#include "Base.h"
#include "AnimationClip.h"
#include "Animation.h"
#include "AnimationTarget.h"
#include "Game.h"
#include "Quaternion.h"

namespace gameplay
{

AnimationClip::AnimationClip(const char* id, Animation* animation, unsigned long startTime, unsigned long endTime)
    : _id(id), _animation(animation), _startTime(startTime), _endTime(endTime), _duration(_endTime - _startTime), 
      _stateBits(0x00), _repeatCount(1.0f), _activeDuration(_duration * _repeatCount), _speed(1.0f), _timeStarted(0), 
      _elapsedTime(0), _crossFadeToClip(NULL), _crossFadeOutElapsed(0), _crossFadeOutDuration(0), _blendWeight(1.0f), 
      _beginListeners(NULL), _endListeners(NULL), _listeners(NULL), _listenerItr(NULL)
{
    GP_ASSERT(_animation);
    GP_ASSERT(0 <= startTime && startTime <= _animation->_duration && 0 <= endTime && endTime <= _animation->_duration);
    
    unsigned int channelCount = _animation->_channels.size();
    for (unsigned int i = 0; i < channelCount; i++)
    {
        GP_ASSERT(_animation->_channels[i]);
        GP_ASSERT(_animation->_channels[i]->getCurve());
        _values.push_back(new AnimationValue(_animation->_channels[i]->getCurve()->getComponentCount()));
    }
}

AnimationClip::~AnimationClip()
{
    std::vector<AnimationValue*>::iterator valueIter = _values.begin();
    while (valueIter != _values.end())
    {
        SAFE_DELETE(*valueIter);
        valueIter++;
    }
    _values.clear();

    SAFE_RELEASE(_crossFadeToClip);
    SAFE_DELETE(_beginListeners);
    SAFE_DELETE(_endListeners);

    if (_listeners)
    {
        *_listenerItr = _listeners->begin();
        while (*_listenerItr != _listeners->end())
        {
            ListenerEvent* lEvt = **_listenerItr;
            SAFE_DELETE(lEvt);
            ++*_listenerItr;
        }
        SAFE_DELETE(_listeners);
    }
    SAFE_DELETE(_listenerItr);
}

AnimationClip::ListenerEvent::ListenerEvent(Listener* listener, unsigned long eventTime)
{
    _listener = listener;
    _eventTime = eventTime;
}

AnimationClip::ListenerEvent::~ListenerEvent()
{
}

const char* AnimationClip::getID() const
{
    return _id.c_str();
}

Animation* AnimationClip::getAnimation() const
{
    return _animation;
}

unsigned long AnimationClip::getStartTime() const
{
    return _startTime;
}

unsigned long AnimationClip::getEndTime() const
{
    return _endTime;
}

unsigned long AnimationClip::getElaspedTime() const
{
    return _elapsedTime;
}

void AnimationClip::setRepeatCount(float repeatCount)
{
    GP_ASSERT(repeatCount == REPEAT_INDEFINITE || repeatCount > 0.0f);

    _repeatCount = repeatCount;

    if (repeatCount == REPEAT_INDEFINITE)
    {
        _activeDuration = _duration;
    }
    else
    {
        _activeDuration = _repeatCount * _duration;
    }
}

float AnimationClip::getRepeatCount() const
{
    return _repeatCount;
}

void AnimationClip::setActiveDuration(unsigned long duration)
{
    if (duration == REPEAT_INDEFINITE)
    {
        _repeatCount = REPEAT_INDEFINITE;
        _activeDuration = _duration;
    }
    else
    {
        _activeDuration = _duration;
        _repeatCount = (float) _activeDuration / (float) _duration;
    }
}

unsigned long AnimationClip::getActiveDuration() const
{
    if (_repeatCount == REPEAT_INDEFINITE)
        return REPEAT_INDEFINITE;

    return _activeDuration;
}

unsigned long AnimationClip::getDuration() const
{
    return _duration;
}

void AnimationClip::setSpeed(float speed)
{
    _speed = speed;
}

float AnimationClip::getSpeed() const
{
    return _speed;
}

void AnimationClip::setBlendWeight(float blendWeight)
{
    _blendWeight = blendWeight;
}

float AnimationClip::getBlendWeight() const
{
    return _blendWeight;
}

bool AnimationClip::isPlaying() const
{
    return isClipStateBitSet(CLIP_IS_PLAYING_BIT);
}

void AnimationClip::play()
{
    if (isClipStateBitSet(CLIP_IS_PLAYING_BIT))
    {
        // If paused, reset the bit and return.
        if (isClipStateBitSet(CLIP_IS_PAUSED_BIT))
        {
            resetClipStateBit(CLIP_IS_PAUSED_BIT);
            return;
        }

        // If the clip is set to be removed, reset the flag.
        if (isClipStateBitSet(CLIP_IS_MARKED_FOR_REMOVAL_BIT))
            resetClipStateBit(CLIP_IS_MARKED_FOR_REMOVAL_BIT);

        // Set the state bit to restart.
        setClipStateBit(CLIP_IS_RESTARTED_BIT);
    }
    else
    {
        setClipStateBit(CLIP_IS_PLAYING_BIT);
        GP_ASSERT(_animation);
        GP_ASSERT(_animation->_controller);
        _animation->_controller->schedule(this);
    }
    
    _timeStarted = Game::getGameTime();
}

void AnimationClip::stop()
{
    if (isClipStateBitSet(CLIP_IS_PLAYING_BIT))
    {
        // Reset the restarted and paused bits. 
        resetClipStateBit(CLIP_IS_RESTARTED_BIT);
        resetClipStateBit(CLIP_IS_PAUSED_BIT);

        // Mark the clip to removed from the AnimationController.
        setClipStateBit(CLIP_IS_MARKED_FOR_REMOVAL_BIT);
    }
}

void AnimationClip::pause()
{
    if (isClipStateBitSet(CLIP_IS_PLAYING_BIT) && !isClipStateBitSet(CLIP_IS_MARKED_FOR_REMOVAL_BIT))
    {
        setClipStateBit(CLIP_IS_PAUSED_BIT);
    }
}

void AnimationClip::crossFade(AnimationClip* clip, unsigned long duration)
{
    GP_ASSERT(clip);

    // Check if the given clip is fading into this clip.
    // We should reset the clip from fading out, and this one from fading in 
    // in order to start the crossfade back the other way.
    if (clip->isClipStateBitSet(CLIP_IS_FADING_OUT_BIT) && clip->_crossFadeToClip == this)
    {
        clip->resetClipStateBit(CLIP_IS_FADING_OUT_BIT);
        clip->_crossFadeToClip->resetClipStateBit(CLIP_IS_FADING_IN_BIT);
        SAFE_RELEASE(clip->_crossFadeToClip);
    }

    // If I already have a clip I'm fading to and it's not the same as the given clip release it.
    // Assign the new clip and increase it's ref count.
    if (_crossFadeToClip)
    {
        SAFE_RELEASE(_crossFadeToClip);
    }

    // Set and initialize the crossfade clip
    _crossFadeToClip = clip;
    _crossFadeToClip->addRef();
    _crossFadeToClip->setClipStateBit(CLIP_IS_FADING_IN_BIT);
    _crossFadeToClip->_blendWeight = 0.0f;
    
    // Set and intiliaze this clip to fade out
    setClipStateBit(CLIP_IS_FADING_OUT_STARTED_BIT);
    setClipStateBit(CLIP_IS_FADING_OUT_BIT);
    _crossFadeOutElapsed = 0L;
    _crossFadeOutDuration = duration;
    
    // If this clip is currently not playing, we should start playing it.
    if (!isClipStateBitSet(CLIP_IS_PLAYING_BIT))
        play();

    // Start playing the cross fade clip.
    _crossFadeToClip->play(); 
}

void AnimationClip::addListener(AnimationClip::Listener* listener, unsigned long eventTime)
{
    GP_ASSERT(listener);
    GP_ASSERT(eventTime < _activeDuration);

    ListenerEvent* listenerEvent = new ListenerEvent(listener, eventTime);

    if (!_listeners)
    {
        _listeners = new std::list<ListenerEvent*>;
        _listeners->push_front(listenerEvent);

        _listenerItr = new std::list<ListenerEvent*>::iterator;
        if (isClipStateBitSet(CLIP_IS_PLAYING_BIT))
            *_listenerItr = _listeners->begin();
    }
    else
    {
        for (std::list<ListenerEvent*>::iterator itr = _listeners->begin(); itr != _listeners->end(); itr++)
        {
            GP_ASSERT(*itr);
            if (eventTime < (*itr)->_eventTime)
            {
                itr = _listeners->insert(itr, listenerEvent);

                // If playing, update the iterator if we need to.
                // otherwise, it will just be set the next time the clip gets played.
                if (isClipStateBitSet(CLIP_IS_PLAYING_BIT))
                {
                    unsigned long currentTime = _elapsedTime % _duration;
                    GP_ASSERT(**_listenerItr);
                    if ((_speed >= 0.0f && currentTime < eventTime && (*_listenerItr == _listeners->end() || eventTime < (**_listenerItr)->_eventTime)) || 
                        (_speed <= 0 && currentTime > eventTime && (*_listenerItr == _listeners->begin() || eventTime > (**_listenerItr)->_eventTime)))
                        *_listenerItr = itr;
                }
                return;
            }
        }
        _listeners->push_back(listenerEvent);
    }
}

void AnimationClip::addBeginListener(AnimationClip::Listener* listener)
{
    if (!_beginListeners)
        _beginListeners = new std::vector<Listener*>;

    GP_ASSERT(listener);
    _beginListeners->push_back(listener);
}

void AnimationClip::addEndListener(AnimationClip::Listener* listener)
{
    if (!_endListeners)
        _endListeners = new std::vector<Listener*>;

    GP_ASSERT(listener);
    _endListeners->push_back(listener);
}

bool AnimationClip::update(unsigned long elapsedTime)
{
    if (isClipStateBitSet(CLIP_IS_PAUSED_BIT))
    {
        return false;
    }
    else if (isClipStateBitSet(CLIP_IS_MARKED_FOR_REMOVAL_BIT))
    {   // If the marked for removal bit is set, it means stop() was called on the AnimationClip at some point
        // after the last update call. Reset the flag, and return true so the AnimationClip is removed from the 
        // running clips on the AnimationController.
        onEnd();
        return true;
    }
    else if (!isClipStateBitSet(CLIP_IS_STARTED_BIT))
    {
        onBegin();
    }
    else
    {
        _elapsedTime += elapsedTime * _speed;

        if (_repeatCount == REPEAT_INDEFINITE && _elapsedTime <= 0)
            _elapsedTime = _activeDuration + _elapsedTime;
    }

    unsigned long currentTime = 0L;
    // Check to see if clip is complete.
    if (_repeatCount != REPEAT_INDEFINITE && ((_speed >= 0.0f && _elapsedTime >= (long) _activeDuration) || (_speed <= 0.0f && _elapsedTime <= 0L)))
    {
        resetClipStateBit(CLIP_IS_STARTED_BIT);
        if (_speed >= 0.0f)
        {
            // If _duration == 0, we have a "pose". Just set currentTime to 0.
            if (_duration == 0)
            {
                currentTime = 0L;
            }
            else
            {
                currentTime = _activeDuration % _duration; // Get's the fractional part of the final repeat.
                if (currentTime == 0L)
                    currentTime = _duration;
            }
        }
        else
        {
            currentTime = 0L; // If we are negative speed, the end value should be 0.
        }
    }
    else
    {
        // If _duration == 0, we have a "pose". Just set currentTime to 0.
        if (_duration == 0)
            currentTime = 0L;
        else // Gets portion/fraction of the repeat.
            currentTime = _elapsedTime % _duration;
    }

    // Notify any listeners of Animation events.
    if (_listeners)
    {
        GP_ASSERT(_listenerItr);
        GP_ASSERT(**_listenerItr);

        if (_speed >= 0.0f)
        {
            while (*_listenerItr != _listeners->end() && _elapsedTime >= (long) (**_listenerItr)->_eventTime)
            {
                GP_ASSERT(_listenerItr);
                GP_ASSERT(**_listenerItr);
                GP_ASSERT((**_listenerItr)->_listener);

                (**_listenerItr)->_listener->animationEvent(this, Listener::DEFAULT);
                ++*_listenerItr;
            }
        }
        else
        {
            while (*_listenerItr != _listeners->begin() && _elapsedTime <= (long) (**_listenerItr)->_eventTime)
            {
                GP_ASSERT(_listenerItr);
                GP_ASSERT(**_listenerItr);
                GP_ASSERT((**_listenerItr)->_listener);

                (**_listenerItr)->_listener->animationEvent(this, Listener::DEFAULT);
                --*_listenerItr;
            }
        }
    }

    // Add back in start time, and divide by the total animation's duration to get the actual percentage complete
    GP_ASSERT(_animation);
    GP_ASSERT(_animation->_duration > 0);
    float percentComplete = (float)(_startTime + currentTime) / (float) _animation->_duration;
    
    if (isClipStateBitSet(CLIP_IS_FADING_OUT_BIT))
    {
        GP_ASSERT(_crossFadeToClip);
        GP_ASSERT(_crossFadeOutDuration > 0);

        if (isClipStateBitSet(CLIP_IS_FADING_OUT_STARTED_BIT)) // Calculate elapsed time since the fade out begin.
        {
            GP_ASSERT(_crossFadeToClip);
            _crossFadeOutElapsed = (Game::getGameTime() - _crossFadeToClip->_timeStarted) * abs(_speed); 
            resetClipStateBit(CLIP_IS_FADING_OUT_STARTED_BIT);
        }
        else
        {
            // continue tracking elapsed time.
            _crossFadeOutElapsed += elapsedTime * abs(_speed);
        }

        if (_crossFadeOutElapsed < _crossFadeOutDuration)
        {
            // Calculate this clip's blend weight.
            float tempBlendWeight = (float) (_crossFadeOutDuration - _crossFadeOutElapsed) / (float) _crossFadeOutDuration;
            
            // If this clip is fading in, adjust the crossfade clip's weight to be a percentage of your current blend weight
            if (isClipStateBitSet(CLIP_IS_FADING_IN_BIT))
            {
                _crossFadeToClip->_blendWeight = (1.0f - tempBlendWeight) * _blendWeight;
                _blendWeight -= _crossFadeToClip->_blendWeight;
            }
            else
            {
                // Just set the blend weight.
                _crossFadeToClip->_blendWeight = (1.0f - tempBlendWeight);
                _blendWeight = tempBlendWeight;
            }
        }
        else
        {   // Fade is done.
            _crossFadeToClip->_blendWeight = 1.0f;
            _blendWeight = 0.0f;
            resetClipStateBit(CLIP_IS_STARTED_BIT);            
            resetClipStateBit(CLIP_IS_FADING_OUT_BIT);
            _crossFadeToClip->resetClipStateBit(CLIP_IS_FADING_IN_BIT);
            SAFE_RELEASE(_crossFadeToClip);
        }
    }
    
    // Evaluate this clip.
    Animation::Channel* channel = NULL;
    AnimationValue* value = NULL;
    AnimationTarget* target = NULL;
    unsigned int channelCount = _animation->_channels.size();
    for (unsigned int i = 0; i < channelCount; i++)
    {
        channel = _animation->_channels[i];
        GP_ASSERT(channel);
        target = channel->_target;
        GP_ASSERT(target);
        value = _values[i];
        GP_ASSERT(value);

        // Evaluate the point on Curve
        GP_ASSERT(channel->getCurve());
        channel->getCurve()->evaluate(percentComplete, value->_value);
        // Set the animation value on the target property.
        target->setAnimationPropertyValue(channel->_propertyId, value, _blendWeight);
    }

    // When ended. Probably should move to it's own method so we can call it when the clip is ended early.
    if (isClipStateBitSet(CLIP_IS_MARKED_FOR_REMOVAL_BIT) || !isClipStateBitSet(CLIP_IS_STARTED_BIT))
    {
        onEnd();
        return true;
    }

    return false;
}

void AnimationClip::onBegin()
{
    // Initialize animation to play.
    setClipStateBit(CLIP_IS_STARTED_BIT);
    if (_speed >= 0)
    {
        _elapsedTime = (Game::getGameTime() - _timeStarted) * _speed;

        if (_listeners)
            *_listenerItr = _listeners->begin(); 
    }
    else
    {
        _elapsedTime = _activeDuration + (Game::getGameTime() - _timeStarted) * _speed;

        if (_listeners)
            *_listenerItr = _listeners->end();
    }
    
    // Notify begin listeners if any.
    if (_beginListeners)
    {
        std::vector<Listener*>::iterator listener = _beginListeners->begin();
        while (listener != _beginListeners->end())
        {
            GP_ASSERT(*listener);
            (*listener)->animationEvent(this, Listener::BEGIN);
            listener++;
        }
    }
}

void AnimationClip::onEnd()
{
    _blendWeight = 1.0f;
    resetClipStateBit(CLIP_ALL_BITS);

    // Notify end listeners if any.
    if (_endListeners)
    {
        std::vector<Listener*>::iterator listener = _endListeners->begin();
        while (listener != _endListeners->end())
        {
            GP_ASSERT(*listener);
            (*listener)->animationEvent(this, Listener::END);
            listener++;
        }
    }
}

bool AnimationClip::isClipStateBitSet(unsigned char bit) const
{
    return (_stateBits & bit) == bit;
}

void AnimationClip::setClipStateBit(unsigned char bit)
{
    _stateBits |= bit;
}

void AnimationClip::resetClipStateBit(unsigned char bit)
{
    _stateBits &= ~bit;
}

}