// Copyright 2024 Dolphin Emulator Project
// SPDX-License-Identifier: GPL-2.0-or-later

#ifdef ENABLE_VR

// VulkanLoader.h must come first — it defines VK_NO_PROTOTYPES before vulkan.h.
#include "VideoBackends/Vulkan/VulkanLoader.h"

#define XR_USE_GRAPHICS_API_VULKAN

#include "VideoBackends/Vulkan/VulkanOpenXR.h"

#include <algorithm>
#include <array>
#include <sstream>
#include <string>
#include <vector>

#include "Common/Assert.h"
#include "Common/Logging/Log.h"

#include "VideoBackends/Vulkan/CommandBufferManager.h"
#include "VideoBackends/Vulkan/StateTracker.h"
#include "VideoBackends/Vulkan/VKTexture.h"
#include "VideoBackends/Vulkan/VulkanContext.h"
#include "VideoCommon/TextureConfig.h"
#include "VideoCommon/VR/OpenXRManager.h"

#ifdef _WIN32
#include <windows.h>  // for SEH __try/__except
#endif

namespace Vulkan
{
std::unique_ptr<VulkanOpenXR> g_openxr_vk;

static const char* VkFormatToString(int64_t format)
{
  switch (static_cast<VkFormat>(format))
  {
  case VK_FORMAT_R8G8B8A8_UNORM:
    return "VK_FORMAT_R8G8B8A8_UNORM";
  case VK_FORMAT_R8G8B8A8_SRGB:
    return "VK_FORMAT_R8G8B8A8_SRGB";
  case VK_FORMAT_B8G8R8A8_UNORM:
    return "VK_FORMAT_B8G8R8A8_UNORM";
  case VK_FORMAT_B8G8R8A8_SRGB:
    return "VK_FORMAT_B8G8R8A8_SRGB";
  case VK_FORMAT_R16G16B16A16_SFLOAT:
    return "VK_FORMAT_R16G16B16A16_SFLOAT";
  default:
    return "UNKNOWN_VK_FORMAT";
  }
}

static AbstractTextureFormat VkFormatToAbstractFormat(VkFormat format)
{
  switch (format)
  {
  case VK_FORMAT_R8G8B8A8_UNORM:
  case VK_FORMAT_R8G8B8A8_SRGB:
    return AbstractTextureFormat::RGBA8;
  case VK_FORMAT_B8G8R8A8_UNORM:
  case VK_FORMAT_B8G8R8A8_SRGB:
    return AbstractTextureFormat::BGRA8;
  case VK_FORMAT_R16G16B16A16_SFLOAT:
    return AbstractTextureFormat::RGBA16F;
  default:
    return AbstractTextureFormat::RGBA8;
  }
}

static bool SelectSwapchainFormat(XrSession session, int64_t* out_format)
{
  uint32_t format_count = 0;
  XrResult result = xrEnumerateSwapchainFormats(session, 0, &format_count, nullptr);
  if (XR_FAILED(result) || format_count == 0)
  {
    ERROR_LOG_FMT(VIDEO, "OpenXR: xrEnumerateSwapchainFormats (count) failed ({}).",
                  static_cast<int>(result));
    return false;
  }

  std::vector<int64_t> runtime_formats(format_count);
  result = xrEnumerateSwapchainFormats(session, format_count, &format_count, runtime_formats.data());
  if (XR_FAILED(result))
  {
    ERROR_LOG_FMT(VIDEO, "OpenXR: xrEnumerateSwapchainFormats failed ({}).",
                  static_cast<int>(result));
    return false;
  }

  for (const int64_t format : runtime_formats)
  {
    INFO_LOG_FMT(VIDEO, "OpenXR: Runtime swapchain format {} ({})", static_cast<long long>(format),
                 VkFormatToString(format));
  }

  // Prefer linear (non-sRGB) formats — Dolphin handles gamma in shaders.
  static constexpr std::array<VkFormat, 5> preferred_formats = {
      VK_FORMAT_R8G8B8A8_UNORM, VK_FORMAT_B8G8R8A8_UNORM, VK_FORMAT_R8G8B8A8_SRGB,
      VK_FORMAT_B8G8R8A8_SRGB, VK_FORMAT_R16G16B16A16_SFLOAT};

  for (const VkFormat preferred : preferred_formats)
  {
    const int64_t wanted = static_cast<int64_t>(preferred);
    if (std::find(runtime_formats.begin(), runtime_formats.end(), wanted) != runtime_formats.end())
    {
      *out_format = wanted;
      INFO_LOG_FMT(VIDEO, "OpenXR: Selected swapchain format {} ({}).",
                   static_cast<long long>(*out_format), VkFormatToString(*out_format));
      return true;
    }
  }

  *out_format = runtime_formats.front();
  WARN_LOG_FMT(VIDEO,
               "OpenXR: No preferred Vulkan swapchain format found; falling back to runtime "
               "format {} ({}).",
               static_cast<long long>(*out_format), VkFormatToString(*out_format));
  return true;
}

// Separate function for SEH protection — __try cannot be used in functions
// that have C++ objects requiring unwinding.
#ifdef _WIN32
static XrResult SafeCreateSession(XrInstance instance, const XrSessionCreateInfo* info,
                                   XrSession* session)
{
  __try
  {
    return xrCreateSession(instance, info, session);
  }
  __except (EXCEPTION_EXECUTE_HANDLER)
  {
    ERROR_LOG_FMT(VIDEO,
                  "OpenXR: xrCreateSession CRASHED (exception {:#010x}). "
                  "The OpenXR runtime may require Vulkan extensions that Dolphin did not enable. "
                  "Check the 'Required Vulkan instance/device extensions' log lines above.",
                  static_cast<unsigned>(GetExceptionCode()));
    return XR_ERROR_RUNTIME_FAILURE;
  }
}
#else
static XrResult SafeCreateSession(XrInstance instance, const XrSessionCreateInfo* info,
                                   XrSession* session)
{
  return xrCreateSession(instance, info, session);
}
#endif

VulkanOpenXR::VulkanOpenXR() = default;

VulkanOpenXR::~VulkanOpenXR()
{
  Shutdown();
}

// static
bool VulkanOpenXR::PreQueryVulkanExtensions(VulkanExtensionRequirements& out)
{
  INFO_LOG_FMT(VIDEO, "OpenXR Vulkan: Pre-querying required Vulkan extensions...");

  auto mgr = std::make_unique<VR::OpenXRManager>();

  const std::vector<const char*> extensions = {XR_KHR_VULKAN_ENABLE_EXTENSION_NAME};
  if (!mgr->CreateInstance(extensions))
    return false;

  if (!mgr->InitializeSystem())
    return false;

  if (!mgr->EnumerateViewConfigurations())
    return false;

  const XrInstance xr_instance = mgr->GetInstance();
  const XrSystemId xr_system = mgr->GetSystemId();

  // Query required Vulkan instance extensions.
  PFN_xrGetVulkanInstanceExtensionsKHR pfnGetInstanceExts = nullptr;
  xrGetInstanceProcAddr(xr_instance, "xrGetVulkanInstanceExtensionsKHR",
                        reinterpret_cast<PFN_xrVoidFunction*>(&pfnGetInstanceExts));
  if (pfnGetInstanceExts)
  {
    uint32_t ext_len = 0;
    pfnGetInstanceExts(xr_instance, xr_system, 0, &ext_len, nullptr);
    if (ext_len > 0)
    {
      std::string ext_str(ext_len, '\0');
      pfnGetInstanceExts(xr_instance, xr_system, ext_len, &ext_len, ext_str.data());
      INFO_LOG_FMT(VIDEO, "OpenXR: Required Vulkan instance extensions: {}", ext_str);
      // Parse space-separated extension list.
      std::istringstream iss(ext_str);
      std::string ext;
      while (iss >> ext)
        out.instance_extensions.push_back(ext);
    }
  }

  // Query required Vulkan device extensions.
  PFN_xrGetVulkanDeviceExtensionsKHR pfnGetDeviceExts = nullptr;
  xrGetInstanceProcAddr(xr_instance, "xrGetVulkanDeviceExtensionsKHR",
                        reinterpret_cast<PFN_xrVoidFunction*>(&pfnGetDeviceExts));
  if (pfnGetDeviceExts)
  {
    uint32_t ext_len = 0;
    pfnGetDeviceExts(xr_instance, xr_system, 0, &ext_len, nullptr);
    if (ext_len > 0)
    {
      std::string ext_str(ext_len, '\0');
      pfnGetDeviceExts(xr_instance, xr_system, ext_len, &ext_len, ext_str.data());
      INFO_LOG_FMT(VIDEO, "OpenXR: Required Vulkan device extensions: {}", ext_str);
      std::istringstream iss(ext_str);
      std::string ext;
      while (iss >> ext)
        out.device_extensions.push_back(ext);
    }
  }

  // Keep the OpenXRManager alive — Initialize() will reuse it.
  VR::g_openxr = std::move(mgr);

  INFO_LOG_FMT(VIDEO, "OpenXR Vulkan: Pre-query complete ({} instance, {} device extensions).",
               out.instance_extensions.size(), out.device_extensions.size());
  return true;
}

bool VulkanOpenXR::Initialize()
{
  INFO_LOG_FMT(VIDEO, "OpenXR Vulkan: Starting initialization...");

  // If PreQueryVulkanExtensions() was called, VR::g_openxr already exists.
  if (!VR::g_openxr)
  {
    auto mgr = std::make_unique<VR::OpenXRManager>();

    const std::vector<const char*> extensions = {XR_KHR_VULKAN_ENABLE_EXTENSION_NAME};
    if (!mgr->CreateInstance(extensions))
      return false;

    if (!mgr->InitializeSystem())
      return false;

    if (!mgr->EnumerateViewConfigurations())
      return false;

    VR::g_openxr = std::move(mgr);
  }

  INFO_LOG_FMT(VIDEO, "OpenXR Vulkan: Creating session...");
  if (!CreateSessionVulkan())
  {
    ERROR_LOG_FMT(VIDEO, "OpenXR Vulkan: Session creation failed — disabling VR.");
    VR::g_openxr.reset();
    return false;
  }

  INFO_LOG_FMT(VIDEO, "OpenXR Vulkan: Creating reference space...");
  if (!VR::g_openxr->CreateReferenceSpace())
  {
    ERROR_LOG_FMT(VIDEO, "OpenXR Vulkan: Reference space creation failed — disabling VR.");
    VR::g_openxr.reset();
    return false;
  }

  INFO_LOG_FMT(VIDEO, "OpenXR Vulkan: Creating swapchains...");
  if (!CreateSwapchains())
  {
    ERROR_LOG_FMT(VIDEO, "OpenXR Vulkan: Swapchain creation failed — disabling VR.");
    VR::g_openxr.reset();
    return false;
  }

  // Register this object as the swapchain provider so Presenter can acquire eye images.
  VR::g_openxr->SetSwapchain(this);

  INFO_LOG_FMT(VIDEO, "OpenXR Vulkan: Initialization complete.");
  return true;
}

void VulkanOpenXR::Shutdown()
{
  // Clear swapchain pointer before destroying swapchains so no dangling use occurs.
  if (VR::g_openxr)
    VR::g_openxr->SetSwapchain(nullptr);

  DestroySwapchains();
  VR::g_openxr.reset();

  // Wait for all GPU work to finish before the Vulkan device is destroyed.
  if (g_vulkan_context)
    vkDeviceWaitIdle(g_vulkan_context->GetDevice());

  INFO_LOG_FMT(VIDEO, "OpenXR Vulkan: Shut down.");
}

bool VulkanOpenXR::CreateSessionVulkan()
{
  ASSERT(g_vulkan_context != nullptr);
  ASSERT(VR::g_openxr != nullptr);

  const XrInstance xr_instance = VR::g_openxr->GetInstance();
  const XrSystemId xr_system = VR::g_openxr->GetSystemId();

  // --- Query Vulkan graphics requirements (mandatory before session creation) ---
  INFO_LOG_FMT(VIDEO, "OpenXR Vulkan: Querying graphics requirements...");
  PFN_xrGetVulkanGraphicsRequirementsKHR pfnGetVulkanRequirements = nullptr;
  XrResult result = xrGetInstanceProcAddr(
      xr_instance, "xrGetVulkanGraphicsRequirementsKHR",
      reinterpret_cast<PFN_xrVoidFunction*>(&pfnGetVulkanRequirements));

  if (XR_FAILED(result) || pfnGetVulkanRequirements == nullptr)
  {
    ERROR_LOG_FMT(VIDEO, "OpenXR: Could not load xrGetVulkanGraphicsRequirementsKHR.");
    return false;
  }

  XrGraphicsRequirementsVulkanKHR requirements{XR_TYPE_GRAPHICS_REQUIREMENTS_VULKAN_KHR};
  result = pfnGetVulkanRequirements(xr_instance, xr_system, &requirements);
  if (XR_FAILED(result))
  {
    ERROR_LOG_FMT(VIDEO, "OpenXR: xrGetVulkanGraphicsRequirementsKHR failed ({}).",
                  static_cast<int>(result));
    return false;
  }

  INFO_LOG_FMT(VIDEO, "OpenXR: Vulkan requirements — min API {}.{}.{}, max API {}.{}.{}",
               XR_VERSION_MAJOR(requirements.minApiVersionSupported),
               XR_VERSION_MINOR(requirements.minApiVersionSupported),
               XR_VERSION_PATCH(requirements.minApiVersionSupported),
               XR_VERSION_MAJOR(requirements.maxApiVersionSupported),
               XR_VERSION_MINOR(requirements.maxApiVersionSupported),
               XR_VERSION_PATCH(requirements.maxApiVersionSupported));

  // Log Dolphin's Vulkan API version for comparison.
  const u32 dolphin_api = g_vulkan_context->GetDeviceInfo().apiVersion;
  INFO_LOG_FMT(VIDEO, "OpenXR: Dolphin VkPhysicalDevice API version {}.{}.{}",
               VK_VERSION_MAJOR(dolphin_api), VK_VERSION_MINOR(dolphin_api),
               VK_VERSION_PATCH(dolphin_api));

  // --- Query required Vulkan instance extensions ---
  INFO_LOG_FMT(VIDEO, "OpenXR Vulkan: Querying required Vulkan instance extensions...");
  PFN_xrGetVulkanInstanceExtensionsKHR pfnGetInstanceExts = nullptr;
  result = xrGetInstanceProcAddr(xr_instance, "xrGetVulkanInstanceExtensionsKHR",
                                 reinterpret_cast<PFN_xrVoidFunction*>(&pfnGetInstanceExts));
  if (XR_SUCCEEDED(result) && pfnGetInstanceExts != nullptr)
  {
    uint32_t ext_len = 0;
    pfnGetInstanceExts(xr_instance, xr_system, 0, &ext_len, nullptr);
    if (ext_len > 0)
    {
      std::string ext_str(ext_len, '\0');
      pfnGetInstanceExts(xr_instance, xr_system, ext_len, &ext_len, ext_str.data());
      INFO_LOG_FMT(VIDEO, "OpenXR: Required Vulkan instance extensions: {}", ext_str);
    }
    else
    {
      INFO_LOG_FMT(VIDEO, "OpenXR: No additional Vulkan instance extensions required.");
    }
  }

  // --- Query required Vulkan device extensions ---
  INFO_LOG_FMT(VIDEO, "OpenXR Vulkan: Querying required Vulkan device extensions...");
  PFN_xrGetVulkanDeviceExtensionsKHR pfnGetDeviceExts = nullptr;
  result = xrGetInstanceProcAddr(xr_instance, "xrGetVulkanDeviceExtensionsKHR",
                                 reinterpret_cast<PFN_xrVoidFunction*>(&pfnGetDeviceExts));
  if (XR_SUCCEEDED(result) && pfnGetDeviceExts != nullptr)
  {
    uint32_t ext_len = 0;
    pfnGetDeviceExts(xr_instance, xr_system, 0, &ext_len, nullptr);
    if (ext_len > 0)
    {
      std::string ext_str(ext_len, '\0');
      pfnGetDeviceExts(xr_instance, xr_system, ext_len, &ext_len, ext_str.data());
      INFO_LOG_FMT(VIDEO, "OpenXR: Required Vulkan device extensions: {}", ext_str);
    }
    else
    {
      INFO_LOG_FMT(VIDEO, "OpenXR: No additional Vulkan device extensions required.");
    }
  }

  // --- Verify the physical device matches what the runtime expects ---
  INFO_LOG_FMT(VIDEO, "OpenXR Vulkan: Checking physical device...");
  PFN_xrGetVulkanGraphicsDeviceKHR pfnGetVulkanDevice = nullptr;
  result = xrGetInstanceProcAddr(xr_instance, "xrGetVulkanGraphicsDeviceKHR",
                                 reinterpret_cast<PFN_xrVoidFunction*>(&pfnGetVulkanDevice));
  if (XR_SUCCEEDED(result) && pfnGetVulkanDevice != nullptr)
  {
    VkPhysicalDevice xr_physical_device = VK_NULL_HANDLE;
    result = pfnGetVulkanDevice(xr_instance, xr_system,
                                g_vulkan_context->GetVulkanInstance(), &xr_physical_device);
    if (XR_SUCCEEDED(result))
    {
      if (xr_physical_device != g_vulkan_context->GetPhysicalDevice())
      {
        WARN_LOG_FMT(VIDEO,
                     "OpenXR: Runtime wants a different VkPhysicalDevice than Dolphin selected. "
                     "VR may not work correctly.");
      }
      else
      {
        INFO_LOG_FMT(VIDEO, "OpenXR: VkPhysicalDevice matches runtime expectation.");
      }
    }
  }

  // --- Create XrSession bound to the active Vulkan device ---
  INFO_LOG_FMT(VIDEO, "OpenXR Vulkan: Creating XrSession with Vulkan binding...");
  INFO_LOG_FMT(VIDEO, "  VkInstance={}, VkPhysicalDevice={}, VkDevice={}, queueFamily={}, "
                       "queueIndex=0",
               reinterpret_cast<void*>(g_vulkan_context->GetVulkanInstance()),
               reinterpret_cast<void*>(g_vulkan_context->GetPhysicalDevice()),
               reinterpret_cast<void*>(g_vulkan_context->GetDevice()),
               g_vulkan_context->GetGraphicsQueueFamilyIndex());

  XrGraphicsBindingVulkanKHR vk_binding{XR_TYPE_GRAPHICS_BINDING_VULKAN_KHR};
  vk_binding.instance = g_vulkan_context->GetVulkanInstance();
  vk_binding.physicalDevice = g_vulkan_context->GetPhysicalDevice();
  vk_binding.device = g_vulkan_context->GetDevice();
  vk_binding.queueFamilyIndex = g_vulkan_context->GetGraphicsQueueFamilyIndex();
  vk_binding.queueIndex = 0;

  XrSessionCreateInfo session_info{XR_TYPE_SESSION_CREATE_INFO};
  session_info.next = &vk_binding;
  session_info.systemId = xr_system;

  XrSession session = XR_NULL_HANDLE;
  result = SafeCreateSession(xr_instance, &session_info, &session);

  if (XR_FAILED(result))
  {
    ERROR_LOG_FMT(VIDEO, "OpenXR: xrCreateSession failed ({}).", static_cast<int>(result));
    return false;
  }

  VR::g_openxr->SetSession(session);
  INFO_LOG_FMT(VIDEO, "OpenXR Vulkan: Session created successfully.");
  return true;
}

bool VulkanOpenXR::CreateSwapchains()
{
  ASSERT(VR::g_openxr != nullptr);

  const auto& view_cfgs = VR::g_openxr->GetViewConfigViews();
  int64_t swapchain_format = 0;
  if (!SelectSwapchainFormat(VR::g_openxr->GetSession(), &swapchain_format))
    return false;

  const AbstractTextureFormat abstract_format =
      VkFormatToAbstractFormat(static_cast<VkFormat>(swapchain_format));

  for (uint32_t eye = 0; eye < 2; ++eye)
  {
    auto& sc = m_eye_swapchains[eye];
    sc.width = view_cfgs[eye].recommendedImageRectWidth;
    sc.height = view_cfgs[eye].recommendedImageRectHeight;

    // Format must come from xrEnumerateSwapchainFormats.
    XrSwapchainCreateInfo info{XR_TYPE_SWAPCHAIN_CREATE_INFO};
    info.arraySize = 1;
    info.format = swapchain_format;
    info.width = sc.width;
    info.height = sc.height;
    info.mipCount = 1;
    info.faceCount = 1;
    info.sampleCount = 1;
    info.usageFlags =
        XR_SWAPCHAIN_USAGE_COLOR_ATTACHMENT_BIT | XR_SWAPCHAIN_USAGE_TRANSFER_DST_BIT;

    XrResult result = xrCreateSwapchain(VR::g_openxr->GetSession(), &info, &sc.swapchain);
    if (XR_FAILED(result))
    {
      ERROR_LOG_FMT(VIDEO, "OpenXR: xrCreateSwapchain failed for eye {} ({}).", eye,
                    static_cast<int>(result));
      return false;
    }

    // Enumerate the Vulkan images backing this swapchain.
    uint32_t image_count = 0;
    xrEnumerateSwapchainImages(sc.swapchain, 0, &image_count, nullptr);

    std::vector<XrSwapchainImageVulkanKHR> images(image_count,
                                                   {XR_TYPE_SWAPCHAIN_IMAGE_VULKAN_KHR});
    xrEnumerateSwapchainImages(sc.swapchain, image_count, &image_count,
                               reinterpret_cast<XrSwapchainImageBaseHeader*>(images.data()));

    sc.textures.resize(image_count);
    sc.framebuffers.resize(image_count);

    for (uint32_t i = 0; i < image_count; ++i)
    {
      // Build a TextureConfig matching the swapchain image properties.
      TextureConfig tex_config(sc.width, sc.height, /*levels=*/1, /*layers=*/1, /*samples=*/1,
                               abstract_format, AbstractTextureFlag_RenderTarget,
                               AbstractTextureType::Texture_2D);

      // Adopt the runtime-owned VkImage. VKTexture::CreateAdopted wraps the image
      // without allocating device memory (the runtime owns it).
      sc.textures[i] = VKTexture::CreateAdopted(tex_config, images[i].image,
                                                VK_IMAGE_VIEW_TYPE_2D,
                                                VK_IMAGE_LAYOUT_UNDEFINED);
      if (!sc.textures[i])
      {
        ERROR_LOG_FMT(VIDEO, "OpenXR: VKTexture::CreateAdopted failed for eye {}, image {}.", eye,
                      i);
        return false;
      }

      sc.framebuffers[i] = VKFramebuffer::Create(sc.textures[i].get(), nullptr, {});
      if (!sc.framebuffers[i])
      {
        ERROR_LOG_FMT(VIDEO, "OpenXR: VKFramebuffer::Create failed for eye {}, image {}.", eye, i);
        return false;
      }
    }

    INFO_LOG_FMT(VIDEO, "OpenXR: Eye {} swapchain ready: {}x{}, {} images.", eye, sc.width,
                 sc.height, image_count);
  }

  return true;
}

void VulkanOpenXR::DestroySwapchains()
{
  // Wait for the GPU to finish all pending work before destroying resources.
  if (g_vulkan_context)
    vkDeviceWaitIdle(g_vulkan_context->GetDevice());

  for (uint32_t eye = 0; eye < 2; ++eye)
  {
    auto& sc = m_eye_swapchains[eye];

    if (m_image_acquired[eye] && sc.swapchain != XR_NULL_HANDLE)
    {
      XrSwapchainImageReleaseInfo release_info{XR_TYPE_SWAPCHAIN_IMAGE_RELEASE_INFO};
      const XrResult release_result = xrReleaseSwapchainImage(sc.swapchain, &release_info);
      if (XR_FAILED(release_result))
      {
        WARN_LOG_FMT(VIDEO,
                     "OpenXR: xrReleaseSwapchainImage during shutdown failed for eye {} ({}).",
                     eye, static_cast<int>(release_result));
      }
      m_image_acquired[eye] = false;
    }

    // Release Dolphin wrappers before destroying the swapchain so the
    // runtime's VkImages are only freed after our views are gone.
    sc.framebuffers.clear();
    sc.textures.clear();

    if (sc.swapchain != XR_NULL_HANDLE)
    {
      const XrResult destroy_result = xrDestroySwapchain(sc.swapchain);
      if (XR_FAILED(destroy_result))
      {
        WARN_LOG_FMT(VIDEO, "OpenXR: xrDestroySwapchain failed for eye {} ({}).", eye,
                     static_cast<int>(destroy_result));
      }
      sc.swapchain = XR_NULL_HANDLE;
    }
  }
}

AbstractFramebuffer* VulkanOpenXR::AcquireEyeFramebuffer(uint32_t eye_index)
{
  ASSERT(eye_index < 2);
  auto& sc = m_eye_swapchains[eye_index];

  XrSwapchainImageAcquireInfo acquire_info{XR_TYPE_SWAPCHAIN_IMAGE_ACQUIRE_INFO};
  if (XR_FAILED(
          xrAcquireSwapchainImage(sc.swapchain, &acquire_info, &m_acquired_image_index[eye_index])))
  {
    ERROR_LOG_FMT(VIDEO, "OpenXR: xrAcquireSwapchainImage failed for eye {}.", eye_index);
    return nullptr;
  }
  m_image_acquired[eye_index] = true;

  // Block until the acquired image is safe to write.
  XrSwapchainImageWaitInfo wait_info{XR_TYPE_SWAPCHAIN_IMAGE_WAIT_INFO};
  wait_info.timeout = XR_INFINITE_DURATION;
  if (XR_FAILED(xrWaitSwapchainImage(sc.swapchain, &wait_info)))
  {
    ERROR_LOG_FMT(VIDEO, "OpenXR: xrWaitSwapchainImage failed for eye {}.", eye_index);

    // Ensure we don't leak an acquired image if waiting fails.
    XrSwapchainImageReleaseInfo release_info{XR_TYPE_SWAPCHAIN_IMAGE_RELEASE_INFO};
    const XrResult release_result = xrReleaseSwapchainImage(sc.swapchain, &release_info);
    if (XR_FAILED(release_result))
    {
      WARN_LOG_FMT(VIDEO,
                   "OpenXR: xrReleaseSwapchainImage after wait failure failed for eye {} ({}).",
                   eye_index, static_cast<int>(release_result));
    }
    m_image_acquired[eye_index] = false;
    return nullptr;
  }

  // Reset the image layout to UNDEFINED — the runtime may have changed it since last release,
  // and we're about to clear the image anyway via SetAndClearFramebuffer.
  const uint32_t idx = m_acquired_image_index[eye_index];
  sc.textures[idx]->OverrideImageLayout(VK_IMAGE_LAYOUT_UNDEFINED);

  return sc.framebuffers[idx].get();
}

void VulkanOpenXR::ReleaseEyeTexture(uint32_t eye_index)
{
  ASSERT(eye_index < 2);
  if (!m_image_acquired[eye_index])
    return;

  // End any active render pass so the image layout transitions are recorded
  // and the image is no longer being written to.
  StateTracker::GetInstance()->EndRenderPass();

  XrSwapchainImageReleaseInfo release_info{XR_TYPE_SWAPCHAIN_IMAGE_RELEASE_INFO};
  const XrResult result =
      xrReleaseSwapchainImage(m_eye_swapchains[eye_index].swapchain, &release_info);
  if (XR_FAILED(result))
  {
    WARN_LOG_FMT(VIDEO, "OpenXR: xrReleaseSwapchainImage failed for eye {} ({}).", eye_index,
                 static_cast<int>(result));
  }
  m_image_acquired[eye_index] = false;
}

bool VulkanOpenXR::SubmitFrame()
{
  ASSERT(VR::g_openxr != nullptr);

  const auto& eye_views = VR::g_openxr->GetEyeViews();

  for (uint32_t eye = 0; eye < 2; ++eye)
  {
    auto& pv = m_projection_views[eye];
    pv = {XR_TYPE_COMPOSITION_LAYER_PROJECTION_VIEW};
    pv.pose = eye_views[eye].pose;
    pv.fov = eye_views[eye].fov;
    pv.subImage.swapchain = m_eye_swapchains[eye].swapchain;
    pv.subImage.imageArrayIndex = 0;
    pv.subImage.imageRect = {
        {0, 0},
        {static_cast<int32_t>(m_eye_swapchains[eye].width),
         static_cast<int32_t>(m_eye_swapchains[eye].height)}};
  }

  m_projection_layer = {XR_TYPE_COMPOSITION_LAYER_PROJECTION};
  m_projection_layer.space = VR::g_openxr->GetReferenceSpace();
  m_projection_layer.viewCount = 2;
  m_projection_layer.views = m_projection_views.data();

  const std::vector<XrCompositionLayerBaseHeader*> layers = {
      reinterpret_cast<XrCompositionLayerBaseHeader*>(&m_projection_layer)};

  return VR::g_openxr->EndFrame(layers);
}

}  // namespace Vulkan

#endif  // ENABLE_VR