// Copyright 2017 The Fuchsia Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

#include "garnet/lib/ui/gfx/resources/image_pipe.h"

#include <trace/event.h>

#include "garnet/lib/ui/gfx/engine/session.h"
#include "garnet/lib/ui/gfx/engine/update_scheduler.h"
#include "garnet/lib/ui/gfx/resources/memory.h"
#include "lib/escher/flib/fence.h"

namespace scenic_impl {
namespace gfx {

const ResourceTypeInfo ImagePipe::kTypeInfo = {
    ResourceType::kImagePipe | ResourceType::kImageBase, "ImagePipe"};

ImagePipe::ImagePipe(Session* session, ResourceId id,
                     UpdateScheduler* update_scheduler)
    : ImageBase(session, id, ImagePipe::kTypeInfo),
      update_scheduler_(update_scheduler),
      weak_ptr_factory_(this) {
  FXL_DCHECK(update_scheduler);
}

ImagePipe::ImagePipe(
    Session* session, ResourceId id,
    ::fidl::InterfaceRequest<fuchsia::images::ImagePipe> request,
    UpdateScheduler* update_scheduler)
    : ImageBase(session, id, ImagePipe::kTypeInfo),
      handler_(std::make_unique<ImagePipeHandler>(std::move(request), this)),
      update_scheduler_(update_scheduler),
      weak_ptr_factory_(this) {
  FXL_DCHECK(update_scheduler);
}

void ImagePipe::AddImage(uint32_t image_id,
                         fuchsia::images::ImageInfo image_info, zx::vmo vmo,
                         uint64_t offset_bytes, uint64_t size_bytes,
                         fuchsia::images::MemoryType memory_type) {
  if (image_id == 0) {
    session()->error_reporter()->ERROR()
        << "ImagePipe::AddImage: Image can not be assigned an ID of 0.";
    CloseConnectionAndCleanUp();
    return;
  }
  uint64_t vmo_size;
  auto status = vmo.get_size(&vmo_size);

  if (status != ZX_OK) {
    session()->error_reporter()->ERROR()
        << "ImagePipe::AddImage(): zx_vmo_get_size failed (err=" << status
        << ").";
    CloseConnectionAndCleanUp();
    return;
  }
  ::fuchsia::ui::gfx::MemoryArgs memory_args;
  memory_args.memory_type = memory_type;
  memory_args.vmo = std::move(vmo);
  memory_args.allocation_size = vmo_size;
  MemoryPtr memory = Memory::New(session(), 0u, std::move(memory_args),
                                 session()->error_reporter());
  if (!memory) {
    session()->error_reporter()->ERROR()
        << "ImagePipe::AddImage: Unable to create a memory object.";
    CloseConnectionAndCleanUp();
    return;
  }
  auto image = CreateImage(session(), image_id, memory, image_info,
                           offset_bytes, session()->error_reporter());
  auto result = images_.insert({image_id, std::move(image)});
  if (!result.second) {
    session()->error_reporter()->ERROR()
        << "ImagePipe::AddImage(): resource with ID " << image_id
        << " already exists.";
    CloseConnectionAndCleanUp();
    return;
  }
};

void ImagePipe::CloseConnectionAndCleanUp() {
  handler_.reset();
  is_valid_ = false;
  frames_ = {};
  images_.clear();

  // Schedule a new frame.
  update_scheduler_->ScheduleUpdate(0);
}

void ImagePipe::OnConnectionError() { CloseConnectionAndCleanUp(); }

ImagePtr ImagePipe::CreateImage(Session* session, ResourceId id,
                                MemoryPtr memory,
                                const fuchsia::images::ImageInfo& image_info,
                                uint64_t memory_offset,
                                ErrorReporter* error_reporter) {
  return Image::New(session, id, memory, image_info, memory_offset,
                    error_reporter);
}

void ImagePipe::RemoveImage(uint32_t image_id) {
  size_t erased_count = images_.erase(image_id);
  if (erased_count == 0) {
    session()->error_reporter()->ERROR()
        << "ImagePipe::RemoveImage(): Could not find image with id=" << image_id
        << ".";
    CloseConnectionAndCleanUp();
  }
};

void ImagePipe::PresentImage(
    uint32_t image_id, uint64_t presentation_time,
    ::std::vector<zx::event> acquire_fences,
    ::std::vector<zx::event> release_fences,
    fuchsia::images::ImagePipe::PresentImageCallback callback) {
  if (!frames_.empty() &&
      presentation_time < frames_.back().presentation_time) {
    session()->error_reporter()->ERROR()
        << "ImagePipe: Present called with out-of-order "
           "presentation time."
        << "presentation_time=" << presentation_time
        << ", last scheduled presentation time="
        << frames_.back().presentation_time;
    CloseConnectionAndCleanUp();
    return;
  }

  // Verify that image_id is valid.
  auto image_it = images_.find(image_id);
  if (image_it == images_.end()) {
    session()->error_reporter()->ERROR()
        << "ImagePipe::PresentImage could not find Image with ID: " << image_id;
    CloseConnectionAndCleanUp();
    return;
  }

  auto acquire_fences_listener =
      std::make_unique<escher::FenceSetListener>(std::move(acquire_fences));
  acquire_fences_listener->WaitReadyAsync(
      [weak = weak_ptr_factory_.GetWeakPtr(), presentation_time] {
        if (weak) {
          weak->session()->ScheduleImagePipeUpdate(presentation_time,
                                                   ImagePipePtr(weak.get()));
        }
      });
  frames_.push(Frame{
      image_it->second, presentation_time, std::move(acquire_fences_listener),
      fidl::VectorPtr(std::move(release_fences)), std::move(callback)});
};

bool ImagePipe::Update(escher::ReleaseFenceSignaller* release_fence_signaller,
                       uint64_t presentation_time,
                       uint64_t presentation_interval) {
  FXL_DCHECK(release_fence_signaller);

  TRACE_DURATION("gfx", "ImagePipe::Update", "session_id", session()->id(),
                 "id", id(), "time", presentation_time, "interval",
                 presentation_interval);

  bool present_next_image = false;
  ResourceId next_image_id = current_image_id_;
  ::fidl::VectorPtr<zx::event> next_release_fences;

  ImagePtr next_image = nullptr;
  while (!frames_.empty() &&
         frames_.front().presentation_time <= presentation_time &&
         frames_.front().acquire_fences->ready()) {
    if (next_image) {
      // We're skipping a frame, so we should also mark the image as dirty, in
      // case the producer updates the pixels in the buffer between now and a
      // future present call.
      next_image->MarkAsDirty();
    }

    next_image = frames_.front().image;
    FXL_DCHECK(next_image);
    next_image_id = next_image->id();

    if (!next_release_fences->empty()) {
      // We're skipping a frame, so we can immediately signal its release
      // fences.
      for (auto& fence : *next_release_fences) {
        fence.signal(0u, escher::kFenceSignalled);
      }
    }

    next_release_fences = std::move(frames_.front().release_fences);

    auto info = fuchsia::images::PresentationInfo();
    info.presentation_time = presentation_time;
    info.presentation_interval = presentation_interval;
    if (frames_.front().present_image_callback) {
      frames_.front().present_image_callback(std::move(info));
    }
    frames_.pop();
    present_next_image = true;
  }

  if (!present_next_image)
    return false;

  // TODO(SCN-151): This code, and the code below that marks an image as dirty,
  // assumes that the same image cannot be presented twice in a row on the same
  // image pipe, while also requiring a call to UpdatePixels(). If not, this
  // needs a new test.
  if (next_image_id == current_image_id_) {
    // This ImagePipe did not change since the last frame was rendered.
    return false;
  }

  // We're replacing a frame with a new one, so we hand off its release
  // fence to the |ReleaseFenceSignaller|, which will signal it as soon as
  // all work previously submitted to the GPU is finished.
  if (current_release_fences_) {
    release_fence_signaller->AddCPUReleaseFences(
        std::move(current_release_fences_));
  }
  current_release_fences_ = std::move(next_release_fences);
  current_image_id_ = next_image_id;
  // TODO(SCN-1010): Determine proper signaling for marking images as dirty.
  // For now, mark all released images as dirty, with the assumption that the
  // client will likely write into the buffer before submitting it again.
  if (current_image_) {
    current_image_->MarkAsDirty();
  }
  current_image_ = std::move(next_image);

  return true;
}

void ImagePipe::UpdateEscherImage(escher::BatchGpuUploader* gpu_uploader) {
  if (current_image_) {
    current_image_->UpdateEscherImage(gpu_uploader);
  }
}

const escher::ImagePtr& ImagePipe::GetEscherImage() {
  if (current_image_) {
    return current_image_->GetEscherImage();
  }
  static const escher::ImagePtr kNullEscherImage;
  return kNullEscherImage;
}

}  // namespace gfx
}  // namespace scenic_impl