/*
 *   Copyright 2011 Marco Martin <mart@kde.org>
 *
 *   This program 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, 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 Library General Public License for more details
 *
 *   You should have received a copy of the GNU Library General Public
 *   License along with this program; if not, write to the
 *   Free Software Foundation, Inc.,
 *   51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
 */

#ifndef FALLBACKCOMPONENT_H
#define FALLBACKCOMPONENT_H

#include <QObject>
#include <QCache>
#include <QStringList>

/**
 * Component that loads a qml file based on a chain of different fallback paths
 * @deprecated this can be done with qmlregistertype on c++ side or a Loader on QML side
 */
class FallbackComponent : public QObject
{
    Q_OBJECT

    /**
     * Prefix of the path
     * This should be something like "plasma","kwin","plasmate",etc
     * If the basePath is "plasma", it will be set for the data of plasma like,
     * or it can be an absolute path
     **/
    Q_PROPERTY(QString basePath READ basePath WRITE setBasePath NOTIFY basePathChanged)

    /**
     * The possible candidates in order to have a complete path.
     * basepath/candidate, where candidate is the first one in the list of candidates
     * in order of importance that matches an existing file
     **/
    Q_PROPERTY(QStringList candidates READ candidates WRITE setCandidates NOTIFY candidatesChanged)

public:
    FallbackComponent(QObject *parent = 0);

    /**
    * This method must be called after the the basePath and the candidates property
    * This method resolves a file path based on the base path and the candidates.
    * it searches for a file named key under basepath/candidate/key, and returns
    * the path constructed with the first candidate that matches, if any.
    *
    * @param key the name of the file to search for
    **/
    Q_INVOKABLE QString filePath(const QString &key = QString());

    QString basePath() const;
    void setBasePath(const QString &basePath);

    QStringList candidates() const;
    void setCandidates(const QStringList &candidates);

Q_SIGNALS:
    void basePathChanged();
    void candidatesChanged();

private:
    QCache<QString, QString> m_possiblePaths;
    QString m_basePath;
    QStringList m_candidates;
};

#endif
