#include "RenderEngine.h"

#include <queue>
#include <set>
#include <stdexcept>
#include <string>

#include "CoreInstance.h"
#include "Log/Log.h"

#include "GLFW/glfw3.h"

#ifdef _DEBUG
static VKAPI_ATTR VkBool32 VKAPI_CALL debugCallback(
    VkDebugUtilsMessageSeverityFlagBitsEXT messageSeverity,
    VkDebugUtilsMessageTypeFlagsEXT messageType,
    const VkDebugUtilsMessengerCallbackDataEXT* pCallbackData,
    void* pUserData) {

    std::string msg = "validation layer: ";
    msg += pCallbackData->pMessage;
    Log(msg);

    return VK_FALSE;
}

VkResult RenderEngine::enable_layer_validation(VkDebugUtilsMessengerCreateInfoEXT* create_info)
{
    PFN_vkCreateDebugUtilsMessengerEXT debug_creator = reinterpret_cast<PFN_vkCreateDebugUtilsMessengerEXT>(vkGetInstanceProcAddr(instance_, "vkCreateDebugUtilsMessengerEXT"));
    return debug_creator(instance_, create_info, nullptr, &debug_messenger_);
}
#endif

std::vector<const char*> RenderEngine::get_required_extensions()
{
    uint32_t extensions_count = 0;
    const char** glfw_extension = glfwGetRequiredInstanceExtensions(&extensions_count);
    std::vector<const char*> extensions(glfw_extension, glfw_extension + extensions_count);

#ifdef _DEBUG
    extensions.push_back(VK_EXT_DEBUG_UTILS_EXTENSION_NAME);
#endif
    return extensions;
}


bool RenderEngine::QueueFamilyIndices::is_complete()
{
    return graphycs_family.has_value() && present_family.has_value();
}

bool RenderEngine::is_device_suitable(VkPhysicalDevice device, VkSurfaceKHR surface)
{
    VkPhysicalDeviceProperties device_properties;
    VkPhysicalDeviceFeatures device_features;
    vkGetPhysicalDeviceProperties(device, &device_properties);
    vkGetPhysicalDeviceFeatures(device, &device_features);

    QueueFamilyIndices indices =  find_queue_family_indices(device, surface);
    
    return device_properties.deviceType == VK_PHYSICAL_DEVICE_TYPE_DISCRETE_GPU
           && device_features.geometryShader
           && indices.is_complete();
}

RenderEngine::QueueFamilyIndices RenderEngine::find_queue_family_indices(VkPhysicalDevice physical_device, VkSurfaceKHR surface)
{
    QueueFamilyIndices queue_family_indices;
    
    uint32_t queueFamilyCount = 0;
    vkGetPhysicalDeviceQueueFamilyProperties(physical_device, &queueFamilyCount, nullptr);
    std::vector<VkQueueFamilyProperties> family_propertieses(queueFamilyCount);
    vkGetPhysicalDeviceQueueFamilyProperties(physical_device, &queueFamilyCount, family_propertieses.data());

    for (uint32_t i = 0; i < family_propertieses.size(); ++i)
    {
        if (family_propertieses[i].queueFlags & VK_QUEUE_GRAPHICS_BIT)
            queue_family_indices.graphycs_family = i;
        
        VkBool32 present_support = false;
        VK_CHECK(vkGetPhysicalDeviceSurfaceSupportKHR(physical_device, i, surface, &present_support));
        if (present_support)
            queue_family_indices.present_family = i;
        if(queue_family_indices.is_complete())
            break;
    }

    return queue_family_indices;
}

void RenderEngine::create_instance()
{
    std::vector<const char*> extensions = get_required_extensions();

    VkApplicationInfo app_info{};
    app_info.sType = VK_STRUCTURE_TYPE_APPLICATION_INFO;
    app_info.apiVersion = VK_API_VERSION_1_0;
    app_info.applicationVersion = VK_MAKE_VERSION(0, 0, 0);
    app_info.pApplicationName = core_.getGameName().c_str();
    app_info.pEngineName = "UwU Engine";
    app_info.engineVersion = VK_MAKE_VERSION(0, 0, 0);
        
        
    VkInstanceCreateInfo instance_create_info{};
    instance_create_info.sType = VK_STRUCTURE_TYPE_INSTANCE_CREATE_INFO;
    instance_create_info.pApplicationInfo = &app_info;
    instance_create_info.enabledExtensionCount = static_cast<uint32_t>(extensions.size());
    instance_create_info.ppEnabledExtensionNames = extensions.data();
#ifdef _DEBUG
    std::vector<const char*> layers_validation = {
        "VK_LAYER_KHRONOS_validation"
    };
    instance_create_info.enabledLayerCount = static_cast<uint32_t>(layers_validation.size());
    instance_create_info.ppEnabledLayerNames = layers_validation.data();
    VkDebugUtilsMessengerCreateInfoEXT debug_messenger_create_info{};
    debug_messenger_create_info.sType = VK_STRUCTURE_TYPE_DEBUG_UTILS_MESSENGER_CREATE_INFO_EXT;
    debug_messenger_create_info.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;
    debug_messenger_create_info.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;
    debug_messenger_create_info.pfnUserCallback = &debugCallback;
    instance_create_info.pNext = &debug_messenger_create_info;
#endif
    VK_CHECK(vkCreateInstance(&instance_create_info, nullptr, &instance_));
#ifdef _DEBUG
    VK_CHECK(enable_layer_validation(&debug_messenger_create_info));
#endif
}

void RenderEngine::pick_physical_device()
{
        uint32_t device_count = 0;
        std::vector<VkPhysicalDevice> devices;
        VK_CHECK(vkEnumeratePhysicalDevices(instance_, &device_count, nullptr));
        devices.resize(device_count);
        VK_CHECK(vkEnumeratePhysicalDevices(instance_, &device_count, devices.data()));

        for (const auto& device : devices)
        {
            if (is_device_suitable(device, surface_))
            {
                physical_device_ = device;
                VkPhysicalDeviceProperties device_properties;
                vkGetPhysicalDeviceProperties(physical_device_, &device_properties);
                Log("Using device: " + std::string(device_properties.deviceName));
                break;
            }
        }

        if (VK_NULL_HANDLE == physical_device_)
            throw std::runtime_error("No suitable device found");
    }

void RenderEngine::create_logical_device()
{
    QueueFamilyIndices indices = find_queue_family_indices(physical_device_, surface_);

    VkPhysicalDeviceFeatures device_features{};

    std::vector<VkDeviceQueueCreateInfo> queue_create_infos;
    std::set<uint32_t> unique_queue_families = {indices.graphycs_family.value(), indices.present_family.value()};
    
    float queue_priority = 1.0f;
    VkDeviceQueueCreateInfo device_queue_create_info{};
    device_queue_create_info.sType = VK_STRUCTURE_TYPE_DEVICE_QUEUE_CREATE_INFO;
        device_queue_create_info.pQueuePriorities = &queue_priority;
    for (auto queue_family : unique_queue_families)
    {
        device_queue_create_info.queueFamilyIndex = queue_family;
        device_queue_create_info.queueCount = 1;
        queue_create_infos.push_back(device_queue_create_info);
    }

    VkDeviceCreateInfo device_create_info{};
    device_create_info.sType = VK_STRUCTURE_TYPE_DEVICE_CREATE_INFO;
    device_create_info.queueCreateInfoCount = static_cast<uint32_t>(unique_queue_families.size());
    device_create_info.pQueueCreateInfos = queue_create_infos.data();
    device_create_info.pEnabledFeatures = &device_features;
    device_create_info.enabledExtensionCount = 0;
    device_create_info.ppEnabledExtensionNames = nullptr;

#ifdef _DEBUG
    std::vector<const char*> layers_validation = {
        "VK_LAYER_KHRONOS_validation"
    };
    device_create_info.enabledLayerCount = static_cast<uint32_t>(layers_validation.size());
    device_create_info.ppEnabledLayerNames = layers_validation.data();
#else
    device_create_info.enabledLayerCount = 0;
    device_create_info.ppEnabledLayerNames = nullptr;

#endif
    VK_CHECK(vkCreateDevice(physical_device_, &device_create_info, nullptr, &device_));
    vkGetDeviceQueue(device_, indices.graphycs_family.value(), 0, &graphics_queue_);
    vkGetDeviceQueue(device_, indices.present_family.value(), 0, &present_queue_);
}

void RenderEngine::create_surface()
{
    VK_CHECK(glfwCreateWindowSurface(instance_, window_, nullptr, &surface_));
}

RenderEngine::RenderEngine(CoreInstance& core, GLFWwindow* window):
core_(core),
window_(window)
#ifdef _DEBUG
,debug_messenger_(nullptr)
#endif
{
    create_instance();
    create_surface();
    pick_physical_device();
    create_logical_device();
}

RenderEngine::~RenderEngine()
{
    if (device_ != VK_NULL_HANDLE)
        vkDestroyDevice(device_, nullptr);
    
    if (surface_ != VK_NULL_HANDLE)
        vkDestroySurfaceKHR(instance_, surface_, nullptr);
    
#ifdef _DEBUG
    if (debug_messenger_ != nullptr && instance_ != nullptr) {
        PFN_vkDestroyDebugUtilsMessengerEXT destroyer_messenger = reinterpret_cast<PFN_vkDestroyDebugUtilsMessengerEXT>(vkGetInstanceProcAddr(instance_, "vkDestroyDebugUtilsMessengerEXT"));
        destroyer_messenger(instance_, debug_messenger_, nullptr);
    }
#endif

    if (instance_ != VK_NULL_HANDLE)
        vkDestroyInstance(instance_, nullptr);
    
    if (window_ != nullptr)
        glfwDestroyWindow(window_);
    glfwTerminate();
}

void RenderEngine::start()
{
    while (!glfwWindowShouldClose(window_))
    {
        glfwSwapBuffers(window_);
        glfwPollEvents();
    }
}

void RenderEngine::stop_render()
{
    if (window_ != nullptr && !glfwWindowShouldClose(window_))
        glfwSetWindowShouldClose(window_, true);
}