/****************************************************************************

**

** Copyright (C) 2008-2010 Nokia Corporation and/or its subsidiary(-ies).

** All rights reserved.

** Contact: Nokia Corporation (developer.feedback@nokia.com)

**

** This file is part of the HbCore module of the UI Extensions for Mobile.

**

** GNU Lesser General Public License Usage

** This file may be used under the terms of the GNU Lesser General Public

** License version 2.1 as published by the Free Software Foundation and

** appearing in the file LICENSE.LGPL included in the packaging of this file.

** Please review the following information to ensure the GNU Lesser General

** Public License version 2.1 requirements will be met:

** http://www.gnu.org/licenses/old-licenses/lgpl-2.1.html.

**

** In addition, as a special exception, Nokia gives you certain additional

** rights.  These rights are described in the Nokia Qt LGPL Exception

** version 1.1, included in the file LGPL_EXCEPTION.txt in this package.

**

** If you have questions regarding the use of this file, please contact

** Nokia at developer.feedback@nokia.com.

**

****************************************************************************/

#include <QInputContextPlugin>

#include <QLocale>

#include <QFileSystemWatcher>

#include <QLibrary>

#include <QPluginLoader>

#include <QDir>

#include "hbinputmodecache_p.h"

#include "hbinpututils.h"

#include "hbinputmethod.h"

#include "hbinputsettingproxy.h"

#include "hbinputmodeproperties.h"

#include "hbinputkeymapfactory.h"

#include "hbinputmethod_p.h"

#include "hbinputmethodnull_p.h"

/*!

@alpha

@hbcore

\class HbInputModeCache

\brief Input framework's internal input mode resolver class.

*/

/// @cond

class HbInputMethodListItem

{

public:

    HbInputMethodListItem() : cached(0), toBeRemoved(false) {}

    bool operator==(const HbInputMethodListItem &item) const {

        return (descriptor.pluginNameAndPath() == item.descriptor.pluginNameAndPath() &&

                descriptor.key() == item.descriptor.key());

    }

public:

    HbInputMethodDescriptor descriptor;

    QStringList languages;

    HbInputMethod *cached;

    bool toBeRemoved;

};

class HbInputModeCachePrivate

{

public:

    HbInputModeCachePrivate() : mWatcher(new QFileSystemWatcher()), mShuttingDown(false) {}

    ~HbInputModeCachePrivate() {}

    void refresh(const QString &directory = QString());

    QInputContextPlugin *pluginInstance(const QString& pluginFileName) const;

    HbInputMethod *methodInstance(const QString &pluginFileName, const QString &key) const;

    HbInputModeProperties propertiesFromString(const QString &entry) const;

    HbInputModeProperties propertiesFromState(const HbInputState &state) const;

    HbInputMethod *cachedMethod(HbInputMethodListItem &item);

    void updateMonitoredPaths();

public:

    QFileSystemWatcher *mWatcher;

    QList<HbInputMethodListItem> mMethods;

    bool mShuttingDown;

};

QInputContextPlugin* HbInputModeCachePrivate::pluginInstance(const QString& pluginFileName) const

{

    if (QLibrary::isLibrary(pluginFileName)) {

        QPluginLoader loader(pluginFileName);

        QObject* plugin = loader.instance();

        if (plugin) {

            return qobject_cast<QInputContextPlugin*>(plugin);

        }

    }

    return 0;

}

HbInputMethod *HbInputModeCachePrivate::methodInstance(const QString &pluginFileName, const QString &key) const

{

    QInputContextPlugin *plugin = pluginInstance(pluginFileName);

    if (plugin) {

        QInputContext *instance = plugin->create(key);

        HbInputMethod *result = qobject_cast<HbInputMethod*>(instance);

        if (result) {

            QStringList languages = plugin->languages(key);

            QList<HbInputModeProperties> modeList;

            foreach (QString language, languages) {

                  modeList.append(propertiesFromString(language));

            }

            result->d_ptr->mInputModes = modeList;

        }

        return result;

    }

    return 0;

}

void HbInputModeCachePrivate::refresh(const QString &directory)

{

    Q_UNUSED(directory);

    // optimize later so that if the directory is given, only changes concerning

    // it are taken into account.

    // First go through all the previously found entries and

    // tag them not refreshed.

    for (int k = 0; k < mMethods.count(); k++) {

        mMethods[k].toBeRemoved = true;

    }

    // Query plugin paths and scan the folders.

    QStringList folders = HbInputSettingProxy::instance()->inputMethodPluginPaths();

    foreach (QString folder, folders) {

        QDir dir(folder);

        for (unsigned int i = 0; i < dir.count(); i++) {

            QString path = QString(dir.absolutePath());

            if (path.right(1) != "\\" && path.right(1) != "/") {

                path += QDir::separator();

            }

            path += dir[i];

            QInputContextPlugin* inputContextPlugin = pluginInstance(path);

            if (inputContextPlugin) {

                HbInputMethodListItem listItem;

                listItem.descriptor.setPluginNameAndPath(dir.absolutePath() + QDir::separator() + dir[i]);

                // For each found plugin, check if there is already a list item for it.

                // If not, then add one.

                QStringList contextKeys = inputContextPlugin->keys();

                foreach (QString key, contextKeys) {

                    listItem.descriptor.setKey(key);

                    listItem.descriptor.setDisplayName(inputContextPlugin->displayName(key));

                    int index = mMethods.indexOf(listItem);

                    if (index >= 0) {

                        // The method is already in the list, the situation hasn't changed.

                        // just tag it not to be removed.

                        mMethods[index].toBeRemoved = false;

                    } else {

                        listItem.languages = inputContextPlugin->languages(key);

                        mMethods.append(listItem);

                    }

                }

            }

        }

    }

    // Go through the cache list and find out if some of the previous items need to be

    // removed after the refresh.

    for (int i = 0; i < mMethods.count(); i++) {

        if (mMethods[i].toBeRemoved) {

            if (mMethods[i].cached && mMethods[i].cached->isActiveMethod()) {

                // If the item to be removed happens to be the active one,

                // try to deal with the situation.

                mMethods[i].cached->forceUnfocus();

                }

                // Replace it with null input context.

                HbInputMethod *master = HbInputMethodNull::Instance();

                master->d_ptr->mIsActive = true;

            }

            delete mMethods[i].cached;

            mMethods.removeAt(i);

            i--;

        }

    }

}

HbInputModeProperties HbInputModeCachePrivate::propertiesFromString(const QString &entry) const

{

    HbInputModeProperties result;

    QStringList parts = entry.split(" ");

    if (parts.count() == 4) {

        // See HbInputModeProperties::toString() for details,

        QString languageStr = parts[0] + QString(" ") + parts[1];

        HbInputLanguage language;

        language.fromString(languageStr);

        result.setLanguage(language);

        result.setInputMode((HbInputModeType)parts[2].toLong());

        result.setKeyboard((HbKeyboardType)parts[3].toLong());

    }

    return result;

}

HbInputModeProperties HbInputModeCachePrivate::propertiesFromState(const HbInputState &state) const

{

    HbInputModeProperties result;

    result.setLanguage(state.language());

    result.setKeyboard(state.keyboard());

    result.setInputMode(state.inputMode());

    return HbInputModeProperties(result);

}

HbInputMethod *HbInputModeCachePrivate::cachedMethod(HbInputMethodListItem &item)

{

    if (!item.cached) {

        item.cached = methodInstance(item.descriptor.pluginNameAndPath(), item.descriptor.key());

    }

    return item.cached;

}

void HbInputModeCachePrivate::updateMonitoredPaths()

{

    QStringList watchedDirs = mWatcher->directories();

    if (!watchedDirs.isEmpty()) {

        mWatcher->removePaths(watchedDirs);

    }

    QStringList paths = HbInputSettingProxy::instance()->inputMethodPluginPaths();

    foreach (QString path, paths) {

        QDir dir(path);

        if (!dir.exists() && path.left(1) == "f") {

            mWatcher->addPath(QString("f:") + QDir::separator());

        } else {

            mWatcher->addPath(path);

        }

    }

}

/// @endcond

/*!

\internal

Returns the singleton instance.

*/

HbInputModeCache* HbInputModeCache::instance()

{

    static HbInputModeCache theCache;

    return &theCache;

}

/*!

\internal

Construct the object.

*/

HbInputModeCache::HbInputModeCache() : d_ptr(new HbInputModeCachePrivate())

{

    Q_D(HbInputModeCache);

    // Start to monitor file system for changes.

    d->updateMonitoredPaths();

    connect(d->mWatcher, SIGNAL(directoryChanged(const QString &)), this, SLOT(directoryChanged(const QString &)));

    d->refresh();

}

/*!

\internal

Destruct the object.

*/

HbInputModeCache::~HbInputModeCache()

{

    delete d_ptr;

}

/*!

\internal

This slot is called whenever a change in input method plugin file system is detected and

the list needs to be refreshed.

*/

void HbInputModeCache::directoryChanged(const QString &directory)

{

    Q_D(HbInputModeCache);

    d->updateMonitoredPaths();

    if (!d->mShuttingDown) {

        d->refresh(directory);

    }

}

/*!

\internal

Shuts down the object safely. This is needed mainly for singleton object. There has been a lot

of problems related to randown singleton desctruction order and additional shutdown step is

needed to guarantee that it will be done safely. The slot is connected to

QCoreApplication::aboutToQuit when the framework is initialized.

*/

void HbInputModeCache::shutdown()

{

    Q_D(HbInputModeCache);

    d->mShuttingDown = true;

    foreach (HbInputMethodListItem method, d->mMethods) {

        delete method.cached;

        method.cached = 0;

    }

    d->mMethods.clear();

    delete d->mWatcher;

    d->mWatcher = 0;

}

/*!

\internal

Loads given input method and caches it.

*/

HbInputMethod* HbInputModeCache::loadInputMethod(const HbInputMethodDescriptor &inputMethod)

{

    Q_D(HbInputModeCache);

    for (int i = 0; i < d->mMethods.count(); i++) {

        if (d->mMethods[i].descriptor.pluginNameAndPath() == inputMethod.pluginNameAndPath() &&

            d->mMethods[i].descriptor.key() == inputMethod.key()) {

            if (!d->mMethods[i].cached) {

                d->mMethods[i].cached = d->methodInstance(inputMethod.pluginNameAndPath(), inputMethod.key());

            }

            return d->mMethods[i].cached;

        }

    }

    return 0;

}

/*!

\internal

Lists custom input methods.

*/

QList<HbInputMethodDescriptor> HbInputModeCache::listCustomInputMethods()

{

    Q_D(HbInputModeCache);

    QList<HbInputMethodDescriptor> result;

    foreach (HbInputMethodListItem item, d->mMethods) {

        foreach (QString language, item.languages) {

            HbInputModeProperties properties = d->propertiesFromString(language);

            if (properties.inputMode() == HbInputModeCustom) {

                result.append(item.descriptor);

                break;

            }

        }

    }

    return result;

}

/*!

\internal

Find correct handler for given input state.

*/

HbInputMethod* HbInputModeCache::findStateHandler(const HbInputState& state)

{

    Q_D(HbInputModeCache);

    HbInputModeProperties stateProperties = d->propertiesFromState(state);

    int languageRangeIndex = -1;    

    // First check if there is a method that matches excatly (ie. also specifies

    // the language).

    for (int i = 0; i < d->mMethods.count(); i++) {

        foreach (QString language, d->mMethods[i].languages) {

            HbInputModeProperties properties = d->propertiesFromString(language);

            if (properties.language().undefined() &&

                properties.keyboard() == stateProperties.keyboard() &&

                properties.inputMode() == stateProperties.inputMode()) {

                // Remember the index, we'll need this in the next phase if no exact

                // match is found.

                languageRangeIndex = i;

            }

            if (properties.inputMode() != HbInputModeCustom) {

                if (properties == stateProperties) {

                    return d->cachedMethod(d->mMethods[i]);

                }

            }

        }

    }

    // No exact match found. Then see if there was a method that matches to language

    // range, meaning that the language is left unspecified in which case we'll

    // use key mapping factory for matching.

    if (languageRangeIndex >= 0) {

        QList<HbInputLanguage> languages = HbKeymapFactory::instance()->availableLanguages();

        foreach(HbInputLanguage language, languages) {

            // exact match is returned If the country variant is specified in state language,

            // otherwise a method that matches to only language range is returned.

            bool exactMatchFound = (stateProperties.language().variant() != QLocale::AnyCountry) ?

                (language == stateProperties.language()) :

                (language.language() == stateProperties.language().language());

            if (exactMatchFound) {

                return d->cachedMethod(d->mMethods[languageRangeIndex]);

            }

        }

    }

    return 0;

}

/*!

\internal

Returns the active input method.

\sa HbInputMethod

*/

HbInputMethod* HbInputModeCache::activeMethod() const

{

    Q_D(const HbInputModeCache);

    foreach (HbInputMethodListItem item, d->mMethods) {

        if (item.cached && item.cached->isActiveMethod()) {

            return item.cached;

        }

    }

    return 0;

}

/*!

\internal

Lists available input languages.

*/

QList<HbInputLanguage> HbInputModeCache::listInputLanguages() const

{

    Q_D(const HbInputModeCache);

    QList<HbInputLanguage> result;

    foreach (HbInputMethodListItem item, d->mMethods) {

        foreach (QString language, item.languages) {

            HbInputModeProperties mode = d->propertiesFromString(language);

            if (mode.inputMode() != HbInputModeCustom) {

                if (mode.language().undefined()) {

                    // This is language range. Let's add everything

                    // we have key mappings for.

                    QList<HbInputLanguage> languages = HbKeymapFactory::instance()->availableLanguages();

                    foreach (HbInputLanguage mappedLanguage, languages) {

                        if (!result.contains(mappedLanguage)) {

                            result.append(mappedLanguage);

                        }

                    }

                } else {

                    if (!result.contains(mode.language())) {

                        result.append(mode.language());

                    }

                }

            }

        }

    }

    return result;

}