//
//  Particle.cpp
//  hifi
//
//  Created by Brad Hefta-Gaub on 12/4/13.
//  Copyright (c) 2013 High Fidelity, Inc. All rights reserved.
//
//

#include <QtScript/QScriptEngine>
#include <QtCore/QObject>

#include <RegisteredMetaTypes.h>
#include <SharedUtil.h> // usecTimestampNow()
#include <Octree.h>

#include <VoxelsScriptingInterface.h>
#include "ParticlesScriptingInterface.h"

#include "Particle.h"

uint32_t Particle::_nextID = 0;
VoxelsScriptingInterface* Particle::_voxelsScriptingInterface = NULL;
ParticlesScriptingInterface* Particle::_particlesScriptingInterface = NULL;


Particle::Particle(glm::vec3 position, float radius, rgbColor color, glm::vec3 velocity, glm::vec3 gravity, 
                    float damping, bool inHand, QString updateScript, uint32_t id) {
                    
    init(position, radius, color, velocity, gravity, damping, inHand, updateScript, id);
}

Particle::Particle() {
    rgbColor noColor = { 0, 0, 0 };
    init(glm::vec3(0,0,0), 0, noColor, glm::vec3(0,0,0), 
            DEFAULT_GRAVITY, DEFAULT_DAMPING, NOT_IN_HAND, DEFAULT_SCRIPT, NEW_PARTICLE);
}

Particle::~Particle() {
}

void Particle::init(glm::vec3 position, float radius, rgbColor color, glm::vec3 velocity, glm::vec3 gravity, 
                    float damping, bool inHand, QString updateScript, uint32_t id) {
    if (id == NEW_PARTICLE) {
        _id = _nextID;
        _nextID++;
    } else {
        _id = id;
    }
    uint64_t now = usecTimestampNow();
    _lastEdited = now;
    _lastUpdated = now;
    _created = now; // will get updated as appropriate in setLifetime()
    
    _position = position;
    _radius = radius;
    memcpy(_color, color, sizeof(_color));
    _velocity = velocity;
    _damping = damping;
    _gravity = gravity;
    _script = updateScript;
    _inHand = inHand;
    _shouldDie = false;
}


bool Particle::appendParticleData(OctreePacketData* packetData) const {

    bool success = packetData->appendValue(getID());

    //printf("Particle::appendParticleData()... getID()=%d\n", getID());

    if (success) {
        success = packetData->appendValue(getLifetime());
    }
    if (success) {
        success = packetData->appendValue(getLastUpdated());
    }
    if (success) {
        success = packetData->appendValue(getLastEdited());
    }
    if (success) {
        success = packetData->appendValue(getRadius());
    }
    if (success) {
        success = packetData->appendPosition(getPosition());
    }
    if (success) {
        success = packetData->appendColor(getColor());
    }
    if (success) {
        success = packetData->appendValue(getVelocity());
    }
    if (success) {
        success = packetData->appendValue(getGravity());
    }
    if (success) {
        success = packetData->appendValue(getDamping());
    }
    if (success) {
        success = packetData->appendValue(getInHand());
    }
    if (success) {
        uint16_t scriptLength = _script.size() + 1; // include NULL
        success = packetData->appendValue(scriptLength);
        if (success) {
            success = packetData->appendRawData((const unsigned char*)qPrintable(_script), scriptLength);
        }
    }
    return success;
}

int Particle::expectedBytes() {
    int expectedBytes = sizeof(uint32_t) // id
                + sizeof(float) // lifetime
                + sizeof(uint64_t) // last updated
                + sizeof(uint64_t) // lasted edited
                + sizeof(float) // radius
                + sizeof(glm::vec3) // position
                + sizeof(rgbColor) // color
                + sizeof(glm::vec3) // velocity
                + sizeof(glm::vec3) // gravity
                + sizeof(float) // damping
                + sizeof(bool); // inhand
                // potentially more...
    return expectedBytes;
}

int Particle::expectedEditMessageBytes() {
    int expectedBytes = sizeof(uint32_t) // id
                + sizeof(uint64_t) // lasted edited
                + sizeof(float) // radius
                + sizeof(glm::vec3) // position
                + sizeof(rgbColor) // color
                + sizeof(glm::vec3) // velocity
                + sizeof(glm::vec3) // gravity
                + sizeof(float) // damping
                + sizeof(bool); // inhand
                // potentially more...
    return expectedBytes;
}

int Particle::readParticleDataFromBuffer(const unsigned char* data, int bytesLeftToRead, ReadBitstreamToTreeParams& args) {
    int bytesRead = 0;
    if (bytesLeftToRead >= expectedBytes()) {
        int clockSkew = args.sourceNode ? args.sourceNode->getClockSkewUsec() : 0;

        const unsigned char* dataAt = data;

        // id
        memcpy(&_id, dataAt, sizeof(_id));
        dataAt += sizeof(_id);
        bytesRead += sizeof(_id);

        // lifetime
        float lifetime;
        memcpy(&lifetime, dataAt, sizeof(lifetime));
        dataAt += sizeof(lifetime);
        bytesRead += sizeof(lifetime);
        setLifetime(lifetime);

        // _lastUpdated
        memcpy(&_lastUpdated, dataAt, sizeof(_lastUpdated));
        dataAt += sizeof(_lastUpdated);
        bytesRead += sizeof(_lastUpdated);
        _lastUpdated -= clockSkew;

        // _lastEdited
        memcpy(&_lastEdited, dataAt, sizeof(_lastEdited));
        dataAt += sizeof(_lastEdited);
        bytesRead += sizeof(_lastEdited);
        _lastEdited -= clockSkew;

        // radius
        memcpy(&_radius, dataAt, sizeof(_radius));
        dataAt += sizeof(_radius);
        bytesRead += sizeof(_radius);

        // position
        memcpy(&_position, dataAt, sizeof(_position));
        dataAt += sizeof(_position);
        bytesRead += sizeof(_position);

        // color
        memcpy(_color, dataAt, sizeof(_color));
        dataAt += sizeof(_color);
        bytesRead += sizeof(_color);

        // velocity
        memcpy(&_velocity, dataAt, sizeof(_velocity));
        dataAt += sizeof(_velocity);
        bytesRead += sizeof(_velocity);

        // gravity
        memcpy(&_gravity, dataAt, sizeof(_gravity));
        dataAt += sizeof(_gravity);
        bytesRead += sizeof(_gravity);

        // damping
        memcpy(&_damping, dataAt, sizeof(_damping));
        dataAt += sizeof(_damping);
        bytesRead += sizeof(_damping);

        // inHand
        memcpy(&_inHand, dataAt, sizeof(_inHand));
        dataAt += sizeof(_inHand);
        bytesRead += sizeof(_inHand);

        // script
        uint16_t scriptLength;
        memcpy(&scriptLength, dataAt, sizeof(scriptLength));
        dataAt += sizeof(scriptLength);
        bytesRead += sizeof(scriptLength);
        QString tempString((const char*)dataAt);
        _script = tempString;
        dataAt += scriptLength;
        bytesRead += scriptLength;
        
        //printf("Particle::readParticleDataFromBuffer()... "); debugDump();
    }
    return bytesRead;
}


Particle Particle::fromEditPacket(unsigned char* data, int length, int& processedBytes) {
    Particle newParticle; // id and _lastUpdated will get set here...
    unsigned char* dataAt = data;
    processedBytes = 0;

    // the first part of the data is our octcode...    
    int octets = numberOfThreeBitSectionsInCode(data);
    int lengthOfOctcode = bytesRequiredForCodeLength(octets);
    
    // we don't actually do anything with this octcode... 
    dataAt += lengthOfOctcode;
    processedBytes += lengthOfOctcode;

    // id
    uint32_t editID;
    memcpy(&editID, dataAt, sizeof(editID));
    dataAt += sizeof(editID);
    processedBytes += sizeof(editID);
    
    // special case for handling "new" particles
    if (editID == NEW_PARTICLE) {
        // If this is a NEW_PARTICLE, then we assume that there's an additional uint32_t creatorToken, that
        // we want to send back to the creator as an map to the actual id
        uint32_t creatorTokenID;
        memcpy(&creatorTokenID, dataAt, sizeof(creatorTokenID));
        dataAt += sizeof(creatorTokenID);
        processedBytes += sizeof(creatorTokenID);
        newParticle.setCreatorTokenID(creatorTokenID);
        newParticle._newlyCreated = true;
        
        newParticle.setLifetime(0); // this guy is new!

    } else {
        newParticle._id = editID;
        newParticle._newlyCreated = false;
    } 

    // lastEdited
    memcpy(&newParticle._lastEdited, dataAt, sizeof(newParticle._lastEdited));
    dataAt += sizeof(newParticle._lastEdited);
    processedBytes += sizeof(newParticle._lastEdited);
        
    // radius
    memcpy(&newParticle._radius, dataAt, sizeof(newParticle._radius));
    dataAt += sizeof(newParticle._radius);
    processedBytes += sizeof(newParticle._radius);

    // position
    memcpy(&newParticle._position, dataAt, sizeof(newParticle._position));
    dataAt += sizeof(newParticle._position);
    processedBytes += sizeof(newParticle._position);

    // color
    memcpy(newParticle._color, dataAt, sizeof(newParticle._color));
    dataAt += sizeof(newParticle._color);
    processedBytes += sizeof(newParticle._color);

    // velocity
    memcpy(&newParticle._velocity, dataAt, sizeof(newParticle._velocity));
    dataAt += sizeof(newParticle._velocity);
    processedBytes += sizeof(newParticle._velocity);
    
    // gravity
    memcpy(&newParticle._gravity, dataAt, sizeof(newParticle._gravity));
    dataAt += sizeof(newParticle._gravity);
    processedBytes += sizeof(newParticle._gravity);
    
    // damping
    memcpy(&newParticle._damping, dataAt, sizeof(newParticle._damping));
    dataAt += sizeof(newParticle._damping);
    processedBytes += sizeof(newParticle._damping);

    // inHand
    memcpy(&newParticle._inHand, dataAt, sizeof(newParticle._inHand));
    dataAt += sizeof(newParticle._inHand);
    processedBytes += sizeof(newParticle._inHand);

    // script
    uint16_t scriptLength;
    memcpy(&scriptLength, dataAt, sizeof(scriptLength));
    dataAt += sizeof(scriptLength);
    processedBytes += sizeof(scriptLength);
    QString tempString((const char*)dataAt);
    newParticle._script = tempString;
    dataAt += scriptLength;
    processedBytes += scriptLength;

    const bool wantDebugging = false;
    if (wantDebugging) {
        printf("Particle::fromEditPacket()...\n"); 
        printf("   Particle id in packet:%u\n", editID);
        newParticle.debugDump();
    }
    
    return newParticle;
}

void Particle::debugDump() const {
    printf("Particle id  :%u\n", _id);
    printf(" lifetime:%f\n", getLifetime());
    printf(" edited ago:%f\n", getEditedAgo());
    printf(" position:%f,%f,%f\n", _position.x, _position.y, _position.z);
    printf(" velocity:%f,%f,%f\n", _velocity.x, _velocity.y, _velocity.z);
    printf(" gravity:%f,%f,%f\n", _gravity.x, _gravity.y, _gravity.z);
    printf(" color:%d,%d,%d\n", _color[0], _color[1], _color[2]);
}

bool Particle::encodeParticleEditMessageDetails(PACKET_TYPE command, int count, const ParticleDetail* details, 
        unsigned char* bufferOut, int sizeIn, int& sizeOut) {

    bool success = true; // assume the best
    unsigned char* copyAt = bufferOut;
    sizeOut = 0;

    for (int i = 0; i < count && success; i++) {
        // get the octal code for the particle
        unsigned char* octcode = pointToOctalCode(details[i].position.x, details[i].position.y, 
                                                    details[i].position.z, details[i].radius);

        int octets = numberOfThreeBitSectionsInCode(octcode);
        int lengthOfOctcode = bytesRequiredForCodeLength(octets);
        int lenfthOfEditData = lengthOfOctcode + expectedEditMessageBytes();
        
        // make sure we have room to copy this particle
        if (sizeOut + lenfthOfEditData > sizeIn) {
            success = false;
        } else {
            // add it to our message
            memcpy(copyAt, octcode, lengthOfOctcode);
            copyAt += lengthOfOctcode;
            sizeOut += lengthOfOctcode;
            
            // Now add our edit content details...
            
            // id
            memcpy(copyAt, &details[i].id, sizeof(details[i].id));
            copyAt += sizeof(details[i].id);
            sizeOut += sizeof(details[i].id);
            // special case for handling "new" particles
            if (details[i].id == NEW_PARTICLE) {
                // If this is a NEW_PARTICLE, then we assume that there's an additional uint32_t creatorToken, that
                // we want to send back to the creator as an map to the actual id
                memcpy(copyAt, &details[i].creatorTokenID, sizeof(details[i].creatorTokenID));
                copyAt += sizeof(details[i].creatorTokenID);
                sizeOut += sizeof(details[i].creatorTokenID);
            }

            // lastEdited
            memcpy(copyAt, &details[i].lastEdited, sizeof(details[i].lastEdited));
            copyAt += sizeof(details[i].lastEdited);
            sizeOut += sizeof(details[i].lastEdited);

            // radius
            memcpy(copyAt, &details[i].radius, sizeof(details[i].radius));
            copyAt += sizeof(details[i].radius);
            sizeOut += sizeof(details[i].radius);

            // position
            memcpy(copyAt, &details[i].position, sizeof(details[i].position));
            copyAt += sizeof(details[i].position);
            sizeOut += sizeof(details[i].position);

            // color
            memcpy(copyAt, details[i].color, sizeof(details[i].color));
            copyAt += sizeof(details[i].color);
            sizeOut += sizeof(details[i].color);

            // velocity
            memcpy(copyAt, &details[i].velocity, sizeof(details[i].velocity));
            copyAt += sizeof(details[i].velocity);
            sizeOut += sizeof(details[i].velocity);

            // gravity
            memcpy(copyAt, &details[i].gravity, sizeof(details[i].gravity));
            copyAt += sizeof(details[i].gravity);
            sizeOut += sizeof(details[i].gravity);

            // damping
            memcpy(copyAt, &details[i].damping, sizeof(details[i].damping));
            copyAt += sizeof(details[i].damping);
            sizeOut += sizeof(details[i].damping);

            // inHand
            memcpy(copyAt, &details[i].inHand, sizeof(details[i].inHand));
            copyAt += sizeof(details[i].inHand);
            sizeOut += sizeof(details[i].inHand);

            // script
            uint16_t scriptLength = details[i].updateScript.size() + 1;
            memcpy(copyAt, &scriptLength, sizeof(scriptLength));
            copyAt += sizeof(scriptLength);
            sizeOut += sizeof(scriptLength);
            memcpy(copyAt, qPrintable(details[i].updateScript), scriptLength);
            copyAt += scriptLength;
            sizeOut += scriptLength;

            bool wantDebugging = false;
            if (wantDebugging) {            
                printf("encodeParticleEditMessageDetails()....\n");
                printf("Particle id  :%u\n", details[i].id);
                printf(" nextID:%u\n", _nextID);
            }
        }
        // cleanup
        delete[] octcode;
    }

    return success;
}

// adjust any internal timestamps to fix clock skew for this server
void Particle::adjustEditPacketForClockSkew(unsigned char* codeColorBuffer, ssize_t length, int clockSkew) { 
    unsigned char* dataAt = codeColorBuffer;
    int octets = numberOfThreeBitSectionsInCode(dataAt);
    int lengthOfOctcode = bytesRequiredForCodeLength(octets);
    dataAt += lengthOfOctcode;

    // id
    uint32_t id;
    memcpy(&id, dataAt, sizeof(id));
    dataAt += sizeof(id);
    // special case for handling "new" particles
    if (id == NEW_PARTICLE) {
        // If this is a NEW_PARTICLE, then we assume that there's an additional uint32_t creatorToken, that
        // we want to send back to the creator as an map to the actual id
        dataAt += sizeof(uint32_t);
    }

    // lastEdited
    uint64_t lastEditedInLocalTime;
    memcpy(&lastEditedInLocalTime, dataAt, sizeof(lastEditedInLocalTime));
    uint64_t lastEditedInServerTime = lastEditedInLocalTime + clockSkew;
    memcpy(dataAt, &lastEditedInServerTime, sizeof(lastEditedInServerTime));
    const bool wantDebug = false;
    if (wantDebug) {    
        qDebug("Particle::adjustEditPacketForClockSkew()...\n");
        qDebug("     lastEditedInLocalTime: %llu\n", lastEditedInLocalTime);
        qDebug("                 clockSkew: %d\n", clockSkew);
        qDebug("    lastEditedInServerTime: %llu\n", lastEditedInServerTime);
    }
}


void Particle::update() {
    uint64_t now = usecTimestampNow();
    float elapsed = static_cast<float>(now - _lastUpdated);
    _lastUpdated = now;
    float timeElapsed = elapsed / static_cast<float>(USECS_PER_SECOND);
    
    // calculate our default shouldDie state... then allow script to change it if it wants...
    float velocityScalar = glm::length(getVelocity());
    const float STILL_MOVING = 0.05f / static_cast<float>(TREE_SCALE);
    bool isStillMoving = (velocityScalar > STILL_MOVING);
    const float REALLY_OLD = 30.0f; // 30 seconds
    bool isReallyOld = (getLifetime() > REALLY_OLD);
    bool isInHand = getInHand();
    bool shouldDie = getShouldDie() || (!isInHand && !isStillMoving && isReallyOld);
    setShouldDie(shouldDie);
    
    const bool wantDebug = false;
    if (wantDebug) {
        printf("Particle::update()... timeElapsed: %f lifeTime:%f editedAgo:%f "
            "isInHand:%s isStillMoveing:%s isReallyOld:%s shouldDie:%s\n", 
            timeElapsed, getLifetime(), getEditedAgo(), debug::valueOf(isInHand), debug::valueOf(isStillMoving), 
            debug::valueOf(isReallyOld), debug::valueOf(shouldDie));
    }
        
    runUpdateScript(); // allow the javascript to alter our state
    
    // If the ball is in hand, it doesn't move or have gravity effect it
    if (!isInHand) {
        _position += _velocity * timeElapsed;
    
        // handle bounces off the ground...
        if (_position.y <= 0) {
            _velocity = _velocity * glm::vec3(1,-1,1);
            _position.y = 0;
        }

        // handle gravity....
        _velocity += _gravity * timeElapsed;

        // handle damping
        glm::vec3 dampingResistance = _velocity * _damping;
        _velocity -= dampingResistance * timeElapsed;
        //printf("applying damping to Particle timeElapsed=%f\n",timeElapsed);
    }
}

void Particle::runUpdateScript() {
    if (!_script.isEmpty()) {

        QScriptEngine engine;
    
        // register meta-type for glm::vec3 and rgbColor conversions
        registerMetaTypes(&engine);
    
        ParticleScriptObject particleScriptable(this);
        QScriptValue particleValue = engine.newQObject(&particleScriptable);
        engine.globalObject().setProperty("Particle", particleValue);
        
        QScriptValue treeScaleValue = engine.newVariant(QVariant(TREE_SCALE));
        engine.globalObject().setProperty("TREE_SCALE", TREE_SCALE);
    
        QScriptValue result = engine.evaluate(_script);
        
        particleScriptable.emitUpdate();
    
        if (engine.hasUncaughtException()) {
            int line = engine.uncaughtExceptionLineNumber();
            qDebug() << "Uncaught exception at line" << line << ":" << result.toString() << "\n";
        }
    }
}

void Particle::collisionWithParticle(Particle* other) {
    if (!_script.isEmpty()) {

        QScriptEngine engine;
    
        // register meta-type for glm::vec3 and rgbColor conversions
        registerMetaTypes(&engine);
    
        ParticleScriptObject particleScriptable(this);
        QScriptValue particleValue = engine.newQObject(&particleScriptable);
        engine.globalObject().setProperty("Particle", particleValue);
        
        QScriptValue treeScaleValue = engine.newVariant(QVariant(TREE_SCALE));
        engine.globalObject().setProperty("TREE_SCALE", TREE_SCALE);


        if (getVoxelsScriptingInterface()) {
            QScriptValue voxelScripterValue =  engine.newQObject(getVoxelsScriptingInterface());
            engine.globalObject().setProperty("Voxels", voxelScripterValue);
        }

        if (getParticlesScriptingInterface()) {
            QScriptValue particleScripterValue =  engine.newQObject(getParticlesScriptingInterface());
            engine.globalObject().setProperty("Particles", particleScripterValue);
        }
        
        QScriptValue result = engine.evaluate(_script);
        
        ParticleScriptObject otherParticleScriptable(other);
        particleScriptable.emitCollisionWithParticle(&otherParticleScriptable);

        if (getVoxelsScriptingInterface()) {
            getVoxelsScriptingInterface()->getPacketSender()->releaseQueuedMessages();
        }

        if (getParticlesScriptingInterface()) {
            getParticlesScriptingInterface()->getPacketSender()->releaseQueuedMessages();
        }

        if (engine.hasUncaughtException()) {
            int line = engine.uncaughtExceptionLineNumber();
            qDebug() << "Uncaught exception at line" << line << ":" << result.toString() << "\n";
        }
    }
}

void Particle::collisionWithVoxel(VoxelDetail* voxelDetails) {
    if (!_script.isEmpty()) {

        QScriptEngine engine;
    
        // register meta-type for glm::vec3 and rgbColor conversions
        registerMetaTypes(&engine);
    
        ParticleScriptObject particleScriptable(this);
        QScriptValue particleValue = engine.newQObject(&particleScriptable);
        engine.globalObject().setProperty("Particle", particleValue);
        
        QScriptValue treeScaleValue = engine.newVariant(QVariant(TREE_SCALE));
        engine.globalObject().setProperty("TREE_SCALE", TREE_SCALE);


        if (getVoxelsScriptingInterface()) {
            QScriptValue voxelScripterValue =  engine.newQObject(getVoxelsScriptingInterface());
            engine.globalObject().setProperty("Voxels", voxelScripterValue);
        }

        if (getParticlesScriptingInterface()) {
            QScriptValue particleScripterValue =  engine.newQObject(getParticlesScriptingInterface());
            engine.globalObject().setProperty("Particles", particleScripterValue);
        }
        
        QScriptValue result = engine.evaluate(_script);
        
        VoxelDetailScriptObject voxelDetailsScriptable(voxelDetails);
        particleScriptable.emitCollisionWithVoxel(&voxelDetailsScriptable);

        if (getVoxelsScriptingInterface()) {
            getVoxelsScriptingInterface()->getPacketSender()->releaseQueuedMessages();
        }

        if (getParticlesScriptingInterface()) {
            getParticlesScriptingInterface()->getPacketSender()->releaseQueuedMessages();
        }

        if (engine.hasUncaughtException()) {
            int line = engine.uncaughtExceptionLineNumber();
            qDebug() << "Uncaught exception at line" << line << ":" << result.toString() << "\n";
        }
    }
}



void Particle::setLifetime(float lifetime) {
    uint64_t lifetimeInUsecs = lifetime * USECS_PER_SECOND;
    _created = usecTimestampNow() - lifetimeInUsecs; 
}

void Particle::copyChangedProperties(const Particle& other) {
    float lifetime = getLifetime();
    *this = other;
    setLifetime(lifetime);
}