};

#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;
    int presentFamily = -1;

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

struct SwapChainSupportDetails {
    VkSurfaceCapabilitiesKHR capabilities;
    std::vector<VkSurfaceFormatKHR> formats;
    std::vector<VkPresentModeKHR> presentModes;
};

struct Vertex {
    glm::vec2 pos;
    glm::vec3 color;

    static VkVertexInputBindingDescription getBindingDescription() {
        VkVertexInputBindingDescription bindingDescription = {};
        bindingDescription.binding = 0;
        bindingDescription.stride = sizeof(Vertex);
        bindingDescription.inputRate = VK_VERTEX_INPUT_RATE_VERTEX;

        return bindingDescription;
    }

    static std::array<VkVertexInputAttributeDescription, 2> getAttributeDescriptions() {
        std::array<VkVertexInputAttributeDescription, 2> attributeDescriptions = {};

        attributeDescriptions[0].binding = 0;
        attributeDescriptions[0].location = 0;
        attributeDescriptions[0].format = VK_FORMAT_R32G32_SFLOAT;
        attributeDescriptions[0].offset = offsetof(Vertex, pos);

        attributeDescriptions[1].binding = 0;
        attributeDescriptions[1].location = 1;
        attributeDescriptions[1].format = VK_FORMAT_R32G32B32_SFLOAT;
        attributeDescriptions[1].offset = offsetof(Vertex, color);

        return attributeDescriptions;
    }
};

struct UniformBufferObject {
    glm::mat4 model;
    glm::mat4 view;
    glm::mat4 proj;
};

const std::vector<Vertex> vertices = {
    {{-0.5f, -0.5f}, {1.0f, 0.0f, 0.0f}},
    {{0.5f, -0.5f}, {0.0f, 1.0f, 0.0f}},
    {{0.5f, 0.5f}, {0.0f, 0.0f, 1.0f}},
    {{-0.5f, 0.5f}, {1.0f, 1.0f, 1.0f}}
};

const std::vector<uint16_t> indices = {
    0, 1, 2, 2, 3, 0
};

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

private:
    GLFWwindow* window;

    VkInstance instance;
    VkDebugReportCallbackEXT callback;
    VkSurfaceKHR surface;

    VkPhysicalDevice physicalDevice = VK_NULL_HANDLE;
    VkDevice device;

    VkQueue graphicsQueue;
    VkQueue presentQueue;

    VkSwapchainKHR swapChain;
    std::vector<VkImage> swapChainImages;
    VkFormat swapChainImageFormat;
    VkExtent2D swapChainExtent;
    std::vector<VkImageView> swapChainImageViews;
    std::vector<VkFramebuffer> swapChainFramebuffers;

    VkRenderPass renderPass;
    VkDescriptorSetLayout descriptorSetLayout;
    VkPipelineLayout pipelineLayout;
    VkPipeline graphicsPipeline;

    VkCommandPool commandPool;

    VkImage textureImage;
    VkDeviceMemory textureImageMemory;

    VkBuffer vertexBuffer;
    VkDeviceMemory vertexBufferMemory;
    VkBuffer indexBuffer;
    VkDeviceMemory indexBufferMemory;

    VkBuffer uniformBuffer;
    VkDeviceMemory uniformBufferMemory;

    VkDescriptorPool descriptorPool;
    VkDescriptorSet descriptorSet;

    std::vector<VkCommandBuffer> commandBuffers;

    VkSemaphore imageAvailableSemaphore;
    VkSemaphore renderFinishedSemaphore;

    void initWindow() {
        glfwInit();

        glfwWindowHint(GLFW_CLIENT_API, GLFW_NO_API);

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

        glfwSetWindowUserPointer(window, this);
        glfwSetWindowSizeCallback(window, HelloTriangleApplication::onWindowResized);
    }

    void initVulkan() {
        createInstance();
        setupDebugCallback();
        createSurface();
        pickPhysicalDevice();
        createLogicalDevice();
        createSwapChain();
        createImageViews();
        createRenderPass();
        createDescriptorSetLayout();
        createGraphicsPipeline();
        createFramebuffers();
        createCommandPool();
        createTextureImage();
        createVertexBuffer();
        createIndexBuffer();
        createUniformBuffer();
        createDescriptorPool();
        createDescriptorSet();
        createCommandBuffers();
        createSemaphores();
    }

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

            updateUniformBuffer();
            drawFrame();
        }

        vkDeviceWaitIdle(device);
    }

    void cleanupSwapChain() {
        for (size_t i = 0; i < swapChainFramebuffers.size(); i++) {
            vkDestroyFramebuffer(device, swapChainFramebuffers[i], nullptr);
        }

        vkFreeCommandBuffers(device, commandPool, static_cast<uint32_t>(commandBuffers.size()), commandBuffers.data());

        vkDestroyPipeline(device, graphicsPipeline, nullptr);
        vkDestroyPipelineLayout(device, pipelineLayout, nullptr);
        vkDestroyRenderPass(device, renderPass, nullptr);

        for (size_t i = 0; i < swapChainImageViews.size(); i++) {
            vkDestroyImageView(device, swapChainImageViews[i], nullptr);
        }

        vkDestroySwapchainKHR(device, swapChain, nullptr);
    }

    void cleanup() {
        cleanupSwapChain();

        vkDestroyImage(device, textureImage, nullptr);
        vkFreeMemory(device, textureImageMemory, nullptr);

        vkDestroyDescriptorPool(device, descriptorPool, nullptr);

        vkDestroyDescriptorSetLayout(device, descriptorSetLayout, nullptr);
        vkDestroyBuffer(device, uniformBuffer, nullptr);
        vkFreeMemory(device, uniformBufferMemory, nullptr);

        vkDestroyBuffer(device, indexBuffer, nullptr);
        vkFreeMemory(device, indexBufferMemory, nullptr);

        vkDestroyBuffer(device, vertexBuffer, nullptr);
        vkFreeMemory(device, vertexBufferMemory, nullptr);

        vkDestroySemaphore(device, renderFinishedSemaphore, nullptr);
        vkDestroySemaphore(device, imageAvailableSemaphore, nullptr);

        vkDestroyCommandPool(device, commandPool, nullptr);

        vkDestroyDevice(device, nullptr);
        DestroyDebugReportCallbackEXT(instance, callback, nullptr);
        vkDestroySurfaceKHR(instance, surface, nullptr);
        vkDestroyInstance(instance, nullptr);

        glfwDestroyWindow(window);

        glfwTerminate();
    }

    static void onWindowResized(GLFWwindow* window, int width, int height) {
        if (width == 0 || height == 0) return;

        HelloTriangleApplication* app = reinterpret_cast<HelloTriangleApplication*>(glfwGetWindowUserPointer(window));
        app->recreateSwapChain();
    }

    void recreateSwapChain() {
        vkDeviceWaitIdle(device);

        cleanupSwapChain();

        createSwapChain();
        createImageViews();
        createRenderPass();
        createGraphicsPipeline();
        createFramebuffers();
        createCommandBuffers();
    }

    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 createSurface() {
        if (glfwCreateWindowSurface(instance, window, nullptr, &surface) != VK_SUCCESS) {
            throw std::runtime_error("failed to create window surface!");
        }
    }

    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);

        std::vector<VkDeviceQueueCreateInfo> queueCreateInfos;
        std::set<int> uniqueQueueFamilies = {indices.graphicsFamily, indices.presentFamily};

        float queuePriority = 1.0f;
        for (int queueFamily : uniqueQueueFamilies) {
            VkDeviceQueueCreateInfo queueCreateInfo = {};
            queueCreateInfo.sType = VK_STRUCTURE_TYPE_DEVICE_QUEUE_CREATE_INFO;
            queueCreateInfo.queueFamilyIndex = queueFamily;
            queueCreateInfo.queueCount = 1;
            queueCreateInfo.pQueuePriorities = &queuePriority;
            queueCreateInfos.push_back(queueCreateInfo);
        }

        VkPhysicalDeviceFeatures deviceFeatures = {};

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

        createInfo.queueCreateInfoCount = static_cast<uint32_t>(queueCreateInfos.size());
        createInfo.pQueueCreateInfos = queueCreateInfos.data();

        createInfo.pEnabledFeatures = &deviceFeatures;

        createInfo.enabledExtensionCount = static_cast<uint32_t>(deviceExtensions.size());
        createInfo.ppEnabledExtensionNames = deviceExtensions.data();

        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);
        vkGetDeviceQueue(device, indices.presentFamily, 0, &presentQueue);
    }

    void createSwapChain() {
        SwapChainSupportDetails swapChainSupport = querySwapChainSupport(physicalDevice);

        VkSurfaceFormatKHR surfaceFormat = chooseSwapSurfaceFormat(swapChainSupport.formats);
        VkPresentModeKHR presentMode = chooseSwapPresentMode(swapChainSupport.presentModes);
        VkExtent2D extent = chooseSwapExtent(swapChainSupport.capabilities);

        uint32_t imageCount = swapChainSupport.capabilities.minImageCount + 1;
        if (swapChainSupport.capabilities.maxImageCount > 0 && imageCount > swapChainSupport.capabilities.maxImageCount) {
            imageCount = swapChainSupport.capabilities.maxImageCount;
        }

        VkSwapchainCreateInfoKHR createInfo = {};
        createInfo.sType = VK_STRUCTURE_TYPE_SWAPCHAIN_CREATE_INFO_KHR;
        createInfo.surface = surface;

        createInfo.minImageCount = imageCount;
        createInfo.imageFormat = surfaceFormat.format;
        createInfo.imageColorSpace = surfaceFormat.colorSpace;
        createInfo.imageExtent = extent;
        createInfo.imageArrayLayers = 1;
        createInfo.imageUsage = VK_IMAGE_USAGE_COLOR_ATTACHMENT_BIT;

        QueueFamilyIndices indices = findQueueFamilies(physicalDevice);
        uint32_t queueFamilyIndices[] = {(uint32_t) indices.graphicsFamily, (uint32_t) indices.presentFamily};

        if (indices.graphicsFamily != indices.presentFamily) {
            createInfo.imageSharingMode = VK_SHARING_MODE_CONCURRENT;
            createInfo.queueFamilyIndexCount = 2;
            createInfo.pQueueFamilyIndices = queueFamilyIndices;
        } else {
            createInfo.imageSharingMode = VK_SHARING_MODE_EXCLUSIVE;
        }

        createInfo.preTransform = swapChainSupport.capabilities.currentTransform;
        createInfo.compositeAlpha = VK_COMPOSITE_ALPHA_OPAQUE_BIT_KHR;
        createInfo.presentMode = presentMode;
        createInfo.clipped = VK_TRUE;

        if (vkCreateSwapchainKHR(device, &createInfo, nullptr, &swapChain) != VK_SUCCESS) {
            throw std::runtime_error("failed to create swap chain!");
        }

        vkGetSwapchainImagesKHR(device, swapChain, &imageCount, nullptr);
        swapChainImages.resize(imageCount);
        vkGetSwapchainImagesKHR(device, swapChain, &imageCount, swapChainImages.data());

        swapChainImageFormat = surfaceFormat.format;
        swapChainExtent = extent;
    }

    void createImageViews() {
        swapChainImageViews.resize(swapChainImages.size());

        for (size_t i = 0; i < swapChainImages.size(); i++) {
            VkImageViewCreateInfo createInfo = {};
            createInfo.sType = VK_STRUCTURE_TYPE_IMAGE_VIEW_CREATE_INFO;
            createInfo.image = swapChainImages[i];
            createInfo.viewType = VK_IMAGE_VIEW_TYPE_2D;
            createInfo.format = swapChainImageFormat;
            createInfo.components.r = VK_COMPONENT_SWIZZLE_IDENTITY;
            createInfo.components.g = VK_COMPONENT_SWIZZLE_IDENTITY;
            createInfo.components.b = VK_COMPONENT_SWIZZLE_IDENTITY;
            createInfo.components.a = VK_COMPONENT_SWIZZLE_IDENTITY;
            createInfo.subresourceRange.aspectMask = VK_IMAGE_ASPECT_COLOR_BIT;
            createInfo.subresourceRange.baseMipLevel = 0;
            createInfo.subresourceRange.levelCount = 1;
            createInfo.subresourceRange.baseArrayLayer = 0;
            createInfo.subresourceRange.layerCount = 1;

            if (vkCreateImageView(device, &createInfo, nullptr, &swapChainImageViews[i]) != VK_SUCCESS) {
                throw std::runtime_error("failed to create image views!");
            }
        }
    }

    void createRenderPass() {
        VkAttachmentDescription colorAttachment = {};
        colorAttachment.format = swapChainImageFormat;
        colorAttachment.samples = VK_SAMPLE_COUNT_1_BIT;
        colorAttachment.loadOp = VK_ATTACHMENT_LOAD_OP_CLEAR;
        colorAttachment.storeOp = VK_ATTACHMENT_STORE_OP_STORE;
        colorAttachment.stencilLoadOp = VK_ATTACHMENT_LOAD_OP_DONT_CARE;
        colorAttachment.stencilStoreOp = VK_ATTACHMENT_STORE_OP_DONT_CARE;
        colorAttachment.initialLayout = VK_IMAGE_LAYOUT_UNDEFINED;
        colorAttachment.finalLayout = VK_IMAGE_LAYOUT_PRESENT_SRC_KHR;

        VkAttachmentReference colorAttachmentRef = {};
        colorAttachmentRef.attachment = 0;
        colorAttachmentRef.layout = VK_IMAGE_LAYOUT_COLOR_ATTACHMENT_OPTIMAL;

        VkSubpassDescription subpass = {};
        subpass.pipelineBindPoint = VK_PIPELINE_BIND_POINT_GRAPHICS;
        subpass.colorAttachmentCount = 1;
        subpass.pColorAttachments = &colorAttachmentRef;

        VkSubpassDependency dependency = {};
        dependency.srcSubpass = VK_SUBPASS_EXTERNAL;
        dependency.dstSubpass = 0;
        dependency.srcStageMask = VK_PIPELINE_STAGE_COLOR_ATTACHMENT_OUTPUT_BIT;
        dependency.srcAccessMask = 0;
        dependency.dstStageMask = VK_PIPELINE_STAGE_COLOR_ATTACHMENT_OUTPUT_BIT;
        dependency.dstAccessMask = VK_ACCESS_COLOR_ATTACHMENT_READ_BIT | VK_ACCESS_COLOR_ATTACHMENT_WRITE_BIT;

        VkRenderPassCreateInfo renderPassInfo = {};
        renderPassInfo.sType = VK_STRUCTURE_TYPE_RENDER_PASS_CREATE_INFO;
        renderPassInfo.attachmentCount = 1;
        renderPassInfo.pAttachments = &colorAttachment;
        renderPassInfo.subpassCount = 1;
        renderPassInfo.pSubpasses = &subpass;
        renderPassInfo.dependencyCount = 1;
        renderPassInfo.pDependencies = &dependency;

        if (vkCreateRenderPass(device, &renderPassInfo, nullptr, &renderPass) != VK_SUCCESS) {
            throw std::runtime_error("failed to create render pass!");
        }
    }

    void createDescriptorSetLayout() {
        VkDescriptorSetLayoutBinding uboLayoutBinding = {};
        uboLayoutBinding.binding = 0;
        uboLayoutBinding.descriptorCount = 1;
        uboLayoutBinding.descriptorType = VK_DESCRIPTOR_TYPE_UNIFORM_BUFFER;
        uboLayoutBinding.pImmutableSamplers = nullptr;
        uboLayoutBinding.stageFlags = VK_SHADER_STAGE_VERTEX_BIT;

        VkDescriptorSetLayoutCreateInfo layoutInfo = {};
        layoutInfo.sType = VK_STRUCTURE_TYPE_DESCRIPTOR_SET_LAYOUT_CREATE_INFO;
        layoutInfo.bindingCount = 1;
        layoutInfo.pBindings = &uboLayoutBinding;

        if (vkCreateDescriptorSetLayout(device, &layoutInfo, nullptr, &descriptorSetLayout) != VK_SUCCESS) {
            throw std::runtime_error("failed to create descriptor set layout!");
        }
    }

    void createGraphicsPipeline() {
        auto vertShaderCode = readFile("shaders/vert.spv");
        auto fragShaderCode = readFile("shaders/frag.spv");

        VkShaderModule vertShaderModule = createShaderModule(vertShaderCode);
        VkShaderModule fragShaderModule = createShaderModule(fragShaderCode);

        VkPipelineShaderStageCreateInfo vertShaderStageInfo = {};
        vertShaderStageInfo.sType = VK_STRUCTURE_TYPE_PIPELINE_SHADER_STAGE_CREATE_INFO;
        vertShaderStageInfo.stage = VK_SHADER_STAGE_VERTEX_BIT;
        vertShaderStageInfo.module = vertShaderModule;
        vertShaderStageInfo.pName = "main";

        VkPipelineShaderStageCreateInfo fragShaderStageInfo = {};
        fragShaderStageInfo.sType = VK_STRUCTURE_TYPE_PIPELINE_SHADER_STAGE_CREATE_INFO;
        fragShaderStageInfo.stage = VK_SHADER_STAGE_FRAGMENT_BIT;
        fragShaderStageInfo.module = fragShaderModule;
        fragShaderStageInfo.pName = "main";

        VkPipelineShaderStageCreateInfo shaderStages[] = {vertShaderStageInfo, fragShaderStageInfo};

        VkPipelineVertexInputStateCreateInfo vertexInputInfo = {};
        vertexInputInfo.sType = VK_STRUCTURE_TYPE_PIPELINE_VERTEX_INPUT_STATE_CREATE_INFO;

        auto bindingDescription = Vertex::getBindingDescription();
        auto attributeDescriptions = Vertex::getAttributeDescriptions();

        vertexInputInfo.vertexBindingDescriptionCount = 1;
        vertexInputInfo.vertexAttributeDescriptionCount = static_cast<uint32_t>(attributeDescriptions.size());
        vertexInputInfo.pVertexBindingDescriptions = &bindingDescription;
        vertexInputInfo.pVertexAttributeDescriptions = attributeDescriptions.data();

        VkPipelineInputAssemblyStateCreateInfo inputAssembly = {};
        inputAssembly.sType = VK_STRUCTURE_TYPE_PIPELINE_INPUT_ASSEMBLY_STATE_CREATE_INFO;
        inputAssembly.topology = VK_PRIMITIVE_TOPOLOGY_TRIANGLE_LIST;
        inputAssembly.primitiveRestartEnable = VK_FALSE;

        VkViewport viewport = {};
        viewport.x = 0.0f;
        viewport.y = 0.0f;
        viewport.width = (float) swapChainExtent.width;
        viewport.height = (float) swapChainExtent.height;
        viewport.minDepth = 0.0f;
        viewport.maxDepth = 1.0f;

        VkRect2D scissor = {};
        scissor.offset = {0, 0};
        scissor.extent = swapChainExtent;

        VkPipelineViewportStateCreateInfo viewportState = {};
        viewportState.sType = VK_STRUCTURE_TYPE_PIPELINE_VIEWPORT_STATE_CREATE_INFO;
        viewportState.viewportCount = 1;
        viewportState.pViewports = &viewport;
        viewportState.scissorCount = 1;
        viewportState.pScissors = &scissor;

        VkPipelineRasterizationStateCreateInfo rasterizer = {};
        rasterizer.sType = VK_STRUCTURE_TYPE_PIPELINE_RASTERIZATION_STATE_CREATE_INFO;
        rasterizer.depthClampEnable = VK_FALSE;
        rasterizer.rasterizerDiscardEnable = VK_FALSE;
        rasterizer.polygonMode = VK_POLYGON_MODE_FILL;
        rasterizer.lineWidth = 1.0f;
        rasterizer.cullMode = VK_CULL_MODE_BACK_BIT;
        rasterizer.frontFace = VK_FRONT_FACE_COUNTER_CLOCKWISE;
        rasterizer.depthBiasEnable = VK_FALSE;

        VkPipelineMultisampleStateCreateInfo multisampling = {};
        multisampling.sType = VK_STRUCTURE_TYPE_PIPELINE_MULTISAMPLE_STATE_CREATE_INFO;
        multisampling.sampleShadingEnable = VK_FALSE;
        multisampling.rasterizationSamples = VK_SAMPLE_COUNT_1_BIT;

        VkPipelineColorBlendAttachmentState colorBlendAttachment = {};
        colorBlendAttachment.colorWriteMask = VK_COLOR_COMPONENT_R_BIT | VK_COLOR_COMPONENT_G_BIT | VK_COLOR_COMPONENT_B_BIT | VK_COLOR_COMPONENT_A_BIT;
        colorBlendAttachment.blendEnable = VK_FALSE;

        VkPipelineColorBlendStateCreateInfo colorBlending = {};
        colorBlending.sType = VK_STRUCTURE_TYPE_PIPELINE_COLOR_BLEND_STATE_CREATE_INFO;
        colorBlending.logicOpEnable = VK_FALSE;
        colorBlending.logicOp = VK_LOGIC_OP_COPY;
        colorBlending.attachmentCount = 1;
        colorBlending.pAttachments = &colorBlendAttachment;
        colorBlending.blendConstants[0] = 0.0f;
        colorBlending.blendConstants[1] = 0.0f;
        colorBlending.blendConstants[2] = 0.0f;
        colorBlending.blendConstants[3] = 0.0f;

        VkPipelineLayoutCreateInfo pipelineLayoutInfo = {};
        pipelineLayoutInfo.sType = VK_STRUCTURE_TYPE_PIPELINE_LAYOUT_CREATE_INFO;
        pipelineLayoutInfo.setLayoutCount = 1;
        pipelineLayoutInfo.pSetLayouts = &descriptorSetLayout;

        if (vkCreatePipelineLayout(device, &pipelineLayoutInfo, nullptr, &pipelineLayout) != VK_SUCCESS) {
            throw std::runtime_error("failed to create pipeline layout!");
        }

        VkGraphicsPipelineCreateInfo pipelineInfo = {};
        pipelineInfo.sType = VK_STRUCTURE_TYPE_GRAPHICS_PIPELINE_CREATE_INFO;
        pipelineInfo.stageCount = 2;
        pipelineInfo.pStages = shaderStages;
        pipelineInfo.pVertexInputState = &vertexInputInfo;
        pipelineInfo.pInputAssemblyState = &inputAssembly;
        pipelineInfo.pViewportState = &viewportState;
        pipelineInfo.pRasterizationState = &rasterizer;
        pipelineInfo.pMultisampleState = &multisampling;
        pipelineInfo.pColorBlendState = &colorBlending;
        pipelineInfo.layout = pipelineLayout;
        pipelineInfo.renderPass = renderPass;
        pipelineInfo.subpass = 0;
        pipelineInfo.basePipelineHandle = VK_NULL_HANDLE;

        if (vkCreateGraphicsPipelines(device, VK_NULL_HANDLE, 1, &pipelineInfo, nullptr, &graphicsPipeline) != VK_SUCCESS) {
            throw std::runtime_error("failed to create graphics pipeline!");
        }

        vkDestroyShaderModule(device, fragShaderModule, nullptr);
        vkDestroyShaderModule(device, vertShaderModule, nullptr);
    }

    void createFramebuffers() {
        swapChainFramebuffers.resize(swapChainImageViews.size());

        for (size_t i = 0; i < swapChainImageViews.size(); i++) {
            VkImageView attachments[] = {
                swapChainImageViews[i]
            };

            VkFramebufferCreateInfo framebufferInfo = {};
            framebufferInfo.sType = VK_STRUCTURE_TYPE_FRAMEBUFFER_CREATE_INFO;
            framebufferInfo.renderPass = renderPass;
            framebufferInfo.attachmentCount = 1;
            framebufferInfo.pAttachments = attachments;
            framebufferInfo.width = swapChainExtent.width;
            framebufferInfo.height = swapChainExtent.height;
            framebufferInfo.layers = 1;

            if (vkCreateFramebuffer(device, &framebufferInfo, nullptr, &swapChainFramebuffers[i]) != VK_SUCCESS) {
                throw std::runtime_error("failed to create framebuffer!");
            }
        }
    }

    void createCommandPool() {
        QueueFamilyIndices queueFamilyIndices = findQueueFamilies(physicalDevice);

        VkCommandPoolCreateInfo poolInfo = {};
        poolInfo.sType = VK_STRUCTURE_TYPE_COMMAND_POOL_CREATE_INFO;
        poolInfo.queueFamilyIndex = queueFamilyIndices.graphicsFamily;

        if (vkCreateCommandPool(device, &poolInfo, nullptr, &commandPool) != VK_SUCCESS) {
            throw std::runtime_error("failed to create graphics command pool!");
        }
    }

    void createTextureImage() {
        int texWidth, texHeight, texChannels;
        stbi_uc* pixels = stbi_load("textures/texture.jpg", &texWidth, &texHeight, &texChannels, STBI_rgb_alpha);
        VkDeviceSize imageSize = texWidth * texHeight * 4;

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

        VkBuffer stagingBuffer;
        VkDeviceMemory stagingBufferMemory;
        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(device, stagingBufferMemory, 0, imageSize, 0, &data);
            memcpy(data, pixels, static_cast<size_t>(imageSize));
        vkUnmapMemory(device, stagingBufferMemory);

        stbi_image_free(pixels);

        createImage(texWidth, texHeight, VK_FORMAT_R8G8B8A8_UNORM, 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_UNORM, 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_UNORM, VK_IMAGE_LAYOUT_TRANSFER_DST_OPTIMAL, VK_IMAGE_LAYOUT_SHADER_READ_ONLY_OPTIMAL);

        vkDestroyBuffer(device, stagingBuffer, nullptr);
        vkFreeMemory(device, stagingBufferMemory, nullptr);
    }

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

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

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

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

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

    void transitionImageLayout(VkImage image, VkFormat format, VkImageLayout oldLayout, VkImageLayout newLayout) {
        VkCommandBuffer commandBuffer = 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
        );

        endSingleTimeCommands(commandBuffer);
    }

    void copyBufferToImage(VkBuffer buffer, VkImage image, uint32_t width, uint32_t height) {
        VkCommandBuffer commandBuffer = 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);

        endSingleTimeCommands(commandBuffer);
    }

    void createVertexBuffer() {
        VkDeviceSize bufferSize = sizeof(vertices[0]) * vertices.size();

        VkBuffer stagingBuffer;
        VkDeviceMemory stagingBufferMemory;
        createBuffer(bufferSize, VK_BUFFER_USAGE_TRANSFER_SRC_BIT, VK_MEMORY_PROPERTY_HOST_VISIBLE_BIT | VK_MEMORY_PROPERTY_HOST_COHERENT_BIT, stagingBuffer, stagingBufferMemory);

        void* data;
        vkMapMemory(device, stagingBufferMemory, 0, bufferSize, 0, &data);
            memcpy(data, vertices.data(), (size_t) bufferSize);
        vkUnmapMemory(device, stagingBufferMemory);

        createBuffer(bufferSize, VK_BUFFER_USAGE_TRANSFER_DST_BIT | VK_BUFFER_USAGE_VERTEX_BUFFER_BIT, VK_MEMORY_PROPERTY_DEVICE_LOCAL_BIT, vertexBuffer, vertexBufferMemory);

        copyBuffer(stagingBuffer, vertexBuffer, bufferSize);

        vkDestroyBuffer(device, stagingBuffer, nullptr);
        vkFreeMemory(device, stagingBufferMemory, nullptr);
    }

    void createIndexBuffer() {
        VkDeviceSize bufferSize = sizeof(indices[0]) * indices.size();

        VkBuffer stagingBuffer;
        VkDeviceMemory stagingBufferMemory;
        createBuffer(bufferSize, VK_BUFFER_USAGE_TRANSFER_SRC_BIT, VK_MEMORY_PROPERTY_HOST_VISIBLE_BIT | VK_MEMORY_PROPERTY_HOST_COHERENT_BIT, stagingBuffer, stagingBufferMemory);

        void* data;
        vkMapMemory(device, stagingBufferMemory, 0, bufferSize, 0, &data);
            memcpy(data, indices.data(), (size_t) bufferSize);
        vkUnmapMemory(device, stagingBufferMemory);

        createBuffer(bufferSize, VK_BUFFER_USAGE_TRANSFER_DST_BIT | VK_BUFFER_USAGE_INDEX_BUFFER_BIT, VK_MEMORY_PROPERTY_DEVICE_LOCAL_BIT, indexBuffer, indexBufferMemory);

        copyBuffer(stagingBuffer, indexBuffer, bufferSize);

        vkDestroyBuffer(device, stagingBuffer, nullptr);
        vkFreeMemory(device, stagingBufferMemory, nullptr);
    }

    void createUniformBuffer() {
        VkDeviceSize bufferSize = sizeof(UniformBufferObject);
        createBuffer(bufferSize, VK_BUFFER_USAGE_UNIFORM_BUFFER_BIT, VK_MEMORY_PROPERTY_HOST_VISIBLE_BIT | VK_MEMORY_PROPERTY_HOST_COHERENT_BIT, uniformBuffer, uniformBufferMemory);
    }

    void createDescriptorPool() {
        VkDescriptorPoolSize poolSize = {};
        poolSize.type = VK_DESCRIPTOR_TYPE_UNIFORM_BUFFER;
        poolSize.descriptorCount = 1;

        VkDescriptorPoolCreateInfo poolInfo = {};
        poolInfo.sType = VK_STRUCTURE_TYPE_DESCRIPTOR_POOL_CREATE_INFO;
        poolInfo.poolSizeCount = 1;
        poolInfo.pPoolSizes = &poolSize;
        poolInfo.maxSets = 1;

        if (vkCreateDescriptorPool(device, &poolInfo, nullptr, &descriptorPool) != VK_SUCCESS) {
            throw std::runtime_error("failed to create descriptor pool!");
        }
    }

    void createDescriptorSet() {
        VkDescriptorSetLayout layouts[] = {descriptorSetLayout};
        VkDescriptorSetAllocateInfo allocInfo = {};
        allocInfo.sType = VK_STRUCTURE_TYPE_DESCRIPTOR_SET_ALLOCATE_INFO;
        allocInfo.descriptorPool = descriptorPool;
        allocInfo.descriptorSetCount = 1;
        allocInfo.pSetLayouts = layouts;

        if (vkAllocateDescriptorSets(device, &allocInfo, &descriptorSet) != VK_SUCCESS) {
            throw std::runtime_error("failed to allocate descriptor set!");
        }

        VkDescriptorBufferInfo bufferInfo = {};
        bufferInfo.buffer = uniformBuffer;
        bufferInfo.offset = 0;
        bufferInfo.range = sizeof(UniformBufferObject);

        VkWriteDescriptorSet descriptorWrite = {};
        descriptorWrite.sType = VK_STRUCTURE_TYPE_WRITE_DESCRIPTOR_SET;
        descriptorWrite.dstSet = descriptorSet;
        descriptorWrite.dstBinding = 0;
        descriptorWrite.dstArrayElement = 0;
        descriptorWrite.descriptorType = VK_DESCRIPTOR_TYPE_UNIFORM_BUFFER;
        descriptorWrite.descriptorCount = 1;
        descriptorWrite.pBufferInfo = &bufferInfo;

        vkUpdateDescriptorSets(device, 1, &descriptorWrite, 0, nullptr);
    }

    void createBuffer(VkDeviceSize size, VkBufferUsageFlags usage, VkMemoryPropertyFlags properties, VkBuffer& buffer, VkDeviceMemory& bufferMemory) {
        VkBufferCreateInfo bufferInfo = {};
        bufferInfo.sType = VK_STRUCTURE_TYPE_BUFFER_CREATE_INFO;
        bufferInfo.size = size;
        bufferInfo.usage = usage;
            bufferInfo.sharingMode = VK_SHARING_MODE_EXCLUSIVE;

        if (vkCreateBuffer(device, &bufferInfo, nullptr, &buffer) != VK_SUCCESS) {
            throw std::runtime_error("failed to create buffer!");
        }

        VkMemoryRequirements memRequirements;
        vkGetBufferMemoryRequirements(device, buffer, &memRequirements);

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

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

        vkBindBufferMemory(device, buffer, bufferMemory, 0);
    }

    VkCommandBuffer beginSingleTimeCommands() {
        VkCommandBufferAllocateInfo allocInfo = {};
        allocInfo.sType = VK_STRUCTURE_TYPE_COMMAND_BUFFER_ALLOCATE_INFO;
        allocInfo.level = VK_COMMAND_BUFFER_LEVEL_PRIMARY;
        allocInfo.commandPool = commandPool;
        allocInfo.commandBufferCount = 1;

        VkCommandBuffer commandBuffer;
        vkAllocateCommandBuffers(device, &allocInfo, &commandBuffer);

        VkCommandBufferBeginInfo beginInfo = {};
        beginInfo.sType = VK_STRUCTURE_TYPE_COMMAND_BUFFER_BEGIN_INFO;
        beginInfo.flags = VK_COMMAND_BUFFER_USAGE_ONE_TIME_SUBMIT_BIT;

        vkBeginCommandBuffer(commandBuffer, &beginInfo);

        return commandBuffer;
    }

    void endSingleTimeCommands(VkCommandBuffer commandBuffer) {
        vkEndCommandBuffer(commandBuffer);

        VkSubmitInfo submitInfo = {};
        submitInfo.sType = VK_STRUCTURE_TYPE_SUBMIT_INFO;
        submitInfo.commandBufferCount = 1;
        submitInfo.pCommandBuffers = &commandBuffer;

        vkQueueSubmit(graphicsQueue, 1, &submitInfo, VK_NULL_HANDLE);
        vkQueueWaitIdle(graphicsQueue);

        vkFreeCommandBuffers(device, commandPool, 1, &commandBuffer);
    }

    void copyBuffer(VkBuffer srcBuffer, VkBuffer dstBuffer, VkDeviceSize size) {
        VkCommandBuffer commandBuffer = beginSingleTimeCommands();

        VkBufferCopy copyRegion = {};
        copyRegion.size = size;
        vkCmdCopyBuffer(commandBuffer, srcBuffer, dstBuffer, 1, &copyRegion);

        endSingleTimeCommands(commandBuffer);
    }

    uint32_t findMemoryType(uint32_t typeFilter, VkMemoryPropertyFlags properties) {
        VkPhysicalDeviceMemoryProperties memProperties;
        vkGetPhysicalDeviceMemoryProperties(physicalDevice, &memProperties);

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

        throw std::runtime_error("failed to find suitable memory type!");
    }

    void createCommandBuffers() {
        commandBuffers.resize(swapChainFramebuffers.size());

        VkCommandBufferAllocateInfo allocInfo = {};
        allocInfo.sType = VK_STRUCTURE_TYPE_COMMAND_BUFFER_ALLOCATE_INFO;
        allocInfo.commandPool = commandPool;
        allocInfo.level = VK_COMMAND_BUFFER_LEVEL_PRIMARY;
        allocInfo.commandBufferCount = (uint32_t) commandBuffers.size();

        if (vkAllocateCommandBuffers(device, &allocInfo, commandBuffers.data()) != VK_SUCCESS) {
            throw std::runtime_error("failed to allocate command buffers!");
        }

        for (size_t i = 0; i < commandBuffers.size(); i++) {
            VkCommandBufferBeginInfo beginInfo = {};
            beginInfo.sType = VK_STRUCTURE_TYPE_COMMAND_BUFFER_BEGIN_INFO;
            beginInfo.flags = VK_COMMAND_BUFFER_USAGE_SIMULTANEOUS_USE_BIT;

            vkBeginCommandBuffer(commandBuffers[i], &beginInfo);

            VkRenderPassBeginInfo renderPassInfo = {};
            renderPassInfo.sType = VK_STRUCTURE_TYPE_RENDER_PASS_BEGIN_INFO;
            renderPassInfo.renderPass = renderPass;
            renderPassInfo.framebuffer = swapChainFramebuffers[i];
            renderPassInfo.renderArea.offset = {0, 0};
            renderPassInfo.renderArea.extent = swapChainExtent;

            VkClearValue clearColor = {0.0f, 0.0f, 0.0f, 1.0f};
            renderPassInfo.clearValueCount = 1;
            renderPassInfo.pClearValues = &clearColor;

            vkCmdBeginRenderPass(commandBuffers[i], &renderPassInfo, VK_SUBPASS_CONTENTS_INLINE);

                vkCmdBindPipeline(commandBuffers[i], VK_PIPELINE_BIND_POINT_GRAPHICS, graphicsPipeline);

                VkBuffer vertexBuffers[] = {vertexBuffer};
                VkDeviceSize offsets[] = {0};
                vkCmdBindVertexBuffers(commandBuffers[i], 0, 1, vertexBuffers, offsets);

                vkCmdBindIndexBuffer(commandBuffers[i], indexBuffer, 0, VK_INDEX_TYPE_UINT16);

                vkCmdBindDescriptorSets(commandBuffers[i], VK_PIPELINE_BIND_POINT_GRAPHICS, pipelineLayout, 0, 1, &descriptorSet, 0, nullptr);

                vkCmdDrawIndexed(commandBuffers[i], static_cast<uint32_t>(indices.size()), 1, 0, 0, 0);

            vkCmdEndRenderPass(commandBuffers[i]);

            if (vkEndCommandBuffer(commandBuffers[i]) != VK_SUCCESS) {
                throw std::runtime_error("failed to record command buffer!");
            }
        }
    }

    void createSemaphores() {
        VkSemaphoreCreateInfo semaphoreInfo = {};
        semaphoreInfo.sType = VK_STRUCTURE_TYPE_SEMAPHORE_CREATE_INFO;

        if (vkCreateSemaphore(device, &semaphoreInfo, nullptr, &imageAvailableSemaphore) != VK_SUCCESS ||
            vkCreateSemaphore(device, &semaphoreInfo, nullptr, &renderFinishedSemaphore) != VK_SUCCESS) {

            throw std::runtime_error("failed to create semaphores!");
        }
    }

    void updateUniformBuffer() {
        static auto startTime = std::chrono::high_resolution_clock::now();

        auto currentTime = std::chrono::high_resolution_clock::now();
        float time = std::chrono::duration_cast<std::chrono::milliseconds>(currentTime - startTime).count() / 1000.0f;

        UniformBufferObject ubo = {};
        ubo.model = glm::rotate(glm::mat4(1.0f), time * glm::radians(90.0f), glm::vec3(0.0f, 0.0f, 1.0f));
        ubo.view = glm::lookAt(glm::vec3(2.0f, 2.0f, 2.0f), glm::vec3(0.0f, 0.0f, 0.0f), glm::vec3(0.0f, 0.0f, 1.0f));
        ubo.proj = glm::perspective(glm::radians(45.0f), swapChainExtent.width / (float) swapChainExtent.height, 0.1f, 10.0f);
        ubo.proj[1][1] *= -1;

        void* data;
        vkMapMemory(device, uniformBufferMemory, 0, sizeof(ubo), 0, &data);
            memcpy(data, &ubo, sizeof(ubo));
        vkUnmapMemory(device, uniformBufferMemory);
    }

    void drawFrame() {
        uint32_t imageIndex;
        VkResult result = vkAcquireNextImageKHR(device, swapChain, std::numeric_limits<uint64_t>::max(), imageAvailableSemaphore, VK_NULL_HANDLE, &imageIndex);

        if (result == VK_ERROR_OUT_OF_DATE_KHR) {
            recreateSwapChain();
            return;
        } else if (result != VK_SUCCESS && result != VK_SUBOPTIMAL_KHR) {
            throw std::runtime_error("failed to acquire swap chain image!");
        }

        VkSubmitInfo submitInfo = {};
        submitInfo.sType = VK_STRUCTURE_TYPE_SUBMIT_INFO;

        VkSemaphore waitSemaphores[] = {imageAvailableSemaphore};
        VkPipelineStageFlags waitStages[] = {VK_PIPELINE_STAGE_COLOR_ATTACHMENT_OUTPUT_BIT};
        submitInfo.waitSemaphoreCount = 1;
        submitInfo.pWaitSemaphores = waitSemaphores;
        submitInfo.pWaitDstStageMask = waitStages;

        submitInfo.commandBufferCount = 1;
        submitInfo.pCommandBuffers = &commandBuffers[imageIndex];

        VkSemaphore signalSemaphores[] = {renderFinishedSemaphore};
        submitInfo.signalSemaphoreCount = 1;
        submitInfo.pSignalSemaphores = signalSemaphores;

        if (vkQueueSubmit(graphicsQueue, 1, &submitInfo, VK_NULL_HANDLE) != VK_SUCCESS) {
            throw std::runtime_error("failed to submit draw command buffer!");
        }

        VkPresentInfoKHR presentInfo = {};
        presentInfo.sType = VK_STRUCTURE_TYPE_PRESENT_INFO_KHR;

        presentInfo.waitSemaphoreCount = 1;
        presentInfo.pWaitSemaphores = signalSemaphores;

        VkSwapchainKHR swapChains[] = {swapChain};
        presentInfo.swapchainCount = 1;
        presentInfo.pSwapchains = swapChains;

        presentInfo.pImageIndices = &imageIndex;

        result = vkQueuePresentKHR(presentQueue, &presentInfo);

        if (result == VK_ERROR_OUT_OF_DATE_KHR || result == VK_SUBOPTIMAL_KHR) {
            recreateSwapChain();
        } else if (result != VK_SUCCESS) {
            throw std::runtime_error("failed to present swap chain image!");
        }

        vkQueueWaitIdle(presentQueue);
    }

    VkShaderModule createShaderModule(const std::vector<char>& code) {
        VkShaderModuleCreateInfo createInfo = {};
        createInfo.sType = VK_STRUCTURE_TYPE_SHADER_MODULE_CREATE_INFO;
        createInfo.codeSize = code.size();
        createInfo.pCode = reinterpret_cast<const uint32_t*>(code.data());

        VkShaderModule shaderModule;
        if (vkCreateShaderModule(device, &createInfo, nullptr, &shaderModule) != VK_SUCCESS) {
            throw std::runtime_error("failed to create shader module!");
        }

        return shaderModule;
    }

    VkSurfaceFormatKHR chooseSwapSurfaceFormat(const std::vector<VkSurfaceFormatKHR>& availableFormats) {
        if (availableFormats.size() == 1 && availableFormats[0].format == VK_FORMAT_UNDEFINED) {
            return{VK_FORMAT_B8G8R8A8_UNORM, VK_COLOR_SPACE_SRGB_NONLINEAR_KHR};
        }

        for (const auto& availableFormat : availableFormats) {
            if (availableFormat.format == VK_FORMAT_B8G8R8A8_UNORM && availableFormat.colorSpace == VK_COLOR_SPACE_SRGB_NONLINEAR_KHR) {
                return availableFormat;
            }
        }

        return availableFormats[0];
    }

    VkPresentModeKHR chooseSwapPresentMode(const std::vector<VkPresentModeKHR> availablePresentModes) {
        VkPresentModeKHR bestMode = VK_PRESENT_MODE_FIFO_KHR;

        for (const auto& availablePresentMode : availablePresentModes) {
            if (availablePresentMode == VK_PRESENT_MODE_MAILBOX_KHR) {
                return availablePresentMode;
            } else if (availablePresentMode == VK_PRESENT_MODE_IMMEDIATE_KHR) {
                bestMode = availablePresentMode;
            }
        }

        return bestMode;
    }

    VkExtent2D chooseSwapExtent(const VkSurfaceCapabilitiesKHR& capabilities) {
        if (capabilities.currentExtent.width != std::numeric_limits<uint32_t>::max()) {
            return capabilities.currentExtent;
        } else {
            int width, height;
            glfwGetWindowSize(window, &width, &height);

            VkExtent2D actualExtent = {
                static_cast<uint32_t>(width),
                static_cast<uint32_t>(height)
            };

            actualExtent.width = std::max(capabilities.minImageExtent.width, std::min(capabilities.maxImageExtent.width, actualExtent.width));
            actualExtent.height = std::max(capabilities.minImageExtent.height, std::min(capabilities.maxImageExtent.height, actualExtent.height));

            return actualExtent;
        }
    }

    SwapChainSupportDetails querySwapChainSupport(VkPhysicalDevice device) {
        SwapChainSupportDetails details;

        vkGetPhysicalDeviceSurfaceCapabilitiesKHR(device, surface, &details.capabilities);

        uint32_t formatCount;
        vkGetPhysicalDeviceSurfaceFormatsKHR(device, surface, &formatCount, nullptr);

        if (formatCount != 0) {
            details.formats.resize(formatCount);
            vkGetPhysicalDeviceSurfaceFormatsKHR(device, surface, &formatCount, details.formats.data());
        }

        uint32_t presentModeCount;
        vkGetPhysicalDeviceSurfacePresentModesKHR(device, surface, &presentModeCount, nullptr);

        if (presentModeCount != 0) {
            details.presentModes.resize(presentModeCount);
            vkGetPhysicalDeviceSurfacePresentModesKHR(device, surface, &presentModeCount, details.presentModes.data());
        }

        return details;
    }

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

        bool extensionsSupported = checkDeviceExtensionSupport(device);

        bool swapChainAdequate = false;
        if (extensionsSupported) {
            SwapChainSupportDetails swapChainSupport = querySwapChainSupport(device);
            swapChainAdequate = !swapChainSupport.formats.empty() && !swapChainSupport.presentModes.empty();
        }

        return indices.isComplete() && extensionsSupported && swapChainAdequate;
    }

    bool checkDeviceExtensionSupport(VkPhysicalDevice device) {
        uint32_t extensionCount;
        vkEnumerateDeviceExtensionProperties(device, nullptr, &extensionCount, nullptr);

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

        std::set<std::string> requiredExtensions(deviceExtensions.begin(), deviceExtensions.end());

        for (const auto& extension : availableExtensions) {
            requiredExtensions.erase(extension.extensionName);
        }

        return requiredExtensions.empty();
    }

    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;
            }

            VkBool32 presentSupport = false;
            vkGetPhysicalDeviceSurfaceSupportKHR(device, i, surface, &presentSupport);

            if (queueFamily.queueCount > 0 && presentSupport) {
                indices.presentFamily = i;
            }

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

            i++;
        }

        return indices;
    }

    std::vector<const char*> getRequiredExtensions() {
        std::vector<const char*> extensions;

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

        for (unsigned int i = 0; i < glfwExtensionCount; i++) {
            extensions.push_back(glfwExtensions[i]);
        }

        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 std::vector<char> readFile(const std::string& filename) {
        std::ifstream file(filename, std::ios::ate | std::ios::binary);

        if (!file.is_open()) {
            throw std::runtime_error("failed to open file!");
        }

        size_t fileSize = (size_t) file.tellg();
        std::vector<char> buffer(fileSize);

        file.seekg(0);
        file.read(buffer.data(), fileSize);

        file.close();

        return buffer;
    }

    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;
}