/* === This file is part of Calamares - <http://github.com/calamares> ===
 *
 *   Copyright 2019, Adriaan de Groot <groot@kde.org>
 *
 *   Calamares 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.
 *
 *   Calamares 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 Calamares. If not, see <http://www.gnu.org/licenses/>.
 */
#ifndef CALAMARES_REQUIREMENTSCHECKER_H
#define CALAMARES_REQUIREMENTSCHECKER_H

#include "Requirement.h"

#include <QFutureWatcher>
#include <QObject>
#include <QTimer>
#include <QVector>


namespace Calamares
{

class Module;

/** @brief A manager-class that checks all the module requirements
 *
 * Asynchronously checks the requirements for each module, and
 * emits progress signals as appropriate.
 */
class RequirementsChecker : public QObject
{
    Q_OBJECT

public:
    RequirementsChecker( QVector< Module* > modules, QObject* parent = nullptr );
    virtual ~RequirementsChecker() override;

public slots:
    /// @brief Start checking all the requirements
    void run();

    /// @brief Called when requirements are reported by a module
    void addCheckedRequirements( RequirementsList );

    /// @brief Called when all requirements have been checked
    void finished();

    /// @brief Called periodically while requirements are being checked
    void reportProgress();

signals:
    /// @brief Human-readable progress message
    void requirementsProgress( const QString& );
    /// @brief Requirements from a single module
    void requirementsResult( RequirementsList );
    /** @brief When all requirements are collected
     *
     * The argument indicates if all mandatory requirements are satisfied.
     */
    void requirementsComplete( bool );
    /// @brief Emitted after requirementsComplete
    void done();

private:
    QVector< Module* > m_modules;

    using Watcher = QFutureWatcher< void >;
    QVector< Watcher* > m_watchers;

    RequirementsList m_collectedRequirements;

    QTimer *m_progressTimer;
    unsigned m_progressTimeouts;
} ;

}

#endif