/* vim: set ts=8 sts=2 et sw=2 tw=80: */
/* This Source Code Form is subject to the terms of the Mozilla Public
 * License, v. 2.0. If a copy of the MPL was not distributed with this
 * file, You can obtain one at http://mozilla.org/MPL/2.0/. */

#include "SourceBuffer.h"

#include "AsyncEventRunner.h"
#include "DecoderTraits.h"
#include "MediaDecoder.h"
#include "MediaSourceDecoder.h"
#include "SourceBufferResource.h"
#include "mozilla/ErrorResult.h"
#include "mozilla/FloatingPoint.h"
#include "mozilla/dom/MediaSourceBinding.h"
#include "mozilla/dom/TimeRanges.h"
#include "nsError.h"
#include "nsIEventTarget.h"
#include "nsIRunnable.h"
#include "nsThreadUtils.h"
#include "prlog.h"
#include "SubBufferDecoder.h"

struct JSContext;
class JSObject;

#ifdef PR_LOGGING
extern PRLogModuleInfo* gMediaSourceLog;
#define MSE_DEBUG(...) PR_LOG(gMediaSourceLog, PR_LOG_DEBUG, (__VA_ARGS__))
#else
#define MSE_DEBUG(...)
#endif

namespace mozilla {

class MediaResource;
class ReentrantMonitor;

namespace layers {

class ImageContainer;

} // namespace layers

ReentrantMonitor&
SubBufferDecoder::GetReentrantMonitor()
{
  return mParentDecoder->GetReentrantMonitor();
}

bool
SubBufferDecoder::OnStateMachineThread() const
{
  return mParentDecoder->OnStateMachineThread();
}

bool
SubBufferDecoder::OnDecodeThread() const
{
  return mParentDecoder->OnDecodeThread();
}

SourceBufferResource*
SubBufferDecoder::GetResource() const
{
  return static_cast<SourceBufferResource*>(mResource.get());
}

void
SubBufferDecoder::SetMediaDuration(int64_t aDuration)
{
  mParentDecoder->SetMediaDuration(aDuration);
}

void
SubBufferDecoder::UpdateEstimatedMediaDuration(int64_t aDuration)
{
  mParentDecoder->UpdateEstimatedMediaDuration(aDuration);
}

void
SubBufferDecoder::SetMediaSeekable(bool aMediaSeekable)
{
  mParentDecoder->SetMediaSeekable(aMediaSeekable);
}

void
SubBufferDecoder::SetTransportSeekable(bool aTransportSeekable)
{
  mParentDecoder->SetTransportSeekable(aTransportSeekable);
}

layers::ImageContainer*
SubBufferDecoder::GetImageContainer()
{
  return mParentDecoder->GetImageContainer();
}

int64_t
SubBufferDecoder::ConvertToByteOffset(double aTime)
{
  // Uses a conversion based on (aTime/duration) * length.  For the
  // purposes of eviction this should be adequate since we have the
  // byte threshold as well to ensure data actually gets evicted and
  // we ensure we don't evict before the current playable point.
  double duration = mParentDecoder->GetMediaSourceDuration();
  if (duration <= 0.0 || IsNaN(duration)) {
    return -1;
  }
  int64_t length = GetResource()->GetLength();
  MOZ_ASSERT(length > 0);
  int64_t offset = (aTime / duration) * length;
  return offset;
}

namespace dom {

void
SourceBuffer::SetMode(SourceBufferAppendMode aMode, ErrorResult& aRv)
{
  if (!IsAttached() || mUpdating) {
    aRv.Throw(NS_ERROR_DOM_INVALID_STATE_ERR);
    return;
  }
  MOZ_ASSERT(mMediaSource->ReadyState() != MediaSourceReadyState::Closed);
  if (mMediaSource->ReadyState() == MediaSourceReadyState::Ended) {
    mMediaSource->SetReadyState(MediaSourceReadyState::Open);
  }
  // TODO: Test append state.
  // TODO: If aMode is "sequence", set sequence start time.
  mAppendMode = aMode;
}

void
SourceBuffer::SetTimestampOffset(double aTimestampOffset, ErrorResult& aRv)
{
  if (!IsAttached() || mUpdating) {
    aRv.Throw(NS_ERROR_DOM_INVALID_STATE_ERR);
    return;
  }
  MOZ_ASSERT(mMediaSource->ReadyState() != MediaSourceReadyState::Closed);
  if (mMediaSource->ReadyState() == MediaSourceReadyState::Ended) {
    mMediaSource->SetReadyState(MediaSourceReadyState::Open);
  }
  // TODO: Test append state.
  // TODO: If aMode is "sequence", set sequence start time.
  mTimestampOffset = aTimestampOffset;
}

already_AddRefed<TimeRanges>
SourceBuffer::GetBuffered(ErrorResult& aRv)
{
  if (!IsAttached()) {
    aRv.Throw(NS_ERROR_DOM_INVALID_STATE_ERR);
    return nullptr;
  }
  nsRefPtr<TimeRanges> ranges = new TimeRanges();
  mDecoder->GetBuffered(ranges);
  return ranges.forget();
}

void
SourceBuffer::SetAppendWindowStart(double aAppendWindowStart, ErrorResult& aRv)
{
  if (!IsAttached() || mUpdating) {
    aRv.Throw(NS_ERROR_DOM_INVALID_STATE_ERR);
    return;
  }
  if (aAppendWindowStart < 0 || aAppendWindowStart >= mAppendWindowEnd) {
    aRv.Throw(NS_ERROR_DOM_INVALID_ACCESS_ERR);
    return;
  }
  mAppendWindowStart = aAppendWindowStart;
}

void
SourceBuffer::SetAppendWindowEnd(double aAppendWindowEnd, ErrorResult& aRv)
{
  if (!IsAttached() || mUpdating) {
    aRv.Throw(NS_ERROR_DOM_INVALID_STATE_ERR);
    return;
  }
  if (IsNaN(aAppendWindowEnd) ||
      aAppendWindowEnd <= mAppendWindowStart) {
    aRv.Throw(NS_ERROR_DOM_INVALID_ACCESS_ERR);
    return;
  }
  mAppendWindowEnd = aAppendWindowEnd;
}

void
SourceBuffer::AppendBuffer(const ArrayBuffer& aData, ErrorResult& aRv)
{
  AppendData(aData.Data(), aData.Length(), aRv);
}

void
SourceBuffer::AppendBuffer(const ArrayBufferView& aData, ErrorResult& aRv)
{
  AppendData(aData.Data(), aData.Length(), aRv);
}

void
SourceBuffer::Abort(ErrorResult& aRv)
{
  if (!IsAttached()) {
    aRv.Throw(NS_ERROR_DOM_INVALID_STATE_ERR);
    return;
  }
  if (mMediaSource->ReadyState() != MediaSourceReadyState::Open) {
    aRv.Throw(NS_ERROR_DOM_INVALID_STATE_ERR);
    return;
  }
  if (mUpdating) {
    // TODO: Abort segment parser loop, buffer append, and stream append loop algorithms.
    AbortUpdating();
  }
  // TODO: Run reset parser algorithm.
  mAppendWindowStart = 0;
  mAppendWindowEnd = PositiveInfinity<double>();
}

void
SourceBuffer::Remove(double aStart, double aEnd, ErrorResult& aRv)
{
  if (!IsAttached() || mUpdating ||
      mMediaSource->ReadyState() != MediaSourceReadyState::Open) {
    aRv.Throw(NS_ERROR_DOM_INVALID_STATE_ERR);
    return;
  }
  if (aStart < 0 || aStart > mMediaSource->Duration() ||
      aEnd <= aStart) {
    aRv.Throw(NS_ERROR_DOM_INVALID_ACCESS_ERR);
    return;
  }
  StartUpdating();
  /// TODO: Run coded frame removal algorithm asynchronously (would call StopUpdating()).
  StopUpdating();
}

void
SourceBuffer::Detach()
{
  Ended();
  mDecoder = nullptr;
  mMediaSource = nullptr;
}

void
SourceBuffer::Ended()
{
  mDecoder->GetResource()->Ended();
}

SourceBuffer::SourceBuffer(MediaSource* aMediaSource, const nsACString& aType)
  : nsDOMEventTargetHelper(aMediaSource->GetParentObject())
  , mMediaSource(aMediaSource)
  , mAppendWindowStart(0)
  , mAppendWindowEnd(PositiveInfinity<double>())
  , mTimestampOffset(0)
  , mAppendMode(SourceBufferAppendMode::Segments)
  , mUpdating(false)
{
  MOZ_ASSERT(aMediaSource);
  MediaSourceDecoder* parentDecoder = aMediaSource->GetDecoder();
  mDecoder = parentDecoder->CreateSubDecoder(aType);
  MOZ_ASSERT(mDecoder);
}

SourceBuffer::~SourceBuffer()
{
  if (mDecoder) {
    mDecoder->GetResource()->Ended();
  }
}

MediaSource*
SourceBuffer::GetParentObject() const
{
  return mMediaSource;
}

JSObject*
SourceBuffer::WrapObject(JSContext* aCx, JS::Handle<JSObject*> aScope)
{
  return SourceBufferBinding::Wrap(aCx, aScope, this);
}

void
SourceBuffer::DispatchSimpleEvent(const char* aName)
{
  MSE_DEBUG("%p Dispatching event %s to SourceBuffer", this, aName);
  DispatchTrustedEvent(NS_ConvertUTF8toUTF16(aName));
}

void
SourceBuffer::QueueAsyncSimpleEvent(const char* aName)
{
  MSE_DEBUG("%p Queuing event %s to SourceBuffer", this, aName);
  nsCOMPtr<nsIRunnable> event = new AsyncEventRunner<SourceBuffer>(this, aName);
  NS_DispatchToMainThread(event, NS_DISPATCH_NORMAL);
}

void
SourceBuffer::StartUpdating()
{
  MOZ_ASSERT(!mUpdating);
  mUpdating = true;
  QueueAsyncSimpleEvent("updatestart");
}

void
SourceBuffer::StopUpdating()
{
  MOZ_ASSERT(mUpdating);
  mUpdating = false;
  QueueAsyncSimpleEvent("update");
  QueueAsyncSimpleEvent("updateend");
}

void
SourceBuffer::AbortUpdating()
{
  MOZ_ASSERT(mUpdating);
  mUpdating = false;
  QueueAsyncSimpleEvent("abort");
  QueueAsyncSimpleEvent("updateend");
}

void
SourceBuffer::AppendData(const uint8_t* aData, uint32_t aLength, ErrorResult& aRv)
{
  if (!IsAttached() || mUpdating) {
    aRv.Throw(NS_ERROR_DOM_INVALID_STATE_ERR);
    return;
  }
  if (mMediaSource->ReadyState() == MediaSourceReadyState::Ended) {
    mMediaSource->SetReadyState(MediaSourceReadyState::Open);
  }
  // TODO: Run coded frame eviction algorithm.
  // TODO: Test buffer full flag.
  MSE_DEBUG("%p Append(ArrayBuffer=%u)", this, aLength);
  StartUpdating();
  // XXX: For future reference: NDA call must run on the main thread.
  mDecoder->NotifyDataArrived(reinterpret_cast<const char*>(aData),
                              aLength,
                              mDecoder->GetResource()->GetLength());
  // TODO: Run buffer append algorithm asynchronously (would call StopUpdating()).
  mDecoder->GetResource()->AppendData(aData, aLength);

  // Eviction uses a byte threshold. If the buffer is greater than the
  // number of bytes then data is evicted. The time range for this
  // eviction is reported back to the media source. It will then
  // evict data before that range across all SourceBuffer's it knows
  // about.
  const int evict_threshold = 1000000;
  bool evicted = mDecoder->GetResource()->EvictData(evict_threshold);
  if (evicted) {
    double start = 0.0;
    double end = 0.0;
    GetBufferedStartEndTime(&start, &end);

    // We notify that we've evicted from the time range 0 through to
    // the current start point.
    mMediaSource->NotifyEvicted(0.0, start);
  }
  StopUpdating();

  // Schedule the state machine thread to ensure playback starts
  // if required when data is appended.
  mMediaSource->GetDecoder()->ScheduleStateMachineThread();
}

void
SourceBuffer::GetBufferedStartEndTime(double* aStart, double* aEnd)
{
  nsRefPtr<TimeRanges> ranges = new TimeRanges();
  mDecoder->GetBuffered(ranges);
  ranges->Normalize();
  int length = ranges->Length();
  ErrorResult rv;

  if (aStart) {
    *aStart = length > 0 ? ranges->Start(0, rv) : 0.0;
  }

  if (aEnd) {
    *aEnd = length > 0 ? ranges->End(length - 1, rv) : 0.0;
  }
}

void
SourceBuffer::Evict(double aStart, double aEnd)
{
  // Need to map time to byte offset then evict
  int64_t end = mDecoder->ConvertToByteOffset(aEnd);
  if (end > 0) {
    mDecoder->GetResource()->EvictBefore(end);
  }
}

NS_IMPL_CYCLE_COLLECTION_INHERITED_1(SourceBuffer, nsDOMEventTargetHelper, mMediaSource)

NS_IMPL_ADDREF_INHERITED(SourceBuffer, nsDOMEventTargetHelper)
NS_IMPL_RELEASE_INHERITED(SourceBuffer, nsDOMEventTargetHelper)

NS_INTERFACE_MAP_BEGIN_CYCLE_COLLECTION_INHERITED(SourceBuffer)
NS_INTERFACE_MAP_END_INHERITING(nsDOMEventTargetHelper)

} // namespace dom

} // namespace mozilla