//============================================================================
//                                 INCLUDES
//============================================================================
#include "FreeVirtualKeyboardInputContext.h"

#include <QDebug>
#include <QPointer>
#include <QEvent>
#include <QGuiApplication>
#include <QQmlEngine>
#include <QQmlContext>
#include <QVariant>
#include <QQmlEngine>
#include <QJSEngine>
#include <QPropertyAnimation>

#include <private/qquickflickable_p.h>
#include "DeclarativeInputEngine.h"


/**
 * Private data class for FreeVirtualKeyboardInputContext
 */
class FreeVirtualKeyboardInputContextPrivate
{
public:
    FreeVirtualKeyboardInputContextPrivate();
    QQuickFlickable* Flickable;
    QQuickItem* FocusItem;
    bool Visible;
    DeclarativeInputEngine* InputEngine;
    QPropertyAnimation* FlickableContentScrollAnimation;//< for smooth scrolling of flickable content item
};


//==============================================================================
FreeVirtualKeyboardInputContextPrivate::FreeVirtualKeyboardInputContextPrivate()
    : Flickable(0),
      FocusItem(0),
      Visible(false),
      InputEngine(new DeclarativeInputEngine())
{
    qDebug() << "FreeVirtualKeyboardInputContextPrivate :: CONSTRUCTOR";
}


//==============================================================================
FreeVirtualKeyboardInputContext::FreeVirtualKeyboardInputContext() :
    QPlatformInputContext(), d(new FreeVirtualKeyboardInputContextPrivate)
{
    d->FlickableContentScrollAnimation = new QPropertyAnimation(this);
    d->FlickableContentScrollAnimation->setPropertyName("contentY");
    d->FlickableContentScrollAnimation->setDuration(400);
    d->FlickableContentScrollAnimation->setEasingCurve(QEasingCurve(QEasingCurve::OutBack));
    qmlRegisterSingletonType<DeclarativeInputEngine>("FreeVirtualKeyboard", 1, 0,
                                                     "InputEngine", inputEngineProvider);
    connect(d->InputEngine, SIGNAL(animatingChanged()), this, SLOT(ensureFocusedObjectVisible()));
}


//==============================================================================
FreeVirtualKeyboardInputContext::~FreeVirtualKeyboardInputContext()
{
    qDebug( "FreeVirtualKeyboardInputContext DESTRUCTOR !!!");
}


//==============================================================================
FreeVirtualKeyboardInputContext* FreeVirtualKeyboardInputContext::instance()
{
    static FreeVirtualKeyboardInputContext* InputContextInstance = new FreeVirtualKeyboardInputContext;
    return InputContextInstance;
}



//==============================================================================
bool FreeVirtualKeyboardInputContext::isValid() const
{
    qDebug("IS VALID called");
    return true;
}


//==============================================================================
QRectF FreeVirtualKeyboardInputContext::keyboardRect() const
{
    qDebug("QRect called");
    return QRectF();
}


//==============================================================================
void FreeVirtualKeyboardInputContext::showInputPanel()
{
    qDebug( "showInputPanel");
    d->Visible = true;
    QPlatformInputContext::showInputPanel();
    emitInputPanelVisibleChanged();
}


//==============================================================================
void FreeVirtualKeyboardInputContext::hideInputPanel()
{
    qDebug( "hideInputPanel");
    d->Visible = false;
    QPlatformInputContext::hideInputPanel();
    emitInputPanelVisibleChanged();
}


//==============================================================================
bool FreeVirtualKeyboardInputContext::isInputPanelVisible() const
{
    return d->Visible;
}


//==============================================================================
bool FreeVirtualKeyboardInputContext::isAnimating() const
{
    return false;
}


//==============================================================================
void FreeVirtualKeyboardInputContext::setFocusObject(QObject *object)
{
    static const int NumericInputHints = Qt::ImhPreferNumbers | Qt::ImhDate
            | Qt::ImhTime | Qt::ImhDigitsOnly | Qt::ImhFormattedNumbersOnly;
    static const int DialableInputHints = Qt::ImhDialableCharactersOnly;

    d->Flickable = 0;

    qDebug() << "FreeVirtualKeyboardInputContext::setFocusObject";
    if (!object)
    {
        return;
    }

    // we only support QML at the moment - so if this is not a QML item, then
    // we leave immediatelly
    d->FocusItem = dynamic_cast<QQuickItem*>(object);
    if (!d->FocusItem)
    {
        return;
    }

    // Check if an input control has focus that accepts text input - if not,
    // then we can leave immediatelly
    bool AcceptsInput = d->FocusItem->inputMethodQuery(Qt::ImEnabled).toBool();
    if (!AcceptsInput)
    {
        return;
    }

    // Set input mode depending on input method hints queried from focused
    // object / item
    Qt::InputMethodHints InputMethodHints(d->FocusItem->inputMethodQuery(Qt::ImHints).toInt());
    qDebug() << QString("InputMethodHints: %1").arg(InputMethodHints, 0, 16);
    if (InputMethodHints & DialableInputHints)
    {
        d->InputEngine->setInputMode(DeclarativeInputEngine::Dialable);
    }
    else if (InputMethodHints & NumericInputHints)
    {
        d->InputEngine->setInputMode(DeclarativeInputEngine::Numeric);
    }
    else
    {
        d->InputEngine->setInputMode(DeclarativeInputEngine::Latin);
    }

    // Search for the top most flickable so that we can scroll the control
    // into the visible area, if the keyboard hides the control
    //    QQuickItem* i = d->FocusItem;
    //    while (i)
    //    {
    //        QQuickFlickable* Flickable = dynamic_cast<QQuickFlickable*>(i);
    //        if (Flickable)
    //        {
    //            d->Flickable = Flickable;
    //            qDebug() << "is QQuickFlickable";
    //        }
    //        i = i->parentItem();
    //    }

    ensureFocusedObjectVisible();
}

//==============================================================================
void FreeVirtualKeyboardInputContext::ensureFocusedObjectVisible()
{
    if (d->Visible && !d->InputEngine->isAnimating() )
    {
        QQuickItem* i = d->FocusItem;
        while (i)
        {
            QQuickFlickable* Flickable = dynamic_cast<QQuickFlickable*>(i);
            if (Flickable)
            {
                d->Flickable = Flickable;
                qDebug() << "is QQuickFlickable";
            }
            i = i->parentItem();
        }
    }


    // If the keyboard is hidden, no scrollable element exists or the keyboard
    // is just animating, then we leave here
    if (!d->Visible || !d->Flickable || d->InputEngine->isAnimating() )
    {
        return;
    }

    qDebug() << "FreeVirtualKeyboardInputContext::ensureFocusedObjectVisible";

    QRectF FocusItemRect(0, 0, d->FocusItem->width(), d->FocusItem->height());
    FocusItemRect = d->Flickable->mapRectFromItem(d->FocusItem, FocusItemRect);
    qDebug() << "FocusItemRect: " << FocusItemRect;
    qDebug() << "Content origin: " << QPointF(d->Flickable->contentX(), d->Flickable->contentY());

    qDebug() << "Flickable size: " << QSize(d->Flickable->width(), d->Flickable->height());
    d->FlickableContentScrollAnimation->setTargetObject(d->Flickable);
    qreal ContentY = d->Flickable->contentY();
    if (FocusItemRect.bottom() >= d->Flickable->height())
    {
        qDebug() << "Item outside!!!  FocusItemRect.bottom() >= d->Flickable->height()";
        qDebug() << "ContentY " << d->Flickable->contentY() << "FocusItem Bottom : " << FocusItemRect.bottom()
                 << "Flickable Height " << d->Flickable->height();
        ContentY = d->Flickable->contentY() + (FocusItemRect.bottom() - d->Flickable->height());
        d->FlickableContentScrollAnimation->setEndValue(ContentY);
        d->FlickableContentScrollAnimation->start();
    }
    else if (FocusItemRect.top() < 0)
    {
        qDebug() << "Item outside!!!  d->FocusItem->position().x < 0";
        ContentY = d->Flickable->contentY() + FocusItemRect.top();
        d->FlickableContentScrollAnimation->setEndValue(ContentY);
        d->FlickableContentScrollAnimation->start();
    }

}


//==============================================================================
QObject* FreeVirtualKeyboardInputContext::inputEngineProvider(QQmlEngine *engine, QJSEngine *scriptEngine)
{
    Q_UNUSED(engine)
    Q_UNUSED(scriptEngine)
    return FreeVirtualKeyboardInputContext::instance()->d->InputEngine;
}

//------------------------------------------------------------------------------
// EOF FreeVirtualKeyboardInpitContext.cpp