/**

 * This file is part of the XSL implementation.

 *

 * Copyright (C) 2004, 2005, 2006 Apple Computer, Inc.

 *

 * 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 "XSLStyleSheet.h"

#if ENABLE(XSLT)

#include "CString.h"

#include "DocLoader.h"

#include "Document.h"

#include "Node.h"

#include "XSLImportRule.h"

#include "loader.h"

#include "XMLTokenizer.h"

#include <libxml/uri.h>

#include <libxslt/xsltutils.h>

#if PLATFORM(MAC)

#include "SoftLinking.h"

#endif

#if PLATFORM(MAC)

SOFT_LINK_LIBRARY(libxslt)

SOFT_LINK(libxslt, xsltIsBlank, int, (xmlChar *str), (str))

SOFT_LINK(libxslt, xsltGetNsProp, xmlChar *, (xmlNodePtr node, const xmlChar *name, const xmlChar *nameSpace), (node, name, nameSpace))

SOFT_LINK(libxslt, xsltParseStylesheetDoc, xsltStylesheetPtr, (xmlDocPtr doc), (doc))

SOFT_LINK(libxslt, xsltLoadStylesheetPI, xsltStylesheetPtr, (xmlDocPtr doc), (doc))

#endif

namespace WebCore {

#define IS_BLANK_NODE(n)                                                \

    (((n)->type == XML_TEXT_NODE) && (xsltIsBlank((n)->content)))

XSLStyleSheet::XSLStyleSheet(XSLImportRule* parentRule, const String& href)

    : StyleSheet(parentRule, href)

    , m_ownerDocument(0)

    , m_stylesheetDoc(0)

    , m_embedded(false)

    , m_processed(false) // Child sheets get marked as processed when the libxslt engine has finally seen them.

    , m_stylesheetDocTaken(false)

{

}

XSLStyleSheet::XSLStyleSheet(Node* parentNode, const String& href,  bool embedded)

    : StyleSheet(parentNode, href)

    , m_ownerDocument(parentNode->document())

    , m_stylesheetDoc(0)

    , m_embedded(embedded)

    , m_processed(true) // The root sheet starts off processed.

    , m_stylesheetDocTaken(false)

{

}

XSLStyleSheet::~XSLStyleSheet()

{

    if (!m_stylesheetDocTaken)

        xmlFreeDoc(m_stylesheetDoc);

}

bool XSLStyleSheet::isLoading()

{

    unsigned len = length();

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

        StyleBase* rule = item(i);

        if (rule->isImportRule()) {

            XSLImportRule* import = static_cast<XSLImportRule*>(rule);

            if (import->isLoading())

                return true;

        }

    }

    return false;

}

void XSLStyleSheet::checkLoaded()

{

    if (isLoading()) 

        return;

    if (parent())

        parent()->checkLoaded();

    if (m_parentNode)

        m_parentNode->sheetLoaded();

}

xmlDocPtr XSLStyleSheet::document()

{

    if (m_embedded && ownerDocument())

        return (xmlDocPtr)ownerDocument()->transformSource();

    return m_stylesheetDoc;

}

void XSLStyleSheet::clearDocuments()

{

    m_stylesheetDoc = 0;

    unsigned len = length();

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

        StyleBase* rule = item(i);

        if (rule->isImportRule()) {

            XSLImportRule* import = static_cast<XSLImportRule*>(rule);

            if (import->styleSheet())

                import->styleSheet()->clearDocuments();

        }

    }

}

DocLoader* XSLStyleSheet::docLoader()

{

    if (!m_ownerDocument)

        return 0;

    return m_ownerDocument->docLoader();

}

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

{

    // Parse in a single chunk into an xmlDocPtr

    const UChar BOM = 0xFEFF;

    const unsigned char BOMHighByte = *reinterpret_cast<const unsigned char*>(&BOM);

    setLoaderForLibXMLCallbacks(docLoader());

    if (!m_stylesheetDocTaken)

        xmlFreeDoc(m_stylesheetDoc);

    m_stylesheetDocTaken = false;

    m_stylesheetDoc = xmlReadMemory(reinterpret_cast<const char*>(string.characters()), string.length() * sizeof(UChar),

        m_ownerDocument->URL().ascii(),

        BOMHighByte == 0xFF ? "UTF-16LE" : "UTF-16BE", 

        XML_PARSE_NOENT | XML_PARSE_DTDATTR | XML_PARSE_NOERROR | XML_PARSE_NOWARNING | XML_PARSE_NOCDATA);

    loadChildSheets();

    setLoaderForLibXMLCallbacks(0);

    return m_stylesheetDoc;

}

void XSLStyleSheet::loadChildSheets()

{

    if (!document())

        return;

    xmlNodePtr stylesheetRoot = document()->children;

    // Top level children may include other things such as DTD nodes, we ignore those.

    while (stylesheetRoot && stylesheetRoot->type != XML_ELEMENT_NODE)

        stylesheetRoot = stylesheetRoot->next;

    if (m_embedded) {

        // We have to locate (by ID) the appropriate embedded stylesheet element, so that we can walk the 

        // import/include list.

        xmlAttrPtr idNode = xmlGetID(document(), (const xmlChar*)(href().utf8().data()));

        if (!idNode)

            return;

        stylesheetRoot = idNode->parent;

    } else {

        // FIXME: Need to handle an external URI with a # in it.  This is a pretty minor edge case, so we'll deal

        // with it later.

    }

    if (stylesheetRoot) {

        // Walk the children of the root element and look for import/include elements.

        // Imports must occur first.

        xmlNodePtr curr = stylesheetRoot->children;

        while (curr) {

            if (IS_BLANK_NODE(curr)) {

                curr = curr->next;

                continue;

            }

            if (curr->type == XML_ELEMENT_NODE && IS_XSLT_ELEM(curr) && IS_XSLT_NAME(curr, "import")) {

                xmlChar* uriRef = xsltGetNsProp(curr, (const xmlChar*)"href", XSLT_NAMESPACE);                

                loadChildSheet(DeprecatedString::fromUtf8((const char*)uriRef));

                xmlFree(uriRef);

            } else

                break;

            curr = curr->next;

        }

        // Now handle includes.

        while (curr) {

            if (curr->type == XML_ELEMENT_NODE && IS_XSLT_ELEM(curr) && IS_XSLT_NAME(curr, "include")) {

                xmlChar* uriRef = xsltGetNsProp(curr, (const xmlChar*)"href", XSLT_NAMESPACE);

                loadChildSheet(DeprecatedString::fromUtf8((const char*)uriRef));

                xmlFree(uriRef);

            }

            curr = curr->next;

        }

    }

}

void XSLStyleSheet::loadChildSheet(const DeprecatedString& href)

{

    RefPtr<XSLImportRule> childRule = new XSLImportRule(this, href);

    append(childRule);

    childRule->loadSheet();

}

xsltStylesheetPtr XSLStyleSheet::compileStyleSheet()

{

    // FIXME: Hook up error reporting for the stylesheet compilation process.

    if (m_embedded)

        return xsltLoadStylesheetPI(document());

    // xsltParseStylesheetDoc makes the document part of the stylesheet

    // so we have to release our pointer to it.

    ASSERT(!m_stylesheetDocTaken);

    xsltStylesheetPtr result = xsltParseStylesheetDoc(m_stylesheetDoc);

    if (result)

        m_stylesheetDocTaken = true;

    return result;

}

xmlDocPtr XSLStyleSheet::locateStylesheetSubResource(xmlDocPtr parentDoc, const xmlChar* uri)

{

    bool matchedParent = (parentDoc == document());

    unsigned len = length();

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

        StyleBase* rule = item(i);

        if (rule->isImportRule()) {

            XSLImportRule* import = static_cast<XSLImportRule*>(rule);

            XSLStyleSheet* child = import->styleSheet();

            if (!child)

                continue;

            if (matchedParent) {

                if (child->processed())

                    continue; // libxslt has been given this sheet already.

                // Check the URI of the child stylesheet against the doc URI.

                // In order to ensure that libxml canonicalized both URLs, we get the original href

                // string from the import rule and canonicalize it using libxml before comparing it

                // with the URI argument.

                CString importHref = import->href().utf8();

                xmlChar* base = xmlNodeGetBase(parentDoc, (xmlNodePtr)parentDoc);

                xmlChar* childURI = xmlBuildURI((const xmlChar*)importHref.data(), base);

                bool equalURIs = xmlStrEqual(uri, childURI);

                xmlFree(base);

                xmlFree(childURI);

                if (equalURIs) {

                    child->markAsProcessed();

                    return child->document();

                }

            } else {

                xmlDocPtr result = import->styleSheet()->locateStylesheetSubResource(parentDoc, uri);

                if (result)

                    return result;

            }

        }

    }

    return 0;

}

void XSLStyleSheet::markAsProcessed()

{

    ASSERT(!m_processed);

    ASSERT(!m_stylesheetDocTaken);

    m_processed = true;

    m_stylesheetDocTaken = true;

}

} // namespace WebCore

#endif // ENABLE(XSLT)