//
//  EntityTreeSendThread.cpp
//  assignment-client/src/entities
//
//  Created by Stephen Birarda on 2/15/17.
//  Copyright 2017 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 "EntityTreeSendThread.h"

#include <EntityNodeData.h>
#include <EntityTypes.h>

#include "EntityServer.h"

void EntityTreeSendThread::preDistributionProcessing() {
    auto node = _node.toStrongRef();
    auto nodeData = static_cast<EntityNodeData*>(node->getLinkedData());

    if (nodeData) {
        auto jsonQuery = nodeData->getJSONParameters();

        // check if we have a JSON query with flags
        auto flags = jsonQuery[EntityJSONQueryProperties::FLAGS_PROPERTY].toObject();
        if (!flags.isEmpty()) {
            // check the flags object for specific flags that require special pre-processing

            bool includeAncestors = flags[EntityJSONQueryProperties::INCLUDE_ANCESTORS_PROPERTY].toBool();
            bool includeDescendants = flags[EntityJSONQueryProperties::INCLUDE_DESCENDANTS_PROPERTY].toBool();

            if (includeAncestors || includeDescendants) {
                // we need to either include the ancestors, descendants, or both for entities matching the filter
                // included in the JSON query

                // first reset our flagged extra entities so we start with an empty set
                nodeData->resetFlaggedExtraEntities();

                auto entityTree = std::static_pointer_cast<EntityTree>(_myServer->getOctree());

                bool requiresFullScene = false;

                // enumerate the set of entity IDs we know currently match the filter
                foreach(const QUuid& entityID, nodeData->getSentFilteredEntities()) {
                    if (includeAncestors) {
                        // we need to include ancestors - recurse up to reach them all and add their IDs
                        // to the set of extra entities to include for this node
                        entityTree->withReadLock([&]{
                            auto filteredEntity = entityTree->findEntityByID(entityID);
                            if (filteredEntity) {
                                requiresFullScene |= addAncestorsToExtraFlaggedEntities(entityID, *filteredEntity, *nodeData);
                            }
                        });
                    }

                    if (includeDescendants) {
                        // we need to include descendants - recurse down to reach them all and add their IDs
                        // to the set of extra entities to include for this node
                        entityTree->withReadLock([&]{
                            auto filteredEntity = entityTree->findEntityByID(entityID);
                            if (filteredEntity) {
                                requiresFullScene |= addDescendantsToExtraFlaggedEntities(entityID, *filteredEntity, *nodeData);
                            }
                        });
                    }
                }

                if (requiresFullScene) {
                    // for one or more of the entities matching our filter we found new extra entities to include

                    // because it is possible that one of these entities hasn't changed since our last send
                    // and therefore would not be recursed to, we need to force a full traversal for this pass
                    // of the tree to allow it to grab all of the extra entities we're asking it to include
                    nodeData->setShouldForceFullScene(requiresFullScene);
                }
            }
        }
    }
}

bool EntityTreeSendThread::addAncestorsToExtraFlaggedEntities(const QUuid& filteredEntityID,
                                                              EntityItem& entityItem, EntityNodeData& nodeData) {
    // check if this entity has a parent that is also an entity
    bool success = false;
    auto entityParent = entityItem.getParentPointer(success);

    if (success && entityParent && entityParent->getNestableType() == NestableType::Entity) {
        // we found a parent that is an entity item

        // first add it to the extra list of things we need to send
        bool parentWasNew = nodeData.insertFlaggedExtraEntity(filteredEntityID, entityParent->getID());

        // now recursively call ourselves to get its ancestors added too
        auto parentEntityItem = std::static_pointer_cast<EntityItem>(entityParent);
        bool ancestorsWereNew = addAncestorsToExtraFlaggedEntities(filteredEntityID, *parentEntityItem, nodeData);

        // return boolean if our parent or any of our ancestors were new additions (via insertFlaggedExtraEntity)
        return parentWasNew || ancestorsWereNew;
    }

    // since we didn't have a parent niether of our parents or ancestors could be new additions
    return false;
}

bool EntityTreeSendThread::addDescendantsToExtraFlaggedEntities(const QUuid& filteredEntityID,
                                                                EntityItem& entityItem, EntityNodeData& nodeData) {
    bool hasNewChild = false;
    bool hasNewDescendants = false;

    // enumerate the immediate children of this entity
    foreach (SpatiallyNestablePointer child, entityItem.getChildren()) {

        if (child && child->getNestableType() == NestableType::Entity) {
            // this is a child that is an entity

            // first add it to the extra list of things we need to send
            hasNewChild |= nodeData.insertFlaggedExtraEntity(filteredEntityID, child->getID());

            // now recursively call ourselves to get its descendants added too
            auto childEntityItem = std::static_pointer_cast<EntityItem>(child);
            hasNewDescendants |= addDescendantsToExtraFlaggedEntities(filteredEntityID, *childEntityItem, nodeData);
        }
    }

    // return our boolean indicating if we added new children or descendants as extra entities to send
    // (via insertFlaggedExtraEntity)
    return hasNewChild || hasNewDescendants;
}