/****************************************************************************
**
** Copyright (C) 2016 The Qt Company Ltd.
** Contact: https://www.qt.io/licensing/
**
** This file is part of Qt Creator.
**
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** Licensees holding valid commercial Qt licenses may use this file in
** accordance with the commercial license agreement provided with the
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** GNU General Public License Usage
** Alternatively, this file may be used under the terms of the GNU
** General Public License version 3 as published by the Free Software
** Foundation with exceptions as appearing in the file LICENSE.GPL3-EXCEPT
** included in the packaging of this file. Please review the following
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****************************************************************************/

#pragma once

#include "sqliteglobal.h"

#include "utf8stringvector.h"

#include <QStringList>

struct sqlite3;

class SQLITE_EXPORT SqliteDatabaseBackend
{
public:

    SqliteDatabaseBackend();
    ~SqliteDatabaseBackend();

    static void setMmapSize(qint64 defaultSize, qint64 maximumSize);
    static void activateMultiThreading();
    static void activateLogging();
    static void initializeSqliteLibrary();
    static void shutdownSqliteLibrary();
    static void checkpointFullWalLog();

    void open(const QString &databaseFilePath);
    void close();
    void closeWithoutException();

    static SqliteDatabaseBackend *threadLocalInstance();
    static sqlite3* sqliteDatabaseHandle();

    void setJournalMode(JournalMode journalMode);
    JournalMode journalMode() const;

    void setTextEncoding(TextEncoding textEncoding);
    TextEncoding textEncoding();



    static Utf8StringVector columnNames(const Utf8String &tableName);

    static int changesCount();
    static int totalChangesCount();

protected:
    bool databaseIsOpen() const;

    void setPragmaValue(const Utf8String &pragma, const Utf8String &value);
    Utf8String pragmaValue(const Utf8String &pragma) const;

    void registerBusyHandler();
    void registerRankingFunction();
    static int busyHandlerCallback(void*, int counter);

    void cacheTextEncoding();

    void checkForOpenDatabaseWhichCanBeClosed();
    void checkDatabaseClosing(int resultCode);
    void checkCanOpenDatabase(const QString &databaseFilePath);
    void checkDatabaseCouldBeOpened(int resultCode);
    void checkPragmaValue(const Utf8String &databaseValue, const Utf8String &expectedValue);
    static void checkDatabaseHandleIsNotNull();
    static void checkDatabaseBackendIsNotNull();
    static void checkIfMultithreadingIsActivated(int resultCode);
    static void checkIfLoogingIsActivated(int resultCode);
    static void checkMmapSizeIsSet(int resultCode);
    static void checkInitializeSqliteLibraryWasSuccesful(int resultCode);
    static void checkShutdownSqliteLibraryWasSuccesful(int resultCode);
    static void checkIfLogCouldBeCheckpointed(int resultCode);

    static int indexOfPragma(const Utf8String pragma, const Utf8String pragmas[], size_t pragmaCount);
    static const Utf8String &journalModeToPragma(JournalMode journalMode);
    static JournalMode pragmaToJournalMode(const Utf8String &pragma);
    static const Utf8String &textEncodingToPragma(TextEncoding textEncoding);
    static TextEncoding pragmaToTextEncoding(const Utf8String &pragma);

    Q_NORETURN static void throwException(const char *whatHasHappens);

private:
    sqlite3 *databaseHandle;
    TextEncoding cachedTextEncoding;

};