/*
    Copyright (c) 2006 Till Adam <adam@kde.org>
    Copyright (c) 2009 David Jarvie <djarvie@kde.org>

    This library is free software; you can redistribute it and/or modify it
    under the terms of the GNU Library General Public License as published by
    the Free Software Foundation; either version 2 of the License, or (at your
    option) any later version.

    This library 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 Library General Public
    License for more details.

    You should have received a copy of the GNU Library General Public License
    along with this library; see the file COPYING.LIB.  If not, write to the
    Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
    02110-1301, USA.
*/

#ifndef ICALRESOURCEBASE_H
#define ICALRESOURCEBASE_H

#include "singlefileresource.h"
#include "settings.h"

#include <KCalendarCore/MemoryCalendar>
#include <KCalendarCore/FileStorage>

class ICalResourceBase : public Akonadi::SingleFileResource<SETTINGS_NAMESPACE::Settings>
{
    Q_OBJECT

public:
    explicit ICalResourceBase(const QString &id);
    ~ICalResourceBase();

protected:
    using ResourceBase::retrieveItems; // Suppress -Woverload-virtual

protected Q_SLOTS:
    bool retrieveItem(const Akonadi::Item &item, const QSet<QByteArray> &parts) override;
    void retrieveItems(const Akonadi::Collection &col) override;

protected:
    enum CheckType {
        CheckForAdded, CheckForChanged
    };

    void initialise(const QStringList &mimeTypes, const QString &icon);
    bool readFromFile(const QString &fileName) override;
    bool writeToFile(const QString &fileName) override;

    void aboutToQuit() override;

    /**
     * Retrieve an incidence from the calendar, and set it into a new item's payload.
     * Retrieval of the item should be signalled by calling @p itemRetrieved().
     * @param item the incidence ID to retrieve is provided by @c item.remoteId()
     * @return true if item retrieved, false if not.
     */
    virtual bool doRetrieveItem(const Akonadi::Item &item, const QSet<QByteArray> &parts) = 0;

    /**
     * Retrieve all incidences from the calendar, and set each into a new item's payload.
     * Retrieval of the items should be signalled by calling @p itemsRetrieved().
     */
    virtual void doRetrieveItems(const Akonadi::Collection &col) = 0;

    /**
     * To be called at the start of derived class implementations of itemAdded()
     * or itemChanged() to verify that required conditions are true.
     * @param type the type of change to perform the checks for.
     * @return true if all checks are successful, and processing can continue;
     *         false if a check failed, in which case itemAdded() or itemChanged()
     *               should stop processing.
     */
    template<typename PayloadPtr> bool checkItemAddedChanged(const Akonadi::Item &item, CheckType type);

    void itemRemoved(const Akonadi::Item &item) override;

    /** Return the local calendar. */
    KCalendarCore::MemoryCalendar::Ptr calendar() const;

    /** Return the calendar file storage. */
    KCalendarCore::FileStorage::Ptr fileStorage() const;

private:
    KCalendarCore::MemoryCalendar::Ptr mCalendar;
    KCalendarCore::FileStorage::Ptr mFileStorage;
};

template<typename PayloadPtr>
bool ICalResourceBase::checkItemAddedChanged(const Akonadi::Item &item, CheckType type)
{
    if (!mCalendar) {
        cancelTask(i18n("Calendar not loaded."));
        return false;
    }
    if (!item.hasPayload<PayloadPtr>()) {
        QString msg = (type == CheckForAdded)
                      ? i18n("Unable to retrieve added item %1.", item.id())
                      : i18n("Unable to retrieve modified item %1.", item.id());
        cancelTask(msg);
        return false;
    }
    return true;
}

#endif
