#include "Base.h"
#include "AnimationClip.h"
#include "Animation.h"
#include "AnimationTarget.h"
#include "Game.h"
#include "Quaternion.h"
#include "ScriptController.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), _loopBlendTime(0), _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), _scriptListeners(NULL)
{
    GP_ASSERT(_animation);
    GP_ASSERT(0 <= startTime && startTime <= _animation->_duration && 0 <= endTime && endTime <= _animation->_duration);

    for (size_t i = 0, count = _animation->_channels.size(); i < count; 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 (_scriptListeners)
    {
        for (size_t i = 0; i < _scriptListeners->size(); i++)
        {
            SAFE_DELETE((*_scriptListeners)[i]);
        }
        SAFE_DELETE(_scriptListeners);
    }

    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;
}

float AnimationClip::getElapsedTime() const
{
    return _elapsedTime;
}

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

    _repeatCount = repeatCount;

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

        if (repeatCount > 1.0f && _loopBlendTime > 0.0f)
            _activeDuration += std::ceil(repeatCount - 1.0f) * _loopBlendTime;
    }
}

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

void AnimationClip::setActiveDuration(unsigned long duration)
{
    GP_ASSERT(duration >= 0);

    if (duration == REPEAT_INDEFINITE)
    {
        _activeDuration = _duration + _loopBlendTime;
    }
    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;
}

void AnimationClip::setLoopBlendTime(float loopBlendTime)
{
    _loopBlendTime = loopBlendTime;
    if (_loopBlendTime < 0.0f)
        _loopBlendTime = 0.0f;
}

float AnimationClip::getLoopBlendTime() const
{
    return _loopBlendTime;
}

bool AnimationClip::isPlaying() const
{
    return (isClipStateBitSet(CLIP_IS_PLAYING_BIT) && !isClipStateBitSet(CLIP_IS_PAUSED_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 initialize this clip to fade out
    setClipStateBit(CLIP_IS_FADING_OUT_STARTED_BIT);
    setClipStateBit(CLIP_IS_FADING_OUT_BIT);
    _crossFadeOutElapsed = 0.0f;
    _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))
                {
                    float currentTime = fmodf(_elapsedTime, (float)_duration);
                    GP_ASSERT(**_listenerItr || *_listenerItr == _listeners->end());
                    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::removeListener(AnimationClip::Listener* listener, unsigned long eventTime)
{
    if (_listeners)
    {
        GP_ASSERT(listener);
        std::list<ListenerEvent*>::iterator iter = std::find_if(_listeners->begin(), _listeners->end(), [&](ListenerEvent* lst){ return lst->_eventTime == eventTime && lst->_listener == listener; });
        if (iter != _listeners->end())
        {
            if (isClipStateBitSet(CLIP_IS_PLAYING_BIT))
            {
                float currentTime = fmodf(_elapsedTime, (float)_duration);
                GP_ASSERT(**_listenerItr || *_listenerItr == _listeners->end());

                // We the listener has not been triggered yet, then check if it is next to be triggered, remove it, and update the iterator
                if (((_speed >= 0.0f && currentTime < eventTime) || (_speed <= 0 && currentTime > eventTime)) &&
                    *iter == **_listenerItr)
                {
                    *_listenerItr = _listeners->erase(iter);
                    return;
                }
            }
            _listeners->erase(iter);
        }
    }
}

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

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

void AnimationClip::removeBeginListener(AnimationClip::Listener* listener)
{
    if (_beginListeners)
    {
        GP_ASSERT(listener);
        std::vector<Listener*>::iterator iter = std::find(_beginListeners->begin(), _beginListeners->end(), listener);
        if (iter != _beginListeners->end())
        {
            _beginListeners->erase(iter);
        }
    }
}

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

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

void AnimationClip::removeEndListener(AnimationClip::Listener* listener)
{
    if (_endListeners)
    {
        GP_ASSERT(listener);
        std::vector<Listener*>::iterator iter = std::find(_endListeners->begin(), _endListeners->end(), listener);
        if (iter != _endListeners->end())
        {
            _endListeners->erase(iter);
        }
    }
}

void AnimationClip::addBeginListener(const char* function)
{
    if (!_scriptListeners)
        _scriptListeners = new std::vector<ScriptListener*>;

    ScriptListener* listener = new ScriptListener(function);
    _scriptListeners->push_back(listener);
    addBeginListener(listener);
}

void AnimationClip::removeBeginListener(const char* function)
{
    if (_scriptListeners)
    {
        std::string functionRef = Game::getInstance()->getScriptController()->loadUrl(function);
        std::vector<ScriptListener*>::iterator iter = std::find_if(_scriptListeners->begin(), _scriptListeners->end(), [&](ScriptListener* listener){ return listener->function == functionRef; });
        if (iter != _scriptListeners->end())
        {
            ScriptListener* listener = *iter;

            removeBeginListener(listener);
            _scriptListeners->erase(iter);
            SAFE_DELETE(listener);
        }
    }
}

void AnimationClip::addEndListener(const char* function)
{
    if (!_scriptListeners)
        _scriptListeners = new std::vector<ScriptListener*>;

    ScriptListener* listener = new ScriptListener(function);
    _scriptListeners->push_back(listener);
    addEndListener(listener);
}

void AnimationClip::removeEndListener(const char* function)
{
    if (_scriptListeners)
    {
        std::string functionRef = Game::getInstance()->getScriptController()->loadUrl(function);
        std::vector<ScriptListener*>::iterator iter = std::find_if(_scriptListeners->begin(), _scriptListeners->end(), [&](ScriptListener* listener){ return listener->function == functionRef; });
        if (iter != _scriptListeners->end())
        {
            ScriptListener* listener = *iter;

            removeEndListener(listener);
            _scriptListeners->erase(iter);
            SAFE_DELETE(listener);
        }
    }
}

void AnimationClip::addListener(const char* function, unsigned long eventTime)
{
    if (!_scriptListeners)
        _scriptListeners = new std::vector<ScriptListener*>;

    ScriptListener* listener = new ScriptListener(function);
    _scriptListeners->push_back(listener);
    addListener(listener, eventTime);
}

void AnimationClip::removeListener(const char* function, unsigned long eventTime)
{
    if (_scriptListeners)
    {
        GP_ASSERT(eventTime < _activeDuration); // Do this check here, before we modify any state
        std::string functionRef = Game::getInstance()->getScriptController()->loadUrl(function);
        std::vector<ScriptListener*>::iterator iter = std::find_if(_scriptListeners->begin(), _scriptListeners->end(), [&](ScriptListener* listener){ return listener->function == functionRef; });
        if (iter != _scriptListeners->end())
        {
            ScriptListener* listener = *iter;

            removeListener(listener, eventTime);
            _scriptListeners->erase(iter);
            SAFE_DELETE(listener);
        }
    }
}

bool AnimationClip::update(float elapsedTime)
{
    if (isClipStateBitSet(CLIP_IS_PAUSED_BIT))
    {
        return false;
    }

    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;
    }

    if (!isClipStateBitSet(CLIP_IS_STARTED_BIT))
    {
        // Clip is just starting
        onBegin();
    }
    else
    {
        // Clip was already running
        _elapsedTime += elapsedTime * _speed;

        if (_repeatCount == REPEAT_INDEFINITE && _elapsedTime <= 0)
        {
            // Elapsed time is moving backwards, so wrap it back around the end when it falls below zero
            _elapsedTime = _activeDuration + _elapsedTime;

            // TODO: account for _loopBlendTime
        }
    }

    // Current time within a loop of the clip
    float currentTime = 0.0f;

    // Check to see if clip is complete.
    if (_repeatCount != REPEAT_INDEFINITE && ((_speed >= 0.0f && _elapsedTime >= _activeDuration) || (_speed <= 0.0f && _elapsedTime <= 0.0f)))
    {
        // We finished our active duration (including repeats), so clamp to our end value.
        resetClipStateBit(CLIP_IS_STARTED_BIT);

        // Ensure we end off at the endpoints of our clip (-speed==0, +speed==_duration)
        currentTime = _speed < 0.0f ? 0.0f : _duration;
    }
    else
    {
        // If _duration == 0, we have a "pose". Just set currentTime to 0.
        if (_duration == 0)
        {
            currentTime = 0.0f;
        }
        else
        {
            // Animation is running normally.
            currentTime = fmodf(_elapsedTime, _duration + _loopBlendTime);
        }
    }

    // Notify any listeners of Animation events.
    if (_listeners)
    {
        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::TIME);
                ++(*_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::TIME);
                --(*_listenerItr);
            }
        }
    }

    // Add back in start time, and divide by the total animation's duration to get the actual percentage complete
    GP_ASSERT(_animation);

    // Compute percentage complete for the current loop (prevent a divide by zero if _duration==0).
    // Note that we don't use (currentTime/(_duration+_loopBlendTime)). That's because we want a
    // % value that is outside the 0-1 range for loop smoothing/blending purposes.
    float percentComplete = _duration == 0 ? 1 : currentTime / (float)_duration;

    if (_loopBlendTime == 0.0f)
        percentComplete = MATH_CLAMP(percentComplete, 0.0f, 1.0f);

    // If we're cross fading, compute blend weights
    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) * fabs(_speed); 
            resetClipStateBit(CLIP_IS_FADING_OUT_STARTED_BIT);
        }
        else
        {
            // continue tracking elapsed time.
            _crossFadeOutElapsed += elapsedTime * fabs(_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;
    size_t channelCount = _animation->_channels.size();
    float percentageStart = (float)_startTime / (float)_animation->_duration;
    float percentageEnd = (float)_endTime / (float)_animation->_duration;
    float percentageBlend = (float)_loopBlendTime / (float)_animation->_duration;
    for (size_t 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, percentageStart, percentageEnd, percentageBlend, 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()
{
    addRef();

    // 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++;
        }
    }

    release();
}

void AnimationClip::onEnd()
{
    addRef();

    _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++;
        }
    }

    release();
}

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;
}

AnimationClip* AnimationClip::clone(Animation* animation) const
{
    // Don't clone the elapsed time, listeners or crossfade information.
    AnimationClip* newClip = new AnimationClip(getId(), animation, getStartTime(), getEndTime());
    newClip->setSpeed(getSpeed());
    newClip->setRepeatCount(getRepeatCount());
    newClip->setBlendWeight(getBlendWeight());
    
    size_t size = _values.size();
    newClip->_values.resize(size, NULL);
    for (size_t i = 0; i < size; ++i)
    {
        if (newClip->_values[i] == NULL)
        {
            newClip->_values[i] = new AnimationValue(*_values[i]);
        }
        else
        {
            *newClip->_values[i] = *_values[i];
        }
    }
    return newClip;
}

AnimationClip::ScriptListener::ScriptListener(const std::string& function)
{
    // Store the function name.
    this->function = Game::getInstance()->getScriptController()->loadUrl(function.c_str());
}

void AnimationClip::ScriptListener::animationEvent(AnimationClip* clip, EventType type)
{
    Game::getInstance()->getScriptController()->executeFunction<void>(function.c_str(), "<AnimationClip>[AnimationClip::Listener::EventType]", clip, type);
}


}