/*
 * Copyright (C) 2018 Apple Inc. All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 *
 * THIS SOFTWARE IS PROVIDED BY APPLE INC. ``AS IS'' AND ANY
 * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
 * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL APPLE INC. OR
 * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
 * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
 * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
 * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY
 * OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */

#include "config.h"
#include "DeclarativeAnimation.h"

#include "Animation.h"
#include "AnimationEvent.h"
#include "CSSAnimation.h"
#include "CSSTransition.h"
#include "DocumentTimeline.h"
#include "Element.h"
#include "EventNames.h"
#include "KeyframeEffect.h"
#include "PseudoElement.h"
#include <wtf/IsoMallocInlines.h>

namespace WebCore {

WTF_MAKE_ISO_ALLOCATED_IMPL(DeclarativeAnimation);

DeclarativeAnimation::DeclarativeAnimation(Element& owningElement, const Animation& backingAnimation)
    : WebAnimation(owningElement.document())
    , m_owningElement(makeWeakPtr(owningElement))
    , m_backingAnimation(const_cast<Animation&>(backingAnimation))
{
}

DeclarativeAnimation::~DeclarativeAnimation()
{
}

Element* DeclarativeAnimation::owningElement() const
{
    return m_owningElement.get();
}

void DeclarativeAnimation::tick()
{
    bool wasRelevant = isRelevant();
    
    WebAnimation::tick();
    invalidateDOMEvents();

    // If a declarative animation transitions from a non-idle state to an idle state, it means it was
    // canceled using the Web Animations API and it should be disassociated from its owner element.
    // From this point on, this animation is like any other animation and should not appear in the
    // maps containing running CSS Transitions and CSS Animations for a given element.
    if (wasRelevant && playState() == WebAnimation::PlayState::Idle)
        disassociateFromOwningElement();
}

bool DeclarativeAnimation::canHaveGlobalPosition()
{
    // https://drafts.csswg.org/css-animations-2/#animation-composite-order
    // https://drafts.csswg.org/css-transitions-2/#animation-composite-order
    // CSS Animations and CSS Transitions generated using the markup defined in this specification are not added
    // to the global animation list when they are created. Instead, these animations are appended to the global
    // animation list at the first moment when they transition out of the idle play state after being disassociated
    // from their owning element.
    return !m_owningElement && playState() != WebAnimation::PlayState::Idle;
}

void DeclarativeAnimation::disassociateFromOwningElement()
{
    if (!m_owningElement)
        return;

    if (auto* animationTimeline = timeline())
        animationTimeline->removeDeclarativeAnimationFromListsForOwningElement(*this, *m_owningElement);
    m_owningElement = nullptr;
}

void DeclarativeAnimation::setBackingAnimation(const Animation& backingAnimation)
{
    m_backingAnimation = const_cast<Animation&>(backingAnimation);
    syncPropertiesWithBackingAnimation();
}

void DeclarativeAnimation::initialize(const RenderStyle* oldStyle, const RenderStyle& newStyle)
{
    // We need to suspend invalidation of the animation's keyframe effect during its creation
    // as it would otherwise trigger invalidation of the document's style and this would be
    // incorrect since it would happen during style invalidation.
    suspendEffectInvalidation();

    ASSERT(m_owningElement);

    setEffect(KeyframeEffect::create(*m_owningElement));
    setTimeline(&m_owningElement->document().timeline());
    downcast<KeyframeEffect>(effect())->computeDeclarativeAnimationBlendingKeyframes(oldStyle, newStyle);
    syncPropertiesWithBackingAnimation();
    if (backingAnimation().playState() == AnimationPlayState::Playing)
        play();
    else
        pause();

    unsuspendEffectInvalidation();
}

void DeclarativeAnimation::syncPropertiesWithBackingAnimation()
{
}

Optional<double> DeclarativeAnimation::startTime() const
{
    flushPendingStyleChanges();
    return WebAnimation::startTime();
}

void DeclarativeAnimation::setStartTime(Optional<double> startTime)
{
    flushPendingStyleChanges();
    return WebAnimation::setStartTime(startTime);
}

Optional<double> DeclarativeAnimation::bindingsCurrentTime() const
{
    flushPendingStyleChanges();
    return WebAnimation::bindingsCurrentTime();
}

ExceptionOr<void> DeclarativeAnimation::setBindingsCurrentTime(Optional<double> currentTime)
{
    flushPendingStyleChanges();
    return WebAnimation::setBindingsCurrentTime(currentTime);
}

WebAnimation::PlayState DeclarativeAnimation::bindingsPlayState() const
{
    flushPendingStyleChanges();
    return WebAnimation::bindingsPlayState();
}

WebAnimation::ReplaceState DeclarativeAnimation::bindingsReplaceState() const
{
    flushPendingStyleChanges();
    return WebAnimation::bindingsReplaceState();
}

bool DeclarativeAnimation::bindingsPending() const
{
    flushPendingStyleChanges();
    return WebAnimation::bindingsPending();
}

WebAnimation::ReadyPromise& DeclarativeAnimation::bindingsReady()
{
    flushPendingStyleChanges();
    return WebAnimation::bindingsReady();
}

WebAnimation::FinishedPromise& DeclarativeAnimation::bindingsFinished()
{
    flushPendingStyleChanges();
    return WebAnimation::bindingsFinished();
}

ExceptionOr<void> DeclarativeAnimation::bindingsPlay()
{
    flushPendingStyleChanges();
    return WebAnimation::bindingsPlay();
}

ExceptionOr<void> DeclarativeAnimation::bindingsPause()
{
    flushPendingStyleChanges();
    return WebAnimation::bindingsPause();
}

void DeclarativeAnimation::flushPendingStyleChanges() const
{
    if (auto* animationEffect = effect()) {
        if (is<KeyframeEffect>(animationEffect)) {
            if (auto* target = downcast<KeyframeEffect>(animationEffect)->target())
                target->document().updateStyleIfNeeded();
        }
    }
}

void DeclarativeAnimation::setTimeline(RefPtr<AnimationTimeline>&& newTimeline)
{
    if (timeline() && !newTimeline)
        cancel();

    WebAnimation::setTimeline(WTFMove(newTimeline));
}

void DeclarativeAnimation::cancel(Silently silently)
{
    auto cancelationTime = 0_s;
    if (auto* animationEffect = effect()) {
        if (auto activeTime = animationEffect->getBasicTiming().activeTime)
            cancelationTime = *activeTime;
    }

    WebAnimation::cancel(silently);

    invalidateDOMEvents(cancelationTime);
}

void DeclarativeAnimation::cancelFromStyle()
{
    cancel();
    disassociateFromOwningElement();
}

AnimationEffectPhase DeclarativeAnimation::phaseWithoutEffect() const
{
    // This shouldn't be called if we actually have an effect.
    ASSERT(!effect());

    auto animationCurrentTime = currentTime();
    if (!animationCurrentTime)
        return AnimationEffectPhase::Idle;

    // Since we don't have an effect, the duration will be zero so the phase is 'before' if the current time is less than zero.
    return *animationCurrentTime < 0_s ? AnimationEffectPhase::Before : AnimationEffectPhase::After;
}

void DeclarativeAnimation::invalidateDOMEvents(Seconds elapsedTime)
{
    if (!m_owningElement)
        return;
    
    auto isPending = pending();
    if (isPending && m_wasPending)
        return;

    double iteration = 0;
    AnimationEffectPhase currentPhase;
    Seconds intervalStart;
    Seconds intervalEnd;

    auto* animationEffect = effect();
    if (animationEffect) {
        auto timing = animationEffect->getComputedTiming();
        if (auto computedIteration = timing.currentIteration)
            iteration = *computedIteration;
        currentPhase = timing.phase;
        intervalStart = std::max(0_s, Seconds::fromMilliseconds(std::min(-timing.delay, timing.activeDuration)));
        intervalEnd = std::max(0_s, Seconds::fromMilliseconds(std::min(timing.endTime - timing.delay, timing.activeDuration)));
    } else {
        iteration = 0;
        currentPhase = phaseWithoutEffect();
        intervalStart = 0_s;
        intervalEnd = 0_s;
    }

    bool wasActive = m_previousPhase == AnimationEffectPhase::Active;
    bool wasAfter = m_previousPhase == AnimationEffectPhase::After;
    bool wasBefore = m_previousPhase == AnimationEffectPhase::Before;
    bool wasIdle = m_previousPhase == AnimationEffectPhase::Idle;

    bool isActive = currentPhase == AnimationEffectPhase::Active;
    bool isAfter = currentPhase == AnimationEffectPhase::After;
    bool isBefore = currentPhase == AnimationEffectPhase::Before;
    bool isIdle = currentPhase == AnimationEffectPhase::Idle;

    if (is<CSSAnimation>(this)) {
        // https://drafts.csswg.org/css-animations-2/#events
        if ((wasIdle || wasBefore) && isActive)
            enqueueDOMEvent(eventNames().animationstartEvent, intervalStart);
        else if ((wasIdle || wasBefore) && isAfter) {
            enqueueDOMEvent(eventNames().animationstartEvent, intervalStart);
            enqueueDOMEvent(eventNames().animationendEvent, intervalEnd);
        } else if (wasActive && isBefore)
            enqueueDOMEvent(eventNames().animationendEvent, intervalStart);
        else if (wasActive && isActive && m_previousIteration != iteration) {
            auto iterationBoundary = iteration;
            if (m_previousIteration > iteration)
                iterationBoundary++;
            auto elapsedTime = animationEffect ? animationEffect->iterationDuration() * (iterationBoundary - animationEffect->iterationStart()) : 0_s;
            enqueueDOMEvent(eventNames().animationiterationEvent, elapsedTime);
        } else if (wasActive && isAfter)
            enqueueDOMEvent(eventNames().animationendEvent, intervalEnd);
        else if (wasAfter && isActive)
            enqueueDOMEvent(eventNames().animationstartEvent, intervalEnd);
        else if (wasAfter && isBefore) {
            enqueueDOMEvent(eventNames().animationstartEvent, intervalEnd);
            enqueueDOMEvent(eventNames().animationendEvent, intervalStart);
        } else if ((!wasIdle && !wasAfter) && isIdle)
            enqueueDOMEvent(eventNames().animationcancelEvent, elapsedTime);
    } else if (is<CSSTransition>(this)) {
        // https://drafts.csswg.org/css-transitions-2/#transition-events
        if (wasIdle && (isPending || isBefore))
            enqueueDOMEvent(eventNames().transitionrunEvent, intervalStart);
        else if (wasIdle && isActive) {
            enqueueDOMEvent(eventNames().transitionrunEvent, intervalStart);
            enqueueDOMEvent(eventNames().transitionstartEvent, intervalStart);
        } else if (wasIdle && isAfter) {
            enqueueDOMEvent(eventNames().transitionrunEvent, intervalStart);
            enqueueDOMEvent(eventNames().transitionstartEvent, intervalStart);
            enqueueDOMEvent(eventNames().transitionendEvent, intervalEnd);
        } else if ((m_wasPending || wasBefore) && isActive)
            enqueueDOMEvent(eventNames().transitionstartEvent, intervalStart);
        else if ((m_wasPending || wasBefore) && isAfter) {
            enqueueDOMEvent(eventNames().transitionstartEvent, intervalStart);
            enqueueDOMEvent(eventNames().transitionendEvent, intervalEnd);
        } else if (wasActive && isAfter)
            enqueueDOMEvent(eventNames().transitionendEvent, intervalEnd);
        else if (wasActive && isBefore)
            enqueueDOMEvent(eventNames().transitionendEvent, intervalStart);
        else if (wasAfter && isActive)
            enqueueDOMEvent(eventNames().transitionstartEvent, intervalEnd);
        else if (wasAfter && isBefore) {
            enqueueDOMEvent(eventNames().transitionstartEvent, intervalEnd);
            enqueueDOMEvent(eventNames().transitionendEvent, intervalStart);
        } else if ((!wasIdle && !wasAfter) && isIdle)
            enqueueDOMEvent(eventNames().transitioncancelEvent, elapsedTime);
    }

    m_wasPending = isPending;
    m_previousPhase = currentPhase;
    m_previousIteration = iteration;
}

void DeclarativeAnimation::enqueueDOMEvent(const AtomString& eventType, Seconds elapsedTime)
{
    if (!m_owningElement)
        return;

    auto time = secondsToWebAnimationsAPITime(elapsedTime) / 1000;
    const auto& pseudoId = PseudoElement::pseudoElementNameForEvents(m_owningElement->pseudoId());
    auto timelineTime = timeline() ? timeline()->currentTime() : WTF::nullopt;
    auto event = createEvent(eventType, time, pseudoId, timelineTime);
    event->setTarget(m_owningElement.get());
    enqueueAnimationEvent(WTFMove(event));
}

} // namespace WebCore