//
// Copyright (C) 2009 Alistair Riddoch
// Copyright (C) 2013 Erik Ogenvik
//
// This program is free software; you can redistribute it and/or modify
// it under the terms of the GNU General Public License as published by
// the Free Software Foundation; either version 2 of the License, or
// (at your option) any later version.
// 
// This program is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
// GNU General Public License for more details.
// 
// You should have received a copy of the GNU General Public License
// along with this program; if not, write to the Free Software Foundation,
// Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA

#include "EntityImporterBase.h"

#include <Atlas/Objects/Anonymous.h>
#include <Atlas/Objects/Operation.h>

#include <fstream>
#include <sstream>

using Atlas::Objects::Root;
using Atlas::Objects::smart_dynamic_cast;
using Atlas::Objects::Entity::Anonymous;
using Atlas::Objects::Entity::RootEntity;
using Atlas::Objects::Operation::Create;
using Atlas::Objects::Operation::Get;
using Atlas::Objects::Operation::Look;
using Atlas::Objects::Operation::Set;
using Atlas::Message::Element;

//The following are adapters to make the Ember logging syntax work with the Cyphesis log.
#include "common/log.h"
#include "common/debug.h"
static const bool debug_flag = false;
#define S_LOG_VERBOSE(message) \
    { debug(std::stringstream ss;\
    ss << message;\
    log(NOTICE, ss.str());) }
#define S_LOG_INFO(message) \
    { std::stringstream ss;\
    ss << message;\
    log(INFO, ss.str()); }
#define S_LOG_WARNING(message) \
    { std::stringstream ss;\
    ss << message;\
    log(WARNING, ss.str()); }
#define S_LOG_FAILURE(message) \
    { std::stringstream ss;\
    ss << message;\
    log(ERROR, ss.str()); }
#define S_LOG_CRITICAL(message) \
    { std::stringstream ss;\
    ss << message;\
    log(CRITICAL, ss.str()); }


StackEntry::StackEntry(const Atlas::Objects::Entity::RootEntity & o, const std::list<std::string>::const_iterator & c) :
        obj(o), currentChildIterator(c)
{
}

StackEntry::StackEntry(const Atlas::Objects::Entity::RootEntity & o) :
        obj(o)
{
    currentChildIterator = obj->getContains().end();
}

bool EntityImporterBase::getEntity(const std::string & id, OpVector & res)
{
    std::map<std::string, Root>::const_iterator I = mPersistedEntities.find(id);
    if (I == mPersistedEntities.end()) {
        S_LOG_VERBOSE("Could not find entity with id " << id << "; this one was probably transient.");
        //This will often happen if the child entity was transient, and therefore wasn't exported (but is still references from the parent entity).
        return false;
    }
    const RootEntity& obj = smart_dynamic_cast<RootEntity>(I->second);
    if (!obj.isValid()) {
        S_LOG_FAILURE("Corrupt dump - non entity found " << id << ".");
        return false;
    }

    m_state = ENTITY_WALKING;
    mTreeStack.emplace_back(obj);

    Anonymous get_arg;
    get_arg->setId(id);
    get_arg->setObjtype("obj");

    Get get;
    get->setArgs1(get_arg);
    get->setFrom(mAccountId);
    get->setSerialno(newSerialNumber());
    res.push_back(get);
    S_LOG_VERBOSE("EntityImporterBase: Getting entity with id " << id);
    return true;
}

void EntityImporterBase::extractChildren(const Root& op, std::list<std::string>& children)
{
    Element childElem;
    if (op->copyAttr("children", childElem) == 0) {
        if (childElem.isList()) {
            for (auto child : childElem.asList()) {
                if (child.isString()) {
                    children.push_back(child.asString());
                }
            }
        }
    }
}

bool EntityImporterBase::getRule(const std::string & id, OpVector & res)
{
    auto I = mPersistedRules.find(id);
    if (I == mPersistedRules.end()) {
        S_LOG_WARNING("Could not find rule with id " << id << ".");
        return false;
    }

    auto definition = I->second;

    m_state = RULE_WALKING;

    std::list<std::string> children;
    extractChildren(definition, children);

    RuleStackEntry entry = { id, definition, children };
    mRuleStack.push_back(entry);

    Get get;
    Anonymous arg;
    arg->setId(id);
    get->setArgs1(arg);
//  get->setObjtype("op");
    get->setSerialno(newSerialNumber());

    res.push_back(get);

    Anonymous get_arg;
    get_arg->setId(id);
    get_arg->setObjtype("obj");

    return true;
}

void EntityImporterBase::walkRules(OpVector & res)
{
    if (mRuleStack.empty()) {
        startEntityWalking();
    } else {
        auto & current = mRuleStack.back();
        auto definition = current.definition;
        //Check if there are any children. If not, we should pop the stack and

        if (current.children.empty()) {
            // Pop: Go back to WALKING parent
            assert(!mRuleStack.empty());
            mRuleStack.pop_back();
            while (!mRuleStack.empty()) {
                auto & se = mRuleStack.back();
                //Try to get the next child rule (unless we've reached the end of the list of children).
                for (; ++se.currentChildIterator, se.currentChildIterator != se.children.end();) {
                    if (getRule(*se.currentChildIterator, res)) {
                        //We've sent a request for a rule; we should break out and await a response from the server.
                        return;
                    }
                }

                //If we've reached the end of the contained rules we should pop the current stack entry.
                mRuleStack.pop_back();
            }
        } else {
            for (auto I = current.children.begin(); I != current.children.end(); ++I) {
                current.currentChildIterator = I;
                bool foundRule = getRule(*current.currentChildIterator, res);
                if (foundRule) {
                    return;
                }
            }
        }
        if (mRuleStack.empty()) {
            startEntityWalking();
        }
    }
}

void EntityImporterBase::walkEntities(OpVector & res)
{
    if (mTreeStack.empty()) {
        sendResolvedEntityReferences();
    } else {
        StackEntry & current = mTreeStack.back();
        //Check if there are any children. If not, we should pop the stack and
        if (current.obj->getContains().empty()) {
            // Pop: Go back to WALKING parent
            assert(!mTreeStack.empty());
            mTreeStack.pop_back();
            while (!mTreeStack.empty()) {
                StackEntry & se = mTreeStack.back();
                //Try to get the next child entity (unless we've reached the end of the list of children).
                //Since some entities are references but not persisted we need to loop until we find one that we know of.
                for (; ++se.currentChildIterator, se.currentChildIterator != se.obj->getContains().end();) {
                    if (getEntity(*se.currentChildIterator, res)) {
                        //We've sent a request for an entity; we should break out and await a response from the server.
                        return;
                    }
                }

                //If we've reached the end of the contained entities we should pop the current stack entry.
                mTreeStack.pop_back();
            }
        } else {
            //Iterate until we find an entity that's persisted.
            //Note that there might be a reference to an entity in CONTAINS which can't be found
            //in the list of entities; this happens with transient entities.
            for (auto I = current.obj->getContains().begin(); I != current.obj->getContains().end(); ++I) {
                current.currentChildIterator = I;
                bool foundEntity = getEntity(*current.currentChildIterator, res);
                if (foundEntity) {
                    return;
                }
            }
        }
        if (mTreeStack.empty()) {
            sendResolvedEntityReferences();
        }
    }
}

void EntityImporterBase::sendMinds()
{
    if (!mResolvedMindMapping.empty()) {
        S_LOG_INFO("Sending minds.");
        for (auto mind : mResolvedMindMapping) {
            Atlas::Message::MapType message;
            mind.second->addToMessage(message);

            Atlas::Message::Element thoughtsElem = message["thoughts"];
            Atlas::Message::ListType thoughtArgs;

            if (thoughtsElem.isList()) {
                Atlas::Message::ListType thoughtList = thoughtsElem.List();

                for (auto& thought : thoughtList) {
                    //If the thought is a list of things the entity owns, we should adjust it with the new entity ids.
                    if (thought.isMap()) {
                        auto& thoughtMap = thought.Map();
                        if (thoughtMap.count("things") > 0) {
                            auto& thingsElement = thoughtMap.find("things")->second;
                            if (thingsElement.isMap()) {
                                for (auto& thingI : thingsElement.asMap()) {
                                    if (thingI.second.isList()) {
                                        Atlas::Message::ListType newList;
                                        for (auto& thingId : thingI.second.asList()) {
                                            if (thingId.isString()) {
                                                const auto& entityIdLookupI = mEntityIdMap.find(thingId.asString());
                                                //Check if the owned entity has been created with a new id. If so, replace the data.
                                                if (entityIdLookupI != mEntityIdMap.end()) {
                                                    newList.push_back(entityIdLookupI->second);
                                                } else {
                                                    newList.push_back(thingId);
                                                }
                                            } else {
                                                newList.push_back(thingId);
                                            }
                                        }
                                        thingI.second = newList;
                                    }
                                }
                            }
                        }

                        if (thoughtMap.count("pending_things") > 0) {
                            //things that the entity owns, but haven't yet discovered are expressed as a list of entity ids
                            auto& pendingThingsElement = thoughtMap.find("pending_things")->second;
                            if (pendingThingsElement.isList()) {
                                Atlas::Message::ListType newList;
                                for (auto& thingId : pendingThingsElement.asList()) {
                                    if (thingId.isString()) {
                                        const auto& entityIdLookupI = mEntityIdMap.find(thingId.asString());
                                        //Check if the owned entity has been created with a new id. If so, replace the data.
                                        if (entityIdLookupI != mEntityIdMap.end()) {
                                            newList.push_back(entityIdLookupI->second);
                                        } else {
                                            newList.push_back(thingId);
                                        }
                                    } else {
                                        newList.push_back(thingId);
                                    }
                                }
                                pendingThingsElement = newList;
                            }
                        }

                        if (thoughtMap.count("object") > 0) {
                            auto& objectElement = thoughtMap.find("object")->second;
                            if (objectElement.isString()) {
                                std::string& objectString = objectElement.String();
                                //Other entities are referred to using the syntax "'$eid:...'".
                                //For example, the entity with id 2 would be "'$eid:2'".
                                auto pos = objectString.find("$eid:");
                                if (pos != std::string::npos) {
                                    auto quotePos = objectString.find('\'', pos);
                                    if (quotePos != std::string::npos) {
                                        auto id = objectString.substr(pos + 5, quotePos - pos - 5);
                                        auto I = mEntityIdMap.find(id);
                                        if (I != mEntityIdMap.end()) {
                                            objectString.replace(pos + 5, quotePos - 7, I->second);
                                        }
                                    }
                                }
                            }
                        }

                    }
                    thoughtArgs.push_back(thought);
                }
            }

            Atlas::Objects::Operation::RootOperation thinkOp;
            std::list<std::string> parents;
            parents.emplace_back("think");
            thinkOp->setParents(parents);
            thinkOp->setTo(mind.first);
            //By setting it TO an entity and FROM our avatar we'll make the server deliver it as
            //if it came from the entity itself (the server rewrites the FROM to be of the entity).
            thinkOp->setFrom(mAvatarId);
            thinkOp->setSerialno(newSerialNumber());

            Atlas::Objects::Operation::Set setOp;
            setOp->setArgsAsList(thoughtArgs);
            thinkOp->setArgs1(setOp);


            mStats.mindsProcessedCount++;
            S_LOG_VERBOSE("Restoring mind of " << mind.first);
            mThoughtOpsInTransit++;

            sigc::slot<void, const Operation&> slot = sigc::mem_fun(*this, &EntityImporterBase::operationThinkResult);
            sendAndAwaitResponse(thinkOp, slot);
            EventProgress.emit();
        }
        mResolvedMindMapping.clear();
    } else {
        complete();
    }
}

void EntityImporterBase::sendResolvedEntityReferences()
{
    if (!mEntitiesWithReferenceAttributes.empty()) {
        for (auto entryI : mEntitiesWithReferenceAttributes) {
            const auto& persistedEntityId = entryI.first;
            const auto& attributeNames = entryI.second;

            auto createdEntityI = mEntityIdMap.find(persistedEntityId);
            if (createdEntityI == mEntityIdMap.end()) {
                S_LOG_WARNING("Could not find final server side entity id for persisted entity " << persistedEntityId << " when doing entity ref resolving.");
                continue;
            }
            const auto& createdEntityId = createdEntityI->second;

            //This should not fail at this phase, so we're not doing any checks.
            auto& persistedEntity = mPersistedEntities.find(persistedEntityId)->second;

            RootEntity entity;

            for (const auto& attributeName : attributeNames) {
                Element element = persistedEntity->getAttr(attributeName);
                resolveEntityReferences(element);
                entity->setAttr(attributeName, element);
            }

            Set set;
            set->setFrom(mAvatarId);
            set->setSerialno(newSerialNumber());
            set->setTo(createdEntityId);
            set->setArgs1(entity);

            mSetOpsInTransit++;
            sigc::slot<void, const Operation&> slot = sigc::mem_fun(*this, &EntityImporterBase::operationSetResult);
            sendAndAwaitResponse(set, slot);
        }
    } else {
        sendMinds();
    }
}

void EntityImporterBase::resolveEntityReferences(Atlas::Message::Element& element)
{
    if (element.isMap()) {
        auto entityRefI = element.asMap().find("$eid");
        if (entityRefI != element.asMap().end() && entityRefI->second.isString()) {
            auto I = mEntityIdMap.find(entityRefI->second.asString());
            if (I != mEntityIdMap.end()) {
                entityRefI->second = I->second;
            }
        }
        //If it's a map we need to process all child elements too
        for (auto& I : element.asMap()) {
            resolveEntityReferences(I.second);
        }
    } else if (element.isList()) {
        //If it's a list we need to process all child elements too
        for (auto& I : element.asList()) {
            resolveEntityReferences(I);
        }
    }
}


void EntityImporterBase::complete()
{
    S_LOG_INFO("Restore done.");
    S_LOG_INFO("Restored " << mStats.entitiesProcessedCount<< ", created: " << mStats.entitiesCreateCount << ", updated: " << mStats.entitiesUpdateCount << ", create errors: " << mStats.entitiesCreateErrorCount << " .");
    EventCompleted.emit();
}

void EntityImporterBase::createEntity(const RootEntity & obj, OpVector & res)
{
    ++mStats.entitiesProcessedCount;
    ++mStats.entitiesCreateCount;
    EventProgress.emit();

    m_state = ENTITY_CREATING;

    assert(mTreeStack.size() > 1);
    std::deque<StackEntry>::reverse_iterator I = mTreeStack.rbegin();
    ++I;
    assert(I != mTreeStack.rend());
    const std::string & loc = I->restored_id;

    RootEntity create_arg = obj.copy();

    create_arg->removeAttrFlag(Atlas::Objects::Entity::CONTAINS_FLAG);
    create_arg->removeAttrFlag(Atlas::Objects::Entity::VELOCITY_FLAG);
    create_arg->removeAttrFlag(Atlas::Objects::ID_FLAG);
    create_arg->setLoc(loc);

    //Remove any attribute which references another entity from the Create op.
    //This is because the attribute will at this time with certainty refer to the wrong or a non-existing entity.
    //The attribute will later on be set through a Set op in sendResolvedEntityReferences().
    auto referenceMapEntryI = mEntitiesWithReferenceAttributes.find(obj->getId());
    if (referenceMapEntryI != mEntitiesWithReferenceAttributes.end()) {
        for (const auto& attributeName : referenceMapEntryI->second) {
            create_arg->removeAttr(attributeName);
        }
    }

    Create create;
    create->setArgs1(create_arg);
    create->setFrom(mAvatarId);
    create->setSerialno(newSerialNumber());

    mCreateEntityMapping.insert(std::make_pair(create->getSerialno(), obj->getId()));

    res.push_back(create);
}

void EntityImporterBase::createRule(const Atlas::Objects::Root & obj, OpVector & res)
{
    m_state = RULE_CREATING;
    Atlas::Objects::Operation::Create createOp;
    createOp->setFrom(mAccountId);
    createOp->setArgs1(obj);

    createOp->setSerialno(newSerialNumber());
    S_LOG_INFO("Creating new rule '" << obj->getId() << "' on server.");
    res.push_back(createOp);
}

void EntityImporterBase::updateRule(const Root& existingDefinition, const Root& newDefinition, OpVector & res)
{

    m_state = RULE_UPDATING;
    Root updatedDefinition = newDefinition.copy();

    //If the existing definition had any children that aren't part of the import, we should preserve those
    std::list<std::string> existingChildren, newChildren;
    extractChildren(existingDefinition, existingChildren);
    extractChildren(newDefinition, newChildren);

    for (auto& child : newChildren) {
        existingChildren.remove(child);
    }

    for (auto& child : existingChildren) {
        if (mPersistedRules.find(child) == mPersistedRules.end()) {
            newChildren.push_back(child);
        }
    }

    if (!newChildren.empty() && !existingChildren.empty()) {
        Atlas::Message::ListType childrenElement;
        for (auto& child : newChildren) {
            childrenElement.push_back(child);
        }
        updatedDefinition->setAttr("children", childrenElement);
    }

    if (updatedDefinition->asMessage() != existingDefinition->asMessage()) {
        S_LOG_INFO("Updating server rule '"<< updatedDefinition->getId() << "'.");
        Atlas::Objects::Operation::Set setOp;
        setOp->setFrom(mAccountId);
        setOp->setArgs1(updatedDefinition);

        setOp->setSerialno(newSerialNumber());
        res.push_back(setOp);
    } else {
        mStats.rulesProcessedCount++;
        EventProgress.emit();
        S_LOG_VERBOSE("Not updating server rule '"<< updatedDefinition->getId() << "' as nothing is changed.");
        walkRules(res);
    }
}

void EntityImporterBase::errorArrived(const Operation & op, OpVector & res)
{
    std::string errorMessage;
    if (!op->getArgs().empty()) {
        auto arg = op->getArgs().front();
        if (arg->hasAttr("message")) {
            const Atlas::Message::Element messageElem = arg->getAttr("message");
            if (messageElem.isString()) {
                errorMessage = messageElem.asString();
            }
        }
    }

    switch (m_state) {
    case RULE_WALKING:
    {
        //An error here just means that the rule we asked for didn't exist on the server, and we need
        //to create it. This is an expected result.
        auto& current = mRuleStack.back();
        auto definition = current.definition;
        assert(definition.isValid());

        createRule(definition, res);

    }
        break;
    case RULE_CREATING:
    {
        mStats.rulesProcessedCount++;
        mStats.rulesCreateErrorCount++;
        //An error here means that something went wrong when trying to create a rule. This is wrong.
        //It probably means that there's something wrong with the data we're sending.
        auto& current = mRuleStack.back();

        std::string ruleId = current.definition->getId();
        S_LOG_FAILURE("Could not create rule with id '" << ruleId << "', continuing with next. Server message: " << errorMessage);
        EventProgress.emit();
        walkRules(res);
    }
        break;
    case RULE_UPDATING:
    {
        mStats.rulesProcessedCount++;
        //An error here means that something went wrong when trying to update a rule. This is wrong.
        //It probably means that there's something wrong with the data we're sending.
        auto& current = mRuleStack.back();

        std::string ruleId = current.definition->getId();
        S_LOG_FAILURE("Could not update rule with id '" << ruleId << "', continuing with next. Server message: " << errorMessage);
        mStats.rulesCreateErrorCount++;
        EventProgress.emit();
        walkRules(res);
    }
        break;
    case ENTITY_WALKING:
    {
        //An error here just means that the entity we asked for didn't exist on the server, and we need
        //to create it. This is an expected result.
        assert(!mTreeStack.empty());
        StackEntry & current = mTreeStack.back();
        const RootEntity& obj = current.obj;

        assert(obj.isValid());

        createEntity(obj, res);
    }
        break;
    case ENTITY_CREATING:
    {
        //An error here means that something went wrong when trying to create an entity. This is wrong.
        //It probably means that there's something wrong with the data we're sending. Either the
        //persisted data is corrupt, or there have been changes on the server (for example entity types
        //renamed or removed).
        std::string entityType = "unknown";

        auto I = mCreateEntityMapping.find(op->getRefno());
        if (I != mCreateEntityMapping.end()) {
            auto J = mPersistedEntities.find(I->second);
            if (J != mPersistedEntities.end()) {
                auto& entity = J->second;
                if (!entity->getParents().empty()) {
                    entityType = entity->getParents().front();
                }
            }
        }
        S_LOG_FAILURE("Could not create entity of type '" << entityType << "', continuing with next. Server message: " << errorMessage);
        mStats.entitiesCreateErrorCount++;
        EventProgress.emit();
        walkEntities(res);
    }
        break;
    default:
        S_LOG_FAILURE("Unexpected state in state machine. Server message: " << errorMessage);
        break;
    };
}

void EntityImporterBase::infoArrived(const Operation & op, OpVector & res)
{
    if (op->isDefaultRefno()) {
        return;
    }
    if (op->isDefaultArgs() || op->getArgs().empty()) {
        S_LOG_FAILURE("Info with no arg.");
        return;
    }
    const Root & arg = op->getArgs().front();

    if (m_state == RULE_WALKING) {
        auto& current = mRuleStack.back();
        if (arg->getId() != current.definition->getId()) {
            S_LOG_WARNING("Got info on rule " << arg->getId() << " when expecting " << current.definition->getId() << ".");
            return;
        }

        updateRule(arg, current.definition, res);

    } else if (m_state == RULE_CREATING) {
        mStats.rulesProcessedCount++;
        mStats.rulesCreateCount++;
        EventProgress.emit();
        walkRules(res);
    } else if (m_state == RULE_UPDATING) {
        mStats.rulesProcessedCount++;
        mStats.rulesUpdateCount++;
        EventProgress.emit();
        walkRules(res);
    } else if (m_state == ENTITY_CREATING) {
        if (!op.isValid()) {
            return;
        }
        mNewIds.insert(arg->getId());
        StackEntry & current = mTreeStack.back();
        current.restored_id = arg->getId();
        S_LOG_VERBOSE("Created: " << arg->getParents().front() << "(" << arg->getId() << ")");

        auto I = mCreateEntityMapping.find(op->getRefno());
        if (I != mCreateEntityMapping.end()) {
            //Check if there's a mind that we should send further on
            auto mindI = mPersistedMinds.find(I->second);
            if (mindI != mPersistedMinds.end()) {
                mResolvedMindMapping.emplace_back(arg->getId(), mindI->second);
            }
            mEntityIdMap.insert(std::make_pair(I->second, arg->getId()));
            mCreateEntityMapping.erase(op->getRefno());
        } else {
            S_LOG_WARNING("Got info about create for an entity which we didn't seem to have sent.");
        }

        walkEntities(res);
    } else if (m_state == ENTITY_WALKING) {
        const RootEntity& ent = smart_dynamic_cast<RootEntity>(arg);
        if (!ent.isValid()) {
            S_LOG_FAILURE("Info response is not entity.");
            return;
        }
        if (arg->isDefaultId()) {
            S_LOG_FAILURE("Corrupted info response: no id.");
        }
        const std::string & id = arg->getId();

        StackEntry & current = mTreeStack.back();
        const RootEntity& obj = current.obj;

        assert(id == obj->getId());

        if (mNewIds.find(id) != mNewIds.end() || (mTreeStack.size() != 1 && ent->isDefaultLoc()) || ent->getParents().front() != obj->getParents().front()) {
            createEntity(obj, res);
        } else {

            Root update = obj.copy();

            current.restored_id = id;

            S_LOG_VERBOSE("Updating: " << obj->getId() << " ," << obj->getParents().front());

            update->removeAttrFlag(Atlas::Objects::Entity::CONTAINS_FLAG);
            update->removeAttrFlag(Atlas::Objects::STAMP_FLAG);

            Set set;
            set->setArgs1(update);
            set->setFrom(mAvatarId);
            set->setTo(id);
            set->setSerialno(newSerialNumber());

            res.push_back(set);

            //Check if there's a mind, and if so put it in our map of resolved entity-to-mind mappings (since we know the entity id)
            auto mindI = mPersistedMinds.find(obj->getId());
            if (mindI != mPersistedMinds.end()) {
                mResolvedMindMapping.emplace_back(obj->getId(), mindI->second);
            }

            ++mStats.entitiesProcessedCount;
            ++mStats.entitiesUpdateCount;
            EventProgress.emit();

            m_state = ENTITY_UPDATING;
        }
    }
}

void EntityImporterBase::sightArrived(const Operation & op, OpVector & res)
{
    if (op->isDefaultArgs() || op->getArgs().empty()) {
        S_LOG_FAILURE("No arg");
        return;
    }
    const Root & arg = op->getArgs().front();
    switch (m_state) {
    case ENTITY_WALKSTART:
        if (op->isDefaultRefno()) {
            break;
        }
        if (arg->isDefaultId()) {
            S_LOG_WARNING("Corrupted top level entity: no id");
            cancel();
            return;
        } else {
            getEntity(arg->getId(), res);
        }


        // Expecting sight of world root
        break;
    case ENTITY_UPDATING:
    {
        const Operation& sub_op = smart_dynamic_cast<Operation>(arg);
        if (!sub_op.isValid()) {
            break;
        }
        if (sub_op->getClassNo() != Atlas::Objects::Operation::SET_NO || sub_op->getArgs().empty() || sub_op->isDefaultSerialno()) {
            S_LOG_FAILURE("This is not our entity update response.");
            break;
        }
        walkEntities(res);
    }
        break;
    default:
        S_LOG_WARNING("Unexpected state in state machine.");
        break;
    };
}

EntityImporterBase::EntityImporterBase(const std::string& accountId, const std::string& avatarId) :
        mAccountId(accountId), mAvatarId(avatarId), mStats( { }), m_state(INIT), mThoughtOpsInTransit(0), mSetOpsInTransit(0), mResumeWorld(0)
{
}

EntityImporterBase::~EntityImporterBase()
{
}

void EntityImporterBase::start(const std::string& filename)
{
    auto factories = Atlas::Objects::Factories::instance();

    auto rootObj = loadFromFile(filename);

    if (!rootObj.isValid()) {
        EventCompleted.emit();
        return;
    }
    Atlas::Message::Element metaElem;
    Atlas::Message::Element entitiesElem;
    Atlas::Message::Element mindsElem;
    Atlas::Message::Element rulesElem;
    rootObj->copyAttr("meta", metaElem);
    rootObj->copyAttr("entities", entitiesElem);
    rootObj->copyAttr("minds", mindsElem);
    if (rootObj->copyAttr("rules", rulesElem) == 0) {
        if (!rulesElem.isList()) {
            S_LOG_WARNING("Rules element is not list.");
            EventCompleted.emit();
            return;
        } else {
            for (auto& ruleMessage : rulesElem.asList()) {
                if (ruleMessage.isMap()) {
                    auto object = factories->createObject(ruleMessage.asMap());
                    if (object.isValid()) {
                        if (!object->isDefaultId()) {
                            mPersistedRules.insert(std::make_pair(object->getId(), object));
                        }
                    }
                }
            }

        }
    }

    if (!entitiesElem.isList()) {
        S_LOG_WARNING("Entities element is not list.");
        EventCompleted.emit();
        return;
    }
    if (!mindsElem.isList()) {
        S_LOG_WARNING("Minds element is not list.");
        EventCompleted.emit();
        return;
    }

    for (auto& entityMessage : entitiesElem.asList()) {
        if (entityMessage.isMap()) {
            auto& entityMap = entityMessage.asMap();
            auto object = factories->createObject(entityMap);
            if (object.isValid()) {
                if (!object->isDefaultId()) {
                    registerEntityReferences(object->getId(), entityMap);
                    mPersistedEntities.insert(std::make_pair(object->getId(), object));
                }
            }
        }
    }
    //If we should resume the world, check if the world has a "suspended" property,
    //and disable it if so.
    if (mResumeWorld) {
        auto I = mPersistedEntities.find("0");
        if (I != mPersistedEntities.end()) {
            if (I->second->hasAttr("suspended")) {
                I->second->setAttr("suspended", 0);
                S_LOG_INFO("Resuming suspended world.");
            }
        }
    }
    for (auto& mindMessage : mindsElem.asList()) {
        if (mindMessage.isMap()) {
            auto object = factories->createObject(mindMessage.asMap());
            if (object.isValid()) {
                if (!object->isDefaultId()) {
                    mPersistedMinds.insert(std::make_pair(object->getId(), object));
                }
            }
        }
    }

    S_LOG_INFO("Starting loading of world. Number of entities: " << mPersistedEntities.size() << " Number of minds: " << mPersistedMinds.size() << " Number of rules: " << mPersistedRules.size());
    mStats.entitiesCount = static_cast<unsigned int>(mPersistedEntities.size());
    mStats.mindsCount = static_cast<unsigned int>(mPersistedMinds.size());
    mStats.rulesCount = static_cast<unsigned int>(mPersistedRules.size());

    EventProgress.emit();

    if (mPersistedRules.empty()) {
        startEntityWalking();
    } else {
        startRuleWalking();
    }

}

void EntityImporterBase::registerEntityReferences(const std::string& id, const Atlas::Message::MapType& element)
{
    for (auto I : element) {
        const auto& name = I.first;
        if (name == "id" || name == "parents" || name == "contains") {
            continue;
        }
        if (hasEntityReference(I.second)) {
            mEntitiesWithReferenceAttributes[id].push_back(name);
        }
    }
}

bool EntityImporterBase::hasEntityReference(const Element& element)
{
    if (element.isMap()) {
        auto entityRefI = element.asMap().find("$eid");
        if (entityRefI != element.asMap().end() && entityRefI->second.isString()) {
            return true;
        }
        //If it's a map we need to process all child elements too
        for (auto& I : element.asMap()) {
            return hasEntityReference(I.second);
        }
    } else if (element.isList()) {
        //If it's a list we need to process all child elements too
        for (auto& I : element.asList()) {
            return hasEntityReference(I);
        }
    }
    return false;
}



void EntityImporterBase::startEntityWalking()
{
    m_state = ENTITY_WALKSTART;
    Look l;

    l->setFrom(mAvatarId);
    l->setSerialno(newSerialNumber());

    sendOperation(l);

}

void EntityImporterBase::startRuleWalking()
{
    auto ruleI = mPersistedRules.find("root");
    if (ruleI == mPersistedRules.end()) {
        S_LOG_WARNING("Rules exist, but there's no root rule.");
        startEntityWalking();
    }
    m_state = RULE_WALKING;

    OpVector res;
    getRule("root", res);
    for (auto op : res) {
        sendOperation(op);
    }
}

void EntityImporterBase::sendOperation(const Operation& op)
{
    if (!op->isDefaultSerialno()) {
        sigc::slot<void, const Operation&> slot = sigc::mem_fun(*this, &EntityImporterBase::operation);
        sendAndAwaitResponse(op, slot);
    } else {
        send(op);
    }
}

void EntityImporterBase::cancel()
{
    m_state = CANCEL;
}

const EntityImporterBase::Stats& EntityImporterBase::getStats() const
{
    return mStats;
}

void EntityImporterBase::setResume(bool enabled)
{
    mResumeWorld = enabled;
}

void EntityImporterBase::operationThinkResult(const Operation & op)
{
    mThoughtOpsInTransit--;
    if (mThoughtOpsInTransit == 0) {
        complete();
    }
}

void EntityImporterBase::operationSetResult(const Operation & op)
{
    mSetOpsInTransit--;
    if (mSetOpsInTransit == 0) {
        sendMinds();
    }
}

void EntityImporterBase::operation(const Operation & op)
{
    if (m_state == CANCEL) {
        m_state = CANCELLED;
        return;
    }
    if (m_state == CANCELLED) {
        return;
    }
    OpVector res;
    if (op->getClassNo() == Atlas::Objects::Operation::INFO_NO) {
        infoArrived(op, res);
    } else if (op->getClassNo() == Atlas::Objects::Operation::ERROR_NO) {
        errorArrived(op, res);
    } else if (op->getClassNo() == Atlas::Objects::Operation::SIGHT_NO) {
        sightArrived(op, res);
    }

    for (auto& op : res) {
        sendOperation(op);
    }

}