/**

 * Copyright (C) 2004 Allan Sandfeld Jensen (kde@carewolf.com)

 * Copyright (C) 2006, 2007 Apple Inc. All rights reserved.

 *

 * This library is free software; you can redistribute it and/or

 * modify it under the terms of the GNU Library General Public

 * License as published by the Free Software Foundation; either

 * version 2 of the License, or (at your option) any later version.

 *

 * This library is distributed in the hope that it will be useful,

 * but WITHOUT ANY WARRANTY; without even the implied warranty of

 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU

 * Library General Public License for more details.

 *

 * You should have received a copy of the GNU Library General Public License

 * along with this library; see the file COPYING.LIB.  If not, write to

 * the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,

 * Boston, MA 02110-1301, USA.

 *

 */

#include "config.h"

#include "RenderCounter.h"

#include "CounterNode.h"

#include "Document.h"

#include "HTMLNames.h"

#include "HTMLOListElement.h"

#include "RenderListItem.h"

#include "RenderListMarker.h"

#include "RenderStyle.h"

#include <wtf/StdLibExtras.h>

namespace WebCore {

using namespace HTMLNames;

typedef HashMap<RefPtr<AtomicStringImpl>, CounterNode*> CounterMap;

typedef HashMap<const RenderObject*, CounterMap*> CounterMaps;

static CounterNode* makeCounterNode(RenderObject*, const AtomicString& identifier, bool alwaysCreateCounter);

static CounterMaps& counterMaps()

{

    DEFINE_STATIC_LOCAL(CounterMaps, staticCounterMaps, ());

    return staticCounterMaps;

}

static inline RenderObject* previousSiblingOrParent(RenderObject* object)

{

    if (RenderObject* sibling = object->previousSibling())

        return sibling;

    return object->parent();

}

static bool planCounter(RenderObject* object, const AtomicString& identifier, bool& isReset, int& value)

{

    ASSERT(object);

    // Real text nodes don't have their own style so they can't have counters.

    // We can't even look at their styles or we'll see extra resets and increments!

    if (object->isText() && !object->isBR())

        return false;

    RenderStyle* style = object->style();

    ASSERT(style);

    if (const CounterDirectiveMap* directivesMap = style->counterDirectives()) {

        CounterDirectives directives = directivesMap->get(identifier.impl());

        if (directives.m_reset) {

            value = directives.m_resetValue;

            if (directives.m_increment)

                value += directives.m_incrementValue;

            isReset = true;

            return true;

        }

        if (directives.m_increment) {

            value = directives.m_incrementValue;

            isReset = false;

            return true;

        }

    }

    if (identifier == "list-item") {

        if (object->isListItem()) {

            if (toRenderListItem(object)->hasExplicitValue()) {

                value = toRenderListItem(object)->explicitValue();

                isReset = true;

                return true;

            }

            value = 1;

            isReset = false;

            return true;

        }

        if (Node* e = object->node()) {

            if (e->hasTagName(olTag)) {

                value = static_cast<HTMLOListElement*>(e)->start();

                isReset = true;

                return true;

            }

            if (e->hasTagName(ulTag) || e->hasTagName(menuTag) || e->hasTagName(dirTag)) {

                value = 0;

                isReset = true;

                return true;

            }

        }

    }

    return false;

}

// - Finds the insertion point for the counter described by counterOwner, isReset and 

// identifier in the CounterNode tree for identifier and sets parent and

// previousSibling accordingly.

// - The function returns true if the counter whose insertion point is searched is NOT

// the root of the tree.

// - The root of the tree is a counter reference that is not in the scope of any other

// counter with the same identifier.

// - All the counter references with the same identifier as this one that are in

// children or subsequent siblings of the renderer that owns the root of the tree

// form the rest of of the nodes of the tree.

// - The root of the tree is always a reset type reference.

// - A subtree rooted at any reset node in the tree is equivalent to all counter 

// references that are in the scope of the counter or nested counter defined by that

// reset node.

// - Non-reset CounterNodes cannot have descendants.

static bool findPlaceForCounter(RenderObject* counterOwner, const AtomicString& identifier, bool isReset, CounterNode*& parent, CounterNode*& previousSibling)

{

    // We cannot stop searching for counters with the same identifier before we also

    // check this renderer, because it may affect the positioning in the tree of our counter.

    RenderObject* searchEndRenderer = previousSiblingOrParent(counterOwner);

    // We check renderers in preOrder from the renderer that our counter is attached to

    // towards the begining of the document for counters with the same identifier as the one

    // we are trying to find a place for. This is the next renderer to be checked.

    RenderObject* currentRenderer = counterOwner->previousInPreOrder();

    previousSibling = 0;

    while (currentRenderer) {

        CounterNode* currentCounter = makeCounterNode(currentRenderer, identifier, false);

        if (searchEndRenderer == currentRenderer) {

            // We may be at the end of our search.

            if (currentCounter) {

                // We have a suitable counter on the EndSearchRenderer.

                if (previousSibling) { // But we already found another counter that we come after.

                    if (currentCounter->actsAsReset()) {

                        // We found a reset counter that is on a renderer that is a sibling of ours or a parent.

                        if (isReset && currentRenderer->parent() == counterOwner->parent()) {

                            // We are also a reset counter and the previous reset was on a sibling renderer

                            // hence we are the next sibling of that counter if that reset is not a root or

                            // we are a root node if that reset is a root.

                            parent = currentCounter->parent();

                            previousSibling = parent ? currentCounter : 0;

                            return parent;

                        }

                        // We are not a reset node or the previous reset must be on an ancestor of our renderer

                        // hence we must be a child of that reset counter.

                        parent = currentCounter;

                        ASSERT(previousSibling->parent() == currentCounter);

                        return true;

                    }

                    // CurrentCounter, the counter at the EndSearchRenderer, is not reset.

                    if (!isReset || currentRenderer->parent() != counterOwner->parent()) {

                        // If the node we are placing is not reset or we have found a counter that is attached

                        // to an ancestor of the placed counter's renderer we know we are a sibling of that node.

                        ASSERT(currentCounter->parent() == previousSibling->parent());

                        parent = currentCounter->parent();

                        return true;

                    }

                } else { 

                    // We are at the potential end of the search, but we had no previous sibling candidate

                    // In this case we follow pretty much the same logic as above but no ASSERTs about 

                    // previousSibling, and when we are a sibling of the end counter we must set previousSibling

                    // to currentCounter.

                    if (currentCounter->actsAsReset()) {

                        if (isReset && currentRenderer->parent() == counterOwner->parent()) {

                            parent = currentCounter->parent();

                            previousSibling = currentCounter;

                            return parent;

                        }

                        parent = currentCounter;

                        return true;

                    }

                    if (!isReset || currentRenderer->parent() != counterOwner->parent()) {

                        parent = currentCounter->parent();

                        previousSibling = currentCounter;

                        return true;

                    }

                    previousSibling = currentCounter;

                }

            }

            // We come here if the previous sibling or parent of our renderer had no 

            // good counter, or we are a reset node and the counter on the previous sibling

            // of our renderer was not a reset counter.

            // Set a new goal for the end of the search.

            searchEndRenderer = previousSiblingOrParent(currentRenderer);

        } else {

            // We are searching descendants of a previous sibling of the renderer that the

            // counter being placed is attached to.

            if (currentCounter) {

                // We found a suitable counter.

                if (previousSibling) {

                    // Since we had a suitable previous counter before, we should only consider this one as our 

                    // previousSibling if it is a reset counter and hence the current previousSibling is its child.

                    if (currentCounter->actsAsReset()) {

                        previousSibling = currentCounter;

                        // We are no longer interested in previous siblings of the currentRenderer or their children

                        // as counters they may have attached cannot be the previous sibling of the counter we are placing.

                        currentRenderer = currentRenderer->parent();

                        continue;

                    }

                } else

                    previousSibling = currentCounter;

                currentRenderer = previousSiblingOrParent(currentRenderer);

                continue;

            }

        }

        // This function is designed so that the same test is not done twice in an iteration, except for this one

        // which may be done twice in some cases. Rearranging the decision points though, to accommodate this 

        // performance improvement would create more code duplication than is worthwhile in my oppinion and may further

        // impede the readability of this already complex algorithm.

        if (previousSibling)

            currentRenderer = previousSiblingOrParent(currentRenderer);

        else

            currentRenderer = currentRenderer->previousInPreOrder();

    }

    return false;

}

static CounterNode* makeCounterNode(RenderObject* object, const AtomicString& identifier, bool alwaysCreateCounter)

{

    ASSERT(object);

    if (object->m_hasCounterNodeMap)

        if (CounterMap* nodeMap = counterMaps().get(object))

            if (CounterNode* node = nodeMap->get(identifier.impl()))

                return node;

    bool isReset = false;

    int value = 0;

    if (!planCounter(object, identifier, isReset, value) && !alwaysCreateCounter)

        return 0;

    CounterNode* newParent = 0;

    CounterNode* newPreviousSibling = 0;

    CounterNode* newNode = new CounterNode(object, isReset, value);

    if (findPlaceForCounter(object, identifier, isReset, newParent, newPreviousSibling))

        newParent->insertAfter(newNode, newPreviousSibling, identifier);

    CounterMap* nodeMap;

    if (object->m_hasCounterNodeMap)

        nodeMap = counterMaps().get(object);

    else {

        nodeMap = new CounterMap;

        counterMaps().set(object, nodeMap);

        object->m_hasCounterNodeMap = true;

    }

    nodeMap->set(identifier.impl(), newNode);

    if (newNode->parent() || !object->nextInPreOrder(object->parent()))

        return newNode;

    // Checking if some nodes that were previously counter tree root nodes

    // should become children of this node now.

    CounterMaps& maps = counterMaps();

    RenderObject* stayWithin = object->parent();

    for (RenderObject* currentRenderer = object->nextInPreOrder(stayWithin); currentRenderer; currentRenderer = currentRenderer->nextInPreOrder(stayWithin)) {

        if (!currentRenderer->m_hasCounterNodeMap)

            continue;

        CounterNode* currentCounter = maps.get(currentRenderer)->get(identifier.impl());

        if (!currentCounter)

            continue;

        if (currentCounter->parent()) {

            ASSERT(newNode->firstChild());

            if (currentRenderer->lastChild())

                currentRenderer = currentRenderer->lastChild();

            continue;

        }

        if (stayWithin != currentRenderer->parent() || !currentCounter->hasResetType())

            newNode->insertAfter(currentCounter, newNode->lastChild(), identifier);

        if (currentRenderer->lastChild())

            currentRenderer = currentRenderer->lastChild();

    }

    return newNode;

}

RenderCounter::RenderCounter(Document* node, const CounterContent& counter)

    : RenderText(node, StringImpl::empty())

    , m_counter(counter)

    , m_counterNode(0)

{

}

const char* RenderCounter::renderName() const

{

    return "RenderCounter";

}

bool RenderCounter::isCounter() const

{

    return true;

}

PassRefPtr<StringImpl> RenderCounter::originalText() const

{

    if (!parent())

        return 0;

    if (!m_counterNode)

        m_counterNode = makeCounterNode(parent(), m_counter.identifier(), true);

    CounterNode* child = m_counterNode;

    int value = child->actsAsReset() ? child->value() : child->countInParent();

    String text = listMarkerText(m_counter.listStyle(), value);

    if (!m_counter.separator().isNull()) {

        if (!child->actsAsReset())

            child = child->parent();

        while (CounterNode* parent = child->parent()) {

            text = listMarkerText(m_counter.listStyle(), child->countInParent())

                + m_counter.separator() + text;

            child = parent;

        }

    }

    return text.impl();

}

void RenderCounter::calcPrefWidths(int lead)

{

    setTextInternal(originalText());

    RenderText::calcPrefWidths(lead);

}

void RenderCounter::invalidate(const AtomicString& identifier)

{

    if (m_counter.identifier() != identifier)

        return;

    m_counterNode = 0;

    setNeedsLayoutAndPrefWidthsRecalc();

}

static void destroyCounterNodeWithoutMapRemoval(const AtomicString& identifier, CounterNode* node)

{

    CounterNode* previous;

    for (CounterNode* child = node->lastDescendant(); child && child != node; child = previous) {

        previous = child->previousInPreOrder();

        child->parent()->removeChild(child, identifier);

        ASSERT(counterMaps().get(child->renderer())->get(identifier.impl()) == child);

        counterMaps().get(child->renderer())->remove(identifier.impl());

        if (!child->renderer()->documentBeingDestroyed()) {

            RenderObjectChildList* children = child->renderer()->virtualChildren();

            if (children)

                children->invalidateCounters(child->renderer(), identifier);

        }

        delete child;

    }

    RenderObject* renderer = node->renderer();

    if (!renderer->documentBeingDestroyed()) {

        if (RenderObjectChildList* children = renderer->virtualChildren())

            children->invalidateCounters(renderer, identifier);

    }

    if (CounterNode* parent = node->parent())

        parent->removeChild(node, identifier);

    delete node;

}

void RenderCounter::destroyCounterNodes(RenderObject* renderer)

{

    CounterMaps& maps = counterMaps();

    CounterMaps::iterator mapsIterator = maps.find(renderer);

    if (mapsIterator == maps.end())

        return;

    CounterMap* map = mapsIterator->second;

    CounterMap::const_iterator end = map->end();

    for (CounterMap::const_iterator it = map->begin(); it != end; ++it) {

        AtomicString identifier(it->first.get());

        destroyCounterNodeWithoutMapRemoval(identifier, it->second);

    }

    maps.remove(mapsIterator);

    delete map;

    renderer->m_hasCounterNodeMap = false;

}

void RenderCounter::destroyCounterNode(RenderObject* renderer, const AtomicString& identifier)

{

    CounterMap* map = counterMaps().get(renderer);

    if (!map)

        return;

    CounterMap::iterator mapIterator = map->find(identifier.impl());

    if (mapIterator == map->end())

        return;

    destroyCounterNodeWithoutMapRemoval(identifier, mapIterator->second);

    map->remove(mapIterator);

    // We do not delete "map" here even if empty because we expect to reuse

    // it soon. In order for a renderer to lose all its counters permanently,

    // a style change for the renderer involving removal of all counter

    // directives must occur, in which case, RenderCounter::destroyCounterNodes()

    // must be called.

    // The destruction of the Renderer (possibly caused by the removal of its 

    // associated DOM node) is the other case that leads to the permanent

    // destruction of all counters attached to a Renderer. In this case

    // RenderCounter::destroyCounterNodes() must be and is now called, too.

    // RenderCounter::destroyCounterNodes() handles destruction of the counter

    // map associated with a renderer, so there is no risk in leaking the map.

}

static void updateCounters(RenderObject* renderer)

{

    ASSERT(renderer->style());

    const CounterDirectiveMap* directiveMap = renderer->style()->counterDirectives();

    if (!directiveMap)

        return;

    CounterDirectiveMap::const_iterator end = directiveMap->end();

    if (!renderer->m_hasCounterNodeMap) {

        for (CounterDirectiveMap::const_iterator it = directiveMap->begin(); it != end; ++it)

            makeCounterNode(renderer, AtomicString(it->first.get()), false);

        return;

    }

    CounterMap* counterMap = counterMaps().get(renderer);

    ASSERT(counterMap);

    for (CounterDirectiveMap::const_iterator it = directiveMap->begin(); it != end; ++it) {

        CounterNode* node = counterMap->get(it->first.get());

        if (!node) {

            makeCounterNode(renderer, AtomicString(it->first.get()), false);

            continue;

        }

        CounterNode* newParent = 0;

        CounterNode* newPreviousSibling;

        findPlaceForCounter(renderer, AtomicString(it->first.get()), node->hasResetType(), newParent, newPreviousSibling);

        CounterNode* parent = node->parent();

        if (newParent == parent && newPreviousSibling == node->previousSibling())

            continue;

        if (parent)

            parent->removeChild(node, it->first.get());

        if (newParent)

            newParent->insertAfter(node, newPreviousSibling, it->first.get());

    }

}

void RenderCounter::rendererSubtreeAttached(RenderObject* renderer)

{

    for (RenderObject* descendant = renderer; descendant; descendant = descendant->nextInPreOrder(renderer))

        updateCounters(descendant);

}

void RenderCounter::rendererStyleChanged(RenderObject* renderer, const RenderStyle* oldStyle, const RenderStyle* newStyle)

{

    const CounterDirectiveMap* newCounterDirectives;

    const CounterDirectiveMap* oldCounterDirectives;

    if (oldStyle && (oldCounterDirectives = oldStyle->counterDirectives())) {

        if (newStyle && (newCounterDirectives = newStyle->counterDirectives())) {

            CounterDirectiveMap::const_iterator newMapEnd = newCounterDirectives->end();

            CounterDirectiveMap::const_iterator oldMapEnd = oldCounterDirectives->end();

            for (CounterDirectiveMap::const_iterator it = newCounterDirectives->begin(); it != newMapEnd; ++it) {

                CounterDirectiveMap::const_iterator oldMapIt = oldCounterDirectives->find(it->first);

                if (oldMapIt != oldMapEnd) {

                    if (oldMapIt->second == it->second)

                        continue;

                    RenderCounter::destroyCounterNode(renderer, it->first.get());

                }

                // We must create this node here, because the changed node may be a node with no display such as

                // as those created by the increment or reset directives and the re-layout that will happen will

                // not catch the change if the node had no children.

                makeCounterNode(renderer, it->first.get(), false);

            }

            // Destroying old counters that do not exist in the new counterDirective map.

            for (CounterDirectiveMap::const_iterator it = oldCounterDirectives->begin(); it !=oldMapEnd; ++it) {

                if (!newCounterDirectives->contains(it->first))

                    RenderCounter::destroyCounterNode(renderer, it->first.get());

            }

        } else {

            if (renderer->m_hasCounterNodeMap)

                RenderCounter::destroyCounterNodes(renderer);

        }

    } else if (newStyle && (newCounterDirectives = newStyle->counterDirectives())) {

        CounterDirectiveMap::const_iterator newMapEnd = newCounterDirectives->end();

        for (CounterDirectiveMap::const_iterator it = newCounterDirectives->begin(); it != newMapEnd; ++it) {

            // We must create this node here, because the added node may be a node with no display such as

            // as those created by the increment or reset directives and the re-layout that will happen will

            // not catch the change if the node had no children.

            makeCounterNode(renderer, it->first.get(), false);

        }

    }

}

} // namespace WebCore