#include "queryexecutor.h"
#include "db/queryexecutorsteps/queryexecutorfilter.h"
#include "sqlerrorcodes.h"
#include "services/dbmanager.h"
#include "db/sqlerrorcodes.h"
#include "db/dbsqlite3.h"
#include "services/notifymanager.h"
#include "queryexecutorsteps/queryexecutoraddrowids.h"
#include "queryexecutorsteps/queryexecutorcolumns.h"
#include "queryexecutorsteps/queryexecutorparsequery.h"
#include "queryexecutorsteps/queryexecutorattaches.h"
#include "queryexecutorsteps/queryexecutorcountresults.h"
#include "queryexecutorsteps/queryexecutorexecute.h"
#include "queryexecutorsteps/queryexecutorlimit.h"
#include "queryexecutorsteps/queryexecutororder.h"
#include "queryexecutorsteps/queryexecutorwrapdistinctresults.h"
#include "queryexecutorsteps/queryexecutordatasources.h"
#include "queryexecutorsteps/queryexecutorexplainmode.h"
#include "queryexecutorsteps/queryexecutorreplaceviews.h"
#include "queryexecutorsteps/queryexecutordetectschemaalter.h"
#include "queryexecutorsteps/queryexecutorvaluesmode.h"
#include "queryexecutorsteps/queryexecutorcolumntype.h"
#include "db/queryexecutorsteps/queryexecutorsmarthints.h"
#include "common/unused.h"
#include "chainexecutor.h"
#include "log.h"
#include "schemaresolver.h"
#include "parser/lexer.h"
#include "common/table.h"
#include <QMutexLocker>
#include <QDateTime>
#include <QThreadPool>
#include <QDebug>
#include <QtMath>
#include <dbattacher.h>

// TODO modify all executor steps to use rebuildTokensFromContents() method, instead of replacing tokens manually.

QHash<QueryExecutor::StepPosition, QList<QueryExecutorStep*>> QueryExecutor::additionalStatelessSteps;
QList<QueryExecutorStep*> QueryExecutor::allAdditionalStatelsssSteps;
QHash<QueryExecutor::StepPosition, QList<QueryExecutor::StepFactory*>> QueryExecutor::additionalStatefulStepFactories;

QueryExecutor::QueryExecutor(Db* db, const QString& query, QObject *parent) :
    QObject(parent)
{
    context = new Context();
    simpleExecutor = new ChainExecutor(this);
    simpleExecutor->setTransaction(false);
    originalQuery = query;
    setDb(db);
    setAutoDelete(false);

    connect(this, SIGNAL(executionFailed(int,QString)), this, SLOT(cleanupAfterExecFailed(int,QString)));
    connect(DBLIST, SIGNAL(dbAboutToBeUnloaded(Db*,DbPlugin*)), this, SLOT(cleanupBeforeDbDestroy(Db*)));
    connect(DBLIST, SIGNAL(dbRemoved(Db*)), this, SLOT(cleanupBeforeDbDestroy(Db*)));
    connect(simpleExecutor, &ChainExecutor::finished, this, &QueryExecutor::simpleExecutionFinished, Qt::DirectConnection);
}

QueryExecutor::~QueryExecutor()
{
    safe_delete(context);
    if (countingDb)
    {
        if (countingDb->isOpen())
            countingDb->closeQuiet();

        delete countingDb;
    }
}

void QueryExecutor::setupExecutionChain()
{
    executionChain.append(additionalStatelessSteps[FIRST]);
    executionChain.append(createSteps(FIRST));

    executionChain << new QueryExecutorParseQuery("initial")
                   << new QueryExecutorDetectSchemaAlter()
                   << new QueryExecutorExplainMode()
                   << new QueryExecutorValuesMode()
                   << new QueryExecutorAttaches() // needs to be at the begining, because columns needs to know real databases
                   << new QueryExecutorParseQuery("after Attaches");

    executionChain.append(additionalStatelessSteps[AFTER_ATTACHES]);
    executionChain.append(createSteps(AFTER_ATTACHES));

    executionChain << new QueryExecutorDataSources()
                   << new QueryExecutorReplaceViews()
                   << new QueryExecutorParseQuery("after ReplaceViews");

    executionChain.append(additionalStatelessSteps[AFTER_REPLACED_VIEWS]);
    executionChain.append(createSteps(AFTER_REPLACED_VIEWS));

    executionChain << new QueryExecutorFilter()
                   << new QueryExecutorParseQuery("after Filter");

    executionChain.append(additionalStatelessSteps[AFTER_COLUMN_FILTERS]);
    executionChain.append(createSteps(AFTER_COLUMN_FILTERS));

    executionChain << new QueryExecutorAddRowIds()
                   << new QueryExecutorParseQuery("after AddRowIds");

    executionChain.append(additionalStatelessSteps[AFTER_ROW_IDS]);
    executionChain.append(createSteps(AFTER_ROW_IDS));

    executionChain << new QueryExecutorColumns()
                   << new QueryExecutorParseQuery("after Columns");

    executionChain.append(additionalStatelessSteps[AFTER_REPLACED_COLUMNS]);
    executionChain.append(createSteps(AFTER_REPLACED_COLUMNS));

    executionChain << new QueryExecutorOrder();

    executionChain.append(additionalStatelessSteps[AFTER_ORDER]);
    executionChain.append(createSteps(AFTER_ORDER));

    executionChain << new QueryExecutorWrapDistinctResults()
                   << new QueryExecutorParseQuery("after WrapDistinctResults");

    executionChain.append(additionalStatelessSteps[AFTER_DISTINCT_WRAP]);
    executionChain.append(createSteps(AFTER_DISTINCT_WRAP));

    executionChain << new QueryExecutorCountResults()
                   << new QueryExecutorColumnType()
                   << new QueryExecutorParseQuery("after ColumnType");

    executionChain.append(additionalStatelessSteps[AFTER_COLUMN_TYPES]);
    executionChain.append(createSteps(AFTER_COLUMN_TYPES));

    executionChain << new QueryExecutorLimit()
                   << new QueryExecutorParseQuery("after Limit");

    executionChain.append(additionalStatelessSteps[AFTER_ROW_LIMIT_AND_OFFSET]);
    executionChain.append(createSteps(AFTER_ROW_LIMIT_AND_OFFSET));
    executionChain.append(additionalStatelessSteps[JUST_BEFORE_EXECUTION]);
    executionChain.append(createSteps(JUST_BEFORE_EXECUTION));
    executionChain.append(additionalStatelessSteps[LAST]);
    executionChain.append(createSteps(LAST));

    executionChain << new QueryExecutorExecute();
    executionChain << new QueryExecutorSmartHints(); // must be last, as it queries schema and execution might modify schema

    for (QueryExecutorStep*& step : executionChain)
        step->init(this, context);
}

void QueryExecutor::clearChain()
{
    for (QueryExecutorStep*& step : executionChain)
    {
        if (!allAdditionalStatelsssSteps.contains(step))
            delete step;
    }

    executionChain.clear();
}

void QueryExecutor::executeChain()
{
    // Go through all remaining steps
    bool result;
    for (QueryExecutorStep*& currentStep : executionChain)
    {
        if (isInterrupted())
        {
            stepFailed(currentStep);
            return;
        }

        logExecutorStep(currentStep);
        result = currentStep->exec();
        logExecutorAfterStep(context->processedQuery);

        if (!result)
        {
            stepFailed(currentStep);
            return;
        }
    }

    requiredDbAttaches = context->dbNameToAttach.leftValues();

    // We're done.
    clearChain();

    executionMutex.lock();
    executionInProgress = false;
    executionMutex.unlock();

    emit executionFinished(context->executionResults);
}

void QueryExecutor::stepFailed(QueryExecutorStep* currentStep)
{
    qDebug() << "Smart execution failed at step" << currentStep->metaObject()->className() << currentStep->objectName()
             << "\nUsing simple execution method.";

    clearChain();

    if (isInterrupted())
    {
        executionMutex.lock();
        executionInProgress = false;
        executionMutex.unlock();
        emit executionFailed(SqlErrorCode::INTERRUPTED, tr("Execution interrupted."));
        return;
    }

    // Clear anything meaningful set up for smart execution - it's not valid anymore and misleads results for simple method
    context->rowIdColumns.clear();

    executeSimpleMethod();
}

void QueryExecutor::cleanupAfterExecFailed(int code, QString errorMessage)
{
    UNUSED(code);
    UNUSED(errorMessage);
    cleanup();
}

void QueryExecutor::cleanupBeforeDbDestroy(Db* dbToBeUnloaded)
{
    if (!dbToBeUnloaded || dbToBeUnloaded != db)
        return;

    setDb(nullptr);
    context->executionResults.clear();
}

void QueryExecutor::setQuery(const QString& query)
{
    originalQuery = query;
}

void QueryExecutor::exec(Db::QueryResultsHandler resultsHandler)
{
    if (!db)
    {
        qWarning() << "Database is not set in QueryExecutor::exec().";
        return;
    }

    if (!db->isOpen())
    {
        error(SqlErrorCode::DB_NOT_OPEN, tr("Database is not open."));
        return;
    }

    // Get exclusive flow for execution on this query executor
    executionMutex.lock();
    if (executionInProgress)
    {
        error(SqlErrorCode::QUERY_EXECUTOR_ERROR, tr("Only one query can be executed simultaneously."));
        executionMutex.unlock();
        return;
    }
    executionInProgress = true;
    executionMutex.unlock();

    if (countingDb && countingDb->isOpen())
        countingDb->interrupt();

    this->resultsHandler = resultsHandler;

    if (asyncMode)
        QThreadPool::globalInstance()->start(this);
    else
        run();
}

void QueryExecutor::run()
{
    execInternal();
}

void QueryExecutor::execInternal()
{
    queriesForSimpleExecution.clear();
    if (forceSimpleMode)
    {
        executeSimpleMethod();
        return;
    }

    if (queryCountLimitForSmartMode > -1)
    {
        queriesForSimpleExecution = splitQueries(originalQuery, false, true);
        int queryCount = queriesForSimpleExecution.size();
        if (queryCount > queryCountLimitForSmartMode)
        {
            qDebug() << "Number of queries" << queryCount << "exceeds maximum number allowed for smart execution method" <<
                        queryCountLimitForSmartMode << ". Simple method will be used to retain efficiency.";
            executeSimpleMethod();
            return;
        }
    }

    simpleExecution = false;
    interrupted = false;

    // Reset context
    delete context;
    context = new Context();
    context->processedQuery = originalQuery;
    context->explainMode = explainMode;
    context->skipRowCounting = skipRowCounting;
    context->noMetaColumns = noMetaColumns;
    context->resultsHandler = resultsHandler;
    context->preloadResults = preloadResults;
    context->queryParameters = queryParameters;

    // Start the execution
    setupExecutionChain();
    executeChain();
}

void QueryExecutor::interrupt()
{
    if (!db)
    {
        qWarning() << "Called interrupt() on empty db in QueryExecutor.";
        return;
    }

    QMutexLocker lock(&interruptionMutex);
    interrupted = true;
    db->asyncInterrupt();
}

bool QueryExecutor::countResults()
{
    if (context->skipRowCounting)
        return false;

    if (context->countingQuery.isEmpty()) // simple method doesn't provide that
        return false;

    if (!countingDb)
        return false; // no db defined, so no countingDb defined

    if (!countingDb->isOpen() && !countingDb->openQuiet())
    {
        notifyError(tr("An error occured while executing the count(*) query, thus data paging will be disabled. Error details from the database: %1")
                    .arg("Failed to establish dedicated connection for results counting."));
        return false;
    }

    // Apply all transparent attaches to the counting DB
    auto it = context->dbNameToAttach.iterator();
    while (it.hasNext())
    {
        auto entry = it.next();
        Db* dbToAttach = DBLIST->getByName(entry.key());
        SqlQueryPtr attachRes = countingDb->exec(QString("ATTACH '%1' AS %2").arg(dbToAttach->getPath(), entry.value()));
        if (attachRes->isError())
        {
            notifyError(tr("An error occured while executing the count(*) query, thus data paging will be disabled. Error details from the database: %1")
                        .arg("Failed to attach necessary databases for counting."));

            qDebug() << "Error while attaching db for counting:" << attachRes->getErrorText();
            countingDb->detachAll();
            return false;
        }
    }

    if (asyncMode)
    {
        // Start asynchronous results counting query
        countingDb->asyncExec(context->countingQuery, context->queryParameters, [=](SqlQueryPtr results)
        {
            handleRowCountingResults(results);
        }, Db::Flag::PRELOAD);
    }
    else
    {
        SqlQueryPtr results = countingDb->exec(context->countingQuery, context->queryParameters, Db::Flag::PRELOAD);
        handleRowCountingResults(results);
    }
    return true;
}

qint64 QueryExecutor::getLastExecutionTime() const
{
    return context->executionTime;
}

qint64 QueryExecutor::getRowsAffected() const
{
    return context->rowsAffected;
}

qint64 QueryExecutor::getTotalRowsReturned() const
{
    return context->totalRowsReturned;
}

SqliteQueryType QueryExecutor::getExecutedQueryType(int index)
{
    if (context->parsedQueries.size() == 0)
        return SqliteQueryType::UNDEFINED;

    if (index < 0)
        return context->parsedQueries.last()->queryType;

    if (index < context->parsedQueries.size())
        return context->parsedQueries[index]->queryType;

    return SqliteQueryType::UNDEFINED;
}

QSet<QueryExecutor::SourceTablePtr> QueryExecutor::getSourceTables() const
{
    return context->sourceTables;
}

int QueryExecutor::getTotalPages() const
{
    return context->totalPages;
}

QList<QueryExecutor::ResultColumnPtr> QueryExecutor::getResultColumns() const
{
    return context->resultColumns;
}

QHash<QString, QString> QueryExecutor::getTypeColumns() const
{
    return context->typeColumnToResultColumnAlias;
}

QList<QueryExecutor::ResultRowIdColumnPtr> QueryExecutor::getRowIdResultColumns() const
{
    return context->rowIdColumns;
}

int QueryExecutor::getMetaColumnCount() const
{
    int count = 0;
    for (ResultRowIdColumnPtr& rowIdCol : context->rowIdColumns)
        count += rowIdCol->queryExecutorAliasToColumn.size();

    return count;
}

QSet<QueryExecutor::EditionForbiddenReason> QueryExecutor::getEditionForbiddenGlobalReasons() const
{
    return context->editionForbiddenReasons;
}

void QueryExecutor::setParam(const QString& name, const QVariant& value)
{
    queryParameters[name] = value;
}

void QueryExecutor::setParams(const QHash<QString, QVariant>& params)
{
    queryParameters = params;
}

void QueryExecutor::exec(const QString& query)
{
    setQuery(query);
    exec();
}

void QueryExecutor::executeSimpleMethod()
{
    simpleExecution = true;
    context->editionForbiddenReasons << EditionForbiddenReason::SMART_EXECUTION_FAILED;
    if (queriesForSimpleExecution.isEmpty())
        queriesForSimpleExecution = splitQueries(originalQuery, false, true);

    QStringList queriesWithPagination = applyFiltersAndLimitAndOrderForSimpleMethod(queriesForSimpleExecution);
    if (isExecutorLoggingEnabled())
        qDebug() << "Simple Execution Method query:" << queriesWithPagination.join("; ");

    simpleExecutor->setQueries(queriesWithPagination);
    simpleExecutor->setDb(db);
    simpleExecutor->setAsync(false); // this is already in a thread

    simpleExecutionStartTime = QDateTime::currentMSecsSinceEpoch();
    simpleExecutor->exec();
}

void QueryExecutor::simpleExecutionFinished(SqlQueryPtr results)
{
    if (results.isNull() || results->isError() || !simpleExecutor->getSuccessfulExecution())
    {
        executionMutex.lock();
        executionInProgress = false;
        executionMutex.unlock();
        handleErrorsFromSmartAndSimpleMethods(results);
        return;
    }
    context->executionTime = QDateTime::currentMSecsSinceEpoch() - simpleExecutionStartTime;

    if (simpleExecIsSelect())
        context->countingQuery = "SELECT count(*) AS cnt FROM ("+trimQueryEnd(queriesForSimpleExecution.last())+");";
    else
        context->rowsCountingRequired = true;

    ResultColumnPtr resCol;
    context->resultColumns.clear();
    for (QString& colName : results->getColumnNames())
    {
        resCol = ResultColumnPtr::create();
        resCol->displayName = colName;
        context->resultColumns << resCol;
    }

    context->rowsAffected = results->rowsAffected();
    context->totalRowsReturned = 0;
    context->executionResults = results;
    requiredDbAttaches = context->dbNameToAttach.leftValues();

    executionMutex.lock();
    executionInProgress = false;
    executionMutex.unlock();
    if (context->resultsHandler)
    {
        context->resultsHandler(results);
        context->resultsHandler = nullptr;
    }

    if (!forceSimpleMode && queriesForSimpleExecution.size() <= queryCountLimitForSmartMode)
        notifyWarn(tr("SQLiteStudio was unable to extract metadata from the query. Results won't be editable."));

    emit executionFinished(results);
}

bool QueryExecutor::simpleExecIsSelect()
{
    TokenList tokens = Lexer::tokenize(queriesForSimpleExecution.last());
    tokens.trim();

    // First check if it's explicit "SELECT" or "VALUES" (the latter one added in SQLite 3.8.4).
    TokenPtr firstToken = tokens.first();
    QString upper = firstToken->value.toUpper();
    if (firstToken->type == Token::KEYWORD && (upper == "SELECT" || upper == "VALUES"))
        return true;

    // Now it's only possible to be a SELECT if it starts with "WITH" statement.
    if (firstToken->type != Token::KEYWORD || upper != "WITH")
        return false;

    // Go through all tokens and find which one appears first (exclude contents indise parenthesis,
    // cause there will always be a SELECT for Common Table Expression).
    int depth = 0;
    for (const TokenPtr& token : tokens)
    {
        switch (token->type)
        {
            case Token::PAR_LEFT:
                depth--;
                break;
            case Token::PAR_RIGHT:
                depth++;
                break;
            case Token::KEYWORD:
            {
                if (depth > 0)
                    break;

                upper = token->value.toUpper();
                if (upper == "SELECT")
                    return true;

                if (upper == "UPDATE" || upper == "DELETE" || upper == "INSERT")
                    return false;

                break;
            }
            default:
                break;
        }
    }
    return false;
}

void QueryExecutor::cleanup()
{
    Db* attDb = nullptr;
    for (QString& attDbName : context->dbNameToAttach.leftValues())
    {
        attDb = DBLIST->getByName(attDbName, Qt::CaseInsensitive);
        if (attDbName.isNull())
        {
            qWarning() << "Could not find db by name for cleanup after execution in QueryExecutor. Searched for db named:" << attDbName;
            continue;
        }
        db->detach(attDb);
    }
}

bool QueryExecutor::handleRowCountingResults(SqlQueryPtr results)
{
    if (isExecutionInProgress()) // shouldn't be true, but just in case
        return false;

    context->totalRowsReturned = results->getSingleCell().toLongLong();
    context->totalPages = (int)qCeil(((double)(context->totalRowsReturned)) / ((double)getResultsPerPage()));

    emit resultsCountingFinished(context->rowsAffected, context->totalRowsReturned, context->totalPages);

    if (results->isError() && results->getErrorCode() != Sqlite3::INTERRUPT)
    {
        notifyError(tr("An error occured while executing the count(*) query, thus data paging will be disabled. Error details from the database: %1")
                    .arg(results->getErrorText()));
    }

    countingDb->detachAll();
    return true;
}

QStringList QueryExecutor::applyFiltersAndLimitAndOrderForSimpleMethod(const QStringList &queries)
{
    static_qstring(filtersTpl, "SELECT * FROM (%1) WHERE %2");
    static_qstring(tpl, "SELECT * FROM (%1) LIMIT %2 OFFSET %3");
    static_qstring(sortTpl, "SELECT * FROM (%1) ORDER BY %2");
    static_qstring(sortColTpl, "%1 %2");

    if (page < 0 && sortOrder.isEmpty())
        return queries;

    QStringList result = queries;
    QString lastQuery = queries.last();

    bool isSelect = false;
    getQueryAccessMode(lastQuery, &isSelect);

    // FILTERS
    QString filters = getFilters();
    if (isSelect && !filters.isEmpty())
    {
        lastQuery = filtersTpl.arg(
            trimQueryEnd(lastQuery),
            filters
            );
    }

    // ORDER BY
    if (!sortOrder.isEmpty())
    {
        QStringList cols;
        for (QueryExecutor::Sort& sort : sortOrder)
        {
            cols << sortColTpl.arg(
                QString::number(sort.column + 1), // in ORDER BY column indexes are 1-based
                (sort.order == QueryExecutor::Sort::DESC) ? "DESC" : "ASC"
                );
        }
        lastQuery = sortTpl.arg(trimQueryEnd(lastQuery), cols.join(", "));
    }

    // LIMIT
    if (page >= 0 && isSelect)
    {
        lastQuery = tpl.arg(
            trimQueryEnd(lastQuery),
            QString::number(resultsPerPage),
            QString::number(page * resultsPerPage)
            );
    }

    result.removeLast();
    result << lastQuery;
    return result;
}

QList<QueryExecutorStep*> QueryExecutor::createSteps(QueryExecutor::StepPosition position)
{
    QList<QueryExecutorStep*> steps;
    for (StepFactory*& factory : additionalStatefulStepFactories[position])
        steps << factory->produceQueryExecutorStep();

    return steps;
}

int QueryExecutor::getQueryCountLimitForSmartMode() const
{
    return queryCountLimitForSmartMode;
}

void QueryExecutor::setQueryCountLimitForSmartMode(int value)
{
    queryCountLimitForSmartMode = value;
}

void QueryExecutor::registerStep(StepPosition position, QueryExecutorStep *step)
{
    additionalStatelessSteps[position] += step;
    allAdditionalStatelsssSteps += step;
}

void QueryExecutor::registerStep(QueryExecutor::StepPosition position, QueryExecutor::StepFactory* stepFactory)
{
    additionalStatefulStepFactories[position] += stepFactory;
}

void QueryExecutor::deregisterStep(StepPosition position, QueryExecutorStep *step)
{
    additionalStatelessSteps[position].removeOne(step);
    allAdditionalStatelsssSteps.removeOne(step);
}

void QueryExecutor::deregisterStep(QueryExecutor::StepPosition position, QueryExecutor::StepFactory* stepFactory)
{
    additionalStatefulStepFactories[position].removeOne(stepFactory);
}

bool QueryExecutor::getForceSimpleMode() const
{
    return forceSimpleMode;
}

void QueryExecutor::setForceSimpleMode(bool value)
{
    forceSimpleMode = value;
}

bool QueryExecutor::isInterrupted() const
{
    QMutexLocker lock(&interruptionMutex);
    return interrupted;
}

const QStringList& QueryExecutor::getRequiredDbAttaches() const
{
    return requiredDbAttaches;
}

bool QueryExecutor::getNoMetaColumns() const
{
    return noMetaColumns;
}

void QueryExecutor::setNoMetaColumns(bool value)
{
    noMetaColumns = value;
}

void QueryExecutor::handleErrorsFromSmartAndSimpleMethods(SqlQueryPtr results)
{
    // It turns out that currently smart execution error has more sense to be displayed to user than the simple execution error,
    // so we're ignoring error from simple method, because it's usually misleading.
    // The case when simple method error is more true than smart method error is very rare nowdays (but happens sometimes,
    // therefore we need to check code from smart execution, before deciding which one to use).
    // Just rename attach names in the message.
    bool useSmartError = context->errorCodeFromSmartExecution !=  0;
    QString msg;
    int code;

    if (!useSmartError && (results.isNull() || !results->isError()) && !simpleExecutor->getErrors().isEmpty())
    {
        code = simpleExecutor->getErrors().first().first;
        msg = simpleExecutor->getErrors().first().second;
    }
    else
    {
        msg = useSmartError ? context->errorMessageFromSmartExecution : results->getErrorText();
        code = useSmartError ? context->errorCodeFromSmartExecution : results->getErrorCode();
    }

    if (useSmartError)
    {
        QString match;
        QString replaceName;
        for (QString& attachName : context->dbNameToAttach.rightValues())
        {
            match = attachName + ".";
            replaceName = wrapObjIfNeeded(context->dbNameToAttach.valueByRight(attachName)) + ".";
            while (msg.contains(match))
                msg.replace(match, replaceName);
        }
    }

    error(code, msg);
}

void QueryExecutor::releaseResultsAndCleanup()
{
    // The results have to be releases, otherwise attached databases cannot be detached.
    // Results handle cannot be kept elsewhere, otherwise detach will fail.
    context->executionResults.clear();
    cleanup();
}

SqlQueryPtr QueryExecutor::getResults() const
{
    return context->executionResults;
}

bool QueryExecutor::wasSchemaModified() const
{
    return context->schemaModified;
}

bool QueryExecutor::wasDataModifyingQuery() const
{
    return context->dataModifyingQuery;
}

QList<DataType> QueryExecutor::resolveColumnTypes(Db* db, QList<QueryExecutor::ResultColumnPtr>& columns, bool noDbLocking)
{
    QSet<Table> tables;
    for (ResultColumnPtr& col : columns)
        tables << Table(col->database, col->table);

    SchemaResolver resolver(db);
    resolver.setNoDbLocking(noDbLocking);

    QHash<Table,SqliteCreateTablePtr> parsedTables;
    SqliteCreateTablePtr createTable;
    for (const Table& t : tables)
    {
        createTable = resolver.getParsedObject(t.getDatabase(), t.getTable(), SchemaResolver::TABLE).dynamicCast<SqliteCreateTable>();
        if (!createTable)
        {
            qWarning() << "Could not resolve columns of table" << t.getTable() << "while quering datatypes for queryexecutor columns.";
            continue;
        }
        parsedTables[t] = createTable;
    }

    QList<DataType> datatypeList;
    Table t;
    SqliteCreateTable::Column* parsedCol = nullptr;
    for (ResultColumnPtr& col : columns)
    {
        t = Table(col->database, col->table);
        if (!parsedTables.contains(t))
        {
            datatypeList << DataType();
            continue;
        }

        parsedCol = parsedTables[t]->getColumn(col->column);
        if (!parsedCol || !parsedCol->type)
        {
            datatypeList << DataType();
            continue;
        }

        datatypeList << parsedCol->type->toDataType();
    }
    return datatypeList;
}

bool QueryExecutor::getAsyncMode() const
{
    return asyncMode;
}

void QueryExecutor::setAsyncMode(bool value)
{
    asyncMode = value;
}

void QueryExecutor::setPreloadResults(bool value)
{
    preloadResults = value;
}

bool QueryExecutor::getExplainMode() const
{
    return explainMode;
}

void QueryExecutor::setExplainMode(bool value)
{
    explainMode = value;
}


void QueryExecutor::error(int code, const QString& text)
{
    emit executionFailed(code, text);
}

Db* QueryExecutor::getDb() const
{
    return db;
}

void QueryExecutor::setDb(Db* value)
{
    db = value;

    if (countingDb)
    {
        countingDb->closeQuiet();
        safe_delete(countingDb);
    }
    if (db)
        countingDb = db->clone();
}

bool QueryExecutor::getSkipRowCounting() const
{
    return skipRowCounting;
}

void QueryExecutor::setSkipRowCounting(bool value)
{
    skipRowCounting = value;
}

QString QueryExecutor::getOriginalQuery() const
{
    return originalQuery;
}

int qHash(QueryExecutor::EditionForbiddenReason reason)
{
    return static_cast<int>(reason);
}

int qHash(QueryExecutor::ColumnEditionForbiddenReason reason)
{
    return static_cast<int>(reason);
}

int QueryExecutor::getDataLengthLimit() const
{
    return dataLengthLimit;
}

void QueryExecutor::setDataLengthLimit(int value)
{
    dataLengthLimit = value;
}

bool QueryExecutor::isRowCountingRequired() const
{
    return context->rowsCountingRequired;
}

QString QueryExecutor::getCountingQuery() const
{
    return context->countingQuery;
}

int QueryExecutor::getResultsPerPage() const
{
    return resultsPerPage;
}

void QueryExecutor::setResultsPerPage(int value)
{
    resultsPerPage = value;
}

int QueryExecutor::getPage() const
{
    return page;
}

void QueryExecutor::setPage(int value)
{
    page = value;
}

bool QueryExecutor::isExecutionInProgress()
{
    QMutexLocker executionLock(&executionMutex);
    return executionInProgress;
}

QueryExecutor::Sort::Sort()
{
}

QueryExecutor::Sort::Sort(QueryExecutor::Sort::Order order, int column)
    : order(order), column(column)
{
}

QueryExecutor::Sort::Sort(Qt::SortOrder order, int column)
    : column(column)
{
    switch (order)
    {
        case Qt::AscendingOrder:
            this->order = ASC;
            break;
        case Qt::DescendingOrder:
            this->order = DESC;
            break;
        default:
            this->order = NONE;
            qWarning() << "Invalid sort order passed to QueryExecutor::setSortOrder():" << order;
            break;
    }
}

Qt::SortOrder QueryExecutor::Sort::getQtOrder() const
{
    // The column should be checked first for being > -1.
    if (order == QueryExecutor::Sort::DESC)
        return Qt::DescendingOrder;

    return Qt::AscendingOrder;
}

QueryExecutor::SortList QueryExecutor::getSortOrder() const
{
    return sortOrder;
}

void QueryExecutor::setSortOrder(const SortList& value)
{
    sortOrder = value;
}

int operator==(const QueryExecutor::SourceTable& t1, const QueryExecutor::SourceTable& t2)
{
    return t1.database == t2.database && t1.table == t2.table && t1.alias == t2.alias;
}

int qHash(QueryExecutor::SourceTable sourceTable)
{
    return qHash(sourceTable.database + "." + sourceTable.table + "/" + sourceTable.alias);
}


QString QueryExecutor::getFilters() const
{
    return filters;
}

void QueryExecutor::setFilters(const QString& newFilters)
{
    filters = newFilters;
}