/* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
/*
 * This file is part of the LibreOffice project.
 *
 * 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 <sal/config.h>
#include <sal/log.hxx>
#include <osl/diagnose.h>

#include <algorithm>
#include <map>
#include <vector>

#include "vclhelperbufferdevice.hxx"
#include <basegfx/range/b2drange.hxx>
#include <vcl/bitmapex.hxx>
#include <basegfx/matrix/b2dhommatrix.hxx>
#include <tools/stream.hxx>
#include <vcl/timer.hxx>
#include <cppuhelper/basemutex.hxx>
#include <vcl/lazydelete.hxx>
#include <vcl/dibtools.hxx>


// buffered VDev usage

namespace
{
    typedef std::vector< VclPtr<VirtualDevice> > aBuffers;

    class VDevBuffer : public Timer, protected cppu::BaseMutex
    {
    private:
        // available buffers
        aBuffers            maFreeBuffers;

        // allocated/used buffers (remembered to allow deleting them in destructor)
        aBuffers            maUsedBuffers;

        // remember what outputdevice was the template passed to VirtualDevice::Create
        // so we can test if that OutputDevice was disposed before reusing a
        // virtualdevice because that isn't safe to do at least for Gtk2
        std::map< VclPtr<VirtualDevice>, VclPtr<OutputDevice> > maDeviceTemplates;

    public:
        VDevBuffer();
        virtual ~VDevBuffer() override;

        VclPtr<VirtualDevice> alloc(OutputDevice& rOutDev, const Size& rSizePixel, bool bClear, bool bMonoChrome);
        void free(VirtualDevice& rDevice);

        // Timer virtuals
        virtual void Invoke() override;
    };

    VDevBuffer::VDevBuffer()
    :   Timer("VDevBuffer timer"),
        maFreeBuffers(),
        maUsedBuffers()
    {
        SetTimeout(10L * 1000L); // ten seconds
        SetDebugName("drawinglayer::VDevBuffer via Invoke()");
    }

    VDevBuffer::~VDevBuffer()
    {
        ::osl::MutexGuard aGuard(m_aMutex);
        Stop();

        while(!maFreeBuffers.empty())
        {
            (*(maFreeBuffers.end() - 1)).disposeAndClear();
            maFreeBuffers.pop_back();
        }

        while(!maUsedBuffers.empty())
        {
            (*(maUsedBuffers.end() - 1)).disposeAndClear();
            maUsedBuffers.pop_back();
        }
    }

    VclPtr<VirtualDevice> VDevBuffer::alloc(OutputDevice& rOutDev, const Size& rSizePixel, bool bClear, bool bMonoChrome)
    {
        ::osl::MutexGuard aGuard(m_aMutex);
        VclPtr<VirtualDevice> pRetval;

        sal_Int32 nBits = bMonoChrome ? 1 : rOutDev.GetBitCount();

        bool bOkay(false);
        if(!maFreeBuffers.empty())
        {
            aBuffers::iterator aFound(maFreeBuffers.end());

            for(aBuffers::iterator a(maFreeBuffers.begin()); a != maFreeBuffers.end(); ++a)
            {
                assert(*a && "Empty pointer in VDevBuffer (!)");

                if (nBits == (*a)->GetBitCount())
                {
                    // candidate is valid due to bit depth
                    if(aFound != maFreeBuffers.end())
                    {
                        // already found
                        if(bOkay)
                        {
                            // found is valid
                            const bool bCandidateOkay((*a)->GetOutputWidthPixel() >= rSizePixel.getWidth() && (*a)->GetOutputHeightPixel() >= rSizePixel.getHeight());

                            if(bCandidateOkay)
                            {
                                // found and candidate are valid
                                const sal_uLong aSquare((*aFound)->GetOutputWidthPixel() * (*aFound)->GetOutputHeightPixel());
                                const sal_uLong aCandidateSquare((*a)->GetOutputWidthPixel() * (*a)->GetOutputHeightPixel());

                                if(aCandidateSquare < aSquare)
                                {
                                    // candidate is valid and smaller, use it
                                    aFound = a;
                                }
                            }
                            else
                            {
                                // found is valid, candidate is not. Keep found
                            }
                        }
                        else
                        {
                            // found is invalid, use candidate
                            aFound = a;
                            bOkay = (*aFound)->GetOutputWidthPixel() >= rSizePixel.getWidth() && (*aFound)->GetOutputHeightPixel() >= rSizePixel.getHeight();
                        }
                    }
                    else
                    {
                        // none yet, use candidate
                        aFound = a;
                        bOkay = (*aFound)->GetOutputWidthPixel() >= rSizePixel.getWidth() && (*aFound)->GetOutputHeightPixel() >= rSizePixel.getHeight();
                    }
                }
            }

            if(aFound != maFreeBuffers.end())
            {
                pRetval = *aFound;
                maFreeBuffers.erase(aFound);
            }
        }

        if (pRetval)
        {
            // found a suitable cached virtual device, but the
            // outputdevice it was based on has been disposed,
            // drop it and create a new one instead as reusing
            // such devices is unsafe under at least Gtk2
            if (maDeviceTemplates[pRetval]->isDisposed())
            {
                maDeviceTemplates.erase(pRetval);
                pRetval = nullptr;
            }
            else
            {
                if (bOkay)
                {
                    if (bClear)
                    {
                        pRetval->Erase(::tools::Rectangle(0, 0, rSizePixel.getWidth(), rSizePixel.getHeight()));
                    }
                }
                else
                {
                    pRetval->SetOutputSizePixel(rSizePixel, bClear);
                }
            }
        }

        // no success yet, create new buffer
        if(!pRetval)
        {
            pRetval = VclPtr<VirtualDevice>::Create(rOutDev, bMonoChrome ? DeviceFormat::BITMASK : DeviceFormat::DEFAULT);
            maDeviceTemplates[pRetval] = &rOutDev;
            pRetval->SetOutputSizePixel(rSizePixel, bClear);
        }
        else
        {
            // reused, reset some values
            pRetval->SetMapMode();
            pRetval->SetRasterOp(RasterOp::OverPaint);
        }

        // remember allocated buffer
        maUsedBuffers.push_back(pRetval);

        return pRetval;
    }

    void VDevBuffer::free(VirtualDevice& rDevice)
    {
        ::osl::MutexGuard aGuard(m_aMutex);
        const aBuffers::iterator aUsedFound(std::find(maUsedBuffers.begin(), maUsedBuffers.end(), &rDevice));
        OSL_ENSURE(aUsedFound != maUsedBuffers.end(), "OOps, non-registered buffer freed (!)");

        maUsedBuffers.erase(aUsedFound);
        maFreeBuffers.emplace_back(&rDevice);
        SAL_WARN_IF(maFreeBuffers.size() > 1000, "drawinglayer", "excessive cached buffers, "
            << maFreeBuffers.size() << " entries!");
        Start();
    }

    void VDevBuffer::Invoke()
    {
        ::osl::MutexGuard aGuard(m_aMutex);

        while(!maFreeBuffers.empty())
        {
            aBuffers::iterator aLastOne(maFreeBuffers.end() - 1);
            maDeviceTemplates.erase(*aLastOne);
            aLastOne->disposeAndClear();
            maFreeBuffers.pop_back();
        }
    }
}


// support for rendering Bitmap and BitmapEx contents

namespace drawinglayer
{
    // static global VDev buffer for the VclProcessor2D's (VclMetafileProcessor2D and VclPixelProcessor2D)
    VDevBuffer& getVDevBuffer()
    {
        // secure global instance with Vcl's safe destroyer of external (seen by
        // library base) stuff, the remembered VDevs need to be deleted before
        // Vcl's deinit
        static vcl::DeleteOnDeinit< VDevBuffer > aVDevBuffer(new VDevBuffer());
        return *aVDevBuffer.get();
    }

    impBufferDevice::impBufferDevice(
        OutputDevice& rOutDev,
        const basegfx::B2DRange& rRange)
    :   mrOutDev(rOutDev),
        mpContent(nullptr),
        mpMask(nullptr),
        mpAlpha(nullptr)
    {
        basegfx::B2DRange aRangePixel(rRange);
        aRangePixel.transform(mrOutDev.GetViewTransformation());
        const ::tools::Rectangle aRectPixel(
            static_cast<sal_Int32>(floor(aRangePixel.getMinX())), static_cast<sal_Int32>(floor(aRangePixel.getMinY())),
            static_cast<sal_Int32>(ceil(aRangePixel.getMaxX())), static_cast<sal_Int32>(ceil(aRangePixel.getMaxY())));
        const Point aEmptyPoint;
        maDestPixel = ::tools::Rectangle(aEmptyPoint, mrOutDev.GetOutputSizePixel());
        maDestPixel.Intersection(aRectPixel);

        if(isVisible())
        {
#ifdef IOS
            // Exact mechanism unknown, but for some reason SmartArt
            // rendering, especially shadows, is broken on iOS unless
            // we pass 'true' here. Are virtual devices always de
            // facto cleared when created on other platforms?
            mpContent = getVDevBuffer().alloc(mrOutDev, maDestPixel.GetSize(), true, false);
#else
            mpContent = getVDevBuffer().alloc(mrOutDev, maDestPixel.GetSize(), false, false);
#endif

            // #i93485# assert when copying from window to VDev is used
            OSL_ENSURE(mrOutDev.GetOutDevType() != OUTDEV_WINDOW,
                "impBufferDevice render helper: Copying from Window to VDev, this should be avoided (!)");

            const bool bWasEnabledSrc(mrOutDev.IsMapModeEnabled());
            mrOutDev.EnableMapMode(false);
            mpContent->DrawOutDev(aEmptyPoint, maDestPixel.GetSize(), maDestPixel.TopLeft(), maDestPixel.GetSize(), mrOutDev);
            mrOutDev.EnableMapMode(bWasEnabledSrc);

            MapMode aNewMapMode(mrOutDev.GetMapMode());

            const Point aLogicTopLeft(mrOutDev.PixelToLogic(maDestPixel.TopLeft()));
            aNewMapMode.SetOrigin(Point(-aLogicTopLeft.X(), -aLogicTopLeft.Y()));

            mpContent->SetMapMode(aNewMapMode);

            // copy AA flag for new target
            mpContent->SetAntialiasing(mrOutDev.GetAntialiasing());

            // copy RasterOp (e.g. may be RasterOp::Xor on destination)
            mpContent->SetRasterOp(mrOutDev.GetRasterOp());
        }
    }

    impBufferDevice::~impBufferDevice()
    {
        if(mpContent)
        {
            getVDevBuffer().free(*mpContent);
        }

        if(mpMask)
        {
            getVDevBuffer().free(*mpMask);
        }

        if(mpAlpha)
        {
            getVDevBuffer().free(*mpAlpha);
        }
    }

    void impBufferDevice::paint(double fTrans)
    {
        if(isVisible())
        {
            const Point aEmptyPoint;
            const Size aSizePixel(maDestPixel.GetSize());
            const bool bWasEnabledDst(mrOutDev.IsMapModeEnabled());
#ifdef DBG_UTIL
            static bool bDoSaveForVisualControl(false); // loplugin:constvars:ignore
#endif

            mrOutDev.EnableMapMode(false);
            mpContent->EnableMapMode(false);

#ifdef DBG_UTIL
            if(bDoSaveForVisualControl)
            {
                SvFileStream aNew(
#ifdef _WIN32
                    "c:\\content.bmp",
#else
                    "~/content.bmp",
#endif
                    StreamMode::WRITE|StreamMode::TRUNC);
                Bitmap aContent(mpContent->GetBitmap(aEmptyPoint, aSizePixel));
                WriteDIB(aContent, aNew, false, true);
            }
#endif

            // during painting the buffer, disable evtl. set RasterOp (may be RasterOp::Xor)
            const RasterOp aOrigRasterOp(mrOutDev.GetRasterOp());
            mrOutDev.SetRasterOp(RasterOp::OverPaint);

            if(mpAlpha)
            {
                mpAlpha->EnableMapMode(false);
                const AlphaMask aAlphaMask(mpAlpha->GetBitmap(aEmptyPoint, aSizePixel));

#ifdef DBG_UTIL
                if(bDoSaveForVisualControl)
                {
                    SvFileStream aNew(
#ifdef _WIN32
                        "c:\\transparence.bmp",
#else
                        "~/transparence.bmp",
#endif
                        StreamMode::WRITE|StreamMode::TRUNC);
                    WriteDIB(aAlphaMask.GetBitmap(), aNew, false, true);
                }
#endif

                Bitmap aContent(mpContent->GetBitmap(aEmptyPoint, aSizePixel));
                mrOutDev.DrawBitmapEx(maDestPixel.TopLeft(), BitmapEx(aContent, aAlphaMask));
            }
            else if(mpMask)
            {
                mpMask->EnableMapMode(false);
                const Bitmap aMask(mpMask->GetBitmap(aEmptyPoint, aSizePixel));

#ifdef DBG_UTIL
                if(bDoSaveForVisualControl)
                {
                    SvFileStream aNew(
#ifdef _WIN32
                        "c:\\mask.bmp",
#else
                        "~/mask.bmp",
#endif
                        StreamMode::WRITE|StreamMode::TRUNC);
                    WriteDIB(aMask, aNew, false, true);
                }
#endif

                Bitmap aContent(mpContent->GetBitmap(aEmptyPoint, aSizePixel));
                mrOutDev.DrawBitmapEx(maDestPixel.TopLeft(), BitmapEx(aContent, aMask));
            }
            else if(0.0 != fTrans)
            {
                sal_uInt8 nMaskValue(static_cast<sal_uInt8>(basegfx::fround(fTrans * 255.0)));
                const AlphaMask aAlphaMask(aSizePixel, &nMaskValue);
                Bitmap aContent(mpContent->GetBitmap(aEmptyPoint, aSizePixel));
                mrOutDev.DrawBitmapEx(maDestPixel.TopLeft(), BitmapEx(aContent, aAlphaMask));
            }
            else
            {
                mrOutDev.DrawOutDev(maDestPixel.TopLeft(), aSizePixel,
                                    aEmptyPoint, aSizePixel,
                                    *mpContent);
            }

            mrOutDev.SetRasterOp(aOrigRasterOp);
            mrOutDev.EnableMapMode(bWasEnabledDst);
        }
    }

    VirtualDevice& impBufferDevice::getContent()
    {
        assert(mpContent && "impBufferDevice: No content, check isVisible() before accessing (!)");
        return *mpContent;
    }

    VirtualDevice& impBufferDevice::getMask()
    {
        assert(mpContent && "impBufferDevice: No content, check isVisible() before accessing (!)");
        if (!mpMask)
        {
            mpMask = getVDevBuffer().alloc(mrOutDev, maDestPixel.GetSize(), true, true);
            mpMask->SetMapMode(mpContent->GetMapMode());

            // do NOT copy AA flag for mask!
        }

        return *mpMask;
    }

    VirtualDevice& impBufferDevice::getTransparence()
    {
        OSL_ENSURE(mpContent, "impBufferDevice: No content, check isVisible() before accessing (!)");
        if(!mpAlpha)
        {
            mpAlpha = getVDevBuffer().alloc(mrOutDev, maDestPixel.GetSize(), true, false);
            mpAlpha->SetMapMode(mpContent->GetMapMode());

            // copy AA flag for new target; masking needs to be smooth
            mpAlpha->SetAntialiasing(mpContent->GetAntialiasing());
        }

        return *mpAlpha;
    }
} // end of namespace drawinglayer

/* vim:set shiftwidth=4 softtabstop=4 expandtab: */