/******************************************************************************
 * QSkinny - Copyright (C) 2016 Uwe Rathmann
 * This file may be used under the terms of the QSkinny License, Version 1.0
 *****************************************************************************/

#include "QskSetup.h"
#include "QskSkin.h"
#include "QskSkinFactory.h"
#include "QskGraphicProviderMap.h"
#include "QskControl.h"
#include "QskInputPanel.h"
#include "QskWindow.h"
#include "QskObjectTree.h"

#include <QCoreApplication>
#include <QPointer>
#include <QDebug>

QskSetup* QskSetup::s_instance = nullptr;

static inline bool qskHasEnvironment( const char* env )
{
    bool ok;

    const int value = qEnvironmentVariableIntValue( env, &ok );
    if ( ok )
        return value != 0;

    // All other strings are true, apart from "false"
    auto result = qgetenv( env );
    return !result.isEmpty() && result != "false";
}

static inline const QskSetup::Flags qskEnvironmentFlags()
{
    QskSetup::Flags flags;

    if ( qskHasEnvironment( "QSK_PREFER_RASTER" ) )
        flags |= QskSetup::PreferRasterForTextures;

    if ( qskHasEnvironment( "QSK_FORCE_BACKGROUND" ) )
        flags |= QskSetup::DebugForceBackground;

    return flags;
}

static inline QskSetup::Flags qskDefaultControlFlags()
{
    static QskSetup::Flags flags;

    if ( flags == 0 )
    {
        flags |= QskSetup::DeferredUpdate;
        flags |= QskSetup::DeferredPolish;
        flags |= QskSetup::DeferredLayout;
        flags |= QskSetup::CleanupOnVisibility;
        flags |= qskEnvironmentFlags();
    }

    return flags;
}

static void qskApplicationHook()
{
    QskSetup::setup();
    qAddPostRoutine( QskSetup::cleanup );
}

Q_CONSTRUCTOR_FUNCTION( qskApplicationHook )

extern bool qskInheritLocale( QskControl*, const QLocale& );
extern bool qskInheritLocale( QskWindow*, const QLocale& );

namespace
{
    class VisitorLocale final : public QskObjectTree::ResolveVisitor< QLocale >
    {
    public:
        VisitorLocale():
            ResolveVisitor< QLocale >( "locale" )
        {
        }

    private:
        virtual bool setImplicitValue(
            QskControl* control, const QLocale& locale ) override final
        {
            return qskInheritLocale( control, locale );
        }

        virtual bool setImplicitValue(
            QskWindow* window, const QLocale& locale ) override final
        {
            return qskInheritLocale( window, locale );
        }

        virtual QLocale value( const QskControl* control ) const override final
        {
            return control->locale();
        }

        virtual QLocale value( const QskWindow* window ) const override final
        {
            return window->locale();
        }
    };
}

class QskSetup::PrivateData
{
public:
    PrivateData():
        controlFlags( qskDefaultControlFlags() )
    {
    }

    QString skinName;
    QPointer< QskSkin > skin;

    QskGraphicProviderMap graphicProviders;

    QPointer< QskInputPanel > inputPanel;
    QskSetup::Flags controlFlags;
};

QskSetup::QskSetup():
    m_data( new PrivateData() )
{
}

QskSetup::~QskSetup()
{
    s_instance = nullptr; // we might be destroyed from Qml !
}

void QskSetup::setup()
{
    if ( s_instance == nullptr )
        s_instance = new QskSetup();
}

void QskSetup::cleanup()
{
    if ( s_instance )
    {
        delete s_instance;
        s_instance = nullptr;
    }
}

void QskSetup::setControlFlags( QskSetup::Flags flags )
{
    if ( m_data->controlFlags != flags )
    {
        m_data->controlFlags = flags;
        Q_EMIT controlFlagsChanged();
    }
}

QskSetup::Flags QskSetup::controlFlags() const
{
    return m_data->controlFlags;
}

void QskSetup::resetControlFlags()
{
    setControlFlags( qskDefaultControlFlags() );
}

void QskSetup::setControlFlag( QskSetup::Flag flag, bool on )
{
    if ( m_data->controlFlags.testFlag( flag ) != on )
    {
        if ( on )
            m_data->controlFlags |= flag;
        else
            m_data->controlFlags &= ~flag;

        Q_EMIT controlFlagsChanged();
    }
}

void QskSetup::resetControlFlag( QskSetup::Flag flag )
{
    setControlFlag( flag, flag & qskDefaultControlFlags() );
}

bool QskSetup::testControlFlag( QskSetup::Flag flag )
{
    return m_data->controlFlags.testFlag( flag );
}

QskSkin* QskSetup::setSkin( const QString& skinName )
{
    if ( m_data->skin && ( skinName == m_data->skinName ) )
        return m_data->skin;

    QskSkin* skin = Qsk::createSkin( skinName );
    if ( skin == nullptr )
        return nullptr;

    if ( skin->parent() == nullptr )
        skin->setParent( this );

    const QskSkin* oldSkin = m_data->skin;

    m_data->skin = skin;
    m_data->skinName = skinName;

    if ( oldSkin )
    {
        Q_EMIT skinChanged( skin );

        if ( oldSkin->parent() == this )
            delete oldSkin;
    }

    return m_data->skin;
}

QString QskSetup::skinName() const
{
    return m_data->skinName;
}

void QskSetup::setSkin( QskSkin* skin, const QString& skinName )
{
    if ( skin == m_data->skin )
        return;

    if ( skin && skin->parent() == nullptr )
        skin->setParent( this );

    const QskSkin* oldSkin = m_data->skin;

    m_data->skin = skin;
    m_data->skinName = skinName;

    if ( oldSkin )
    {
        Q_EMIT skinChanged( skin );

        if ( oldSkin->parent() == this )
            delete oldSkin;
    }
}

QskSkin* QskSetup::skin()
{
    if ( m_data->skin == nullptr )
    {
        m_data->skin = Qsk::createSkin( nullptr );
        m_data->skin->setParent( this );
        m_data->skinName = m_data->skin->objectName();
    }

    return m_data->skin;
}

void QskSetup::addGraphicProvider( const QString& providerId, QskGraphicProvider* provider )
{
    m_data->graphicProviders.insert( providerId, provider );
}       

QskGraphicProvider* QskSetup::graphicProvider( const QString& providerId ) const
{
    if ( m_data->skin )
    {
        QskGraphicProvider* provider = m_data->skin->graphicProvider( providerId );
        if ( provider )
            return provider;
    }

    return m_data->graphicProviders.provider( providerId );
}   

void QskSetup::setInputPanel( QskInputPanel* inputPanel )
{
    if ( m_data->inputPanel == inputPanel )
        return;

    m_data->inputPanel = inputPanel;
    Q_EMIT inputPanelChanged( m_data->inputPanel );
}

QskInputPanel* QskSetup::inputPanel()
{
    return m_data->inputPanel;
}

QLocale QskSetup::inheritedLocale( const QObject* object )
{
    VisitorLocale visitor;
    visitor.setResolveValue( QLocale() );

    QskObjectTree::traverseUp( const_cast< QObject* >( object ), visitor );
    return visitor.resolveValue();
}


void QskSetup::inheritLocale( QObject* object, const QLocale& locale )
{
    VisitorLocale visitor;
    visitor.setResolveValue( locale );

    QskObjectTree::traverseDown( object, visitor );
}

QskSetup* QskSetup::qmlAttachedProperties( QObject* )
{
    return QskSetup::instance();
}

Q_DECLARE_METATYPE( QskSkin* )
#include "moc_QskSetup.cpp"