/* vim: set shiftwidth=2 tabstop=8 autoindent cindent expandtab: */
/* 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 "AnimationPlayer.h"
#include "AnimationUtils.h"
#include "mozilla/dom/AnimationPlayerBinding.h"
#include "AnimationCommon.h" // For AnimationPlayerCollection,
                             // CommonAnimationManager
#include "nsIDocument.h" // For nsIDocument
#include "nsIPresShell.h" // For nsIPresShell
#include "nsLayoutUtils.h" // For PostRestyleEvent (remove after bug 1073336)

namespace mozilla {
namespace dom {

NS_IMPL_CYCLE_COLLECTION_WRAPPERCACHE(AnimationPlayer, mTimeline, mSource)

NS_IMPL_CYCLE_COLLECTION_ROOT_NATIVE(AnimationPlayer, AddRef)
NS_IMPL_CYCLE_COLLECTION_UNROOT_NATIVE(AnimationPlayer, Release)

JSObject*
AnimationPlayer::WrapObject(JSContext* aCx)
{
  return dom::AnimationPlayerBinding::Wrap(aCx, this);
}

Nullable<double>
AnimationPlayer::GetStartTime() const
{
  return AnimationUtils::TimeDurationToDouble(mStartTime);
}

Nullable<TimeDuration>
AnimationPlayer::GetCurrentTime() const
{
  Nullable<TimeDuration> result;
  if (!mHoldTime.IsNull()) {
    result = mHoldTime;
  } else {
    Nullable<TimeDuration> timelineTime = mTimeline->GetCurrentTime();
    if (!timelineTime.IsNull() && !mStartTime.IsNull()) {
      result.SetValue(timelineTime.Value() - mStartTime.Value());
    }
  }
  return result;
}

AnimationPlayState
AnimationPlayer::PlayState() const
{
  Nullable<TimeDuration> currentTime = GetCurrentTime();
  if (currentTime.IsNull()) {
    return AnimationPlayState::Idle;
  }

  if (mIsPaused) {
    return AnimationPlayState::Paused;
  }

  if (currentTime.Value() >= SourceContentEnd()) {
    return AnimationPlayState::Finished;
  }

  return AnimationPlayState::Running;
}

void
AnimationPlayer::Play()
{
  DoPlay();
  PostUpdate();
}

void
AnimationPlayer::Pause()
{
  DoPause();
  PostUpdate();
}

Nullable<double>
AnimationPlayer::GetCurrentTimeAsDouble() const
{
  return AnimationUtils::TimeDurationToDouble(GetCurrentTime());
}

void
AnimationPlayer::SetSource(Animation* aSource)
{
  if (mSource) {
    mSource->SetParentTime(Nullable<TimeDuration>());
  }
  mSource = aSource;
  if (mSource) {
    mSource->SetParentTime(GetCurrentTime());
  }
}

void
AnimationPlayer::Tick()
{
  if (mSource) {
    mSource->SetParentTime(GetCurrentTime());
  }
}

bool
AnimationPlayer::IsRunning() const
{
  if (IsPaused() || !GetSource() || GetSource()->IsFinishedTransition()) {
    return false;
  }

  ComputedTiming computedTiming = GetSource()->GetComputedTiming();
  return computedTiming.mPhase == ComputedTiming::AnimationPhase_Active;
}

bool
AnimationPlayer::CanThrottle() const
{
  if (!mSource ||
      mSource->IsFinishedTransition() ||
      mSource->Properties().IsEmpty()) {
    return true;
  }

  if (!mIsRunningOnCompositor) {
    return false;
  }

  if (PlayState() != AnimationPlayState::Finished) {
    // Unfinished animations can be throttled.
    return true;
  }

  // The animation has finished but, if this is the first sample since
  // finishing, we need an unthrottled sample so we can apply the correct
  // end-of-animation behavior on the main thread (either removing the
  // animation style or applying the fill mode).
  return mIsPreviousStateFinished;
}

void
AnimationPlayer::ComposeStyle(nsRefPtr<css::AnimValuesStyleRule>& aStyleRule,
                              nsCSSPropertySet& aSetProperties,
                              bool& aNeedsRefreshes)
{
  if (!mSource || mSource->IsFinishedTransition()) {
    return;
  }

  AnimationPlayState playState = PlayState();
  if (playState == AnimationPlayState::Running) {
    aNeedsRefreshes = true;
  }

  mSource->ComposeStyle(aStyleRule, aSetProperties);

  mIsPreviousStateFinished = (playState == AnimationPlayState::Finished);
}

void
AnimationPlayer::DoPlay()
{
  // FIXME: When we implement finishing behavior (bug 1074630) we should
  // not return early if mIsPaused is false since we may still need to seek.
  // (However, we will need to pass a flag so that when we start playing due to
  //  a change in animation-play-state we *don't* trigger finishing behavior.)
  if (!mIsPaused) {
    return;
  }
  mIsPaused = false;

  Nullable<TimeDuration> timelineTime = mTimeline->GetCurrentTime();
  if (timelineTime.IsNull()) {
    // FIXME: We should just sit in the pending state in this case.
    // We will introduce the pending state in Bug 927349.
    return;
  }

  // Update start time to an appropriate offset from the current timeline time
  MOZ_ASSERT(!mHoldTime.IsNull(), "Hold time should not be null when paused");
  mStartTime.SetValue(timelineTime.Value() - mHoldTime.Value());
  mHoldTime.SetNull();
}

void
AnimationPlayer::DoPause()
{
  if (mIsPaused) {
    return;
  }
  mIsPaused = true;
  mIsRunningOnCompositor = false;

  // Bug 927349 - check for null result here and go to pending state
  mHoldTime = GetCurrentTime();
  mStartTime.SetNull();
}

void
AnimationPlayer::FlushStyle() const
{
  nsIDocument* doc = GetRenderedDocument();
  if (doc) {
    doc->FlushPendingNotifications(Flush_Style);
  }
}

void
AnimationPlayer::PostUpdate()
{
  AnimationPlayerCollection* collection = GetCollection();
  if (collection) {
    collection->NotifyPlayerUpdated();
  }
}

StickyTimeDuration
AnimationPlayer::SourceContentEnd() const
{
  if (!mSource) {
    return StickyTimeDuration(0);
  }

  return mSource->Timing().mDelay
         + mSource->GetComputedTiming().mActiveDuration;
}

nsIDocument*
AnimationPlayer::GetRenderedDocument() const
{
  if (!mSource) {
    return nullptr;
  }

  Element* targetElement;
  nsCSSPseudoElements::Type pseudoType;
  mSource->GetTarget(targetElement, pseudoType);
  if (!targetElement) {
    return nullptr;
  }

  return targetElement->GetComposedDoc();
}

nsPresContext*
AnimationPlayer::GetPresContext() const
{
  nsIDocument* doc = GetRenderedDocument();
  if (!doc) {
    return nullptr;
  }
  nsIPresShell* shell = doc->GetShell();
  if (!shell) {
    return nullptr;
  }
  return shell->GetPresContext();
}

AnimationPlayerCollection*
AnimationPlayer::GetCollection() const
{
  css::CommonAnimationManager* manager = GetAnimationManager();
  if (!manager) {
    return nullptr;
  }
  MOZ_ASSERT(mSource, "A player with an animation manager must have a source");

  Element* targetElement;
  nsCSSPseudoElements::Type targetPseudoType;
  mSource->GetTarget(targetElement, targetPseudoType);
  MOZ_ASSERT(targetElement,
             "A player with an animation manager must have a target");

  return manager->GetAnimationPlayers(targetElement, targetPseudoType, false);
}

} // namespace dom
} // namespace mozilla