/****************************************************************************
 ** Modern Linbo GUI
 ** Copyright (C) 2020  Dorian Zedler <dorian@itsblue.de>
 **
 ** This program is free software: you can redistribute it and/or modify
 ** it under the terms of the GNU Affero 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 Affero General Public License for more details.
 **
 ** You should have received a copy of the GNU Affero General Public License
 ** along with this program.  If not, see <http://www.gnu.org/licenses/>.
 ****************************************************************************/

#ifndef LINBOBACKEND_H
#define LINBOBACKEND_H

#include <QObject>
#include <QStringList>
#include <QtDebug>
#include <QProcess>
#include <QTimer>
#include <QElapsedTimer>

#include <vector>
#include <iostream>
#include <fstream>
#include <istream>
#include <stdlib.h>

#include "linbologger.h"
#include "linboconfig.h"
#include "linboos.h"
#include "linboimage.h"
#include "linbodiskpartition.h"

using namespace std;

class LinboBackend : public QObject
{
    Q_OBJECT
    Q_PROPERTY(LinboBackend::LinboState state READ getState NOTIFY stateChanged)
    Q_PROPERTY(LinboOs* currentOs READ getCurrentOs WRITE setCurrentOs NOTIFY currentOsChanged)
    Q_PROPERTY(double autostartTimeoutProgress READ getAutostartTimeoutProgress NOTIFY autostartTimeoutProgressChanged)
    Q_PROPERTY(int autostartTimeoutRemainingSeconds READ getAutostartTimeoutRemainingSeconds NOTIFY autostartTimeoutProgressChanged)

public:
    explicit LinboBackend(QObject *parent = nullptr);

    enum LinboState {
        Initializing,
        Autostarting,
        Idle,
        Starting,
        Syncing,
        Reinstalling,
        Root,
        Partitioning,
        InitializingCache,
        Updating
    };

    LinboState getState();
    LinboLogger* getLogger();
    LinboConfig* getConfig();
    QList<LinboOs*> getOperatingSystems();
    LinboOs* getCurrentOs();
    void setCurrentOs(LinboOs* os);
    double getAutostartTimeoutProgress();
    int getAutostartTimeoutRemainingSeconds();

protected:
    bool read_pair(ifstream* input, QString& key, QString& value);
    bool toBool(const QString& value);
    LinboOs* read_os(ifstream* input);
    LinboDiskPartition* read_partition(ifstream* input);
    void read_globals( ifstream* input, LinboConfig* config );

private:
    LinboState state;
    LinboLogger* logger;
    LinboConfig* config;
    QStringList linboCommandCache;
    QList<LinboOs*> operatingSystems;
    QList<LinboDiskPartition*> diskPartitions;

    QElapsedTimer* autostartElapsedTimer;
    QTimer* autostartTimer;
    QTimer* autostartRemainingTimeRefreshTimer;

    LinboOs* currentOs;

    QString const linboCmdCommand = "linbo_cmd";

    QProcess* asynchronosProcess;
    QProcess* synchronosProcess;

    template<typename ... Strings>
    QString executeCommand(bool waitForFinished, QString argument, const Strings&... arguments) {
        return this->executeCommand(waitForFinished, this->linboCmdCommand, this->buildCommand(argument, arguments ...));
    }

    QStringList buildCommand() {
        QStringList tmpArguments = this->linboCommandCache;
        this->linboCommandCache.clear();
        return tmpArguments;
    }

    template<typename ... Strings>
    QStringList buildCommand(QString argument, const Strings&... arguments) {
        // this appends a quoted space in case item is empty and resolves
        // problems with linbo_cmd's weird "shift"-usage
        if (argument.isEmpty())
            this->linboCommandCache.append("");
        else
            this->linboCommandCache.append(argument);

        return buildCommand(arguments...);
    }

    QString executeCommand(bool wait, QString command, QStringList commandArgs);

    void setState(LinboState state);

public slots:
    void shutdown();
    void reboot();

    bool startCurrentOs();
    bool syncCurrentOs();
    bool reinstallCurrentOs();

    bool partitionDrive(bool format = true);
    bool initializeCache();
    bool updateLinbo();

private slots:
    void executeAutostart();
    void handleAutostartTimerTimeout();
    void readFromStdout();
    void readFromStderr();

signals:
    void stateChanged(LinboBackend::LinboState state);
    void currentOsChanged(LinboOs* os);

};

#endif // LINBOBACKEND_H