/****************************************************************************
**
** Copyright (C) 2013 Digia Plc and/or its subsidiary(-ies).
** Contact: http://www.qt-project.org/legal
**
** This file is part of the plugins of the Qt Toolkit.
**
** $QT_BEGIN_LICENSE:LGPL$
** Commercial License Usage
** Licensees holding valid commercial Qt licenses may use this file in
** accordance with the commercial license agreement provided with the
** Software or, alternatively, in accordance with the terms contained in
** a written agreement between you and Digia.  For licensing terms and
** conditions see http://qt.digia.com/licensing.  For further information
** use the contact form at http://qt.digia.com/contact-us.
**
** GNU Lesser General Public License Usage
** Alternatively, 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, Digia gives you certain additional
** rights.  These rights are described in the Digia Qt LGPL Exception
** version 1.1, included in the file LGPL_EXCEPTION.txt in this package.
**
** GNU General Public License Usage
** 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: http://www.gnu.org/copyleft/gpl.html.
**
**
** $QT_END_LICENSE$
**
****************************************************************************/

#include "qfbscreen_p.h"
#include "qfbcursor_p.h"
#include "qfbwindow_p.h"
#include "qfbbackingstore_p.h"

#include <QtGui/QPainter>

QT_BEGIN_NAMESPACE

QFbScreen::QFbScreen() : mCursor(0), mGeometry(), mDepth(16), mFormat(QImage::Format_RGB16), mScreenImage(0), mCompositePainter(0), mIsUpToDate(false)
{
}

QFbScreen::~QFbScreen()
{
    delete mCompositePainter;
    delete mScreenImage;
}

void QFbScreen::initializeCompositor()
{
    mScreenImage = new QImage(mGeometry.size(), mFormat);

    mRedrawTimer.setSingleShot(true);
    mRedrawTimer.setInterval(0);
    connect(&mRedrawTimer, SIGNAL(timeout()), this, SLOT(doRedraw()));
}

void QFbScreen::addWindow(QFbWindow *window)
{
    mWindowStack.prepend(window);
    invalidateRectCache();
    setDirty(window->geometry());
}

void QFbScreen::removeWindow(QFbWindow *window)
{
    mWindowStack.removeOne(window);
    invalidateRectCache();
    setDirty(window->geometry());
}

void QFbScreen::raise(QFbWindow *window)
{
    int index = mWindowStack.indexOf(window);
    if (index <= 0)
        return;
    mWindowStack.move(index, 0);
    invalidateRectCache();
    setDirty(window->geometry());
}

void QFbScreen::lower(QFbWindow *window)
{
    int index = mWindowStack.indexOf(window);
    if (index == -1 || index == (mWindowStack.size() - 1))
        return;
    mWindowStack.move(index, mWindowStack.size() - 1);
    invalidateRectCache();
    setDirty(window->geometry());
}

QWindow *QFbScreen::topLevelAt(const QPoint & p) const
{
    Q_UNUSED(p);
#if 0
    for (int i = 0; i < mWindowStack.size(); i++) {
        if (mWindowStack[i]->geometry().contains(p, false) &&
            mWindowStack[i]->visible() &&
            !mWindowStack[i]->widget()->isMinimized()) {
            return mWindowStack[i]->widget();
        }
    }
#endif
    return 0;
}

void QFbScreen::setDirty(const QRect &rect)
{
    QRect intersection = rect.intersected(mGeometry);
    QPoint screenOffset = mGeometry.topLeft();
    mRepaintRegion += intersection.translated(-screenOffset);    // global to local translation
    if (!mRedrawTimer.isActive()) {
        mRedrawTimer.start();
    }
}

void QFbScreen::generateRects()
{
    mCachedRects.clear();
    QPoint screenOffset = mGeometry.topLeft();
    QRegion remainingScreen(mGeometry.translated(-screenOffset)); // global to local translation

    for (int i = 0; i < mWindowStack.length(); i++) {
        if (remainingScreen.isEmpty())
            break;
#if 0
        if (!mWindowStack[i]->isVisible())
            continue;
        if (mWindowStack[i]->isMinimized())
            continue;

        if (!mWindowStack[i]->testAttribute(Qt::WA_TranslucentBackground)) {
            QRect localGeometry = mWindowStack.at(i)->geometry().translated(-screenOffset); // global to local translation
            remainingScreen -= localGeometry;
            QRegion windowRegion(localGeometry);
            windowRegion -= remainingScreen;
            foreach (QRect rect, windowRegion.rects()) {
                mCachedRects += QPair<QRect, int>(rect, i);
            }
        }
#endif
    }
    foreach (QRect rect, remainingScreen.rects())
        mCachedRects += QPair<QRect, int>(rect, -1);
    mIsUpToDate = true;
    return;
}

QRegion QFbScreen::doRedraw()
{
    QPoint screenOffset = mGeometry.topLeft();

    QRegion touchedRegion;
    if (mCursor && mCursor->isDirty() && mCursor->isOnScreen()) {
        QRect lastCursor = mCursor->dirtyRect();
        mRepaintRegion += lastCursor;
    }
    if (mRepaintRegion.isEmpty() && (!mCursor || !mCursor->isDirty())) {
        return touchedRegion;
    }

    QVector<QRect> rects = mRepaintRegion.rects();

    if (!mIsUpToDate)
        generateRects();

    if (!mCompositePainter)
        mCompositePainter = new QPainter(mScreenImage);
    for (int rectIndex = 0; rectIndex < mRepaintRegion.rectCount(); rectIndex++) {
        QRegion rectRegion = rects[rectIndex];

        for (int i = 0; i < mCachedRects.length(); i++) {
            QRect screenSubRect = mCachedRects[i].first;
            int layer = mCachedRects[i].second;
            QRegion intersect = rectRegion.intersected(screenSubRect);

            if (intersect.isEmpty())
                continue;

            rectRegion -= intersect;

            // we only expect one rectangle, but defensive coding...
            foreach (QRect rect, intersect.rects()) {
                bool firstLayer = true;
                if (layer == -1) {
                    mCompositePainter->fillRect(rect, Qt::black);
                    firstLayer = false;
                    layer = mWindowStack.size() - 1;
                }

                for (int layerIndex = layer; layerIndex != -1; layerIndex--) {
                    if (!mWindowStack[layerIndex]->window()->isVisible())
                        continue;
                    // if (mWindowStack[layerIndex]->isMinimized())
                    //     continue;
                    QRect windowRect = mWindowStack[layerIndex]->geometry().translated(-screenOffset);
                    QRect windowIntersect = rect.translated(-windowRect.left(),
                                                            -windowRect.top());
                    mCompositePainter->drawImage(rect, mWindowStack[layerIndex]->backingStore()->image(),
                                                windowIntersect);
                    if (firstLayer) {
                        firstLayer = false;
                    }
                }
            }
        }
    }

    QRect cursorRect;
    if (mCursor && (mCursor->isDirty() || mRepaintRegion.intersects(mCursor->lastPainted()))) {
        cursorRect = mCursor->drawCursor(*mCompositePainter);
        touchedRegion += cursorRect;
    }
    touchedRegion += mRepaintRegion;
    mRepaintRegion = QRegion();



//    qDebug() << "QFbScreen::doRedraw"  << mWindowStack.size() << mScreenImage->size() << touchedRegion;


    return touchedRegion;
}

QT_END_NAMESPACE

