//
//  Created by Bradley Austin Davis on 2016/05/09
//  Copyright 2013 High Fidelity, Inc.
//
//  Distributed under the Apache License, Version 2.0.
//  See the accompanying file LICENSE or http://www.apache.org/licenses/LICENSE-2.0.html
//

#include "ShapeEntityItem.h"

#include <glm/gtx/transform.hpp>

#include <QtCore/QDebug>

#include <GeometryUtil.h>

#include "EntitiesLogging.h"
#include "EntityItemProperties.h"
#include "EntityTree.h"
#include "EntityTreeElement.h"

// hullShapeCalculator is a hook for external code that knows how to configure a ShapeInfo
// for given EntityShape and dimensions
ShapeEntityItem::ShapeInfoCalculator hullShapeCalculator = nullptr;

void ShapeEntityItem::setShapeInfoCalulator(ShapeEntityItem::ShapeInfoCalculator callback) {
    hullShapeCalculator = callback;
}

ShapeEntityItem::Pointer ShapeEntityItem::baseFactory(const EntityItemID& entityID, const EntityItemProperties& properties) {
    Pointer entity(new ShapeEntityItem(entityID), [](ShapeEntityItem* ptr) { ptr->deleteLater(); });
    entity->setProperties(properties);
    return entity;
}

EntityItemPointer ShapeEntityItem::factory(const EntityItemID& entityID, const EntityItemProperties& properties) {
    return baseFactory(entityID, properties);
}

EntityItemPointer ShapeEntityItem::boxFactory(const EntityItemID& entityID, const EntityItemProperties& properties) {
    auto result = baseFactory(entityID, properties);
    result->setShape(EntityShape::Cube);
    return result;
}

EntityItemPointer ShapeEntityItem::sphereFactory(const EntityItemID& entityID, const EntityItemProperties& properties) {
    auto result = baseFactory(entityID, properties);
    result->setShape(EntityShape::Sphere);
    return result;
}

// our non-pure virtual subclass for now...
ShapeEntityItem::ShapeEntityItem(const EntityItemID& entityItemID) : EntityItem(entityItemID) {
    _type = EntityTypes::Shape;
    _volumeMultiplier *= PI / 6.0f;
}

EntityItemProperties ShapeEntityItem::getProperties(const EntityPropertyFlags& desiredProperties, bool allowEmptyDesiredProperties) const {
    EntityItemProperties properties = EntityItem::getProperties(desiredProperties, allowEmptyDesiredProperties); // get the properties from our base class

@Shape_ENTITY_COPY_TO@

    return properties;
}

void ShapeEntityItem::setShape(EntityShape shape) {
    switch (shape) {
        case EntityShape::Cube:
            _type = EntityTypes::Box;
            break;
        case EntityShape::Sphere:
            _type = EntityTypes::Sphere;
            break;
        case EntityShape::Circle:
            // Circle is implicitly flat so we enforce flat dimensions
            setUnscaledDimensions(getUnscaledDimensions());
            break;
        case EntityShape::Quad:
            // Quad is implicitly flat so we enforce flat dimensions
            setUnscaledDimensions(getUnscaledDimensions());
            break;
        default:
            _type = EntityTypes::Shape;
            break;
    }

    if (shape != getShape()) {
        // Internally grabs writeLock
        markDirtyFlags(Simulation::DIRTY_SHAPE);
        withWriteLock([&] {
            _needsRenderUpdate = true;
            _shape = shape;
        });
    }
}

EntityShape ShapeEntityItem::getShape() const {
    return resultWithReadLock<EntityShape>([&] {
        return _shape;
    });
}

bool ShapeEntityItem::setSubClassProperties(const EntityItemProperties& properties) {
    bool somethingChanged = false;

@Shape_ENTITY_SET_FROM@

    return somethingChanged;
}

EntityPropertyFlags ShapeEntityItem::getEntityProperties(EncodeBitstreamParams& params) const {
    EntityPropertyFlags requestedProperties = EntityItem::getEntityProperties(params);

@Shape_REQUESTED_PROPS@

    return requestedProperties;
}

void ShapeEntityItem::appendSubclassData(OctreePacketData* packetData, EncodeBitstreamParams& params,
                                         EntityTreeElementExtraEncodeDataPointer entityTreeElementExtraEncodeData,
                                         EntityPropertyFlags& requestedProperties,
                                         EntityPropertyFlags& propertyFlags,
                                         EntityPropertyFlags& propertiesDidntFit,
                                         int& propertyCount,
                                         OctreeElement::AppendState& appendState) const {

    bool successPropertyFits = true;

@Shape_ENTITY_APPEND@

}

int ShapeEntityItem::readEntitySubclassDataFromBuffer(const unsigned char* data, int bytesLeftToRead,
                                                ReadBitstreamToTreeParams& args,
                                                EntityPropertyFlags& propertyFlags, bool overwriteLocalData,
                                                bool& somethingChanged) {

    int bytesRead = 0;
    const unsigned char* dataAt = data;

@Shape_ENTITY_READ@

    return bytesRead;
}

void ShapeEntityItem::setUnscaledDimensions(const glm::vec3& value) {
    const float MAX_FLAT_DIMENSION = 0.0001f;
    const auto shape = getShape();
    if ((shape == EntityShape::Circle || shape == EntityShape::Quad) && value.y > MAX_FLAT_DIMENSION) {
        // enforce flatness in Y
        glm::vec3 newDimensions = value;
        newDimensions.y = MAX_FLAT_DIMENSION;
        EntityItem::setUnscaledDimensions(newDimensions);
    } else {
        EntityItem::setUnscaledDimensions(value);
    }
}

bool ShapeEntityItem::supportsDetailedIntersection() const {
    return getShape() == EntityShape::Sphere;
}

bool ShapeEntityItem::findDetailedRayIntersection(const glm::vec3& origin, const glm::vec3& direction,
                                                  const glm::vec3& viewFrustumPos, OctreeElementPointer& element,
                                                  float& distance, BoxFace& face, glm::vec3& surfaceNormal,
                                                  QVariantMap& extraInfo, bool precisionPicking) const {
    glm::vec3 dimensions = getScaledDimensions();
    BillboardMode billboardMode = getBillboardMode();
    glm::quat rotation = billboardMode == BillboardMode::NONE ? getWorldOrientation() : getLocalOrientation();
    glm::vec3 position = getWorldPosition() + rotation * (dimensions * (ENTITY_ITEM_DEFAULT_REGISTRATION_POINT - getRegistrationPoint()));
    rotation = BillboardModeHelpers::getBillboardRotation(position, rotation, billboardMode, viewFrustumPos);

    // determine the ray in the frame of the entity transformed from a unit sphere
    glm::mat4 entityToWorldMatrix = glm::translate(position) * glm::mat4_cast(rotation) * glm::scale(dimensions);
    glm::mat4 worldToEntityMatrix = glm::inverse(entityToWorldMatrix);
    glm::vec3 entityFrameOrigin = glm::vec3(worldToEntityMatrix * glm::vec4(origin, 1.0f));
    glm::vec3 entityFrameDirection = glm::vec3(worldToEntityMatrix * glm::vec4(direction, 0.0f));

    // NOTE: unit sphere has center of 0,0,0 and radius of 0.5
    if (findRaySphereIntersection(entityFrameOrigin, entityFrameDirection, glm::vec3(0.0f), 0.5f, distance)) {
        bool success;
        glm::vec3 center = getCenterPosition(success);
        if (success) {
            // FIXME: this is only correct for uniformly scaled spheres
            // determine where on the unit sphere the hit point occured
            glm::vec3 hitAt = origin + (direction * distance);
            surfaceNormal = glm::normalize(hitAt - center);
        } else {
            return false;
        }
        return true;
    }
    return false;
}

bool ShapeEntityItem::findDetailedParabolaIntersection(const glm::vec3& origin, const glm::vec3& velocity, const glm::vec3& acceleration,
                                                       const glm::vec3& viewFrustumPos, OctreeElementPointer& element, float& parabolicDistance,
                                                       BoxFace& face, glm::vec3& surfaceNormal,
                                                       QVariantMap& extraInfo, bool precisionPicking) const {
    glm::vec3 dimensions = getScaledDimensions();
    BillboardMode billboardMode = getBillboardMode();
    glm::quat rotation = billboardMode == BillboardMode::NONE ? getWorldOrientation() : getLocalOrientation();
    glm::vec3 position = getWorldPosition() + rotation * (dimensions * (ENTITY_ITEM_DEFAULT_REGISTRATION_POINT - getRegistrationPoint()));
    rotation = BillboardModeHelpers::getBillboardRotation(position, rotation, billboardMode, viewFrustumPos);

    // determine the parabola in the frame of the entity transformed from a unit sphere
    glm::mat4 entityToWorldMatrix = glm::translate(position) * glm::mat4_cast(rotation) * glm::scale(dimensions);
    glm::mat4 worldToEntityMatrix = glm::inverse(entityToWorldMatrix);
    glm::vec3 entityFrameOrigin = glm::vec3(worldToEntityMatrix * glm::vec4(origin, 1.0f));
    glm::vec3 entityFrameVelocity = glm::vec3(worldToEntityMatrix * glm::vec4(velocity, 0.0f));
    glm::vec3 entityFrameAcceleration = glm::vec3(worldToEntityMatrix * glm::vec4(acceleration, 0.0f));

    // NOTE: unit sphere has center of 0,0,0 and radius of 0.5
    if (findParabolaSphereIntersection(entityFrameOrigin, entityFrameVelocity, entityFrameAcceleration, glm::vec3(0.0f), 0.5f, parabolicDistance)) {
        bool success;
        glm::vec3 center = getCenterPosition(success);
        if (success) {
            // FIXME: this is only correct for uniformly scaled spheres
            surfaceNormal = glm::normalize((origin + velocity * parabolicDistance + 0.5f * acceleration * parabolicDistance * parabolicDistance) - center);
        } else {
            return false;
        }
        return true;
    }
    return false;
}

bool ShapeEntityItem::getRotateForPicking() const {
    auto shape = getShape();
    return getBillboardMode() != BillboardMode::NONE && (shape < EntityShape::Cube || shape > EntityShape::Icosahedron);
}

void ShapeEntityItem::debugDump() const {
    qCDebug(entities) << "ShapeEntityItem id:" << getEntityItemID() << "---------------------------------------------";
    qCDebug(entities) << "    name:" << _name;
    qCDebug(entities) << "    position:" << debugTreeVector(getWorldPosition());
    qCDebug(entities) << "    dimensions:" << debugTreeVector(getScaledDimensions());
    qCDebug(entities) << "    editedAgo:" << debugTime(getLastEdited(), usecTimestampNow());
    qCDebug(entities) << "    pointer:" << this;

@Shape_ENTITY_DEBUG@

}

void ShapeEntityItem::computeShapeInfo(ShapeInfo& info) {

    // This will be called whenever DIRTY_SHAPE flag (set by dimension change, etc)
    // is set.

    const glm::vec3 entityDimensions = getScaledDimensions();
    const auto shape = getShape();

    switch (shape){
        case EntityShape::Quad:
            // Quads collide like flat Cubes
        case EntityShape::Cube: {
            _collisionShapeType = SHAPE_TYPE_BOX;
        }
        break;
        case EntityShape::Sphere: {
            float diameter = entityDimensions.x;
            const float MIN_DIAMETER = 0.001f;
            const float MIN_RELATIVE_SPHERICAL_ERROR = 0.001f;
            if (diameter > MIN_DIAMETER
                && fabsf(diameter - entityDimensions.y) / diameter < MIN_RELATIVE_SPHERICAL_ERROR
                && fabsf(diameter - entityDimensions.z) / diameter < MIN_RELATIVE_SPHERICAL_ERROR) {

                _collisionShapeType = SHAPE_TYPE_SPHERE;
            } else {
                _collisionShapeType = SHAPE_TYPE_ELLIPSOID;
            }
        }
        break;
        case EntityShape::Circle:
            // Circles collide like flat Cylinders
        case EntityShape::Cylinder: {
            float diameter = entityDimensions.x;
            const float MIN_DIAMETER = 0.001f;
            const float MIN_RELATIVE_SPHERICAL_ERROR = 0.001f;
            if (diameter > MIN_DIAMETER
                && fabsf(diameter - entityDimensions.z) / diameter < MIN_RELATIVE_SPHERICAL_ERROR) {
                _collisionShapeType = SHAPE_TYPE_CYLINDER_Y;
            } else if (hullShapeCalculator) {
                hullShapeCalculator(this, info);
                _collisionShapeType = SHAPE_TYPE_SIMPLE_HULL;
            } else {
                // woops, someone forgot to hook up the hullShapeCalculator()!
                // final fallback is ellipsoid
                _collisionShapeType = SHAPE_TYPE_ELLIPSOID;
            }
        }
        break;
        case EntityShape::Cone: {
            if (hullShapeCalculator) {
                hullShapeCalculator(this, info);
                _collisionShapeType = SHAPE_TYPE_SIMPLE_HULL;
            } else {
                _collisionShapeType = SHAPE_TYPE_ELLIPSOID;
            }
        }
        break;
        // gons, ones, & angles built via GeometryCache::extrudePolygon
        case EntityShape::Triangle:
        case EntityShape::Hexagon:
        case EntityShape::Octagon: {
            if (hullShapeCalculator) {
                hullShapeCalculator(this, info);
                _collisionShapeType = SHAPE_TYPE_SIMPLE_HULL;
            } else {
                _collisionShapeType = SHAPE_TYPE_ELLIPSOID;
            }
        }
        break;
        // hedrons built via GeometryCache::setUpFlatShapes
        case EntityShape::Tetrahedron:
        case EntityShape::Octahedron:
        case EntityShape::Dodecahedron:
        case EntityShape::Icosahedron: {
            if ( hullShapeCalculator ) {
                hullShapeCalculator(this, info);
                _collisionShapeType = SHAPE_TYPE_SIMPLE_HULL;
            } else {
                _collisionShapeType = SHAPE_TYPE_ELLIPSOID;
            }
        }
        break;
        case EntityShape::Torus: {
            // Not in GeometryCache::buildShapes, unsupported.
            _collisionShapeType = SHAPE_TYPE_CYLINDER_Y;
            //TODO handle this shape more correctly
        }
        break;
        default: {
            _collisionShapeType = SHAPE_TYPE_ELLIPSOID;
        }
        break;
    }

    EntityItem::computeShapeInfo(info);
}

// This value specifies how the shape should be treated by physics calculations.
ShapeType ShapeEntityItem::getShapeType() const {
    return _collisionShapeType;
}

PulsePropertyGroup ShapeEntityItem::getPulseProperties() const {
    return resultWithReadLock<PulsePropertyGroup>([&] {
        return _pulseProperties;
    });
}

void ShapeEntityItem::setUserData(const QString& value) {
    bool changed = false;
    withWriteLock([&] {
        changed = _userData != value;
        _needsRenderUpdate |= changed;
    });
    if (changed) {
        EntityItem::setUserData(value);
    }
}