/*

 * (C) 1999-2003 Lars Knoll (knoll@kde.org)

 * Copyright (C) 2004, 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 "CSSStyleSheet.h"

#include "CSSImportRule.h"

#include "CSSNamespace.h"

#include "CSSParser.h"

#include "CSSRuleList.h"

#include "Document.h"

#include "ExceptionCode.h"

#include "Node.h"

#include "SecurityOrigin.h"

#include "TextEncoding.h"

#include <wtf/Deque.h>

namespace WebCore {

CSSStyleSheet::CSSStyleSheet(CSSStyleSheet* parentSheet, const String& href, const KURL& baseURL, const String& charset)

    : StyleSheet(parentSheet, href, baseURL)

    , m_doc(parentSheet ? parentSheet->doc() : 0)

    , m_namespaces(0)

    , m_charset(charset)

    , m_loadCompleted(false)

    , m_strictParsing(!parentSheet || parentSheet->useStrictParsing())

    , m_isUserStyleSheet(parentSheet ? parentSheet->isUserStyleSheet() : false)

    , m_hasSyntacticallyValidCSSHeader(true)

{

}

CSSStyleSheet::CSSStyleSheet(Node* parentNode, const String& href, const KURL& baseURL, const String& charset)

    : StyleSheet(parentNode, href, baseURL)

    , m_doc(parentNode->document())

    , m_namespaces(0)

    , m_charset(charset)

    , m_loadCompleted(false)

    , m_strictParsing(false)

    , m_isUserStyleSheet(false)

    , m_hasSyntacticallyValidCSSHeader(true)

{

}

CSSStyleSheet::CSSStyleSheet(CSSRule* ownerRule, const String& href, const KURL& baseURL, const String& charset)

    : StyleSheet(ownerRule, href, baseURL)

    , m_namespaces(0)

    , m_charset(charset)

    , m_loadCompleted(false)

    , m_strictParsing(!ownerRule || ownerRule->useStrictParsing())

    , m_hasSyntacticallyValidCSSHeader(true)

{

    CSSStyleSheet* parentSheet = ownerRule ? ownerRule->parentStyleSheet() : 0;

    m_doc = parentSheet ? parentSheet->doc() : 0;

    m_isUserStyleSheet = parentSheet ? parentSheet->isUserStyleSheet() : false;

}

CSSStyleSheet::~CSSStyleSheet()

{

    delete m_namespaces;

}

CSSRule *CSSStyleSheet::ownerRule() const

{

    return (parent() && parent()->isRule()) ? static_cast<CSSRule*>(parent()) : 0;

}

unsigned CSSStyleSheet::insertRule(const String& rule, unsigned index, ExceptionCode& ec)

{

    ec = 0;

    if (index > length()) {

        ec = INDEX_SIZE_ERR;

        return 0;

    }

    CSSParser p(useStrictParsing());

    RefPtr<CSSRule> r = p.parseRule(this, rule);

    if (!r) {

        ec = SYNTAX_ERR;

        return 0;

    }

    // Throw a HIERARCHY_REQUEST_ERR exception if the rule cannot be inserted at the specified index.  The best

    // example of this is an @import rule inserted after regular rules.

    if (index > 0) {

        if (r->isImportRule()) {

            // Check all the rules that come before this one to make sure they are only @charset and @import rules.

            for (unsigned i = 0; i < index; ++i) {

                if (!item(i)->isCharsetRule() && !item(i)->isImportRule()) {

                    ec = HIERARCHY_REQUEST_ERR;

                    return 0;

                }

            }

        } else if (r->isCharsetRule()) {

            // The @charset rule has to come first and there can be only one.

            ec = HIERARCHY_REQUEST_ERR;

            return 0;

        }

    }

    insert(index, r.release());

    styleSheetChanged();

    return index;

}

int CSSStyleSheet::addRule(const String& selector, const String& style, int index, ExceptionCode& ec)

{

    insertRule(selector + " { " + style + " }", index, ec);

    // As per Microsoft documentation, always return -1.

    return -1;

}

int CSSStyleSheet::addRule(const String& selector, const String& style, ExceptionCode& ec)

{

    return addRule(selector, style, length(), ec);

}

PassRefPtr<CSSRuleList> CSSStyleSheet::cssRules(bool omitCharsetRules)

{

    KURL url = finalURL();

    if (!url.isEmpty() && doc() && !doc()->securityOrigin()->canRequest(url))

        return 0;

    return CSSRuleList::create(this, omitCharsetRules);

}

void CSSStyleSheet::deleteRule(unsigned index, ExceptionCode& ec)

{

    if (index >= length()) {

        ec = INDEX_SIZE_ERR;

        return;

    }

    ec = 0;

    remove(index);

    styleSheetChanged();

}

void CSSStyleSheet::addNamespace(CSSParser* p, const AtomicString& prefix, const AtomicString& uri)

{

    if (uri.isNull())

        return;

    m_namespaces = new CSSNamespace(prefix, uri, m_namespaces);

    if (prefix.isEmpty())

        // Set the default namespace on the parser so that selectors that omit namespace info will

        // be able to pick it up easily.

        p->m_defaultNamespace = uri;

}

const AtomicString& CSSStyleSheet::determineNamespace(const AtomicString& prefix)

{

    if (prefix.isNull())

        return nullAtom; // No namespace. If an element/attribute has a namespace, we won't match it.

    if (prefix == starAtom)

        return starAtom; // We'll match any namespace.

    if (m_namespaces) {

        CSSNamespace* ns = m_namespaces->namespaceForPrefix(prefix);

        if (ns)

            return ns->uri();

    }

    return nullAtom; // Assume we wont match any namespaces.

}

bool CSSStyleSheet::parseString(const String &string, bool strict)

{

    return parseStringAtLine(string, strict, 0);

}

bool CSSStyleSheet::parseStringAtLine(const String& string, bool strict, int startLineNumber)

{

    setStrictParsing(strict);

    CSSParser p(strict);

    p.parseSheet(this, string, startLineNumber);

    return true;

}

bool CSSStyleSheet::isLoading()

{

    unsigned len = length();

    for (unsigned i = 0; i < len; ++i) {

        StyleBase* rule = item(i);

        if (rule->isImportRule() && static_cast<CSSImportRule*>(rule)->isLoading())

            return true;

    }

    return false;

}

void CSSStyleSheet::checkLoaded()

{

    if (isLoading())

        return;

    if (parent())

        parent()->checkLoaded();

    // Avoid |this| being deleted by scripts that run via

    // ScriptableDocumentParser::executeScriptsWaitingForStylesheets().

    // See <rdar://problem/6622300>.

    RefPtr<CSSStyleSheet> protector(this);

    m_loadCompleted = ownerNode() ? ownerNode()->sheetLoaded() : true;

}

void CSSStyleSheet::styleSheetChanged()

{

    StyleBase* root = this;

    while (StyleBase* parent = root->parent())

        root = parent;

    Document* documentToUpdate = root->isCSSStyleSheet() ? static_cast<CSSStyleSheet*>(root)->doc() : 0;

    /* FIXME: We don't need to do everything updateStyleSelector does,

     * basically we just need to recreate the document's selector with the

     * already existing style sheets.

     */

    if (documentToUpdate)

        documentToUpdate->updateStyleSelector();

}

KURL CSSStyleSheet::completeURL(const String& url) const

{

    // Always return a null URL when passed a null string.

    // FIXME: Should we change the KURL constructor to have this behavior?

    // See also Document::completeURL(const String&)

    if (url.isNull() || m_charset.isEmpty())

        return StyleSheet::completeURL(url);

    const TextEncoding encoding = TextEncoding(m_charset);

    return KURL(baseURL(), url, encoding);

}

void CSSStyleSheet::addSubresourceStyleURLs(ListHashSet<KURL>& urls)

{

    Deque<CSSStyleSheet*> styleSheetQueue;

    styleSheetQueue.append(this);

    while (!styleSheetQueue.isEmpty()) {

        CSSStyleSheet* styleSheet = styleSheetQueue.takeFirst();

        for (unsigned i = 0; i < styleSheet->length(); ++i) {

            StyleBase* styleBase = styleSheet->item(i);

            if (!styleBase->isRule())

                continue;

            CSSRule* rule = static_cast<CSSRule*>(styleBase);

            if (rule->isImportRule()) {

                if (CSSStyleSheet* ruleStyleSheet = static_cast<CSSImportRule*>(rule)->styleSheet())

                    styleSheetQueue.append(ruleStyleSheet);

            }

            rule->addSubresourceStyleURLs(urls);

        }

    }

}

}