/*

 * Copyright (C) 2005 Apple Computer, 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.

 *

 * THIS SOFTWARE IS PROVIDED BY APPLE COMPUTER, INC. ``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 COMPUTER, INC. OR

 * 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 "InsertTextCommand.h"

#include "CharacterNames.h"

#include "CSSComputedStyleDeclaration.h"

#include "CSSMutableStyleDeclaration.h"

#include "CSSPropertyNames.h"

#include "Document.h"

#include "Element.h"

#include "EditingText.h"

#include "Editor.h"

#include "Frame.h"

#include "Logging.h"

#include "HTMLInterchange.h"

#include "htmlediting.h"

#include "TextIterator.h"

#include "TypingCommand.h"

#include "visible_units.h"

namespace WebCore {

InsertTextCommand::InsertTextCommand(Document *document) 

    : CompositeEditCommand(document), m_charactersAdded(0)

{

}

void InsertTextCommand::doApply()

{

}

Position InsertTextCommand::prepareForTextInsertion(const Position& p)

{

    Position pos = p;

    // Prepare for text input by looking at the specified position.

    // It may be necessary to insert a text node to receive characters.

    if (!pos.node()->isTextNode()) {

        RefPtr<Node> textNode = document()->createEditingTextNode("");

        insertNodeAt(textNode.get(), pos);

        return Position(textNode.get(), 0);

    }

    if (isTabSpanTextNode(pos.node())) {

        RefPtr<Node> textNode = document()->createEditingTextNode("");

        insertNodeAtTabSpanPosition(textNode.get(), pos);

        return Position(textNode.get(), 0);

    }

    return pos;

}

// This avoids the expense of a full fledged delete operation, and avoids a layout that typically results

// from text removal.

bool InsertTextCommand::performTrivialReplace(const String& text, bool selectInsertedText)

{

    if (!endingSelection().isRange())

        return false;

    if (text.contains('\t') || text.contains(' ') || text.contains('\n'))

        return false;

    Position start = endingSelection().start();

    Position end = endingSelection().end();

    if (start.node() != end.node() || !start.node()->isTextNode() || isTabSpanTextNode(start.node()))

        return false;

    replaceTextInNode(static_cast<Text*>(start.node()), start.deprecatedEditingOffset(), end.deprecatedEditingOffset() - start.deprecatedEditingOffset(), text);

    Position endPosition(start.node(), start.deprecatedEditingOffset() + text.length());

    // We could have inserted a part of composed character sequence,

    // so we are basically treating ending selection as a range to avoid validation.

    // <http://bugs.webkit.org/show_bug.cgi?id=15781>

    VisibleSelection forcedEndingSelection;

    forcedEndingSelection.setWithoutValidation(start, endPosition);

    setEndingSelection(forcedEndingSelection);

    if (!selectInsertedText)

        setEndingSelection(VisibleSelection(endingSelection().visibleEnd()));

    return true;

}

void InsertTextCommand::input(const String& text, bool selectInsertedText)

{

    ASSERT(text.find('\n') == -1);

    if (endingSelection().isNone())

        return;

    // Delete the current selection.

    // FIXME: This delete operation blows away the typing style.

    if (endingSelection().isRange()) {

        if (performTrivialReplace(text, selectInsertedText))

            return;

        deleteSelection(false, true, true, false);

    }

    Position startPosition(endingSelection().start());

    Position placeholder;

    // We want to remove preserved newlines and brs that will collapse (and thus become unnecessary) when content 

    // is inserted just before them.

    // FIXME: We shouldn't really have to do this, but removing placeholders is a workaround for 9661.

    // If the caret is just before a placeholder, downstream will normalize the caret to it.

    Position downstream(startPosition.downstream());

    if (lineBreakExistsAtPosition(downstream)) {

        // FIXME: This doesn't handle placeholders at the end of anonymous blocks.

        VisiblePosition caret(startPosition);

        if (isEndOfBlock(caret) && isStartOfParagraph(caret))

            placeholder = downstream;

        // Don't remove the placeholder yet, otherwise the block we're inserting into would collapse before

        // we get a chance to insert into it.  We check for a placeholder now, though, because doing so requires

        // the creation of a VisiblePosition, and if we did that post-insertion it would force a layout.

    }

    // Insert the character at the leftmost candidate.

    startPosition = startPosition.upstream();

    // It is possible for the node that contains startPosition to contain only unrendered whitespace,

    // and so deleteInsignificantText could remove it.  Save the position before the node in case that happens.

    Position positionBeforeStartNode(positionInParentBeforeNode(startPosition.node()));

    deleteInsignificantText(startPosition.upstream(), startPosition.downstream());

    if (!startPosition.node()->inDocument())

        startPosition = positionBeforeStartNode;

    if (!startPosition.isCandidate())

        startPosition = startPosition.downstream();

    startPosition = positionAvoidingSpecialElementBoundary(startPosition);

    Position endPosition;

    if (text == "\t") {

        endPosition = insertTab(startPosition);

        startPosition = endPosition.previous();

        if (placeholder.isNotNull())

            removePlaceholderAt(placeholder);

        m_charactersAdded += 1;

    } else {

        // Make sure the document is set up to receive text

        startPosition = prepareForTextInsertion(startPosition);

        if (placeholder.isNotNull())

            removePlaceholderAt(placeholder);

        Text *textNode = static_cast<Text *>(startPosition.node());

        int offset = startPosition.deprecatedEditingOffset();

        insertTextIntoNode(textNode, offset, text);

        endPosition = Position(textNode, offset + text.length());

        // The insertion may require adjusting adjacent whitespace, if it is present.

        rebalanceWhitespaceAt(endPosition);

        // Rebalancing on both sides isn't necessary if we've inserted a space.

        if (text != " ") 

            rebalanceWhitespaceAt(startPosition);

        m_charactersAdded += text.length();

    }

    // We could have inserted a part of composed character sequence,

    // so we are basically treating ending selection as a range to avoid validation.

    // <http://bugs.webkit.org/show_bug.cgi?id=15781>

    VisibleSelection forcedEndingSelection;

    forcedEndingSelection.setWithoutValidation(startPosition, endPosition);

    setEndingSelection(forcedEndingSelection);

    // Handle the case where there is a typing style.

    CSSMutableStyleDeclaration* typingStyle = document()->frame()->typingStyle();

    RefPtr<CSSComputedStyleDeclaration> endingStyle = endPosition.computedStyle();

    RefPtr<CSSValue> unicodeBidi;

    RefPtr<CSSValue> direction;

    if (typingStyle) {

        unicodeBidi = typingStyle->getPropertyCSSValue(CSSPropertyUnicodeBidi);

        direction = typingStyle->getPropertyCSSValue(CSSPropertyDirection);

    }

    endingStyle->diff(typingStyle);

    if (typingStyle && unicodeBidi) {

        ASSERT(unicodeBidi->isPrimitiveValue());

        typingStyle->setProperty(CSSPropertyUnicodeBidi, static_cast<CSSPrimitiveValue*>(unicodeBidi.get())->getIdent());

        if (direction) {

            ASSERT(direction->isPrimitiveValue());

            typingStyle->setProperty(CSSPropertyDirection, static_cast<CSSPrimitiveValue*>(direction.get())->getIdent());

        }

    }

    if (typingStyle && typingStyle->length())

        applyStyle(typingStyle);

    if (!selectInsertedText)

        setEndingSelection(VisibleSelection(endingSelection().end(), endingSelection().affinity()));

}

Position InsertTextCommand::insertTab(const Position& pos)

{

    Position insertPos = VisiblePosition(pos, DOWNSTREAM).deepEquivalent();

    Node *node = insertPos.node();

    unsigned int offset = insertPos.deprecatedEditingOffset();

    // keep tabs coalesced in tab span

    if (isTabSpanTextNode(node)) {

        insertTextIntoNode(static_cast<Text *>(node), offset, "\t");

        return Position(node, offset + 1);

    }

    // create new tab span

    RefPtr<Element> spanNode = createTabSpanElement(document());

    // place it

    if (!node->isTextNode()) {

        insertNodeAt(spanNode.get(), insertPos);

    } else {

        Text *textNode = static_cast<Text *>(node);

        if (offset >= textNode->length()) {

            insertNodeAfter(spanNode.get(), textNode);

        } else {

            // split node to make room for the span

            // NOTE: splitTextNode uses textNode for the

            // second node in the split, so we need to

            // insert the span before it.

            if (offset > 0)

                splitTextNode(textNode, offset);

            insertNodeBefore(spanNode, textNode);

        }

    }

    // return the position following the new tab

    return Position(spanNode->lastChild(), caretMaxOffset(spanNode->lastChild()));

}

bool InsertTextCommand::isInsertTextCommand() const

{

    return true;

}

}