/* VulkanApp.cpp */

#include "VulkanApp.hpp"

void
MinimalImGuiVulkan::run()
{
    this->init_sdl_window();
    this->init_vulkan();
    this->init_imgui();
    this->main_loop();
    this->cleanup();
}

void
MinimalImGuiVulkan::init_sdl_window()
{
    if (SDL_Init(SDL_INIT_VIDEO) != 0) {
        throw std::runtime_error("Failed to initialize SDL!");
    }

    this->window_ = SDL_CreateWindow(
        "ImGui Vulkan SDL2 Example",
        SDL_WINDOWPOS_CENTERED,
        SDL_WINDOWPOS_CENTERED,
        1000, 800,
        SDL_WINDOW_VULKAN | SDL_WINDOW_RESIZABLE
        );

    if (!window_) {
        throw std::runtime_error("Failed to create SDL window!");
    }
}

void
MinimalImGuiVulkan::init_vulkan()
{
    this->create_instance();
    this->create_surface();
    this->pick_physical_device();
    this->create_logical_device();
    this->create_swapchain();
    this->create_image_views();
    this->create_render_pass();   // must come before createFrameBuffers
    this->create_framebuffers();
    this->create_command_pool();
    this->create_command_buffers();
    this->create_sync_objects();
    this->create_descriptor_pool();
}

void
MinimalImGuiVulkan::create_instance()
{
    VkApplicationInfo appInfo{};
    appInfo.sType = VK_STRUCTURE_TYPE_APPLICATION_INFO;
    appInfo.pApplicationName = "ImGui Vulkan App";
    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 extensionCount = 0;
    if (!SDL_Vulkan_GetInstanceExtensions(window_, &extensionCount, nullptr)) {
        throw std::runtime_error("Failed to get SDL Vulkan extensions!");
    }

    std::vector<const char*> extensions(extensionCount);
    if (!SDL_Vulkan_GetInstanceExtensions(window_, &extensionCount, extensions.data())) {
        throw std::runtime_error("Failed to get SDL Vulkan extensions!");
    }

#ifdef __apple__
    // Add portability extension for MoltenVK (macOS)
    extensions.push_back(VK_KHR_PORTABILITY_ENUMERATION_EXTENSION_NAME);
#endif

    createInfo.enabledExtensionCount = extensions.size();
    createInfo.ppEnabledExtensionNames = extensions.data();
    createInfo.enabledLayerCount = 0;

#ifdef __apple__
    // CRITICAL: Enable portability enumeration flag for MoltenVK
    createInfo.flags |= VK_INSTANCE_CREATE_ENUMERATE_PORTABILITY_BIT_KHR;
#endif

    int result = vkCreateInstance(&createInfo, nullptr, &(this->instance_));
    if (result != VK_SUCCESS) {
        printf("vkCreateInstance failed with error: %d\n", result);
        throw std::runtime_error("Failed to create instance!");
    }
}

void
MinimalImGuiVulkan::create_surface()
{
    if (!SDL_Vulkan_CreateSurface(window_, instance_, &(this->surface_))) {
        throw std::runtime_error("Failed to create SDL Vulkan surface!");
    }
}

void
MinimalImGuiVulkan::pick_physical_device()
{
    uint32_t n_device = 0;
    vkEnumeratePhysicalDevices(instance_, &n_device, nullptr);

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

    std::vector<VkPhysicalDevice> devices(n_device);
    vkEnumeratePhysicalDevices(instance_, &n_device, devices.data());

    this->physical_device_ = devices[0]; // Just pick the first one for simplicity

    // Find graphics queue family
    uint32_t n_queue_family = 0;
    vkGetPhysicalDeviceQueueFamilyProperties(physical_device_, &n_queue_family, nullptr);
    std::vector<VkQueueFamilyProperties> queue_families(n_queue_family);
    vkGetPhysicalDeviceQueueFamilyProperties(physical_device_, &n_queue_family, queue_families.data());

    for (uint32_t i = 0; i < queue_families.size(); i++) {
        if (queue_families[i].queueFlags & VK_QUEUE_GRAPHICS_BIT) {
            VkBool32 present_support = false;
            vkGetPhysicalDeviceSurfaceSupportKHR(physical_device_, i, surface_, &present_support);
            if (present_support) {
                this->graphics_queue_family_ = i;
                break;
            }
        }
    }
}

void
MinimalImGuiVulkan::create_logical_device()
{
    VkDeviceQueueCreateInfo queue_create_info{};
    queue_create_info.sType = VK_STRUCTURE_TYPE_DEVICE_QUEUE_CREATE_INFO;
    queue_create_info.queueFamilyIndex = graphics_queue_family_;
    queue_create_info.queueCount = 1;
    float queuePriority = 1.0f;
    queue_create_info.pQueuePriorities = &queuePriority;

    VkPhysicalDeviceFeatures deviceFeatures{};

    VkDeviceCreateInfo create_info{};
    create_info.sType = VK_STRUCTURE_TYPE_DEVICE_CREATE_INFO;
    create_info.pQueueCreateInfos = &queue_create_info;
    create_info.queueCreateInfoCount = 1;
    create_info.pEnabledFeatures = &deviceFeatures;

    const char* deviceExtensions[] = { VK_KHR_SWAPCHAIN_EXTENSION_NAME };
    create_info.enabledExtensionCount = 1;
    create_info.ppEnabledExtensionNames = deviceExtensions;

    if (vkCreateDevice(physical_device_, &create_info, nullptr, &(this->device_)) != VK_SUCCESS) {
        throw std::runtime_error("Failed to create logical device!");
    }

    vkGetDeviceQueue(device_, graphics_queue_family_, 0, &graphics_queue_);
}

void
MinimalImGuiVulkan::create_swapchain()
{
    VkSurfaceCapabilitiesKHR capabilities;
    vkGetPhysicalDeviceSurfaceCapabilitiesKHR(physical_device_, surface_, &capabilities);

    uint32_t n_format;
    vkGetPhysicalDeviceSurfaceFormatsKHR(physical_device_, surface_, &n_format, nullptr);
    std::vector<VkSurfaceFormatKHR> formats(n_format);
    vkGetPhysicalDeviceSurfaceFormatsKHR(physical_device_, surface_, &n_format, formats.data());

    VkSurfaceFormatKHR surface_format = formats[0];
    this->swapchain_image_format_ = surface_format.format;

    int width, height;
    SDL_Vulkan_GetDrawableSize(window_, &width, &height);
    this->swapchain_extent_ = {
        static_cast<uint32_t>(width),
        static_cast<uint32_t>(height)
    };

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

    VkSwapchainCreateInfoKHR create_info{};
    create_info.sType = VK_STRUCTURE_TYPE_SWAPCHAIN_CREATE_INFO_KHR;
    create_info.surface = surface_;
    create_info.minImageCount = n_image;
    create_info.imageFormat = surface_format.format;
    create_info.imageColorSpace = surface_format.colorSpace;
    create_info.imageExtent = swapchain_extent_;
    create_info.imageArrayLayers = 1;
    create_info.imageUsage = VK_IMAGE_USAGE_COLOR_ATTACHMENT_BIT;
    create_info.imageSharingMode = VK_SHARING_MODE_EXCLUSIVE;
    create_info.preTransform = capabilities.currentTransform;
    create_info.compositeAlpha = VK_COMPOSITE_ALPHA_OPAQUE_BIT_KHR;
    create_info.presentMode = VK_PRESENT_MODE_FIFO_KHR;
    create_info.clipped = VK_TRUE;

    if (vkCreateSwapchainKHR(device_, &create_info, nullptr, &(this->swapchain_)) != VK_SUCCESS) {
        throw std::runtime_error("Failed to create swap chain!");
    }

    vkGetSwapchainImagesKHR(device_, swapchain_, &n_image, nullptr);
    this->swapchain_images_.resize(n_image);
    vkGetSwapchainImagesKHR(device_, swapchain_, &n_image, this->swapchain_images_.data());
}

void
MinimalImGuiVulkan::create_image_views()
{
    swapchain_image_views_.resize(swapchain_images_.size());

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

        if (vkCreateImageView(device_, &create_info, nullptr, &swapchain_image_views_[i]) != VK_SUCCESS) {
            throw std::runtime_error("Failed to create image views!");
        }
    }
}

void
MinimalImGuiVulkan::create_render_pass()
{
    VkAttachmentDescription color_attachment{};
    color_attachment.format = swapchain_image_format_;
    color_attachment.samples = VK_SAMPLE_COUNT_1_BIT;
    color_attachment.loadOp = VK_ATTACHMENT_LOAD_OP_CLEAR;
    color_attachment.storeOp = VK_ATTACHMENT_STORE_OP_STORE;
    color_attachment.stencilLoadOp = VK_ATTACHMENT_LOAD_OP_DONT_CARE;
    color_attachment.stencilStoreOp = VK_ATTACHMENT_STORE_OP_DONT_CARE;
    color_attachment.initialLayout = VK_IMAGE_LAYOUT_UNDEFINED;
    color_attachment.finalLayout = VK_IMAGE_LAYOUT_PRESENT_SRC_KHR;

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

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

    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_WRITE_BIT;

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

    if (vkCreateRenderPass(device_, &render_pass_info, nullptr, &(this->render_pass_)) != VK_SUCCESS) {
        throw std::runtime_error("Failed to create render pass!");
    }
}

/* end VulkanApp.cpp */