// Copyright 2013 The Flutter Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

#ifndef FLUTTER_SHELL_PLATFORM_FUCHSIA_FLUTTER_VULKAN_SURFACE_H_
#define FLUTTER_SHELL_PLATFORM_FUCHSIA_FLUTTER_VULKAN_SURFACE_H_

#include <lib/async/cpp/wait.h>
#include <lib/zx/event.h>
#include <lib/zx/vmo.h>

#include <array>
#include <cstdint>
#include <memory>

#include "flutter/fml/macros.h"
#include "flutter/vulkan/procs/vulkan_handle.h"
#include "flutter/vulkan/procs/vulkan_proc_table.h"
#include "flutter/vulkan/vulkan_command_buffer.h"
#include "flutter/vulkan/vulkan_provider.h"
#include "third_party/skia/include/core/SkColorType.h"
#include "third_party/skia/include/core/SkRefCnt.h"
#include "third_party/skia/include/core/SkSize.h"
#include "third_party/skia/include/core/SkSurface.h"

#include "surface_producer.h"

namespace flutter_runner {

// A |VkImage| and its relevant metadata.
struct VulkanImage {
  VulkanImage() = default;
  VulkanImage(VulkanImage&&) = default;
  VulkanImage& operator=(VulkanImage&&) = default;

  VkBufferCollectionImageCreateInfoFUCHSIA vk_collection_image_create_info;
  VkImageCreateInfo vk_image_create_info;
  VkMemoryRequirements vk_memory_requirements;
  vulkan::VulkanHandle<VkImage> vk_image;

  FML_DISALLOW_COPY_AND_ASSIGN(VulkanImage);
};

class VulkanSurface final : public SurfaceProducerSurface {
 public:
  VulkanSurface(vulkan::VulkanProvider& vulkan_provider,
                fuchsia::sysmem::AllocatorSyncPtr& sysmem_allocator,
                fuchsia::ui::composition::AllocatorPtr& flatland_allocator,
                sk_sp<GrDirectContext> context,
                const SkISize& size);

  ~VulkanSurface() override;

  // |SurfaceProducerSurface|
  size_t AdvanceAndGetAge() override;

  // |SurfaceProducerSurface|
  bool FlushSessionAcquireAndReleaseEvents() override;

  // |SurfaceProducerSurface|
  bool IsValid() const override;

  // |SurfaceProducerSurface|
  SkISize GetSize() const override;

  // Note: It is safe for the caller to collect the surface in the
  // |on_writes_committed| callback.
  void SignalWritesFinished(
      const std::function<void(void)>& on_writes_committed) override;

  // |SurfaceProducerSurface|
  void SetImageId(uint32_t image_id) override;

  // |SurfaceProducerSurface|
  uint32_t GetImageId() override;

  // |SurfaceProducerSurface|
  sk_sp<SkSurface> GetSkiaSurface() const override;

  // |SurfaceProducerSurface|
  fuchsia::ui::composition::BufferCollectionImportToken
  GetBufferCollectionImportToken() override;

  // |SurfaceProducerSurface|
  zx::event GetAcquireFence() override;

  // |SurfaceProducerSurface|
  zx::event GetReleaseFence() override;

  // |SurfaceProducerSurface|
  void SetReleaseImageCallback(
      ReleaseImageCallback release_image_callback) override;

  const vulkan::VulkanHandle<VkImage>& GetVkImage() {
    return vulkan_image_.vk_image;
  }

  const vulkan::VulkanHandle<VkSemaphore>& GetAcquireVkSemaphore() {
    return acquire_semaphore_;
  }

  vulkan::VulkanCommandBuffer* GetCommandBuffer(
      const vulkan::VulkanHandle<VkCommandPool>& pool) {
    if (!command_buffer_)
      command_buffer_ = std::make_unique<vulkan::VulkanCommandBuffer>(
          vulkan_provider_.vk(), vulkan_provider_.vk_device(), pool);
    return command_buffer_.get();
  }

  const vulkan::VulkanHandle<VkFence>& GetCommandBufferFence() {
    return command_buffer_fence_;
  }

  size_t GetAllocationSize() const { return vk_memory_info_.allocationSize; }

  size_t GetImageMemoryRequirementsSize() const {
    return vulkan_image_.vk_memory_requirements.size;
  }

  bool IsOversized() const {
    return GetAllocationSize() > GetImageMemoryRequirementsSize();
  }

  bool HasStableSizeHistory() const {
    return std::equal(size_history_.begin() + 1, size_history_.end(),
                      size_history_.begin());
  }

 private:
  static constexpr int kSizeHistorySize = 4;

  void OnHandleReady(async_dispatcher_t* dispatcher,
                     async::WaitBase* wait,
                     zx_status_t status,
                     const zx_packet_signal_t* signal);

  bool AllocateDeviceMemory(
      fuchsia::sysmem::AllocatorSyncPtr& sysmem_allocator,
      fuchsia::ui::composition::AllocatorPtr& flatland_allocator,
      sk_sp<GrDirectContext> context,
      const SkISize& size);

  bool CreateVulkanImage(vulkan::VulkanProvider& vulkan_provider,
                         const SkISize& size,
                         VulkanImage* out_vulkan_image);

  bool SetupSkiaSurface(sk_sp<GrDirectContext> context,
                        const SkISize& size,
                        SkColorType color_type,
                        const VkImageCreateInfo& image_create_info,
                        const VkMemoryRequirements& memory_reqs);

  bool CreateFences();

  void Reset();

  vulkan::VulkanHandle<VkSemaphore> SemaphoreFromEvent(
      const zx::event& event) const;

  vulkan::VulkanProvider& vulkan_provider_;
  VulkanImage vulkan_image_;
  vulkan::VulkanHandle<VkDeviceMemory> vk_memory_;
  VkMemoryAllocateInfo vk_memory_info_;
  vulkan::VulkanHandle<VkFence> command_buffer_fence_;
  sk_sp<SkSurface> sk_surface_;
  fuchsia::ui::composition::BufferCollectionImportToken import_token_;
  uint32_t image_id_ = 0;
  vulkan::VulkanHandle<VkBufferCollectionFUCHSIA> collection_;
  zx::event acquire_event_;
  vulkan::VulkanHandle<VkSemaphore> acquire_semaphore_;
  std::unique_ptr<vulkan::VulkanCommandBuffer> command_buffer_;
  zx::event release_event_;
  async::WaitMethod<VulkanSurface, &VulkanSurface::OnHandleReady> wait_;
  std::function<void()> pending_on_writes_committed_;
  std::array<SkISize, kSizeHistorySize> size_history_;
  int size_history_index_ = 0;
  size_t age_ = 0;
  bool valid_ = false;
  ReleaseImageCallback release_image_callback_;

  FML_DISALLOW_COPY_AND_ASSIGN(VulkanSurface);
};

}  // namespace flutter_runner

#endif  // FLUTTER_SHELL_PLATFORM_FUCHSIA_FLUTTER_VULKAN_SURFACE_H_