/****************************************************************************

**

** All rights reserved.

** Contact: Nokia Corporation (qt-info@nokia.com)

**

** This file is part of the QtCore module of the Qt Toolkit.

**

** $QT_BEGIN_LICENSE:LGPL$

** No Commercial Usage

** This file contains pre-release code and may not be distributed.

** You may use this file in accordance with the terms and conditions

** contained in the Technology Preview License Agreement accompanying

** this package.

**

** GNU Lesser General Public License Usage

** Alternatively, this file may be used under the terms of the GNU Lesser

** General Public License version 2.1 as published by the Free Software

** Foundation and appearing in the file LICENSE.LGPL included in the

** packaging of this file.  Please review the following information to

** ensure the GNU Lesser General Public License version 2.1 requirements

** will be met: http://www.gnu.org/licenses/old-licenses/lgpl-2.1.html.

**

** In addition, as a special exception, Nokia gives you certain additional

** rights.  These rights are described in the Nokia Qt LGPL Exception

** version 1.1, included in the file LGPL_EXCEPTION.txt in this package.

**

** If you have questions regarding the use of this file, please contact

** Nokia at qt-info@nokia.com.

**

**

**

**

**

**

**

**

** $QT_END_LICENSE$

**

****************************************************************************/

#include "qsettings.h"

#ifndef QT_NO_SETTINGS

#include "qsettings_p.h"

#include "qvector.h"

#include "qmap.h"

#include "qt_windows.h"

#include "qdebug.h"

QT_BEGIN_NAMESPACE

/*  Keys are stored in QStrings. If the variable name starts with 'u', this is a "user"

    key, ie. "foo/bar/alpha/beta". If the variable name starts with 'r', this is a "registry"

    key, ie. "\foo\bar\alpha\beta". */

/*******************************************************************************

** Some convenience functions

*/

/*

  We don't use KEY_ALL_ACCESS because it gives more rights than what we

  need. See task 199061.

 */

static const REGSAM registryPermissions = KEY_READ | KEY_WRITE;

static QString keyPath(const QString &rKey)

{

    int idx = rKey.lastIndexOf(QLatin1Char('\\'));

    if (idx == -1)

        return QString();

    return rKey.left(idx + 1);

}

static QString keyName(const QString &rKey)

{

    int idx = rKey.lastIndexOf(QLatin1Char('\\'));

    QString res;

    if (idx == -1)

        res = rKey;

    else

        res = rKey.mid(idx + 1);

    if (res == QLatin1String("Default") || res == QLatin1String("."))

        res = QLatin1String("");

    return res;

}

static QString escapedKey(QString uKey)

{

    QChar *data = uKey.data();

    int l = uKey.length();

    for (int i = 0; i < l; ++i) {

        ushort &ucs = data[i].unicode();

        if (ucs == '\\')

            ucs = '/';

        else if (ucs == '/')

            ucs = '\\';

    }

    return uKey;

}

static QString unescapedKey(QString rKey)

{

    return escapedKey(rKey);

}

typedef QMap<QString, QString> NameSet;

static void mergeKeySets(NameSet *dest, const NameSet &src)

{

    NameSet::const_iterator it = src.constBegin();

    for (; it != src.constEnd(); ++it)

        dest->insert(unescapedKey(it.key()), QString());

}

static void mergeKeySets(NameSet *dest, const QStringList &src)

{

    QStringList::const_iterator it = src.constBegin();

    for (; it != src.constEnd(); ++it)

        dest->insert(unescapedKey(*it), QString());

}

/*******************************************************************************

** Wrappers for the insane windows registry API

*/

static QString errorCodeToString(DWORD errorCode)

{

    wchar_t *data = 0;

    FormatMessage(FORMAT_MESSAGE_ALLOCATE_BUFFER | FORMAT_MESSAGE_FROM_SYSTEM, 0, errorCode, 0, data, 0, 0);

    QString result = QString::fromWCharArray(data);

    if (data != 0)

        LocalFree(data);

    if (result.endsWith(QLatin1Char('\n')))

        result.truncate(result.length() - 1);

    return result;

}

// Open a key with the specified perms

static HKEY openKey(HKEY parentHandle, REGSAM perms, const QString &rSubKey)

{

    HKEY resultHandle = 0;

    LONG res = RegOpenKeyEx(parentHandle, reinterpret_cast<const wchar_t *>(rSubKey.utf16()),

                            0, perms, &resultHandle);

    if (res == ERROR_SUCCESS)

        return resultHandle;

    return 0;

}

// Open a key with the specified perms, create it if it does not exist

static HKEY createOrOpenKey(HKEY parentHandle, REGSAM perms, const QString &rSubKey)

{

    // try to open it

    HKEY resultHandle = openKey(parentHandle, perms, rSubKey);

    if (resultHandle != 0)

        return resultHandle;

    // try to create it

    LONG res = RegCreateKeyEx(parentHandle, reinterpret_cast<const wchar_t *>(rSubKey.utf16()), 0, 0,

                              REG_OPTION_NON_VOLATILE, perms, 0, &resultHandle, 0);

    if (res == ERROR_SUCCESS)

        return resultHandle;

    //qWarning("QSettings: Failed to create subkey \"%s\": %s",

    //        rSubKey.toLatin1().data(), errorCodeToString(res).toLatin1().data());

    return 0;

}

// Open or create a key in read-write mode if possible, otherwise read-only

static HKEY createOrOpenKey(HKEY parentHandle, const QString &rSubKey, bool *readOnly)

{

    // try to open or create it read/write

    HKEY resultHandle = createOrOpenKey(parentHandle, registryPermissions, rSubKey);

    if (resultHandle != 0) {

        if (readOnly != 0)

            *readOnly = false;

        return resultHandle;

    }

    // try to open or create it read/only

    resultHandle = createOrOpenKey(parentHandle, KEY_READ, rSubKey);

    if (resultHandle != 0) {

        if (readOnly != 0)

            *readOnly = true;

        return resultHandle;

    }

    return 0;

}

static QStringList childKeysOrGroups(HKEY parentHandle, QSettingsPrivate::ChildSpec spec)

{

    QStringList result;

    DWORD numKeys;

    DWORD maxKeySize;

    DWORD numSubgroups;

    DWORD maxSubgroupSize;

    // Find the number of keys and subgroups, as well as the max of their lengths.

    LONG res = RegQueryInfoKey(parentHandle, 0, 0, 0, &numSubgroups, &maxSubgroupSize, 0,

                               &numKeys, &maxKeySize, 0, 0, 0);

    if (res != ERROR_SUCCESS) {

        qWarning("QSettings: RegQueryInfoKey() failed: %s", errorCodeToString(res).toLatin1().data());

        return result;

    }

    ++maxSubgroupSize;

    ++maxKeySize;

    int n;

    int m;

    if (spec == QSettingsPrivate::ChildKeys) {

        n = numKeys;

        m = maxKeySize;

    } else {

        n = numSubgroups;

        m = maxSubgroupSize;

    }

    /* The size does not include the terminating null character. */

    ++m;

    // Get the list

    QByteArray buff(m * sizeof(wchar_t), 0);

    for (int i = 0; i < n; ++i) {

        QString item;

        DWORD l = buff.size() / sizeof(wchar_t);

        if (spec == QSettingsPrivate::ChildKeys) {

            res = RegEnumValue(parentHandle, i, reinterpret_cast<wchar_t *>(buff.data()), &l, 0, 0, 0, 0);

        } else {

            res = RegEnumKeyEx(parentHandle, i, reinterpret_cast<wchar_t *>(buff.data()), &l, 0, 0, 0, 0);

        }

        if (res == ERROR_SUCCESS)

            item = QString::fromWCharArray((const wchar_t *)buff.constData(), l);

        if (res != ERROR_SUCCESS) {

            qWarning("QSettings: RegEnumValue failed: %s", errorCodeToString(res).toLatin1().data());

            continue;

        }

        if (item.isEmpty())

            item = QLatin1String(".");

        result.append(item);

    }

    return result;

}

static void allKeys(HKEY parentHandle, const QString &rSubKey, NameSet *result)

{

    HKEY handle = openKey(parentHandle, KEY_READ, rSubKey);

    if (handle == 0)

        return;

    QStringList childKeys = childKeysOrGroups(handle, QSettingsPrivate::ChildKeys);

    QStringList childGroups = childKeysOrGroups(handle, QSettingsPrivate::ChildGroups);

    RegCloseKey(handle);

    for (int i = 0; i < childKeys.size(); ++i) {

        QString s = rSubKey;

        if (!s.isEmpty())

            s += QLatin1Char('\\');

        s += childKeys.at(i);

        result->insert(s, QString());

    }

    for (int i = 0; i < childGroups.size(); ++i) {

        QString s = rSubKey;

        if (!s.isEmpty())

            s += QLatin1Char('\\');

        s += childGroups.at(i);

        allKeys(parentHandle, s, result);

    }

}

static void deleteChildGroups(HKEY parentHandle)

{

    QStringList childGroups = childKeysOrGroups(parentHandle, QSettingsPrivate::ChildGroups);

    for (int i = 0; i < childGroups.size(); ++i) {

        QString group = childGroups.at(i);

        // delete subgroups in group

        HKEY childGroupHandle = openKey(parentHandle, registryPermissions, group);

        if (childGroupHandle == 0)

            continue;

        deleteChildGroups(childGroupHandle);

        RegCloseKey(childGroupHandle);

        // delete group itself

        LONG res = RegDeleteKey(parentHandle, reinterpret_cast<const wchar_t *>(group.utf16()));

        if (res != ERROR_SUCCESS) {

            qWarning("QSettings: RegDeleteKey failed on subkey \"%s\": %s",

                      group.toLatin1().data(), errorCodeToString(res).toLatin1().data());

            return;

        }

    }

}

/*******************************************************************************

** class RegistryKey

*/

class RegistryKey

{

public:

    RegistryKey(HKEY parent_handle = 0, const QString &key = QString(), bool read_only = true);

    QString key() const;

    HKEY handle() const;

    HKEY parentHandle() const;

    bool readOnly() const;

    void close();

private:

    HKEY m_parent_handle;

    mutable HKEY m_handle;

    QString m_key;

    mutable bool m_read_only;

};

RegistryKey::RegistryKey(HKEY parent_handle, const QString &key, bool read_only)

{

    m_parent_handle = parent_handle;

    m_handle = 0;

    m_read_only = read_only;

    m_key = key;

}

QString RegistryKey::key() const

{

    return m_key;

}

HKEY RegistryKey::handle() const

{

    if (m_handle != 0)

        return m_handle;

    if (m_read_only)

        m_handle = openKey(m_parent_handle, KEY_READ, m_key);

    else

        m_handle = createOrOpenKey(m_parent_handle, m_key, &m_read_only);

    return m_handle;

}

HKEY RegistryKey::parentHandle() const

{

    return m_parent_handle;

}

bool RegistryKey::readOnly() const

{

    return m_read_only;

}

void RegistryKey::close()

{

    if (m_handle != 0)

        RegCloseKey(m_handle);

    m_handle = 0;

}

typedef QVector<RegistryKey> RegistryKeyList;

/*******************************************************************************

** class QWinSettingsPrivate

*/

class QWinSettingsPrivate : public QSettingsPrivate

{

public:

    QWinSettingsPrivate(QSettings::Scope scope, const QString &organization,

                        const QString &application);

    QWinSettingsPrivate(QString rKey);

    ~QWinSettingsPrivate();

    void remove(const QString &uKey);

    void set(const QString &uKey, const QVariant &value);

    bool get(const QString &uKey, QVariant *value) const;

    QStringList children(const QString &uKey, ChildSpec spec) const;

    void clear();

    void sync();

    void flush();

    bool isWritable() const;

    HKEY writeHandle() const;

    bool readKey(HKEY parentHandle, const QString &rSubKey, QVariant *value) const;

    QString fileName() const;

private:

    RegistryKeyList regList; // list of registry locations to search for keys

    bool deleteWriteHandleOnExit;

};

QWinSettingsPrivate::QWinSettingsPrivate(QSettings::Scope scope, const QString &organization,

                                         const QString &application)

    : QSettingsPrivate(QSettings::NativeFormat, scope, organization, application)

{

    deleteWriteHandleOnExit = false;

    if (!organization.isEmpty()) {

        QString prefix = QLatin1String("Software\\") + organization;

        QString orgPrefix = prefix + QLatin1String("\\OrganizationDefaults");

        QString appPrefix = prefix + QLatin1Char('\\') + application;

        if (scope == QSettings::UserScope) {

            if (!application.isEmpty())

                regList.append(RegistryKey(HKEY_CURRENT_USER, appPrefix, !regList.isEmpty()));

            regList.append(RegistryKey(HKEY_CURRENT_USER, orgPrefix, !regList.isEmpty()));

        }

        if (!application.isEmpty())

            regList.append(RegistryKey(HKEY_LOCAL_MACHINE, appPrefix, !regList.isEmpty()));

        regList.append(RegistryKey(HKEY_LOCAL_MACHINE, orgPrefix, !regList.isEmpty()));

    }

    if (regList.isEmpty())

        setStatus(QSettings::AccessError);

}

QWinSettingsPrivate::QWinSettingsPrivate(QString rPath)

    : QSettingsPrivate(QSettings::NativeFormat)

{

    deleteWriteHandleOnExit = false;

    if (rPath.startsWith(QLatin1String("\\")))

        rPath = rPath.mid(1);

    if (rPath.startsWith(QLatin1String("HKEY_CURRENT_USER\\")))

        regList.append(RegistryKey(HKEY_CURRENT_USER, rPath.mid(18), false));

    else if (rPath == QLatin1String("HKEY_CURRENT_USER"))

        regList.append(RegistryKey(HKEY_CURRENT_USER, QString(), false));

    else if (rPath.startsWith(QLatin1String("HKEY_LOCAL_MACHINE\\")))

        regList.append(RegistryKey(HKEY_LOCAL_MACHINE, rPath.mid(19), false));

    else if (rPath == QLatin1String("HKEY_LOCAL_MACHINE"))

        regList.append(RegistryKey(HKEY_LOCAL_MACHINE, QString(), false));

    else if (rPath.startsWith(QLatin1String("HKEY_CLASSES_ROOT\\")))

        regList.append(RegistryKey(HKEY_CLASSES_ROOT, rPath.mid(18), false));

    else if (rPath == QLatin1String("HKEY_CLASSES_ROOT"))

        regList.append(RegistryKey(HKEY_CLASSES_ROOT, QString(), false));

    else if (rPath.startsWith(QLatin1String("HKEY_USERS\\")))

        regList.append(RegistryKey(HKEY_USERS, rPath.mid(11), false));

    else if (rPath == QLatin1String(QLatin1String("HKEY_USERS")))

        regList.append(RegistryKey(HKEY_USERS, QString(), false));

    else

        regList.append(RegistryKey(HKEY_LOCAL_MACHINE, rPath, false));

}

bool QWinSettingsPrivate::readKey(HKEY parentHandle, const QString &rSubKey, QVariant *value) const

{

    QString rSubkeyName = keyName(rSubKey);

    QString rSubkeyPath = keyPath(rSubKey);

    // open a handle on the subkey

    HKEY handle = openKey(parentHandle, KEY_READ, rSubkeyPath);

    if (handle == 0)

        return false;

    // get the size and type of the value

    DWORD dataType;

    DWORD dataSize;

    LONG res = RegQueryValueEx(handle, reinterpret_cast<const wchar_t *>(rSubkeyName.utf16()), 0, &dataType, 0, &dataSize);

    if (res != ERROR_SUCCESS) {

        RegCloseKey(handle);

        return false;

    }

    // get the value

    QByteArray data(dataSize, 0);

    res = RegQueryValueEx(handle, reinterpret_cast<const wchar_t *>(rSubkeyName.utf16()), 0, 0,

                           reinterpret_cast<unsigned char*>(data.data()), &dataSize);

    if (res != ERROR_SUCCESS) {

        RegCloseKey(handle);

        return false;

    }

    switch (dataType) {

        case REG_EXPAND_SZ:

        case REG_SZ: {

            QString s;

            if (dataSize) {

                s = QString::fromWCharArray(((const wchar_t *)data.constData()));

            }

            if (value != 0)

                *value = stringToVariant(s);

            break;

        }

        case REG_MULTI_SZ: {

            QStringList l;

            if (dataSize) {

                int i = 0;

                for (;;) {

                    QString s = QString::fromWCharArray((const wchar_t *)data.constData() + i);

                    i += s.length() + 1;

                    if (s.isEmpty())

                        break;

                    l.append(s);

                }

            }

            if (value != 0)

                *value = stringListToVariantList(l);

            break;

        }

        case REG_NONE:

        case REG_BINARY: {

            QString s;

            if (dataSize) {

                s = QString::fromWCharArray((const wchar_t *)data.constData(), data.size() / 2);

            }

            if (value != 0)

                *value = stringToVariant(s);

            break;

        }

        case REG_DWORD_BIG_ENDIAN: