/*
 *  Copyright (c) 2002 Patrick Julien <freak@codepimps.org>
 *  Copyright (c) 2005 Casper Boemann <cbr@boemann.dk>
 *  Copyright (c) 2006 Bart Coppens <kde@bartcoppens.be>
 *
 *  This program is free software; you can redistribute it and/or modify
 *  it under the terms of the GNU General Public License as published by
 *  the Free Software Foundation; either version 2 of the License, or
 *  (at your option) any later version.
 *
 *  This program is distributed in the hope that it will be useful,
 *  but WITHOUT ANY WARRANTY; without even the implied warranty of
 *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 *  GNU General Public License for more details.
 *
 *  You should have received a copy of the GNU General Public License
 *  along with this program; if not, write to the Free Software
 *  Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
 */
#ifndef KIS_MERGE_H_
#define KIS_MERGE_H_

#include <qrect.h>

#include "kis_types.h"
#include "kis_paint_device.h"
#include "kis_layer_visitor.h"
#include "kis_painter.h"
#include "kis_image.h"
#include "kis_layer.h"
#include "kis_group_layer.h"
#include "kis_adjustment_layer.h"
#include "kis_paint_layer.h"
#include "kis_part_layer_iface.h"
#include "kis_filter.h"
#include "kis_filter_configuration.h"
#include "kis_filter_registry.h"
#include "kis_selection.h"
#include "kis_transaction.h"
#include "kis_iterators_pixel.h"

class KisMergeVisitor : public KisLayerVisitor {
public:
    /**
     * Don't even _think_ of creating a merge visitor without a projection; without a projection,
     * the adjustmentlayers won't work.
     */
    KisMergeVisitor(KisPaintDeviceSP projection, const QRect& rc) :
        KisLayerVisitor()
    {
        Q_ASSERT(projection);

        m_projection = projection;
        m_rc = rc;
    }

private:
    // Helper for the indirect painting (keep above to inhibit gcc-2.95 ICE)
    template<class Target>
    KSharedPtr<Target> paintIndirect(KisPaintDeviceSP source,
                                     KSharedPtr<Target> target,
                                     KisLayerSupportsIndirectPainting* layer,
                                     Q_INT32 sx, Q_INT32 sy, Q_INT32 dx, Q_INT32 dy,
                                     Q_INT32 w, Q_INT32 h) {
        KisPainter gc2(target.data());
        gc2.bitBlt(dx, dy, COMPOSITE_COPY, source,
                   OPACITY_OPAQUE, sx, sy, w, h);
        gc2.bitBlt(dx, dy, layer->temporaryCompositeOp(), layer->temporaryTarget(),
                   layer->temporaryOpacity(), sx, sy, w, h);
        gc2.end();
        return target;
    }

public:
    virtual bool visit(KisPaintLayer *layer)
    {
        
        if (m_projection == 0) {
            return false;
        }
        
        kdDebug(41010) << "Visiting on paint layer " << layer->name() << ", visible: " << layer->visible()
                << ", temporary: " << layer->temporary() << ", extent: "
                << layer->extent() << ", dirty: " << layer->dirtyRect() << ", paint rect: " << m_rc << endl;
        if (!layer->visible())
            return true;

        Q_INT32 sx, sy, dx, dy, w, h;

        QRect rc = layer->paintDevice()->extent() & m_rc;

        // Indirect painting?
        KisPaintDeviceSP tempTarget = layer->temporaryTarget();
        if (tempTarget) {
            rc = (layer->paintDevice()->extent() | tempTarget->extent()) & m_rc;
        }

        sx = rc.left();
        sy = rc.top();
        w  = rc.width();
        h  = rc.height();
        dx = sx;
        dy = sy;

        KisPainter gc(m_projection);
        KisPaintDeviceSP source = layer->paintDevice();

        if (!layer->hasMask()) {
            if (tempTarget) {
                KisPaintDeviceSP temp = new KisPaintDevice(source->colorSpace());
                source = paintIndirect(source, temp, layer, sx, sy, dx, dy, w, h);
            }

            gc.bitBlt(dx, dy, layer->compositeOp(), source, layer->opacity(), sx, sy, w, h);
        } else {
            if (layer->renderMask()) {
                // To display the mask, we don't do things with composite op and opacity
                // This is like the gimp does it, I guess that's ok?

                // Note that here we'll use m_rc, because even if the extent of the device is
                // empty, we want a full mask to be drawn! (we don't change rc, since
                // it'd mess with setClean). This is because KisPainter::bitBlt &'s with
                // the source device's extent. This is ok in normal circumstances, but
                // we changed the default tile. Fixing this properly would mean fixing it there.
                sx = m_rc.left();
                sy = m_rc.top();
                w  = m_rc.width();
                h  = m_rc.height();
                dx = sx;
                dy = sy;

                // The problem is that the extent of the layer mask might not be extended
                // enough. Check if that is the case
                KisPaintDeviceSP mask = layer->getMask();
                QRect mextent = mask->extent();
                if ((mextent & m_rc) != m_rc) {
                    // Iterate over all pixels in the m_rc area. With just accessing the
                    // tiles in read-write mode, we ensure that the tiles get created if they
                    // do not exist. If they do, they'll remain untouched since we don't
                    // actually write data to it.
                    // XXX Admission: this is actually kind of a hack :-(
                    KisRectIteratorPixel it = mask->createRectIterator(sx, sy, w, h, true);
                    while (!it.isDone())
                        ++it;
                }
                if (tempTarget) {
                    KisPaintDeviceSP temp = new KisPaintDevice(source->colorSpace());
                    mask = paintIndirect(mask, temp, layer, sx, sy, dx, dy, w, h);
                }

                gc.bitBlt(dx, dy, COMPOSITE_OVER, mask, OPACITY_OPAQUE, sx, sy, w, h);
            } else {
                KisSelectionSP mask = layer->getMaskAsSelection();
                // The indirect painting happens on the mask
                if (tempTarget && layer->editMask()) {
                    KisPaintDeviceSP maskSrc = layer->getMask();
                    KisPaintDeviceSP temp = new KisPaintDevice(maskSrc->colorSpace());
                    temp = paintIndirect(maskSrc, temp, layer, sx, sy, dx, dy, w, h);
                    // Blegh
                    KisRectIteratorPixel srcIt = temp->createRectIterator(sx, sy, w, h, false);
                    KisRectIteratorPixel dstIt = mask->createRectIterator(sx, sy, w, h, true);

                    while(!dstIt.isDone()) {
                        // Same as in convertMaskToSelection
                        *dstIt.rawData() = *srcIt.rawData();
                        ++srcIt;
                        ++dstIt;
                    }
                } else if (tempTarget) {
                    // We have a mask, and paint indirect, but not on the mask
                    KisPaintDeviceSP temp = new KisPaintDevice(source->colorSpace());
                    source = paintIndirect(source, temp, layer, sx, sy, dx, dy, w, h);
                }

                gc.bltSelection(dx, dy,
                                layer->compositeOp(),
                                source,
                                mask,
                                layer->opacity(), sx, sy, w, h);
            }
        }

        layer->setClean( rc );
        return true;
    }

    virtual bool visit(KisGroupLayer *layer)
    {
        
        if (m_projection == 0) {
            return false;
        }
        
        kdDebug(41010) << "Visiting on group layer " << layer->name() << ", visible: " << layer->visible() << ", extent: "
                << layer->extent() << ", dirty: " << layer->dirtyRect() << ", paint rect: " << m_rc << endl;
                
        if (!layer->visible())
            return true;
        
        Q_INT32 sx, sy, dx, dy, w, h;

        // This automatically makes sure the projection is up-to-date for the specified rect.
        KisPaintDeviceSP dev = layer->projection(m_rc);
        QRect rc = dev->extent() & m_rc;

        sx = rc.left();
        sy = rc.top();
        w  = rc.width();
        h  = rc.height();
        dx = sx;
        dy = sy;

        KisPainter gc(m_projection);
        gc.bitBlt(dx, dy, layer->compositeOp(), dev, layer->opacity(), sx, sy, w, h);

        return true;
    }

    virtual bool visit(KisPartLayer* layer)
    {

        kdDebug(41010) << "Visiting on part layer " << layer->name() << ", visible: " << layer->visible() << ", extent: "
                << layer->extent() << ", dirty: " << layer->dirtyRect() << ", paint rect: " << m_rc << endl;
        
        if (m_projection == 0) {
            return false;
        }
        if (!layer->visible())
            return true;

        KisPaintDeviceSP dev(layer->prepareProjection(m_projection, m_rc));
        if (!dev)
            return true;

        Q_INT32 sx, sy, dx, dy, w, h;

        QRect rc = dev->extent() & m_rc;

        sx= rc.left();
        sy = rc.top();
        w = rc.width();
        h = rc.height();
        dx = sx;
        dy = sy;

        KisPainter gc(m_projection);
        gc.bitBlt(dx, dy, layer->compositeOp() , dev, layer->opacity(), sx, sy, w, h);

        layer->setClean(rc);
        return true;
    }

    virtual bool visit(KisAdjustmentLayer* layer)
    {
        kdDebug(41010) << "Visiting on adjustment layer " << layer->name() << ", visible: " << layer->visible() << ", extent: "
                << layer->extent() << ", dirty: " << layer->dirtyRect() << ", paint rect: " << m_rc << endl;

        if (m_projection == 0) {
            return true;
        }

        if (!layer->visible())
            return true;

        KisPaintDeviceSP tempTarget = layer->temporaryTarget();
        if (tempTarget) {
            m_rc = (layer->extent() | tempTarget->extent()) & m_rc;
        }

        if (m_rc.width() == 0 || m_rc.height() == 0) // Don't even try
            return true;

        KisFilterConfiguration * cfg = layer->filter();
        if (!cfg) return false;


        KisFilter * f = KisFilterRegistry::instance()->get( cfg->name() );
        if (!f) return false;

        // Possibly enlarge the rect that changed (like for convolution filters)
        // m_rc = f->enlargeRect(m_rc, cfg);
        KisSelectionSP selection = layer->selection();

        // Copy of the projection -- use the copy-on-write trick. XXX NO COPY ON WRITE YET =(
        //KisPaintDeviceSP tmp = new KisPaintDevice(*m_projection);
        KisPaintDeviceSP tmp = 0;
        KisSelectionSP sel = selection;
        // If there's a selection, only keep the selected bits
        if (selection != 0) {
            tmp = new KisPaintDevice(m_projection->colorSpace());

            KisPainter gc(tmp);
            QRect selectedRect = selection->selectedRect();
            selectedRect &= m_rc;

            if (selectedRect.width() == 0 || selectedRect.height() == 0) // Don't even try
                return true;

            // Don't forget that we need to take into account the extended sourcing area as well
            //selectedRect = f->enlargeRect(selectedRect, cfg);

            //kdDebug() << k_funcinfo << selectedRect << endl;
            tmp->setX(selection->getX());
            tmp->setY(selection->getY());

            // Indirect painting
            if (tempTarget) {
                sel = new KisSelection();
                sel = paintIndirect(selection.data(), sel, layer, m_rc.left(), m_rc.top(),
                                    m_rc.left(), m_rc.top(), m_rc.width(), m_rc.height());
            }

            gc.bitBlt(selectedRect.x(), selectedRect.y(), COMPOSITE_COPY, m_projection,
                      selectedRect.x(), selectedRect.y(),
                      selectedRect.width(), selectedRect.height());
            gc.end();
        } else {
            tmp = new KisPaintDevice(*m_projection);
        }

        // Some filters will require usage of oldRawData, which is not available without
        // a transaction!
        KisTransaction* cmd = new KisTransaction("", tmp);

        // Filter the temporary paint device -- remember, these are only the selected bits,
        // if there was a selection.
        f->process(tmp, tmp, cfg, m_rc);

        delete cmd;

        // Copy the filtered bits onto the projection 
        KisPainter gc(m_projection);
        if (selection)
            gc.bltSelection(m_rc.left(), m_rc.top(),
                            COMPOSITE_OVER, tmp, sel, layer->opacity(),
                            m_rc.left(), m_rc.top(), m_rc.width(), m_rc.height());
        else
            gc.bitBlt(m_rc.left(), m_rc.top(),
                      COMPOSITE_OVER, tmp, layer->opacity(),
                      m_rc.left(), m_rc.top(), m_rc.width(), m_rc.height());
        gc.end();

        // Copy the finished projection onto the cache
        gc.begin(layer->cachedPaintDevice());
        gc.bitBlt(m_rc.left(), m_rc.top(),
                  COMPOSITE_COPY, m_projection, OPACITY_OPAQUE,
                  m_rc.left(), m_rc.top(), m_rc.width(), m_rc.height());
        layer->setClean(m_rc);
        return true;
    }

private:
    KisPaintDeviceSP m_projection;
    QRect m_rc;
};

#endif // KIS_MERGE_H_