/*

 * Copyright (C) 2007, 2009 Apple Inc. All rights reserved.

 *

 * Redistribution and use in source and binary forms, with or without

 * modification, are permitted provided that the following conditions

 * are met:

 *

 * 1.  Redistributions of source code must retain the above copyright

 *     notice, this list of conditions and the following disclaimer. 

 * 2.  Redistributions in binary form must reproduce the above copyright

 *     notice, this list of conditions and the following disclaimer in the

 *     documentation and/or other materials provided with the distribution. 

 * 3.  Neither the name of Apple Computer, Inc. ("Apple") nor the names of

 *     its contributors may be used to endorse or promote products derived

 *     from this software without specific prior written permission. 

 *

 * THIS SOFTWARE IS PROVIDED BY APPLE AND ITS CONTRIBUTORS "AS IS" AND ANY

 * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED

 * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE

 * DISCLAIMED. IN NO EVENT SHALL APPLE OR ITS CONTRIBUTORS BE LIABLE FOR ANY

 * DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES

 * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;

 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND

 * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT

 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF

 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.

 */

#include "config.h"

#include "DOMSelection.h"

#include "ExceptionCode.h"

#include "Frame.h"

#include "Node.h"

#include "PlatformString.h"

#include "Range.h"

#include "SelectionController.h"

#include "TextIterator.h"

#include "htmlediting.h"

namespace WebCore {

static Node* selectionShadowAncestor(Frame* frame)

{

    Node* node = frame->selection()->selection().base().anchorNode();

    if (!node)

        return 0;

    Node* shadowAncestor = node->shadowAncestorNode();

    if (shadowAncestor == node)

        return 0;

    return shadowAncestor;

}

DOMSelection::DOMSelection(Frame* frame)

    : m_frame(frame)

{

}

Frame* DOMSelection::frame() const

{

    return m_frame;

}

void DOMSelection::disconnectFrame()

{

    m_frame = 0;

}

const VisibleSelection& DOMSelection::visibleSelection() const

{

    ASSERT(m_frame);

    return m_frame->selection()->selection();

}

static Position anchorPosition(const VisibleSelection& selection)

{

    Position anchor = selection.isBaseFirst() ? selection.start() : selection.end();

    return rangeCompliantEquivalent(anchor);

}

static Position focusPosition(const VisibleSelection& selection)

{

    Position focus = selection.isBaseFirst() ? selection.end() : selection.start();

    return rangeCompliantEquivalent(focus);

}

static Position basePosition(const VisibleSelection& selection)

{

    return rangeCompliantEquivalent(selection.base());

}

static Position extentPosition(const VisibleSelection& selection)

{

    return rangeCompliantEquivalent(selection.extent());

}

Node* DOMSelection::anchorNode() const

{

    if (!m_frame)

        return 0;

    if (Node* shadowAncestor = selectionShadowAncestor(m_frame))

        return shadowAncestor->parentNode();

    return anchorPosition(visibleSelection()).node();

}

int DOMSelection::anchorOffset() const

{

    if (!m_frame)

        return 0;

    if (Node* shadowAncestor = selectionShadowAncestor(m_frame))

        return shadowAncestor->nodeIndex();

    return anchorPosition(visibleSelection()).deprecatedEditingOffset();

}

Node* DOMSelection::focusNode() const

{

    if (!m_frame)

        return 0;

    if (Node* shadowAncestor = selectionShadowAncestor(m_frame))

        return shadowAncestor->parentNode();

    return focusPosition(visibleSelection()).node();

}

int DOMSelection::focusOffset() const

{

    if (!m_frame)

        return 0;

    if (Node* shadowAncestor = selectionShadowAncestor(m_frame))

        return shadowAncestor->nodeIndex();

    return focusPosition(visibleSelection()).deprecatedEditingOffset();

}

Node* DOMSelection::baseNode() const

{

    if (!m_frame)

        return 0;

    if (Node* shadowAncestor = selectionShadowAncestor(m_frame))

        return shadowAncestor->parentNode();

    return basePosition(visibleSelection()).node();

}

int DOMSelection::baseOffset() const

{

    if (!m_frame)

        return 0;

    if (Node* shadowAncestor = selectionShadowAncestor(m_frame))

        return shadowAncestor->nodeIndex();

    return basePosition(visibleSelection()).deprecatedEditingOffset();

}

Node* DOMSelection::extentNode() const

{

    if (!m_frame)

        return 0;

    if (Node* shadowAncestor = selectionShadowAncestor(m_frame))

        return shadowAncestor->parentNode();

    return extentPosition(visibleSelection()).node();

}

int DOMSelection::extentOffset() const

{

    if (!m_frame)

        return 0;

    if (Node* shadowAncestor = selectionShadowAncestor(m_frame))

        return shadowAncestor->nodeIndex();

    return extentPosition(visibleSelection()).deprecatedEditingOffset();

}

bool DOMSelection::isCollapsed() const

{

    if (!m_frame || selectionShadowAncestor(m_frame))

        return true;

    return !m_frame->selection()->isRange();

}

String DOMSelection::type() const

{

    if (!m_frame)

        return String();

    SelectionController* selection = m_frame->selection();

    // This is a WebKit DOM extension, incompatible with an IE extension

    // IE has this same attribute, but returns "none", "text" and "control"

    // http://msdn.microsoft.com/en-us/library/ms534692(VS.85).aspx

    if (selection->isNone())

        return "None";

    if (selection->isCaret())

        return "Caret";

    return "Range";

}

int DOMSelection::rangeCount() const

{

    if (!m_frame)

        return 0;

    return m_frame->selection()->isNone() ? 0 : 1;

}

void DOMSelection::collapse(Node* node, int offset, ExceptionCode& ec)

{

    if (!m_frame)

        return;

    if (offset < 0) {

        ec = INDEX_SIZE_ERR;

        return;

    }

    if (!isValidForPosition(node))

        return;

    m_frame->selection()->moveTo(VisiblePosition(node, offset, DOWNSTREAM));

}

void DOMSelection::collapseToEnd()

{

    if (!m_frame)

        return;

    const VisibleSelection& selection = m_frame->selection()->selection();

    m_frame->selection()->moveTo(VisiblePosition(selection.end(), DOWNSTREAM));

}

void DOMSelection::collapseToStart()

{

    if (!m_frame)

        return;

    const VisibleSelection& selection = m_frame->selection()->selection();

    m_frame->selection()->moveTo(VisiblePosition(selection.start(), DOWNSTREAM));

}

void DOMSelection::empty()

{

    if (!m_frame)

        return;

    m_frame->selection()->clear();

}

void DOMSelection::setBaseAndExtent(Node* baseNode, int baseOffset, Node* extentNode, int extentOffset, ExceptionCode& ec)

{

    if (!m_frame)

        return;

    if (baseOffset < 0 || extentOffset < 0) {

        ec = INDEX_SIZE_ERR;

        return;

    }

    if (!isValidForPosition(baseNode) || !isValidForPosition(extentNode))

        return;

    VisiblePosition visibleBase = VisiblePosition(baseNode, baseOffset, DOWNSTREAM);

    VisiblePosition visibleExtent = VisiblePosition(extentNode, extentOffset, DOWNSTREAM);

    m_frame->selection()->moveTo(visibleBase, visibleExtent);

}

void DOMSelection::setPosition(Node* node, int offset, ExceptionCode& ec)

{

    if (!m_frame)

        return;

    if (offset < 0) {

        ec = INDEX_SIZE_ERR;

        return;

    }

    if (!isValidForPosition(node))

        return;

    m_frame->selection()->moveTo(VisiblePosition(node, offset, DOWNSTREAM));

}

void DOMSelection::modify(const String& alterString, const String& directionString, const String& granularityString)

{

    if (!m_frame)

        return;

    SelectionController::EAlteration alter;

    if (equalIgnoringCase(alterString, "extend"))

        alter = SelectionController::AlterationExtend;

    else if (equalIgnoringCase(alterString, "move"))

        alter = SelectionController::AlterationMove;

    else

        return;

    SelectionController::EDirection direction;

    if (equalIgnoringCase(directionString, "forward"))

        direction = SelectionController::DirectionForward;

    else if (equalIgnoringCase(directionString, "backward"))

        direction = SelectionController::DirectionBackward;

    else if (equalIgnoringCase(directionString, "left"))

        direction = SelectionController::DirectionLeft;

    else if (equalIgnoringCase(directionString, "right"))

        direction = SelectionController::DirectionRight;

    else

        return;

    TextGranularity granularity;

    if (equalIgnoringCase(granularityString, "character"))

        granularity = CharacterGranularity;

    else if (equalIgnoringCase(granularityString, "word"))

        granularity = WordGranularity;

    else if (equalIgnoringCase(granularityString, "sentence"))

        granularity = SentenceGranularity;

    else if (equalIgnoringCase(granularityString, "line"))

        granularity = LineGranularity;

    else if (equalIgnoringCase(granularityString, "paragraph"))

        granularity = ParagraphGranularity;

    else if (equalIgnoringCase(granularityString, "lineboundary"))

        granularity = LineBoundary;

    else if (equalIgnoringCase(granularityString, "sentenceboundary"))

        granularity = SentenceBoundary;

    else if (equalIgnoringCase(granularityString, "paragraphboundary"))

        granularity = ParagraphBoundary;

    else if (equalIgnoringCase(granularityString, "documentboundary"))

        granularity = DocumentBoundary;

    else

        return;

    m_frame->selection()->modify(alter, direction, granularity, false);

}

void DOMSelection::extend(Node* node, int offset, ExceptionCode& ec)

{

    if (!m_frame)

        return;

    if (!node) {

        ec = TYPE_MISMATCH_ERR;

        return;

    }

    if (offset < 0 || offset > (node->offsetInCharacters() ? caretMaxOffset(node) : (int)node->childNodeCount())) {

        ec = INDEX_SIZE_ERR;

        return;

    }

    if (!isValidForPosition(node))

        return;

    m_frame->selection()->setExtent(VisiblePosition(node, offset, DOWNSTREAM));

}

PassRefPtr<Range> DOMSelection::getRangeAt(int index, ExceptionCode& ec)

{

    if (!m_frame)

        return 0;

    if (index < 0 || index >= rangeCount()) {

        ec = INDEX_SIZE_ERR;

        return 0;

    }

    // If you're hitting this, you've added broken multi-range selection support

    ASSERT(rangeCount() == 1);

    if (Node* shadowAncestor = selectionShadowAncestor(m_frame)) {

        Node* container = shadowAncestor->parentNode();

        int offset = shadowAncestor->nodeIndex();

        return Range::create(shadowAncestor->document(), container, offset, container, offset);

    }

    const VisibleSelection& selection = m_frame->selection()->selection();

    return selection.firstRange();

}

void DOMSelection::removeAllRanges()

{

    if (!m_frame)

        return;

    m_frame->selection()->clear();

}

void DOMSelection::addRange(Range* r)

{

    if (!m_frame)

        return;

    if (!r)

        return;

    SelectionController* selection = m_frame->selection();

    if (selection->isNone()) {

        selection->setSelection(VisibleSelection(r));

        return;

    }

    RefPtr<Range> range = selection->selection().toNormalizedRange();

    ExceptionCode ec = 0;

    if (r->compareBoundaryPoints(Range::START_TO_START, range.get(), ec) == -1) {

        // We don't support discontiguous selection. We don't do anything if r and range don't intersect.

        if (r->compareBoundaryPoints(Range::START_TO_END, range.get(), ec) > -1) {

            if (r->compareBoundaryPoints(Range::END_TO_END, range.get(), ec) == -1)

                // The original range and r intersect.

                selection->setSelection(VisibleSelection(r->startPosition(), range->endPosition(), DOWNSTREAM));

            else

                // r contains the original range.

                selection->setSelection(VisibleSelection(r));

        }

    } else {

        // We don't support discontiguous selection. We don't do anything if r and range don't intersect.

        if (r->compareBoundaryPoints(Range::END_TO_START, range.get(), ec) < 1) {

            if (r->compareBoundaryPoints(Range::END_TO_END, range.get(), ec) == -1)

                // The original range contains r.

                selection->setSelection(VisibleSelection(range.get()));

            else

                // The original range and r intersect.

                selection->setSelection(VisibleSelection(range->startPosition(), r->endPosition(), DOWNSTREAM));

        }

    }

}

void DOMSelection::deleteFromDocument()

{

    if (!m_frame)

        return;

    SelectionController* selection = m_frame->selection();

    if (selection->isNone())

        return;

    if (isCollapsed())

        selection->modify(SelectionController::AlterationExtend, SelectionController::DirectionBackward, CharacterGranularity);

    RefPtr<Range> selectedRange = selection->selection().toNormalizedRange();

    ExceptionCode ec = 0;

    selectedRange->deleteContents(ec);

    ASSERT(!ec);

    setBaseAndExtent(selectedRange->startContainer(ec), selectedRange->startOffset(ec), selectedRange->startContainer(ec), selectedRange->startOffset(ec), ec);

    ASSERT(!ec);

}

bool DOMSelection::containsNode(const Node* n, bool allowPartial) const

{

    if (!m_frame)

        return false;

    SelectionController* selection = m_frame->selection();

    if (!n || m_frame->document() != n->document() || selection->isNone())

        return false;

    Node* parentNode = n->parentNode();

    unsigned nodeIndex = n->nodeIndex();

    RefPtr<Range> selectedRange = selection->selection().toNormalizedRange();

    if (!parentNode)

        return false;

    ExceptionCode ec = 0;

    bool nodeFullySelected = Range::compareBoundaryPoints(parentNode, nodeIndex, selectedRange->startContainer(ec), selectedRange->startOffset(ec)) >= 0

        && Range::compareBoundaryPoints(parentNode, nodeIndex + 1, selectedRange->endContainer(ec), selectedRange->endOffset(ec)) <= 0;

    ASSERT(!ec);

    if (nodeFullySelected)

        return true;

    bool nodeFullyUnselected = Range::compareBoundaryPoints(parentNode, nodeIndex, selectedRange->endContainer(ec), selectedRange->endOffset(ec)) > 0

        || Range::compareBoundaryPoints(parentNode, nodeIndex + 1, selectedRange->startContainer(ec), selectedRange->startOffset(ec)) < 0;

    ASSERT(!ec);

    if (nodeFullyUnselected)

        return false;

    return allowPartial || n->isTextNode();

}

void DOMSelection::selectAllChildren(Node* n, ExceptionCode& ec)

{

    if (!n)

        return;

    // This doesn't (and shouldn't) select text node characters.

    setBaseAndExtent(n, 0, n, n->childNodeCount(), ec);

}

String DOMSelection::toString()

{

    if (!m_frame)

        return String();

    return plainText(m_frame->selection()->selection().toNormalizedRange().get());

}

bool DOMSelection::isValidForPosition(Node* node) const

{

    ASSERT(m_frame);

    if (!node)

        return true;

    return node->document() == m_frame->document();

}

} // namespace WebCore