/*
*  Copyright (C) 2017 Sami Vänttinen <sami.vanttinen@protonmail.com>
*  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 3 of the License, or
*  (at your option) any later version.
*
*  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 BROWSERACTION_H
#define BROWSERACTION_H

#include <QtCore>
#include <QObject>
#include <QJsonObject>
#include <QMutex>
#include "BrowserService.h"

class BrowserAction : public QObject
{
    Q_OBJECT

    enum {
        ERROR_KEEPASS_DATABASE_NOT_OPENED =             1,
        ERROR_KEEPASS_DATABASE_HASH_NOT_RECEIVED =      2,
        ERROR_KEEPASS_CLIENT_PUBLIC_KEY_NOT_RECEIVED =  3,
        ERROR_KEEPASS_CANNOT_DECRYPT_MESSAGE =          4,
        ERROR_KEEPASS_TIMEOUT_OR_NOT_CONNECTED =        5,
        ERROR_KEEPASS_ACTION_CANCELLED_OR_DENIED =      6,
        ERROR_KEEPASS_CANNOT_ENCRYPT_MESSAGE =          7,
        ERROR_KEEPASS_ASSOCIATION_FAILED =              8,
        ERROR_KEEPASS_KEY_CHANGE_FAILED =               9,
        ERROR_KEEPASS_ENCRYPTION_KEY_UNRECOGNIZED =     10,
        ERROR_KEEPASS_NO_SAVED_DATABASES_FOUND =        11,
        ERROR_KEEPASS_INCORRECT_ACTION =                12,
        ERROR_KEEPASS_EMPTY_MESSAGE_RECEIVED =          13,
        ERROR_KEEPASS_NO_URL_PROVIDED =                 14,
        ERROR_KEEPASS_NO_LOGINS_FOUND =                 15
    };

public:
    BrowserAction(BrowserService& browserService);
    ~BrowserAction() = default;

    QJsonObject readResponse(const QJsonObject& json);

public slots:
    void        removeSharedEncryptionKeys();
    void        removeStoredPermissions();

private:
    QJsonObject handleAction(const QJsonObject& json);
    QJsonObject handleChangePublicKeys(const QJsonObject& json, const QString& action);
    QJsonObject handleGetDatabaseHash(const QJsonObject& json, const QString& action);
    QJsonObject handleAssociate(const QJsonObject& json, const QString& action);
    QJsonObject handleTestAssociate(const QJsonObject& json, const QString& action);
    QJsonObject handleGetLogins(const QJsonObject& json, const QString& action);
    QJsonObject handleGeneratePassword(const QJsonObject& json, const QString& action);
    QJsonObject handleSetLogin(const QJsonObject& json, const QString& action);
    QJsonObject handleLockDatabase(const QJsonObject& json, const QString& action);

    QJsonObject buildMessage(const QString& nonce) const;
    QJsonObject buildResponse(const QString& action, const QJsonObject& message, const QString& nonce);
    QJsonObject getErrorReply(const QString& action, const int errorCode) const;
    QString     getErrorMessage(const int errorCode) const;
    QString     getDatabaseHash();

    QString     encryptMessage(const QJsonObject& message, const QString& nonce);
    QJsonObject decryptMessage(const QString& message, const QString& nonce, const QString& action = QString());
    QString     encrypt(const QString plaintext, const QString nonce);
    QByteArray  decrypt(const QString encrypted, const QString nonce);

    QString     getBase64FromKey(const uchar* array, const uint len);
    QByteArray  getQByteArray(const uchar* array, const uint len) const;
    QJsonObject getJsonObject(const uchar* pArray, const uint len) const;
    QJsonObject getJsonObject(const QByteArray ba) const;
    QByteArray  base64Decode(const QString str);
    QString     incrementNonce(const QString& nonce);

private:
    QMutex              m_mutex;
    BrowserService&     m_browserService;
    QString             m_clientPublicKey;
    QString             m_publicKey;
    QString             m_secretKey;
    bool                m_associated;
};

#endif // BROWSERACTION_H
