#include "syncmanager.h"


Q_LOGGING_CATEGORY(syncmanager, "sync.manager");


SyncManager::SyncManager(bool dryMode)
    :mDryMode(dryMode)
{

}

bool SyncManager::databaseInitialization()
{
    database = std::make_shared<DatabaseAPI>(&dbMan, mDryMode);
//    connect(database.get(), &DatabaseAPI::error, [=](){
//        QCoreApplication::exit(1);
//    });

    // Open database
    if (!database->open()) {
        qCritical(syncmanager) << "Not possible to open database:" << dbMan.database().hostName();
        return false;
    }

    // Get last synchronizaiton date
    qint64 lastsync_in_ms = database->getLastSync();
    if (lastsync_in_ms == -1) {
        qCritical(syncmanager) << "Not possible to get last synchronization date";
        return false;
    }

    // here -> nothing can fail
    mlastSync.set_timestamp(database->getLastSync());
    colnod = std::make_shared<ColnodAPI>(&reqMan, mlastSync.timestamp(), mDryMode);
    return true;
}


bool SyncManager::startSynchronization()
{
    // I have to current time from database
    qint64 syncBegin = database->getNow();
    if (syncBegin == -1) {
        qCritical(syncmanager) << "Not possible to get last sync date";
        return false;
    }

    qInfo(syncmanager) << equals;
    qInfo(syncmanager) << "SYNCHRONIZATION BEGIN";

    // TODO: check error
    database->initNewTokens();


    // GETTING DATA FROM DATABASE
    auto databaseData = database->downloadData();
    if (!databaseData) {
        qCritical(syncmanager) << "not possible to get data from database";
        return false;
    }
    // NOW I HAVE DATA FROM DATABASE



    colnod->downloadData();
    connect(colnod.get(), &ColnodAPI::downloadDataFinished, [=](std::shared_ptr<Data> data) {
        // NOW I HAVE DATA FROM COLNOD

        // I can process data
        qDebug(syncmanager) << "I have colnod and database data";
        qDebug(syncmanager) << "updated token count" << data->updatedTokens.count();
    });

    return true;
    //downloadData();

    auto colnodDataFinished = [=](std::shared_ptr<Data> data) {
        qDebug() << "Now I can check that I have all data I need";
    };

    //connect(this, &SyncManager::dataReady, processDownloadedData);


    connect(this, &SyncManager::dataReady, [=](){
        prepareData();

        connect(this, &SyncManager::dataProcessFinished, [=](){

            qInfo(syncmanager) << "PROCESSING DATA -> FINISHED";
            qInfo(syncmanager) << equals;

            updateLastUpdate(syncBegin);
            connect(this, &SyncManager::syncFinished, [=](){
                if (database->isValid() && colnod->isValid()) {
                    database->setLastSync(syncBegin);
                }
                else {
                    qWarning(syncmanager) << "Synchronization was unsuccessful, next run of sync will be with same last sync time, check warnings";
                }

                qInfo(syncmanager).noquote() << "Update last synchronization time to time of this sync ("
                                   <<  QDateTime::fromMSecsSinceEpoch(syncBegin).toString("yyyy-MM-dd hh:mm:ss.zzz")
                                   << ")";
                qInfo(syncmanager) << equals;
                qInfo(syncmanager) << "SYNCHRONIZATION FINISHED";
                qInfo(syncmanager) << equals;

                QCoreApplication::exit();
            });
        });

        processData();
    });
    return true;
}

void SyncManager::downloadData()
{
    qInfo(syncmanager) << equals;
    qInfo(syncmanager) << "DOWNLOADING DATA -> BEGIN";
    qInfo(syncmanager) << dash;
    qInfo(syncmanager).noquote() << "Modified data since last synchronization (" << mlastSync.toDateString() << "):";
    qInfo(syncmanager) << dash;

    connect(colnod.get(), &ColnodAPI::downloadDataFinished, this, &SyncManager::saveColnodData);
    //connect(database.get(), &DatabaseAPI::downloadDataFinished, this, &SyncManager::saveDatabaseData);
    //database->downloadData();
    colnod->downloadData();
}

// finds conflicts -> changes on both sides (colnod and DB), apply newer change
void SyncManager::prepareData()
{
    qInfo(syncmanager) << equals;
    qInfo(syncmanager) << "PREPARING DATA -> BEGIN";
    qInfo(syncmanager) << dash;
    qInfo(syncmanager) << "Resolve conflicts ( changes on same item on both Colnod and DB ):";
    qInfo(syncmanager) << dash;


    Q_ASSERT(colnodData);
    Q_ASSERT(databaseData);


    // TODO: why copy data?
    colnodDataToProcess = std::make_shared<Data>(*colnodData);
    databaseDataToProcess = std::make_shared<Data>(*databaseData);

    QList<QString> conflicts;
    QList<QString> alreadySynced;

    // check modifed tokens from colnod, dont want update token, if it was edited in db after or has been already synced
    for (const auto &colnodToken : colnodDataToProcess->updatedTokens) {
        if (databaseDataToProcess->updatedTokens.contains(colnodToken->id())) {
            // updated in db later
            if (databaseDataToProcess->updatedTokens.value(colnodToken->id()) > colnodToken) {
                conflicts.append(colnodToken->id());
            }
            continue;
        }
        auto token = database->getToken(colnodToken->id());
        if ( token )
            // alredy synced ( tokens are same )
            if (token == colnodToken)
                alreadySynced.append(colnodToken->id());
    }
    // remove tokens which should be not updated
    for (const auto &id : conflicts)
        colnodDataToProcess->updatedTokens.remove(id);
    for (const auto &id : alreadySynced)
        colnodDataToProcess->updatedTokens.remove(id);

    qInfo(syncmanager) << tab << "-> COLNOD DATA - CHANGES:";
    qInfo(syncmanager) << tab << tab << conflicts.size() << "TOKENS WERE ADDED/UPDATED IN DATABASE TOO";
    qInfo(syncmanager) << tab << tab << alreadySynced.size() << "TOKENS WERE ALREADY SYNCED";



    conflicts.clear();

    // chech for already deleted ( in previous synced tokens were deleted from colnod, so it come to this sync but we dont want to sync it again
    for (const auto &id : colnodDataToProcess->deletedTokens) {
        if (database->isAlreadyDeleted(id)) {
            conflicts.append(id);
        }
    }
    for (const auto &id : conflicts) {
        colnodDataToProcess->deletedTokens.removeOne(id);
    }

    qInfo(syncmanager) << tab << tab << conflicts.size() << "TOKENS WERE ALREADY DELETED";
    qInfo(syncmanager) << dash;

    conflicts.clear();

    // chech modified from db, remove token if it was edited in colnod later
    for (const auto &databaseToken : databaseDataToProcess->updatedTokens) {
        if (colnodDataToProcess->updatedTokens.contains(databaseToken->id())) {
            if (databaseToken < colnodDataToProcess->updatedTokens.value(databaseToken->id()))
                conflicts.append(databaseToken->id());
        }
        else {
            // restriction cauesed by colnod rest api
            if (databaseToken->description() != "mobile") {
                qCritical(syncmanager) << "Token:" << databaseToken->id() << "doesn't have 'mobile' in description, can't be ";
                conflicts.append(databaseToken->id());
            }
        }
    }
    for (const auto &id : conflicts)
        colnodDataToProcess->updatedTokens.remove(id);

    qInfo(syncmanager) << tab << "-> DATABASE DATA - CHANGES:";
    qInfo(syncmanager) << tab << tab << conflicts.size() << "TOKENS WERE ADDED/UPDATED IN IN COLNOD TOO";
    qInfo(syncmanager) << dash;

    qInfo(syncmanager) << "PREPARING DATA -> FINISHED";
    qInfo(syncmanager) << equals;
}

void SyncManager::processData()
{
    qInfo(syncmanager) << equals;
    qInfo(syncmanager) << "PROCESSING DATA -> BEGIN";
    qInfo(syncmanager) << dash;
    qInfo(syncmanager) << "Push changes to both Colnod and Database:";
    qInfo(syncmanager) << dash;

    database->processData(colnodDataToProcess);
    connect(colnod.get(), &ColnodAPI::dataProcessFinished, this, &SyncManager::dataProcessFinished);
    colnod->processData(databaseDataToProcess);
}

void SyncManager::updateLastUpdate(qint64 syncBegin)
{
    Timestamp time;
    time.set_timestamp(syncBegin);
    colnod->getTokensUpdated(time);
    database->setLastUpdate(databaseDataToProcess->deletedTokens);
    connect(colnod.get(), &ColnodAPI::partOfDataReady, [=](const std::shared_ptr<Data> &data){
        database->setLastUpdate(data->updatedTokens);
        emit syncFinished();
    });
}

void SyncManager::areDataReady()
{
    if (++dataAmount == 1) {

        qInfo(syncmanager) << "DOWNLOADING DATA -> FINISHED";
        qInfo(syncmanager) << equals;

        emit dataReady();
    }
}

void SyncManager::saveColnodData(const std::shared_ptr<Data> &data)
{
    colnodData = data;
    areDataReady();
}

void SyncManager::saveDatabaseData(const std::shared_ptr<Data> &data)
{
    databaseData = data;
    areDataReady();
}