// Copyright 2014 The Chromium 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 MEDIA_GPU_VT_VIDEO_DECODE_ACCELERATOR_MAC_H_
#define MEDIA_GPU_VT_VIDEO_DECODE_ACCELERATOR_MAC_H_

#include <stdint.h>

#include <map>
#include <memory>
#include <queue>

#include <VideoToolbox/VideoToolbox.h>

#include "base/mac/scoped_cftyperef.h"
#include "base/macros.h"
#include "base/memory/linked_ptr.h"
#include "base/memory/weak_ptr.h"
#include "base/message_loop/message_loop.h"
#include "base/threading/thread.h"
#include "base/threading/thread_checker.h"
#include "base/trace_event/memory_dump_provider.h"
#include "media/filters/h264_parser.h"
#include "media/gpu/gpu_video_decode_accelerator_helpers.h"
#include "media/gpu/media_gpu_export.h"
#include "media/video/h264_poc.h"
#include "media/video/video_decode_accelerator.h"
#include "ui/gfx/geometry/size.h"
#include "ui/gl/gl_context_cgl.h"
#include "ui/gl/gl_image_io_surface.h"

namespace media {

// Preload VideoToolbox libraries, needed for sandbox warmup.
MEDIA_GPU_EXPORT bool InitializeVideoToolbox();

// VideoToolbox.framework implementation of the VideoDecodeAccelerator
// interface for Mac OS X (currently limited to 10.9+).
class VTVideoDecodeAccelerator : public VideoDecodeAccelerator,
                                 public base::trace_event::MemoryDumpProvider {
 public:
  explicit VTVideoDecodeAccelerator(
      const MakeGLContextCurrentCallback& make_context_current_cb,
      const BindGLImageCallback& bind_image_cb);

  ~VTVideoDecodeAccelerator() override;

  // VideoDecodeAccelerator implementation.
  bool Initialize(const Config& config, Client* client) override;
  void Decode(const BitstreamBuffer& bitstream) override;
  void AssignPictureBuffers(
      const std::vector<PictureBuffer>& pictures) override;
  void ReusePictureBuffer(int32_t picture_id) override;
  void Flush() override;
  void Reset() override;
  void Destroy() override;
  bool TryToSetupDecodeOnSeparateThread(
      const base::WeakPtr<Client>& decode_client,
      const scoped_refptr<base::SingleThreadTaskRunner>& decode_task_runner)
      override;

  // MemoryDumpProvider implementation.
  bool OnMemoryDump(const base::trace_event::MemoryDumpArgs& args,
                    base::trace_event::ProcessMemoryDump* pmd) override;

  // Called by OutputThunk() when VideoToolbox finishes decoding a frame.
  void Output(void* source_frame_refcon,
              OSStatus status,
              CVImageBufferRef image_buffer);

  static VideoDecodeAccelerator::SupportedProfiles GetSupportedProfiles();

 private:
  // Logged to UMA, so never reuse values. Make sure to update
  // VTVDASessionFailureType in histograms.xml to match.
  enum VTVDASessionFailureType {
    SFT_SUCCESSFULLY_INITIALIZED = 0,
    SFT_PLATFORM_ERROR = 1,
    SFT_INVALID_STREAM = 2,
    SFT_UNSUPPORTED_STREAM_PARAMETERS = 3,
    SFT_DECODE_ERROR = 4,
    SFT_UNSUPPORTED_STREAM = 5,
    // Must always be equal to largest entry logged.
    SFT_MAX = SFT_UNSUPPORTED_STREAM
  };

  enum State {
    STATE_DECODING,
    STATE_ERROR,
    STATE_DESTROYING,
  };

  enum TaskType {
    TASK_FRAME,
    TASK_FLUSH,
    TASK_RESET,
    TASK_DESTROY,
  };

  struct Frame {
    explicit Frame(int32_t bitstream_id);
    ~Frame();

    // Associated bitstream buffer.
    int32_t bitstream_id;

    // Slice header information.
    bool has_slice = false;
    bool is_idr = false;
    bool has_mmco5 = false;
    int32_t pic_order_cnt = 0;
    int32_t reorder_window = 0;

    // Clean aperture size, as computed by CoreMedia.
    gfx::Size image_size;

    // Decoded image, if decoding was successful.
    base::ScopedCFTypeRef<CVImageBufferRef> image;
  };

  struct Task {
    Task(TaskType type);
    Task(const Task& other);
    ~Task();

    TaskType type;
    linked_ptr<Frame> frame;
  };

  struct PictureInfo {
    PictureInfo(uint32_t client_texture_id, uint32_t service_texture_id);
    ~PictureInfo();

    // Image buffer, kept alive while they are bound to pictures.
    base::ScopedCFTypeRef<CVImageBufferRef> cv_image;

    // The GLImage representation of |cv_image|. This is kept around to ensure
    // that Destroy is called on it before it hits its destructor (there is a
    // DCHECK that requires this).
    scoped_refptr<gl::GLImageIOSurface> gl_image;

    // Texture IDs for the image buffer.
    const uint32_t client_texture_id;
    const uint32_t service_texture_id;

   private:
    DISALLOW_COPY_AND_ASSIGN(PictureInfo);
  };

  struct FrameOrder {
    bool operator()(const linked_ptr<Frame>& lhs,
                    const linked_ptr<Frame>& rhs) const;
  };

  //
  // Methods for interacting with VideoToolbox. Run on |decoder_thread_|.
  //

  // Set up VideoToolbox using the current SPS and PPS. Returns true or calls
  // NotifyError() before returning false.
  bool ConfigureDecoder();

  // Wait for VideoToolbox to output all pending frames. Returns true or calls
  // NotifyError() before returning false.
  bool FinishDelayedFrames();

  // |frame| is owned by |pending_frames_|.
  void DecodeTask(const BitstreamBuffer&, Frame* frame);
  void DecodeDone(Frame* frame);

  //
  // Methods for interacting with |client_|. Run on |gpu_task_runner_|.
  //
  void NotifyError(Error vda_error_type,
                   VTVDASessionFailureType session_failure_type);

  // |type| is the type of task that the flush will complete, one of TASK_FLUSH,
  // TASK_RESET, or TASK_DESTROY.
  void QueueFlush(TaskType type);
  void FlushTask(TaskType type);
  void FlushDone(TaskType type);

  // Try to make progress on tasks in the |task_queue_| or sending frames in the
  // |reorder_queue_|.
  void ProcessWorkQueues();

  // These methods returns true if a task was completed, false otherwise.
  bool ProcessTaskQueue();
  bool ProcessReorderQueue();
  bool ProcessFrame(const Frame& frame);
  bool SendFrame(const Frame& frame);

  //
  // GPU thread state.
  //
  MakeGLContextCurrentCallback make_context_current_cb_;
  BindGLImageCallback bind_image_cb_;

  VideoDecodeAccelerator::Client* client_ = nullptr;
  State state_ = STATE_DECODING;

  // Queue of pending flush tasks. This is used to drop frames when a reset
  // is pending.
  std::queue<TaskType> pending_flush_tasks_;

  // Queue of tasks to complete in the GPU thread.
  std::queue<Task> task_queue_;

  // Queue of decoded frames in presentation order.
  std::priority_queue<linked_ptr<Frame>,
                      std::vector<linked_ptr<Frame>>,
                      FrameOrder>
      reorder_queue_;

  // Size of assigned picture buffers.
  gfx::Size picture_size_;

  // Frames that have not yet been decoded, keyed by bitstream ID; maintains
  // ownership of Frame objects while they flow through VideoToolbox.
  std::map<int32_t, linked_ptr<Frame>> pending_frames_;

  // Set of assigned bitstream IDs, so that Destroy() can release them all.
  std::set<int32_t> assigned_bitstream_ids_;

  // All picture buffers assigned to us. Used to check if reused picture buffers
  // should be added back to the available list or released. (They are not
  // released immediately because we need the reuse event to free the binding.)
  std::set<int32_t> assigned_picture_ids_;

  // Texture IDs and image buffers of assigned pictures.
  std::map<int32_t, std::unique_ptr<PictureInfo>> picture_info_map_;

  // Pictures ready to be rendered to.
  std::vector<int32_t> available_picture_ids_;

  //
  // Decoder thread state.
  //
  VTDecompressionOutputCallbackRecord callback_;
  base::ScopedCFTypeRef<CMFormatDescriptionRef> format_;
  base::ScopedCFTypeRef<VTDecompressionSessionRef> session_;
  H264Parser parser_;

  // Last SPS and PPS seen in the bitstream.
  //
  // TODO(sandersd): Keep a map from ID to last SPS/PPS, for streams that
  // maintain multiple active configurations. (I've never seen such a stream.)
  int last_sps_id_ = -1;
  int last_pps_id_ = -1;
  std::vector<uint8_t> last_sps_;
  std::vector<uint8_t> last_spsext_;
  std::vector<uint8_t> last_pps_;

  // Last SPS and PPS referenced by a slice. In practice these will be the same
  // as the last seen values, unless the bitstream is malformatted.
  std::vector<uint8_t> active_sps_;
  std::vector<uint8_t> active_spsext_;
  std::vector<uint8_t> active_pps_;

  // Last SPS and PPS the decoder was confgured with.
  std::vector<uint8_t> configured_sps_;
  std::vector<uint8_t> configured_spsext_;
  std::vector<uint8_t> configured_pps_;
  gfx::Size configured_size_;

  bool waiting_for_idr_ = true;
  bool missing_idr_logged_ = false;
  H264POC poc_;

  // Id number for this instance for memory dumps.
  int memory_dump_id_ = 0;

  //
  // Shared state (set up and torn down on GPU thread).
  //
  scoped_refptr<base::SingleThreadTaskRunner> gpu_task_runner_;
  base::WeakPtr<VTVideoDecodeAccelerator> weak_this_;
  base::Thread decoder_thread_;

  // Declared last to ensure that all weak pointers are invalidated before
  // other destructors run.
  base::WeakPtrFactory<VTVideoDecodeAccelerator> weak_this_factory_;

  DISALLOW_COPY_AND_ASSIGN(VTVideoDecodeAccelerator);
};

}  // namespace media

#endif  // MEDIA_GPU_VT_VIDEO_DECODE_ACCELERATOR_MAC_H_