/****************************************************************************
 Copyright (C) 2013 Henry van Merode. All rights reserved.
 Copyright (c) 2015-2016 Chukong Technologies Inc.
 Copyright (c) 2017-2018 Xiamen Yaji Software Co., Ltd.

 https://axis-project.github.io/

 Permission is hereby granted, free of charge, to any person obtaining a copy
 of this software and associated documentation files (the "Software"), to deal
 in the Software without restriction, including without limitation the rights
 to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
 copies of the Software, and to permit persons to whom the Software is
 furnished to do so, subject to the following conditions:

 The above copyright notice and this permission notice shall be included in
 all copies or substantial portions of the Software.

 THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
 AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
 OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
 THE SOFTWARE.
 ****************************************************************************/

#include "extensions/Particle3D/PU/CCPUObserver.h"
#include "extensions/Particle3D/PU/CCPUEventHandler.h"
#include "extensions/Particle3D/PU/CCPUEventHandlerManager.h"
#include "base/ccMacros.h"

NS_AX_BEGIN

// Constants
const bool PUObserver::DEFAULT_ENABLED                             = true;
const PUParticle3D::ParticleType PUObserver::DEFAULT_PARTICLE_TYPE = PUParticle3D::PT_VISUAL;
const float PUObserver::DEFAULT_INTERVAL                           = 0.05f;
const bool PUObserver::DEFAULT_UNTIL_EVENT                         = false;

//-----------------------------------------------------------------------
PUObserver::PUObserver()
    : _particleSystem(nullptr)
    , _enabled(DEFAULT_ENABLED)
    , _originalEnabled(DEFAULT_ENABLED)
    , _originalEnabledSet(false)
    , _observe(true)
    , _observeUntilEvent(DEFAULT_UNTIL_EVENT)
    , _eventHandlersExecuted(false)
    , _observerScale(Vec3::ONE)
    , _particleTypeToObserve(DEFAULT_PARTICLE_TYPE)
    , _particleTypeToObserveSet(false)
    , _observerInterval(DEFAULT_INTERVAL)
    , _observerIntervalRemainder(0.0)
    , _observerIntervalSet(false)
{
    // mAliasType = AT_OBSERVER;
}
//-----------------------------------------------------------------------
PUObserver::~PUObserver()
{
    destroyAllEventHandlers();
}
//-----------------------------------------------------------------------
void PUObserver::notifyStart()
{
    _eventHandlersExecuted = false;
    _observe               = true;
    setEnabled(_originalEnabled);
}
//-----------------------------------------------------------------------
bool PUObserver::isEnabled() const
{
    return _enabled;
}
//-----------------------------------------------------------------------
bool PUObserver::_getOriginalEnabled() const
{
    return _originalEnabled;
}
//-----------------------------------------------------------------------
void PUObserver::setEnabled(bool enabled)
{
    _enabled = enabled;
    if (!_originalEnabledSet)
    {
        // Only one time is permitted
        _originalEnabled    = enabled;
        _originalEnabledSet = true;
    }
}
//-----------------------------------------------------------------------
void PUObserver::_resetEnabled()
{
    _originalEnabledSet = false;
}
//-----------------------------------------------------------------------
float PUObserver::getObserverInterval() const
{
    return _observerInterval;
}
//-----------------------------------------------------------------------
void PUObserver::setObserverInterval(float observerInterval)
{
    _observerInterval    = observerInterval;
    _observerIntervalSet = true;
}
//-----------------------------------------------------------------------
bool PUObserver::getObserveUntilEvent() const
{
    return _observeUntilEvent;
}
//-----------------------------------------------------------------------
void PUObserver::setObserveUntilEvent(bool observeUntilEvent)
{
    _observeUntilEvent = observeUntilEvent;
}
//-----------------------------------------------------------------------
void PUObserver::notifyRescaled(const Vec3& scale)
{
    _observerScale = scale;

    if (_eventHandlers.empty())
        return;

    ParticleEventHandlerConstIterator it;
    ParticleEventHandlerConstIterator itEnd = _eventHandlers.end();
    for (it = _eventHandlers.begin(); it != itEnd; ++it)
    {
        (*it)->notifyRescaled(scale);
    }
}
//-----------------------------------------------------------------------
PUEventHandler* PUObserver::createEventHandler(std::string_view eventHandlerType)
{
    PUEventHandler* eventHandler = PUEventHandlerManager::Instance()->createEventHandler(eventHandlerType);
    addEventHandler(eventHandler);
    return eventHandler;
}
//-----------------------------------------------------------------------
void PUObserver::addEventHandler(PUEventHandler* eventHandler)
{
    eventHandler->retain();
    _eventHandlers.push_back(eventHandler);
    eventHandler->setParentObserver(this);
    eventHandler->notifyRescaled(_observerScale);
}
//-----------------------------------------------------------------------
void PUObserver::removeEventHandler(PUEventHandler* eventHandler)
{
    ParticleEventHandlerIterator it;
    for (it = _eventHandlers.begin(); it != _eventHandlers.end(); ++it)
    {
        if (*it == eventHandler)
        {
            // Remove it
            (*it)->release();
            _eventHandlers.erase(it);
            break;
        }
    }

    eventHandler->setParentObserver(0);
}
//-----------------------------------------------------------------------
PUEventHandler* PUObserver::getEventHandler(size_t index) const
{
    AXASSERT(index < _eventHandlers.size(), "EventHandler index out of bounds!");
    return _eventHandlers[index];
}
//-----------------------------------------------------------------------
PUEventHandler* PUObserver::getEventHandler(std::string_view eventHandlerName) const
{
    if (eventHandlerName.empty())
        return nullptr;

    ParticleEventHandlerConstIterator it;
    ParticleEventHandlerConstIterator itEnd = _eventHandlers.end();
    for (it = _eventHandlers.begin(); it != itEnd; ++it)
    {
        if ((*it)->getName() == eventHandlerName)
        {
            return *it;
        }
    }

    return nullptr;
}
//-----------------------------------------------------------------------
size_t PUObserver::getNumEventHandlers() const
{
    return _eventHandlers.size();
}
//-----------------------------------------------------------------------
void PUObserver::destroyEventHandler(PUEventHandler* eventHandler)
{
    AXASSERT(eventHandler, "EventHandler is null!");
    ParticleEventHandlerIterator it;
    for (it = _eventHandlers.begin(); it != _eventHandlers.end(); ++it)
    {
        if (*it == eventHandler)
        {
            // Destroy it
            // ParticleSystemManager::getSingletonPtr()->destroyEventHandler(*it);
            (*it)->release();
            _eventHandlers.erase(it);
            break;
        }
    }
}
//-----------------------------------------------------------------------
void PUObserver::destroyEventHandler(size_t index)
{
    destroyEventHandler(getEventHandler(index));
}
//-----------------------------------------------------------------------
void PUObserver::destroyAllEventHandlers()
{
    ParticleEventHandlerIterator it;
    for (it = _eventHandlers.begin(); it != _eventHandlers.end(); ++it)
    {
        (*it)->release();
        // ParticleSystemManager::getSingletonPtr()->destroyEventHandler(*it);
    }
    _eventHandlers.clear();
}
//-----------------------------------------------------------------------
void PUObserver::setParticleTypeToObserve(const PUParticle3D::ParticleType particleTypeToObserve)
{
    _particleTypeToObserve    = particleTypeToObserve;
    _particleTypeToObserveSet = true;
}
//-----------------------------------------------------------------------
void PUObserver::handleObserve(PUParticle3D* particle, float timeElapsed)
{
    if (_enabled && _observe)
    {
        if (_observeUntilEvent && _eventHandlersExecuted)
        {
            // Don't continue if mObserveUntilEvent is set and the event handlers are already called once.
            return;
        }
        if (observe(particle, timeElapsed))
        {
            // Handle the event
            handleEvent(particle, timeElapsed);
        }
    }
}
//-----------------------------------------------------------------------
void PUObserver::handleEvent(PUParticle3D* particle, float timeElapsed)
{
    if (_eventHandlers.empty())
        return;

    ParticleEventHandlerConstIterator it;
    ParticleEventHandlerConstIterator itEnd = _eventHandlers.end();
    for (it = _eventHandlers.begin(); it != itEnd; ++it)
    {
        (*it)->handle(_particleSystem, particle, timeElapsed);
    }
    _eventHandlersExecuted = true;
}
//-----------------------------------------------------------------------
bool PUObserver::isParticleTypeToObserveSet() const
{
    return _particleTypeToObserveSet;
}

void PUObserver::preUpdateObserver(float deltaTime)
{
    if (!_enabled)
        return;

    if (_observerIntervalSet)
    {
        _observerIntervalRemainder -= deltaTime;
        if (_observerIntervalRemainder < 0)
        {
            _observerIntervalRemainder += _observerInterval;
            _observe = true;
        }
        else
        {
            _observe = false;
        }
    }
}

void PUObserver::updateObserver(PUParticle3D* particle, float deltaTime, bool firstParticle)
{
    if (!_enabled)
        return;

    // Call the _firstParticle() function if the first particle in the update loop is encountered.
    if (firstParticle)
    {
        firstParticleUpdate(particle, deltaTime);
    }

    if (_particleTypeToObserveSet && particle->particleType != _particleTypeToObserve)
        return;

    // Observe
    handleObserve(particle, deltaTime);
}

void PUObserver::postUpdateObserver(float /*deltaTime*/) {}

void PUObserver::firstParticleUpdate(PUParticle3D* /*particle*/, float /*deltaTime*/) {}

void PUObserver::copyAttributesTo(PUObserver* observer)
{
    // Copy attributes
    observer->setName(_name);
    observer->setObserverType(_observerType);
    observer->_particleTypeToObserve     = _particleTypeToObserve;
    observer->_particleTypeToObserveSet  = _particleTypeToObserveSet;
    observer->_particleSystem            = _particleSystem;
    observer->_observerScale             = _observerScale;
    observer->_observerInterval          = _observerInterval;
    observer->_observerIntervalRemainder = _observerIntervalRemainder;
    observer->_observerIntervalSet       = _observerIntervalSet;
    observer->_observeUntilEvent         = _observeUntilEvent;
    observer->_eventHandlersExecuted     = _eventHandlersExecuted;
    observer->_enabled                   = _enabled;
    observer->_originalEnabled           = _originalEnabled;
    observer->_originalEnabledSet        = _originalEnabledSet;

    // Copy event handlers
    size_t i                     = 0;
    PUEventHandler* eventHandler = 0;
    for (i = 0; i < getNumEventHandlers(); ++i)
    {
        eventHandler = getEventHandler(i);
        PUEventHandler* clonedEventHandler =
            PUEventHandlerManager::Instance()->createEventHandler(eventHandler->getEventHandlerType());
        eventHandler->copyAttributesTo(clonedEventHandler);
        observer->addEventHandler(clonedEventHandler);
    }
}

NS_AX_END