/*
 * Vulkan implicit layer forces VK 1.4.x (e.g. 1.4.348 via headers)
 */

#include <vulkan/vulkan.h>
#include <vulkan/vk_layer.h>
#include <string.h>

static PFN_vkGetInstanceProcAddr          g_next_gipa  = NULL;
static PFN_vkGetPhysicalDeviceProperties  g_next_gdp   = NULL;
static PFN_vkGetPhysicalDeviceProperties2 g_next_gdp2  = NULL;

#define HASVK14_API_VERSION VK_MAKE_API_VERSION(0, 1, 4, VK_HEADER_VERSION)
#define INTEL_VENDOR_ID     0x8086

static int is_intel_below_14(uint32_t vendorID, uint32_t apiVersion)
{
    return vendorID == INTEL_VENDOR_ID
        && VK_API_VERSION_MAJOR(apiVersion) == 1
        && VK_API_VERSION_MINOR(apiVersion) < 4;
}

VKAPI_ATTR VkResult VKAPI_CALL
HaVK14_EnumerateInstanceVersion(uint32_t *pApiVersion)
{
    *pApiVersion = HASVK14_API_VERSION;
    return VK_SUCCESS;
}

VKAPI_ATTR VkResult VKAPI_CALL
HaVK14_CreateInstance(const VkInstanceCreateInfo  *pCreateInfo,
                      const VkAllocationCallbacks *pAllocator,
                      VkInstance                  *pInstance)
{
    VkLayerInstanceCreateInfo *link =
        (VkLayerInstanceCreateInfo *)pCreateInfo->pNext;

    while (link &&
           !(link->sType    == VK_STRUCTURE_TYPE_LOADER_INSTANCE_CREATE_INFO &&
             link->function == VK_LAYER_LINK_INFO))
        link = (VkLayerInstanceCreateInfo *)link->pNext;

    if (!link) return VK_ERROR_INITIALIZATION_FAILED;

    g_next_gipa        = link->u.pLayerInfo->pfnNextGetInstanceProcAddr;
    link->u.pLayerInfo = link->u.pLayerInfo->pNext;

    PFN_vkCreateInstance next_ci =
        (PFN_vkCreateInstance)g_next_gipa(NULL, "vkCreateInstance");

    VkResult res = next_ci(pCreateInfo, pAllocator, pInstance);
    if (res != VK_SUCCESS) return res;

    g_next_gdp  = (PFN_vkGetPhysicalDeviceProperties)
        g_next_gipa(*pInstance, "vkGetPhysicalDeviceProperties");
        
    g_next_gdp2 = (PFN_vkGetPhysicalDeviceProperties2)
        g_next_gipa(*pInstance, "vkGetPhysicalDeviceProperties2");
        
    if (!g_next_gdp2) {
        g_next_gdp2 = (PFN_vkGetPhysicalDeviceProperties2)
            g_next_gipa(*pInstance, "vkGetPhysicalDeviceProperties2KHR");
    }

    return VK_SUCCESS;
}

VKAPI_ATTR void VKAPI_CALL
HaVK14_GetPhysicalDeviceProperties(VkPhysicalDevice           device,
                                   VkPhysicalDeviceProperties *props)
{
    if (g_next_gdp) g_next_gdp(device, props);

    if (props && is_intel_below_14(props->vendorID, props->apiVersion)) {
        props->apiVersion = HASVK14_API_VERSION;
        
        strncpy(props->deviceName, "Intel(R) HD 9000", VK_MAX_PHYSICAL_DEVICE_NAME_SIZE - 1);
        props->deviceName[VK_MAX_PHYSICAL_DEVICE_NAME_SIZE - 1] = '\0';
    }
}

VKAPI_ATTR void VKAPI_CALL
HaVK14_GetPhysicalDeviceProperties2(VkPhysicalDevice            device,
                                    VkPhysicalDeviceProperties2 *props2)
{
    if (g_next_gdp2) g_next_gdp2(device, props2);

    if (!props2) return;

    VkPhysicalDeviceProperties *props = &props2->properties;
    if (!is_intel_below_14(props->vendorID, props->apiVersion)) return;

    props->apiVersion = HASVK14_API_VERSION;
    
    strncpy(props->deviceName, "Intel(R) HD 9000", VK_MAX_PHYSICAL_DEVICE_NAME_SIZE - 1);
    props->deviceName[VK_MAX_PHYSICAL_DEVICE_NAME_SIZE - 1] = '\0';

    VkBaseOutStructure *s = (VkBaseOutStructure *)props2->pNext;
    while (s) {
        if (s->sType == VK_STRUCTURE_TYPE_PHYSICAL_DEVICE_VULKAN_1_2_PROPERTIES) {
            VkPhysicalDeviceVulkan12Properties *p12 =
                (VkPhysicalDeviceVulkan12Properties *)s;
            p12->conformanceVersion = (VkConformanceVersion){ 1, 4, 1, 1 };
        }
        if (s->sType == VK_STRUCTURE_TYPE_PHYSICAL_DEVICE_DRIVER_PROPERTIES) {
            VkPhysicalDeviceDriverProperties *drv =
                (VkPhysicalDeviceDriverProperties *)s;
            drv->conformanceVersion = (VkConformanceVersion){ 1, 4, 1, 1 };
        }
        s = s->pNext;
    }
}

VKAPI_ATTR PFN_vkVoidFunction VKAPI_CALL
HaVK14_GetInstanceProcAddr(VkInstance instance, const char *pName)
{
#define INTERCEPT(fn) \
    if (strcmp(pName, "vk" #fn) == 0) return (PFN_vkVoidFunction)HaVK14_##fn;

    INTERCEPT(GetInstanceProcAddr)
    INTERCEPT(EnumerateInstanceVersion)
    INTERCEPT(CreateInstance)
    INTERCEPT(GetPhysicalDeviceProperties)
    INTERCEPT(GetPhysicalDeviceProperties2)
    
    if (strcmp(pName, "vkGetPhysicalDeviceProperties2KHR") == 0) {
        return (PFN_vkVoidFunction)HaVK14_GetPhysicalDeviceProperties2;
    }

#undef INTERCEPT

    return g_next_gipa ? g_next_gipa(instance, pName) : NULL;
}