/* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
/*
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 *
 * This Source Code Form is subject to the terms of the Mozilla Public
 * License, v. 2.0. If a copy of the MPL was not distributed with this
 * file, You can obtain one at http://mozilla.org/MPL/2.0/.
 *
 * This file incorporates work covered by the following license notice:
 *
 *   Licensed to the Apache Software Foundation (ASF) under one or more
 *   contributor license agreements. See the NOTICE file distributed
 *   with this work for additional information regarding copyright
 *   ownership. The ASF licenses this file to you under the Apache
 *   License, Version 2.0 (the "License"); you may not use this file
 *   except in compliance with the License. You may obtain a copy of
 *   the License at http://www.apache.org/licenses/LICENSE-2.0 .
 */


#include <comphelper/diagnose_ex.hxx>
#include <basegfx/matrix/b2dhommatrixtools.hxx>
#include <cppcanvas/basegfxfactory.hxx>
#include <cppcanvas/customsprite.hxx>

#include "slidechangebase.hxx"
#include <tools.hxx>

#include <algorithm>
#include <utility>

using namespace com::sun::star;

namespace slideshow::internal {

SlideChangeBase::SlideChangeBase( std::optional<SlideSharedPtr>           leavingSlide,
                                  const SlideSharedPtr&                   pEnteringSlide,
                                  SoundPlayerSharedPtr                    pSoundPlayer,
                                  const UnoViewContainer&                 rViewContainer,
                                  ScreenUpdater&                          rScreenUpdater,
                                  EventMultiplexer&                       rEventMultiplexer,
                                  bool                                    bCreateLeavingSprites,
                                  bool                                    bCreateEnteringSprites ) :
      mpSoundPlayer(std::move( pSoundPlayer )),
      mrEventMultiplexer(rEventMultiplexer),
      mrScreenUpdater(rScreenUpdater),
      maLeavingSlide(std::move( leavingSlide )),
      mpEnteringSlide( pEnteringSlide ),
      maViewData(),
      mrViewContainer(rViewContainer),
      mbCreateLeavingSprites(bCreateLeavingSprites),
      mbCreateEnteringSprites(bCreateEnteringSprites),
      mbSpritesVisible(false),
      mbFinished(false),
      mbPrefetched(false)
{
    ENSURE_OR_THROW(
        pEnteringSlide,
        "SlideChangeBase::SlideChangeBase(): Invalid entering slide!" );
}

SlideBitmapSharedPtr SlideChangeBase::getLeavingBitmap( const ViewEntry& rViewEntry ) const
{
    if( !rViewEntry.mpLeavingBitmap )
        rViewEntry.mpLeavingBitmap = createBitmap(rViewEntry.mpView,
                                                  maLeavingSlide);

    return rViewEntry.mpLeavingBitmap;
}

SlideBitmapSharedPtr SlideChangeBase::getEnteringBitmap( const ViewEntry& rViewEntry ) const
{
    if( !rViewEntry.mpEnteringBitmap )
        rViewEntry.mpEnteringBitmap = createBitmap( rViewEntry.mpView,
                                                    std::optional<SlideSharedPtr>(mpEnteringSlide) );

    return rViewEntry.mpEnteringBitmap;
}

SlideBitmapSharedPtr SlideChangeBase::createBitmap( const UnoViewSharedPtr&                rView,
                                                    const std::optional<SlideSharedPtr>& rSlide ) const
{
    SlideBitmapSharedPtr pRet;
    if( !rSlide )
        return pRet;

    SlideSharedPtr const & pSlide = *rSlide;
    if( !pSlide )
    {
        // TODO(P3): No need to generate a bitmap here. This only made
        // the code more uniform. Faster would be to simply clear the
        // sprite to black.

        // create empty, black-filled bitmap
        auto aSlideSize = mpEnteringSlide->getSlideSize();
        auto aVector = getSlideSizePixel(basegfx::B2DVector(aSlideSize.getWidth(), aSlideSize.getHeight()), rView);
        const basegfx::B2ISize slideSizePixel(aVector.getX(), aVector.getY());

        cppcanvas::CanvasSharedPtr pCanvas( rView->getCanvas() );

        // create a bitmap of appropriate size
        cppcanvas::BitmapSharedPtr pBitmap(
            cppcanvas::BaseGfxFactory::createBitmap(
                pCanvas,
                slideSizePixel ) );

        ENSURE_OR_THROW(
            pBitmap,
            "SlideChangeBase::createBitmap(): Cannot create page bitmap" );

        cppcanvas::BitmapCanvasSharedPtr pBitmapCanvas(
            pBitmap->getBitmapCanvas() );

        ENSURE_OR_THROW( pBitmapCanvas,
                          "SlideChangeBase::createBitmap(): "
                          "Cannot create page bitmap canvas" );

        // set transformation to identity (->device pixel)
        pBitmapCanvas->setTransformation( ::basegfx::B2DHomMatrix() );

        // clear bitmap to black
        fillRect( pBitmapCanvas,
                  ::basegfx::B2DRectangle( 0.0, 0.0,
                                           slideSizePixel.getWidth(),
                                           slideSizePixel.getHeight() ),
                  0x000000FFU );

        pRet = std::make_shared<SlideBitmap>( pBitmap );
    }
    else
    {
        pRet = pSlide->getCurrentSlideBitmap( rView );
    }

    return pRet;
}

::basegfx::B2ISize SlideChangeBase::getEnteringSlideSizePixel( const UnoViewSharedPtr& pView ) const
{
    auto aSlideSize = mpEnteringSlide->getSlideSize();
    auto aSlideSizePixel = getSlideSizePixel( basegfx::B2DVector(aSlideSize.getWidth(), aSlideSize.getHeight()), pView);
    return {aSlideSizePixel.getX(), aSlideSizePixel.getY() };
}

void SlideChangeBase::renderBitmap(
    SlideBitmapSharedPtr const & pSlideBitmap,
    cppcanvas::CanvasSharedPtr const & pCanvas )
{
    if( !(pSlideBitmap && pCanvas) )
        return;

    // need to render without any transformation (we
    // assume device units):
    const basegfx::B2DHomMatrix viewTransform(
        pCanvas->getTransformation() );
    const basegfx::B2DPoint pageOrigin(
        viewTransform * basegfx::B2DPoint() );
    const cppcanvas::CanvasSharedPtr pDevicePixelCanvas(
        pCanvas->clone() );

    // render at output position, don't modify bitmap object (no move!):
    const basegfx::B2DHomMatrix transform(basegfx::utils::createTranslateB2DHomMatrix(
        pageOrigin.getX(), pageOrigin.getY()));

    pDevicePixelCanvas->setTransformation( transform );
    pSlideBitmap->draw( pDevicePixelCanvas );
}

void SlideChangeBase::prefetch()
{
    // we're a one-shot activity, and already finished
    if( mbFinished || mbPrefetched )
        return;

    // register ourselves for view change events
    mrEventMultiplexer.addViewHandler( std::dynamic_pointer_cast<ViewEventHandler>(shared_from_this()) );

    // init views and create slide bitmaps
    for( const auto& pView : mrViewContainer )
        viewAdded( pView );

    mbPrefetched = true;
}

void SlideChangeBase::start( const AnimatableShapeSharedPtr&     /*rShape*/,
                             const ShapeAttributeLayerSharedPtr& /*rLayer*/ )
{
    // we're a one-shot activity, and already finished
    if( mbFinished )
        return;

    prefetch(); // no-op, if already done

    // get the subclasses a chance to do any specific initialization before run
    for ( ViewsVecT::const_iterator aCurr( beginViews() ), aEnd( endViews() ); aCurr != aEnd; ++aCurr )
        prepareForRun( *aCurr, aCurr->mpView->getCanvas() );

    // start accompanying sound effect, if any
    if( mpSoundPlayer )
    {
        mpSoundPlayer->startPlayback();
        // xxx todo: for now, presentation.cxx takes care about the slide
        // #i50492#  transition sound object, so just release it here
        mpSoundPlayer.reset();
    }
}

void SlideChangeBase::end()
{
    // we're a one-shot activity, and already finished
    if( mbFinished )
        return;

    try
    {
        // draw fully entered bitmap:
        ViewsVecT::const_iterator aCurr( beginViews() );
        const ViewsVecT::const_iterator aEnd( endViews() );
        while( aCurr != aEnd )
        {
            // fully clear view content to background color
            aCurr->mpView->clearAll();

            const SlideBitmapSharedPtr pSlideBitmap( getEnteringBitmap( *aCurr ));
            pSlideBitmap->clip( basegfx::B2DPolyPolygon() /* no clipping */ );
            aCurr->mpView->clearAll();
            renderBitmap( pSlideBitmap,
                          aCurr->mpView->getCanvas() );

            ++aCurr;
        }
    }
    catch( uno::Exception& )
    {
        // make sure releasing below happens
    }

    // swap changes to screen
    mrScreenUpdater.notifyUpdate();

    // make object dysfunctional
    mbFinished = true;
    ViewsVecT().swap(maViewData);
    maLeavingSlide.reset();
    mpEnteringSlide.reset();

    // sprites have been binned above
    mbSpritesVisible = false;

    // remove also from event multiplexer, we're dead anyway
    mrEventMultiplexer.removeViewHandler( std::dynamic_pointer_cast<ViewEventHandler>(shared_from_this()) );
}

bool SlideChangeBase::operator()( double nValue )
{
    if( mbFinished )
        return false;

    const std::size_t nEntries( maViewData.size() );
    bool bSpritesVisible( mbSpritesVisible );

    for( ::std::size_t i=0; i<nEntries; ++i )
    {
        // calc sprite offsets. The enter/leaving bitmaps are only
        // as large as the actual slides. For scaled-down
        // presentations, we have to move the left, top edge of
        // those bitmaps to the actual position, governed by the
        // given view transform. The aSpritePosPixel local
        // variable is already in device coordinate space
        // (i.e. pixel).

        ViewEntry& rViewEntry( maViewData[i] );
        const ::cppcanvas::CanvasSharedPtr& rCanvas( rViewEntry.mpView->getCanvas() );
        ::cppcanvas::CustomSpriteSharedPtr& rInSprite( rViewEntry.mpInSprite );
        ::cppcanvas::CustomSpriteSharedPtr& rOutSprite( rViewEntry.mpOutSprite );

        // TODO(F2): Properly respect clip here.

        // Might have to be transformed, too.
        const ::basegfx::B2DHomMatrix aViewTransform(
            rViewEntry.mpView->getTransformation() );
        const ::basegfx::B2DPoint aSpritePosPixel(
            aViewTransform * ::basegfx::B2DPoint() );

        // move sprite to final output position, in
        // device coordinates
        if( rOutSprite )
            rOutSprite->movePixel( aSpritePosPixel );
        if( rInSprite )
            rInSprite->movePixel( aSpritePosPixel );

        if( !mbSpritesVisible )
        {
            if( rOutSprite )
            {
                // only render once: clipping is done
                // exclusively with the sprite
                const ::cppcanvas::CanvasSharedPtr pOutContentCanvas(
                    rOutSprite->getContentCanvas() );
                if( pOutContentCanvas)
                {
                    // TODO(Q2): Use basegfx bitmaps here

                    // TODO(F1): SlideBitmap is not fully portable
                    // between different canvases!

                    // render the content
                    OSL_ASSERT( getLeavingBitmap( rViewEntry ) );
                    if( getLeavingBitmap( rViewEntry ) )
                        getLeavingBitmap( rViewEntry )->draw( pOutContentCanvas );
                }
            }

            if( rInSprite )
            {
                // only render once: clipping is done
                // exclusively with the sprite
                const ::cppcanvas::CanvasSharedPtr pInContentCanvas(
                    rInSprite->getContentCanvas() );
                if( pInContentCanvas )
                {
                    // TODO(Q2): Use basegfx bitmaps here

                    // TODO(F1): SlideBitmap is not fully portable
                    // between different canvases!

                    // render the content
                    getEnteringBitmap( rViewEntry )->draw( pInContentCanvas );
                }
            }
        }

        if( rOutSprite )
            performOut( rOutSprite, rViewEntry, rCanvas, nValue );
        if( rInSprite )
            performIn( rInSprite, rViewEntry, rCanvas, nValue );

        // finishing deeds for first run.
        if( !mbSpritesVisible)
        {
            // enable sprites:
            if( rOutSprite )
                rOutSprite->show();
            if( rInSprite )
                rInSprite->show();
            bSpritesVisible = true;
        }
    } // for_each( sprite )

    mbSpritesVisible = bSpritesVisible;
    mrScreenUpdater.notifyUpdate();

    return true;
}

void SlideChangeBase::prepareForRun(
    const ViewEntry& /* rViewEntry */,
    const cppcanvas::CanvasSharedPtr& /* rDestinationCanvas */ )
{
}

void SlideChangeBase::performIn(
    const cppcanvas::CustomSpriteSharedPtr&   /*rSprite*/,
    const ViewEntry&                          /*rViewEntry*/,
    const cppcanvas::CanvasSharedPtr&         /*rDestinationCanvas*/,
    double                                    /*t*/ )
{
}

void SlideChangeBase::performOut(
    const cppcanvas::CustomSpriteSharedPtr&  /*rSprite*/,
    const ViewEntry&                         /*rViewEntry*/,
    const cppcanvas::CanvasSharedPtr&        /*rDestinationCanvas*/,
    double                                   /*t*/ )
{
}

double SlideChangeBase::getUnderlyingValue() const
{
    return 0.0;     // though this should be used in concert with
                    // ActivitiesFactory::createSimpleActivity, better
                    // explicitly name our start value.
                    // Permissible range for operator() above is [0,1]
}

void SlideChangeBase::viewAdded( const UnoViewSharedPtr& rView )
{
    // we're a one-shot activity, and already finished
    if( mbFinished )
        return;

    maViewData.emplace_back(rView );

    ViewEntry& rEntry( maViewData.back() );
    getEnteringBitmap( rEntry );
    getLeavingBitmap( rEntry );
    addSprites( rEntry );
}

void SlideChangeBase::viewRemoved( const UnoViewSharedPtr& rView )
{
    // we're a one-shot activity, and already finished
    if( mbFinished )
        return;

    // erase corresponding entry from maViewData
    std::erase_if(maViewData,
            [rView]( const ViewEntry& rViewEntry )
            { return rView == rViewEntry.getView(); } );
}

void SlideChangeBase::viewChanged( const UnoViewSharedPtr& rView )
{
    // we're a one-shot activity, and already finished
    if( mbFinished )
        return;

    // find entry corresponding to modified view
    ViewsVecT::iterator aModifiedEntry(
        std::find_if(
            maViewData.begin(),
            maViewData.end(),
            [rView]( const ViewEntry& rViewEntry )
            { return rView == rViewEntry.getView(); } ) );

    OSL_ASSERT( aModifiedEntry != maViewData.end() );
    if( aModifiedEntry == maViewData.end() )
        return;

    // clear stale info (both bitmaps and sprites prolly need a
    // resize)
    clearViewEntry( *aModifiedEntry );
    addSprites( *aModifiedEntry );
}

void SlideChangeBase::viewsChanged()
{
    // we're a one-shot activity, and already finished
    if( mbFinished )
        return;

    for( auto& rView : maViewData )
    {
        // clear stale info (both bitmaps and sprites prolly need a
        // resize)
        clearViewEntry( rView );
        addSprites( rView );
    }
}

cppcanvas::CustomSpriteSharedPtr SlideChangeBase::createSprite(
    UnoViewSharedPtr const & pView,
    basegfx::B2DSize const & rSpriteSize,
    double                   nPrio ) const
{
    // TODO(P2): change to bitmapsprite once that's working
    const cppcanvas::CustomSpriteSharedPtr pSprite(
        pView->createSprite( rSpriteSize,
                             nPrio ));

    // alpha default is 0.0, which seems to be
    // a bad idea when viewing content...
    pSprite->setAlpha( 1.0 );
    if (mbSpritesVisible)
        pSprite->show();

    return pSprite;
}

void SlideChangeBase::addSprites( ViewEntry& rEntry )
{
    if( mbCreateLeavingSprites && maLeavingSlide )
    {
        // create leaving sprite:
        const basegfx::B2ISize leavingSlideSizePixel(
            getLeavingBitmap( rEntry )->getSize() );

        rEntry.mpOutSprite = createSprite( rEntry.mpView,
                                           basegfx::B2DSize( leavingSlideSizePixel ),
                                           100 );
    }

    if( mbCreateEnteringSprites )
    {
        // create entering sprite:
        auto aSlideSizePixel = getSlideSizePixel(basegfx::B2DVector(mpEnteringSlide->getSlideSize().getWidth(), mpEnteringSlide->getSlideSize().getHeight()), rEntry.mpView);
        const basegfx::B2ISize enteringSlideSizePixel(aSlideSizePixel.getX(), aSlideSizePixel.getY());

        rEntry.mpInSprite = createSprite( rEntry.mpView,
                                          basegfx::B2DSize( enteringSlideSizePixel ),
                                          101 );
    }
}

void SlideChangeBase::clearViewEntry( ViewEntry& rEntry )
{
    // clear stale info (both bitmaps and sprites prolly need a
    // resize)
    rEntry.mpEnteringBitmap.reset();
    rEntry.mpLeavingBitmap.reset();
    rEntry.mpInSprite.reset();
    rEntry.mpOutSprite.reset();
}

} // namespace presentation

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