/*
  Copyright (c) 2015-2018 Montel Laurent <montel@kde.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 2 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, write to the Free Software Foundation, Inc.,
  51 Franklin Street, Fifth Floor, Boston, MA  02110-1301  USA
*/

#include "customtoolspluginmanager.h"
#include "customtoolsplugin.h"

#include <KPluginFactory>
#include <KPluginLoader>
#include <KPluginMetaData>

#include <QDebug>
#include <QFileInfo>
#include <QSet>

using namespace PimCommon;

class CustomToolsPluginInfo
{
public:
    CustomToolsPluginInfo()
        : plugin(nullptr)
    {
    }

    QString saveName() const;

    KPluginMetaData metaData;
    PimCommon::CustomToolsPlugin *plugin = nullptr;
};

QString CustomToolsPluginInfo::saveName() const
{
    return QFileInfo(metaData.fileName()).baseName();
}

namespace {
QString pluginVersion()
{
    return QStringLiteral("1.0");
}
}

class PimCommon::CustomToolsPluginManagerPrivate
{
public:
    CustomToolsPluginManagerPrivate(CustomToolsPluginManager *qq)
        : q(qq)
    {
    }

    QVector<PimCommon::CustomToolsPlugin *> pluginsList() const;
    void initializePluginList();
    void loadPlugin(CustomToolsPluginInfo *item);
    QVector<CustomToolsPluginInfo> mPluginList;
    CustomToolsPluginManager *q;
};

void CustomToolsPluginManagerPrivate::initializePluginList()
{
    const QVector<KPluginMetaData> plugins = KPluginLoader::findPlugins(QStringLiteral("pimcommon"), [](const KPluginMetaData &md) {
        return md.serviceTypes().contains(QLatin1String("PimCommonCustomTools/Plugin"));
    });

    QVectorIterator<KPluginMetaData> i(plugins);
    i.toBack();
    QSet<QString> unique;
    while (i.hasPrevious()) {
        CustomToolsPluginInfo info;
        info.metaData = i.previous();
        if (info.metaData.version() == pluginVersion()) {
            // only load plugins once, even if found multiple times!
            if (unique.contains(info.saveName())) {
                continue;
            }
            info.plugin = nullptr;
            mPluginList.push_back(info);
            unique.insert(info.saveName());
        } else {
            qWarning() << "Plugin " << info.metaData.name() << " doesn't have correction plugin version. It will not be loaded.";
        }
    }
    QVector<CustomToolsPluginInfo>::iterator end(mPluginList.end());
    for (QVector<CustomToolsPluginInfo>::iterator it = mPluginList.begin(); it != end; ++it) {
        loadPlugin(&(*it));
    }
}

QVector<PimCommon::CustomToolsPlugin *> CustomToolsPluginManagerPrivate::pluginsList() const
{
    QVector<PimCommon::CustomToolsPlugin *> lst;
    QVector<CustomToolsPluginInfo>::ConstIterator end(mPluginList.constEnd());
    for (QVector<CustomToolsPluginInfo>::ConstIterator it = mPluginList.constBegin(); it != end; ++it) {
        if (auto plugin = (*it).plugin) {
            lst << plugin;
        }
    }
    return lst;
}

void CustomToolsPluginManagerPrivate::loadPlugin(CustomToolsPluginInfo *item)
{
    KPluginLoader pluginLoader(item->metaData.fileName());
    if (pluginLoader.factory()) {
        item->plugin = pluginLoader.factory()->create<PimCommon::CustomToolsPlugin>(q, QVariantList() << item->saveName());
    }
}

CustomToolsPluginManager *CustomToolsPluginManager::self()
{
    static CustomToolsPluginManager s_self;
    return &s_self;
}

CustomToolsPluginManager::CustomToolsPluginManager(QObject *parent)
    : QObject(parent)
    , d(new PimCommon::CustomToolsPluginManagerPrivate(this))
{
    d->initializePluginList();
}

CustomToolsPluginManager::~CustomToolsPluginManager()
{
    delete d;
}

QVector<PimCommon::CustomToolsPlugin *> CustomToolsPluginManager::pluginsList() const
{
    return d->pluginsList();
}
