/*
  Simple DirectMedia Layer
  Copyright (C) 1997-2025 Sam Lantinga <slouken@libsdl.org>

  This software is provided 'as-is', without any express or implied
  warranty.  In no event will the authors be held liable for any damages
  arising from the use of this software.

  Permission is granted to anyone to use this software for any purpose,
  including commercial applications, and to alter it and redistribute it
  freely, subject to the following restrictions:

  1. The origin of this software must not be misrepresented; you must not
     claim that you wrote the original software. If you use this software
     in a product, an acknowledgment in the product documentation would be
     appreciated but is not required.
  2. Altered source versions must be plainly marked as such, and must not be
     misrepresented as being the original software.
  3. This notice may not be removed or altered from any source distribution.
*/

/*
 * @author Mark Callow, www.edgewise-consulting.com. Based on Jacob Lifshay's
 * SDL_x11vulkan.c.
 */

#include "SDL_internal.h"

#if defined(SDL_VIDEO_VULKAN) && defined(SDL_VIDEO_DRIVER_WAYLAND)

#include "../SDL_vulkan_internal.h"

#include "SDL_waylandvideo.h"
#include "SDL_waylandwindow.h"

#include "SDL_waylandvulkan.h"

#ifdef SDL_PLATFORM_OPENBSD
#define DEFAULT_VULKAN "libvulkan.so"
#else
#define DEFAULT_VULKAN "libvulkan.so.1"
#endif

SDL_ELF_NOTE_DLOPEN(
    "wayland-vulkan",
    "Support for Vulkan on wayland backend",
    SDL_ELF_NOTE_DLOPEN_PRIORITY_SUGGESTED,
    DEFAULT_VULKAN
);

bool Wayland_Vulkan_LoadLibrary(SDL_VideoDevice *_this, const char *path)
{
    VkExtensionProperties *extensions = NULL;
    Uint32 i, extensionCount = 0;
    bool hasSurfaceExtension = false;
    bool hasWaylandSurfaceExtension = false;
    PFN_vkGetInstanceProcAddr vkGetInstanceProcAddr = NULL;
    if (_this->vulkan_config.loader_handle) {
        return SDL_SetError("Vulkan already loaded");
    }

    // Load the Vulkan loader library
    if (!path) {
        path = SDL_GetHint(SDL_HINT_VULKAN_LIBRARY);
    }
    if (!path) {
        path = DEFAULT_VULKAN;
    }
    _this->vulkan_config.loader_handle = SDL_LoadObject(path);
    if (!_this->vulkan_config.loader_handle) {
        return false;
    }
    SDL_strlcpy(_this->vulkan_config.loader_path, path,
                SDL_arraysize(_this->vulkan_config.loader_path));
    vkGetInstanceProcAddr = (PFN_vkGetInstanceProcAddr)SDL_LoadFunction(
        _this->vulkan_config.loader_handle, "vkGetInstanceProcAddr");
    if (!vkGetInstanceProcAddr) {
        goto fail;
    }
    _this->vulkan_config.vkGetInstanceProcAddr = (void *)vkGetInstanceProcAddr;
    _this->vulkan_config.vkEnumerateInstanceExtensionProperties =
        (void *)((PFN_vkGetInstanceProcAddr)_this->vulkan_config.vkGetInstanceProcAddr)(
            VK_NULL_HANDLE, "vkEnumerateInstanceExtensionProperties");
    if (!_this->vulkan_config.vkEnumerateInstanceExtensionProperties) {
        goto fail;
    }
    extensions = SDL_Vulkan_CreateInstanceExtensionsList(
        (PFN_vkEnumerateInstanceExtensionProperties)
            _this->vulkan_config.vkEnumerateInstanceExtensionProperties,
        &extensionCount);
    if (!extensions) {
        goto fail;
    }
    for (i = 0; i < extensionCount; i++) {
        if (SDL_strcmp(VK_KHR_SURFACE_EXTENSION_NAME, extensions[i].extensionName) == 0) {
            hasSurfaceExtension = true;
        } else if (SDL_strcmp(VK_KHR_WAYLAND_SURFACE_EXTENSION_NAME, extensions[i].extensionName) == 0) {
            hasWaylandSurfaceExtension = true;
        }
    }
    SDL_free(extensions);
    if (!hasSurfaceExtension) {
        SDL_SetError("Installed Vulkan doesn't implement the " VK_KHR_SURFACE_EXTENSION_NAME " extension");
        goto fail;
    } else if (!hasWaylandSurfaceExtension) {
        SDL_SetError("Installed Vulkan doesn't implement the " VK_KHR_WAYLAND_SURFACE_EXTENSION_NAME " extension");
        goto fail;
    }
    return true;

fail:
    SDL_UnloadObject(_this->vulkan_config.loader_handle);
    _this->vulkan_config.loader_handle = NULL;
    return false;
}

void Wayland_Vulkan_UnloadLibrary(SDL_VideoDevice *_this)
{
    if (_this->vulkan_config.loader_handle) {
        SDL_UnloadObject(_this->vulkan_config.loader_handle);
        _this->vulkan_config.loader_handle = NULL;
    }
}

char const * const *Wayland_Vulkan_GetInstanceExtensions(SDL_VideoDevice *_this, Uint32 *count)
{
    static const char *const extensionsForWayland[] = {
        VK_KHR_SURFACE_EXTENSION_NAME, VK_KHR_WAYLAND_SURFACE_EXTENSION_NAME
    };

    if (count) {
        *count = SDL_arraysize(extensionsForWayland);
    }

    return extensionsForWayland;
}

bool Wayland_Vulkan_CreateSurface(SDL_VideoDevice *_this,
                                 SDL_Window *window,
                                 VkInstance instance,
                                 const struct VkAllocationCallbacks *allocator,
                                 VkSurfaceKHR *surface)
{
    SDL_WindowData *windowData = window->internal;
    PFN_vkGetInstanceProcAddr vkGetInstanceProcAddr =
        (PFN_vkGetInstanceProcAddr)_this->vulkan_config.vkGetInstanceProcAddr;
    PFN_vkCreateWaylandSurfaceKHR vkCreateWaylandSurfaceKHR =
        (PFN_vkCreateWaylandSurfaceKHR)vkGetInstanceProcAddr(
            instance,
            "vkCreateWaylandSurfaceKHR");
    VkWaylandSurfaceCreateInfoKHR createInfo;
    VkResult result;

    if (!_this->vulkan_config.loader_handle) {
        return SDL_SetError("Vulkan is not loaded");
    }

    if (!vkCreateWaylandSurfaceKHR) {
        return SDL_SetError(VK_KHR_WAYLAND_SURFACE_EXTENSION_NAME
                            " extension is not enabled in the Vulkan instance.");
    }
    SDL_zero(createInfo);
    createInfo.sType = VK_STRUCTURE_TYPE_WAYLAND_SURFACE_CREATE_INFO_KHR;
    createInfo.pNext = NULL;
    createInfo.flags = 0;
    createInfo.display = windowData->waylandData->display;
    createInfo.surface = windowData->surface;
    result = vkCreateWaylandSurfaceKHR(instance, &createInfo, allocator, surface);
    if (result != VK_SUCCESS) {
        return SDL_SetError("vkCreateWaylandSurfaceKHR failed: %s", SDL_Vulkan_GetResultString(result));
    }
    return true;
}

void Wayland_Vulkan_DestroySurface(SDL_VideoDevice *_this,
                                   VkInstance instance,
                                   VkSurfaceKHR surface,
                                   const struct VkAllocationCallbacks *allocator)
{
    if (_this->vulkan_config.loader_handle) {
        SDL_Vulkan_DestroySurface_Internal(_this->vulkan_config.vkGetInstanceProcAddr, instance, surface, allocator);
    }
}

bool Wayland_Vulkan_GetPresentationSupport(SDL_VideoDevice *_this,
                                               VkInstance instance,
                                               VkPhysicalDevice physicalDevice,
                                               Uint32 queueFamilyIndex)
{
    PFN_vkGetInstanceProcAddr vkGetInstanceProcAddr =
        (PFN_vkGetInstanceProcAddr)_this->vulkan_config.vkGetInstanceProcAddr;
    PFN_vkGetPhysicalDeviceWaylandPresentationSupportKHR vkGetPhysicalDeviceWaylandPresentationSupportKHR =
        (PFN_vkGetPhysicalDeviceWaylandPresentationSupportKHR)vkGetInstanceProcAddr(
            instance,
            "vkGetPhysicalDeviceWaylandPresentationSupportKHR");

    if (!_this->vulkan_config.loader_handle) {
        return SDL_SetError("Vulkan is not loaded");
    }

    if (!vkGetPhysicalDeviceWaylandPresentationSupportKHR) {
        return SDL_SetError(VK_KHR_WAYLAND_SURFACE_EXTENSION_NAME " extension is not enabled in the Vulkan instance.");
    }

    return vkGetPhysicalDeviceWaylandPresentationSupportKHR(physicalDevice,
                                                            queueFamilyIndex,
                                                            _this->internal->display);
}

#endif
