/*
 *  Copyright (C) 2013 Felix Geyer <debfx@fobos.de>
 *  Copyright (C) 2017 KeePassXC Team <team@keepassxc.org>
 *
 *  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 or (at your option)
 *  version 3 of the License.
 *
 *  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, see <http://www.gnu.org/licenses/>.
 */

#ifndef KEEPASSX_PASSWORDGENERATOR_H
#define KEEPASSX_PASSWORDGENERATOR_H

#include <QFlags>
#include <QString>
#include <QVector>

typedef QVector<QChar> PasswordGroup;

class PasswordGenerator
{
public:
    enum CharClass
    {
        LowerLetters      = 0x1,
        UpperLetters      = 0x2,
        Numbers           = 0x4,
        SpecialCharacters = 0x8,
        EASCII            = 0x10,
        DefaultCharset    = LowerLetters | UpperLetters | Numbers
    };
    Q_DECLARE_FLAGS(CharClasses, CharClass)

    enum GeneratorFlag
    {
        ExcludeLookAlike   = 0x1,
        CharFromEveryGroup = 0x2,
        DefaultFlags       = ExcludeLookAlike | CharFromEveryGroup
    };
    Q_DECLARE_FLAGS(GeneratorFlags, GeneratorFlag)

public:
    PasswordGenerator();

    double calculateEntropy(QString password);
    void setLength(int length);
    void setCharClasses(const CharClasses& classes);
    void setFlags(const GeneratorFlags& flags);

    bool isValid() const;

    QString generatePassword() const;
    int getbits() const;

    static const int DefaultLength = 16;
    static constexpr bool DefaultLower = (DefaultCharset & LowerLetters) != 0;
    static constexpr bool DefaultUpper = (DefaultCharset & UpperLetters) != 0;
    static constexpr bool DefaultNumbers = (DefaultCharset & Numbers) != 0;
    static constexpr bool DefaultSpecial = (DefaultCharset & SpecialCharacters) != 0;
    static constexpr bool DefaultEASCII = (DefaultCharset & EASCII) != 0;
    static constexpr bool DefaultLookAlike = (DefaultFlags & ExcludeLookAlike) != 0;
    static constexpr bool DefaultFromEveryGroup = (DefaultFlags & CharFromEveryGroup) != 0;

private:
    QVector<PasswordGroup> passwordGroups() const;
    int numCharClasses() const;

    int m_length;
    CharClasses m_classes;
    GeneratorFlags m_flags;

    Q_DISABLE_COPY(PasswordGenerator)
};

Q_DECLARE_OPERATORS_FOR_FLAGS(PasswordGenerator::CharClasses)

Q_DECLARE_OPERATORS_FOR_FLAGS(PasswordGenerator::GeneratorFlags)

#endif // KEEPASSX_PASSWORDGENERATOR_H
