/****************************************************************************
**
** Copyright (C) 2011 Nokia Corporation and/or its subsidiary(-ies).
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** Contact: Nokia Corporation (qt-info@nokia.com)
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** This file is part of the QtCore module of the Qt Toolkit.
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** This file may be used under the terms of the GNU Lesser General Public
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** file. Please review the following information to ensure the GNU Lesser
** General Public License version 2.1 requirements will be met:
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** rights. These rights are described in the Nokia Qt LGPL Exception
** version 1.1, included in the file LGPL_EXCEPTION.txt in this package.
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** Alternatively, this file may be used under the terms of the GNU General
** Public License version 3.0 as published by the Free Software Foundation
** and appearing in the file LICENSE.GPL included in the packaging of this
** file. Please review the following information to ensure the GNU General
** Public License version 3.0 requirements will be met:
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** Alternatively, this file may be used in accordance with the terms and
** conditions contained in a signed written agreement between you and Nokia.
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** $QT_END_LICENSE$
**
****************************************************************************/

#include "qfactoryloader_p.h"

#ifndef QT_NO_LIBRARY
#include "qfactoryinterface.h"
#include "qmap.h"
#include <qdir.h>
#include <qdebug.h>
#include "qmutex.h"
#include "qplugin.h"
#include "qpluginloader.h"
#include "private/qobject_p.h"
#include "private/qcoreapplication_p.h"

QT_BEGIN_NAMESPACE

Q_GLOBAL_STATIC(QList<QFactoryLoader *>, qt_factory_loaders)

Q_GLOBAL_STATIC_WITH_ARGS(QMutex, qt_factoryloader_mutex, (QMutex::Recursive))

class QFactoryLoaderPrivate : public QObjectPrivate
{
    Q_DECLARE_PUBLIC(QFactoryLoader)
public:
    QFactoryLoaderPrivate(){}
    ~QFactoryLoaderPrivate();
    mutable QMutex mutex;
    QByteArray iid;
    QList<QLibraryPrivate*> libraryList;
    QMap<QString,QLibraryPrivate*> keyMap;
    QStringList keyList;
    QString suffix;
    Qt::CaseSensitivity cs;
    QStringList loadedPaths;

    void unloadPath(const QString &path);
};

QFactoryLoaderPrivate::~QFactoryLoaderPrivate()
{
    for (int i = 0; i < libraryList.count(); ++i)
        libraryList.at(i)->release();
}

QFactoryLoader::QFactoryLoader(const char *iid,
                               const QString &suffix,
                               Qt::CaseSensitivity cs)
    : QObject(*new QFactoryLoaderPrivate)
{
    moveToThread(QCoreApplicationPrivate::mainThread());
    Q_D(QFactoryLoader);
    d->iid = iid;
    d->cs = cs;
    d->suffix = suffix;


    QMutexLocker locker(qt_factoryloader_mutex());
    update();
    qt_factory_loaders()->append(this);
}



void QFactoryLoader::update()
{
#ifdef QT_SHARED
    Q_D(QFactoryLoader);
    QStringList paths = QCoreApplication::libraryPaths();
    for (int i = 0; i < paths.count(); ++i) {
        const QString &pluginDir = paths.at(i);
        // Already loaded, skip it...
        if (d->loadedPaths.contains(pluginDir))
            continue;
        d->loadedPaths << pluginDir;

        QString path = pluginDir + d->suffix;
        if (!QDir(path).exists(QLatin1String(".")))
            continue;

        QStringList plugins = QDir(path).entryList(QDir::Files);
        QLibraryPrivate *library = 0;
        for (int j = 0; j < plugins.count(); ++j) {
            QString fileName = QDir::cleanPath(path + QLatin1Char('/') + plugins.at(j));
            if (qt_debug_component()) {
                qDebug() << "QFactoryLoader::QFactoryLoader() looking at" << fileName;
            }
            library = QLibraryPrivate::findOrCreate(QFileInfo(fileName).canonicalFilePath());
            if (!library->isPlugin()) {
                if (qt_debug_component()) {
                    qDebug() << library->errorString;
                    qDebug() << "         not a plugin";
                }
                library->release();
                continue;
            }
            QStringList keys;
            if (!library->loadPlugin()) {
                if (qt_debug_component()) {
                    qDebug() << library->errorString;
                    qDebug() << "           could not load";
                }
                library->release();
                continue;
            }
            QObject *instance = library->instance();
            if (!instance) {
                library->release();
                // ignore plugins that have a valid signature but cannot be loaded.
                continue;
            }
            QFactoryInterface *factory = qobject_cast<QFactoryInterface*>(instance);
            if (instance && factory && instance->qt_metacast(d->iid))
                keys = factory->keys();
            if (keys.isEmpty())
                library->unload();
            if (keys.isEmpty()) {
                library->release();
                continue;
            }
            d->libraryList += library;
            for (int k = 0; k < keys.count(); ++k) {
                // first come first serve, unless the first
                // library was built with a future Qt version,
                // whereas the new one has a Qt version that fits
                // better
                QString key = keys.at(k);
                if (!d->cs)
                    key = key.toLower();
                QLibraryPrivate *previous = d->keyMap.value(key);
                if (!previous || (previous->qt_version > QT_VERSION && library->qt_version <= QT_VERSION)) {
                    d->keyMap[key] = library;
                    d->keyList += keys.at(k);
                }
            }
        }
    }
#else
    Q_D(QFactoryLoader);
    if (qt_debug_component()) {
        qDebug() << "QFactoryLoader::QFactoryLoader() ignoring" << d->iid
                 << "since plugins are disabled in static builds";
    }
#endif
}

QFactoryLoader::~QFactoryLoader()
{
    QMutexLocker locker(qt_factoryloader_mutex());
    qt_factory_loaders()->removeAll(this);
}

QStringList QFactoryLoader::keys() const
{
    Q_D(const QFactoryLoader);
    QMutexLocker locker(&d->mutex);
    QStringList keys = d->keyList;
    QObjectList instances = QPluginLoader::staticInstances();
    for (int i = 0; i < instances.count(); ++i)
        if (QFactoryInterface *factory = qobject_cast<QFactoryInterface*>(instances.at(i)))
            if (instances.at(i)->qt_metacast(d->iid))
                keys += factory->keys();
    return keys;
}

QObject *QFactoryLoader::instance(const QString &key) const
{
    Q_D(const QFactoryLoader);
    QMutexLocker locker(&d->mutex);
    QObjectList instances = QPluginLoader::staticInstances();
    for (int i = 0; i < instances.count(); ++i)
        if (QFactoryInterface *factory = qobject_cast<QFactoryInterface*>(instances.at(i)))
            if (instances.at(i)->qt_metacast(d->iid) && factory->keys().contains(key, Qt::CaseInsensitive))
                return instances.at(i);

    QString lowered = d->cs ? key : key.toLower();
    if (QLibraryPrivate* library = d->keyMap.value(lowered)) {
        if (library->instance || library->loadPlugin()) {
            if (QObject *obj = library->instance()) {
                if (obj && !obj->parent())
                    obj->moveToThread(QCoreApplicationPrivate::mainThread());
                return obj;
            }
        }
    }
    return 0;
}

#if defined(Q_OS_UNIX) && !defined (Q_OS_MAC)
QLibraryPrivate *QFactoryLoader::library(const QString &key) const
{
    Q_D(const QFactoryLoader);
    return d->keyMap.value(d->cs ? key : key.toLower());
}
#endif

void QFactoryLoader::refreshAll()
{
    QMutexLocker locker(qt_factoryloader_mutex());
    QList<QFactoryLoader *> *loaders = qt_factory_loaders();
    for (QList<QFactoryLoader *>::const_iterator it = loaders->constBegin();
         it != loaders->constEnd(); ++it) {
        (*it)->update();
    }
}

QT_END_NAMESPACE

#endif // QT_NO_LIBRARY