/* -*- 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 <controller/SlsInsertionIndicatorHandler.hxx>
#include <utility>
#include <view/SlideSorterView.hxx>
#include <view/SlsLayouter.hxx>
#include <view/SlsInsertAnimator.hxx>
#include <view/SlsInsertionIndicatorOverlay.hxx>
#include <model/SlideSorterModel.hxx>
#include <model/SlsPageEnumerationProvider.hxx>
#include <com/sun/star/datatransfer/dnd/DNDConstants.hpp>
#include <osl/diagnose.h>

#include <SlideSorter.hxx>

using namespace ::com::sun::star::datatransfer::dnd::DNDConstants;

namespace sd::slidesorter::controller {

InsertionIndicatorHandler::InsertionIndicatorHandler (SlideSorter& rSlideSorter)
    : mrSlideSorter(rSlideSorter),
      mpInsertionIndicatorOverlay(std::make_shared<view::InsertionIndicatorOverlay>(rSlideSorter)),
      meMode(MoveMode),
      mbIsInsertionTrivial(false),
      mbIsActive(false),
      mbIsReadOnly(mrSlideSorter.GetModel().IsReadOnly()),
      mbIsOverSourceView(true),
      maIconSize(0,0),
      mbIsForcedShow(false)
{
}

InsertionIndicatorHandler::~InsertionIndicatorHandler() COVERITY_NOEXCEPT_FALSE
{
}

void InsertionIndicatorHandler::Start (const bool bIsOverSourceView)
{
    if (mbIsActive)
    {
        OSL_ASSERT(!mbIsActive);
    }

    mbIsReadOnly = mrSlideSorter.GetModel().IsReadOnly();
    if (mbIsReadOnly)
        return;

    mbIsActive = true;
    mbIsOverSourceView = bIsOverSourceView;
}

void InsertionIndicatorHandler::End (const controller::Animator::AnimationMode eMode)
{
    if (mbIsForcedShow ||  ! mbIsActive || mbIsReadOnly)
        return;

    GetInsertAnimator()->Reset(eMode);

    mbIsActive = false;
    //    maInsertPosition = view::InsertPosition();
    meMode = UnknownMode;

    mpInsertionIndicatorOverlay->Hide();
    mpInsertionIndicatorOverlay = std::make_shared<view::InsertionIndicatorOverlay>(mrSlideSorter);
}

void InsertionIndicatorHandler::ForceShow()
{
    mbIsForcedShow = true;
}

void InsertionIndicatorHandler::ForceEnd()
{
    mbIsForcedShow = false;
    End(Animator::AM_Immediate);
}

void InsertionIndicatorHandler::UpdateIndicatorIcon (const SdTransferable* pTransferable)
{
    mpInsertionIndicatorOverlay->Create(pTransferable);
    maIconSize = mpInsertionIndicatorOverlay->GetSize();
}

InsertionIndicatorHandler::Mode InsertionIndicatorHandler::GetModeFromDndAction (
    const sal_Int8 nDndAction)
{
    if ((nDndAction & ACTION_MOVE) != 0)
        return MoveMode;
    else if ((nDndAction & ACTION_COPY) != 0)
        return CopyMode;
    else
        return UnknownMode;
}

void InsertionIndicatorHandler::UpdatePosition (
    const Point& rMouseModelPosition,
    const Mode eMode)
{
    if ( ! mbIsActive)
        return;

    if (mbIsReadOnly)
        return;

    SetPosition(rMouseModelPosition, eMode);
}

void InsertionIndicatorHandler::UpdatePosition (
    const Point& rMouseModelPosition,
    const sal_Int8 nDndAction)
{
    UpdatePosition(rMouseModelPosition, GetModeFromDndAction(nDndAction));
}

sal_Int32 InsertionIndicatorHandler::GetInsertionPageIndex() const
{
    if (mbIsReadOnly)
        return -1;
    else
        return maInsertPosition.GetIndex();
}

void InsertionIndicatorHandler::SetPosition (
    const Point& rPoint,
    const Mode eMode)
{
    view::Layouter& rLayouter (mrSlideSorter.GetView().GetLayouter());

    const view::InsertPosition aInsertPosition (rLayouter.GetInsertPosition(
        rPoint,
        maIconSize,
        mrSlideSorter.GetModel()));

    if (maInsertPosition == aInsertPosition && meMode == eMode)
        return;

    maInsertPosition = aInsertPosition;
    meMode = eMode;
    mbIsInsertionTrivial = IsInsertionTrivial(maInsertPosition.GetIndex(), eMode);
    if (maInsertPosition.GetIndex()>=0 && ! mbIsInsertionTrivial)
    {
        mpInsertionIndicatorOverlay->SetLocation(maInsertPosition.GetLocation());

        GetInsertAnimator()->SetInsertPosition(maInsertPosition);
        mpInsertionIndicatorOverlay->Show();
    }
    else
    {
        GetInsertAnimator()->Reset(Animator::AM_Animated);
        mpInsertionIndicatorOverlay->Hide();
    }
}

std::shared_ptr<view::InsertAnimator> const & InsertionIndicatorHandler::GetInsertAnimator()
{
    if ( ! mpInsertAnimator)
        mpInsertAnimator = std::make_shared<view::InsertAnimator>(mrSlideSorter);
    return mpInsertAnimator;
}

bool InsertionIndicatorHandler::IsInsertionTrivial (
    const sal_Int32 nInsertionIndex,
    const Mode eMode) const
{
    if (eMode == CopyMode)
        return false;
    else if (eMode == UnknownMode)
        return true;

    if ( ! mbIsOverSourceView)
        return false;

    // Iterate over all selected pages and check whether there are
    // holes.  While we do this we remember the indices of the first and
    // last selected page as preparation for the next step.
    sal_Int32 nCurrentIndex = -1;
    sal_Int32 nFirstIndex = -1;
    sal_Int32 nLastIndex = -1;
    model::PageEnumeration aSelectedPages (
        model::PageEnumerationProvider::CreateSelectedPagesEnumeration(
            mrSlideSorter.GetModel()));
    while (aSelectedPages.HasMoreElements())
    {
        model::SharedPageDescriptor pDescriptor (aSelectedPages.GetNextElement());

        // Get the page number and compare it to the last one.
        const sal_Int32 nPageNumber (pDescriptor->GetPageIndex());
        if (nCurrentIndex>=0 && nPageNumber>(nCurrentIndex+1))
            return false;
        else
            nCurrentIndex = nPageNumber;

        // Remember indices of the first and last page of the selection.
        if (nFirstIndex == -1)
            nFirstIndex = nPageNumber;
        nLastIndex = nPageNumber;
    }

    // When we come here then the selection has no holes.  We still have
    // to check that the insertion position is not directly in front or
    // directly behind the selection and thus moving the selection there
    // would not change the model.
    return nInsertionIndex >= nFirstIndex && nInsertionIndex <= (nLastIndex+1);
}

bool InsertionIndicatorHandler::IsInsertionTrivial (const sal_Int8 nDndAction)
{
    return IsInsertionTrivial(GetInsertionPageIndex(), GetModeFromDndAction(nDndAction));
}

//===== InsertionIndicatorHandler::ForceShowContext ===========================

InsertionIndicatorHandler::ForceShowContext::ForceShowContext (
    std::shared_ptr<InsertionIndicatorHandler> pHandler)
    : mpHandler(std::move(pHandler))
{
    mpHandler->ForceShow();
}

InsertionIndicatorHandler::ForceShowContext::~ForceShowContext() COVERITY_NOEXCEPT_FALSE
{
    mpHandler->ForceEnd();
}

} // end of namespace ::sd::slidesorter::controller

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