// Copyright (C) 2019 The Qt Company Ltd.

// SPDX-License-Identifier: LicenseRef-Qt-Commercial OR LGPL-3.0-only OR GPL-2.0-only OR GPL-3.0-only

// Qt-Security score:critical reason:data-parser

#include <QtXml/qtxmlglobal.h>

#if QT_CONFIG(dom)

#include "qdomhelpers_p.h"

#include "qdom_p.h"

#include <QtCore/qshareddata.h>

#include "qxmlstream.h"

#include "private/qxmlstream_p.h"

#include <memory>

#include <stack>

QT_BEGIN_NAMESPACE

using namespace Qt::StringLiterals;

template <typename T, typename...Args>

static QExplicitlySharedDataPointer<T> qdom_make_esdp(Args&&...args)

{

    QExplicitlySharedDataPointer<T> dp{

        new T(std::forward<Args>(args)...),

        QAdoptSharedDataTag{}

    };

    Q_ASSERT(dp->ref.loadRelaxed() == 1);

    return dp;

}

/**************************************************************

 *

 * QDomBuilder

 *

 **************************************************************/

QDomBuilder::QDomBuilder(QDomDocumentPrivate *d, QXmlStreamReader *r,

                         QDomDocument::ParseOptions options)

    : doc(d), node(d), reader(r), parseOptions(options)

{

    Q_ASSERT(doc);

    Q_ASSERT(reader);

}

QDomBuilder::~QDomBuilder() {}

bool QDomBuilder::endDocument()

{

    // ### is this really necessary? (rms)

    if (node != doc)

        return false;

    return true;

}

bool QDomBuilder::startDTD(const QString &name, const QString &publicId, const QString &systemId)

{

    doc->doctype()->name = name;

    doc->doctype()->publicId = publicId;

    doc->doctype()->systemId = systemId;

    return true;

}

QString QDomBuilder::dtdInternalSubset(const QString &dtd)

{

    // https://www.w3.org/TR/xml/#NT-intSubset

    // doctypedecl: '<!DOCTYPE' S Name (S ExternalID)? S? ('[' intSubset ']' S?)? '>'

    const QString &name = doc->doctype()->name;

    QStringView tmp = QStringView(dtd).sliced(dtd.indexOf(name) + name.size());

    const QString &publicId = doc->doctype()->publicId;

    if (!publicId.isEmpty())

        tmp = tmp.sliced(tmp.indexOf(publicId) + publicId.size());

    const QString &systemId = doc->doctype()->systemId;

    if (!systemId.isEmpty())

        tmp = tmp.sliced(tmp.indexOf(systemId) + systemId.size());

    const qsizetype obra = tmp.indexOf(u'[');

    const qsizetype cbra = tmp.lastIndexOf(u']');

    if (obra >= 0 && cbra >= 0)

        return tmp.left(cbra).sliced(obra + 1).toString();

    return QString();

}

bool QDomBuilder::parseDTD(const QString &dtd)

{

    doc->doctype()->internalSubset = dtdInternalSubset(dtd);

    return true;

}

bool QDomBuilder::startElement(const QString &nsURI, const QString &qName,

                               const QXmlStreamAttributes &atts)

{

    const bool nsProcessing =

            parseOptions.testFlag(QDomDocument::ParseOption::UseNamespaceProcessing);

    QDomNodePrivate *n =

            nsProcessing ? doc->createElementNS(nsURI, qName) : doc->createElement(qName);

    if (!n)

        return false;

    n->setLocation(int(reader->lineNumber()), int(reader->columnNumber()));

    node->appendChild(n);

    node = n;

    // attributes

    for (const auto &attr : atts) {

        auto domElement = static_cast<QDomElementPrivate *>(node);

        if (nsProcessing) {

            domElement->setAttributeNS(attr.namespaceUri().toString(),

                                       attr.qualifiedName().toString(),

                                       attr.value().toString());

        } else {

            domElement->setAttribute(attr.qualifiedName().toString(),

                                     attr.value().toString());

        }

    }

    return true;

}

bool QDomBuilder::endElement()

{

    if (!node || node == doc)

        return false;

    node = node->parent();

    return true;

}

bool QDomBuilder::characters(const QString &characters, bool cdata)

{

    // No text as child of some document

    if (node == doc)

        return false;

    QExplicitlySharedDataPointer<QDomNodePrivate> n;

    if (cdata) {

        n.reset(doc->createCDATASection(characters));

    } else if (!entityName.isEmpty()) {

        auto e = qdom_make_esdp<QDomEntityPrivate>(

                    doc, nullptr, entityName, QString(), QString(), QString());

        e->value = characters;

        doc->doctype()->appendChild(e.get());

        e.reset(); // reaps unless appendChild() adopted

        n.reset(doc->createEntityReference(entityName));

    } else {

        n.reset(doc->createTextNode(characters));

    }

    if (!n)

        return false;

    n->setLocation(int(reader->lineNumber()), int(reader->columnNumber()));

    node->appendChild(n.get());

    return true;

}

bool QDomBuilder::processingInstruction(const QString &target, const QString &data)

{

    QDomNodePrivate *n;

    n = doc->createProcessingInstruction(target, data);

    if (n) {

        n->setLocation(int(reader->lineNumber()), int(reader->columnNumber()));

        node->appendChild(n);

        return true;

    } else

        return false;

}

bool QDomBuilder::skippedEntity(const QString &name)

{

    QDomNodePrivate *n = doc->createEntityReference(name);

    if (!n)

        return false;

    n->setLocation(int(reader->lineNumber()), int(reader->columnNumber()));

    node->appendChild(n);

    return true;

}

void QDomBuilder::fatalError(const QString &message)

{

    parseResult.errorMessage = message;

    parseResult.errorLine = reader->lineNumber();

    parseResult.errorColumn = reader->columnNumber();

}

bool QDomBuilder::startEntity(const QString &name)

{

    entityName = name;

    return true;

}

bool QDomBuilder::endEntity()

{

    entityName.clear();

    return true;

}

bool QDomBuilder::comment(const QString &characters)

{

    QDomNodePrivate *n;

    n = doc->createComment(characters);

    if (!n)

        return false;

    n->setLocation(int(reader->lineNumber()), int(reader->columnNumber()));

    node->appendChild(n);

    return true;

}

bool QDomBuilder::unparsedEntityDecl(const QString &name, const QString &publicId,

                                     const QString &systemId, const QString &notationName)

{

    QDomEntityPrivate *e =

            new QDomEntityPrivate(doc, nullptr, name, publicId, systemId, notationName);

    // keep the refcount balanced: appendChild() does a ref anyway.

    e->ref.deref();

    doc->doctype()->appendChild(e);

    return true;

}

bool QDomBuilder::externalEntityDecl(const QString &name, const QString &publicId,

                                     const QString &systemId)

{

    return unparsedEntityDecl(name, publicId, systemId, QString());

}

bool QDomBuilder::notationDecl(const QString &name, const QString &publicId,

                               const QString &systemId)

{

    QDomNotationPrivate *n = new QDomNotationPrivate(doc, nullptr, name, publicId, systemId);

    // keep the refcount balanced: appendChild() does a ref anyway.

    n->ref.deref();

    doc->doctype()->appendChild(n);

    return true;

}

/**************************************************************

 *

 * QDomParser

 *

 **************************************************************/

QDomParser::QDomParser(QDomDocumentPrivate *d, QXmlStreamReader *r,

                       QDomDocument::ParseOptions options)

    : reader(r), domBuilder(d, r, options)

{

}

bool QDomParser::parse()

{

    return parseProlog() && parseBody();

}

bool QDomParser::parseProlog()

{

    Q_ASSERT(reader);

    bool foundDtd = false;

    while (!reader->atEnd()) {

        reader->readNext();

        if (reader->hasError()) {

            domBuilder.fatalError(reader->errorString());

            return false;

        }

        switch (reader->tokenType()) {

        case QXmlStreamReader::StartDocument:

            if (!reader->documentVersion().isEmpty()) {

                QString value(u"version='"_s);

                value += reader->documentVersion();

                value += u'\'';

                if (!reader->documentEncoding().isEmpty()) {

                    value += u" encoding='"_s;

                    value += reader->documentEncoding();

                    value += u'\'';

                }

                if (reader->isStandaloneDocument()) {

                    value += u" standalone='yes'"_s;

                } else {

                    // Add the standalone attribute only if it was specified

                    if (reader->hasStandaloneDeclaration())

                        value += u" standalone='no'"_s;

                }

                if (!domBuilder.processingInstruction(u"xml"_s, value)) {

                    domBuilder.fatalError(

                            QDomParser::tr("Error occurred while processing XML declaration"));

                    return false;

                }

            }

            break;

        case QXmlStreamReader::DTD:

            if (foundDtd) {

                domBuilder.fatalError(QDomParser::tr("Multiple DTD sections are not allowed"));

                return false;

            }

            foundDtd = true;

            if (!domBuilder.startDTD(reader->dtdName().toString(),

                                     reader->dtdPublicId().toString(),

                                     reader->dtdSystemId().toString())) {

                domBuilder.fatalError(

                        QDomParser::tr("Error occurred while processing document type declaration"));

                return false;

            }

            if (!domBuilder.parseDTD(reader->text().toString()))

                return false;

            if (!parseMarkupDecl())

                return false;

            break;

        case QXmlStreamReader::Comment:

            if (!domBuilder.comment(reader->text().toString())) {

                domBuilder.fatalError(QDomParser::tr("Error occurred while processing comment"));

                return false;

            }

            break;

        case QXmlStreamReader::ProcessingInstruction:

            if (!domBuilder.processingInstruction(reader->processingInstructionTarget().toString(),

                                                  reader->processingInstructionData().toString())) {

                domBuilder.fatalError(

                        QDomParser::tr("Error occurred while processing a processing instruction"));

                return false;

            }

            break;

        default:

            // If the token is none of the above, prolog processing is done.

            return true;

        }

    }

    return true;

}

bool QDomParser::parseBody()

{

    Q_ASSERT(reader);

    std::stack<QString> tagStack;

    while (!reader->atEnd() && !reader->hasError()) {

        switch (reader->tokenType()) {

        case QXmlStreamReader::StartElement:

            tagStack.push(reader->qualifiedName().toString());

            if (!domBuilder.startElement(reader->namespaceUri().toString(),

                                         reader->qualifiedName().toString(),

                                         reader->attributes())) {

                domBuilder.fatalError(

                        QDomParser::tr("Error occurred while processing a start element"));

                return false;

            }

            break;

        case QXmlStreamReader::EndElement:

            if (tagStack.empty() || reader->qualifiedName() != tagStack.top()) {

                domBuilder.fatalError(

                        QDomParser::tr("Unexpected end element '%1'").arg(reader->name()));

                return false;

            }

            tagStack.pop();

            if (!domBuilder.endElement()) {

                domBuilder.fatalError(

                        QDomParser::tr("Error occurred while processing an end element"));

                return false;

            }

            break;

        case QXmlStreamReader::Characters:

            // Skip the content if it contains only spacing characters,

            // unless it's CDATA or PreserveSpacingOnlyNodes was specified.

            if (reader->isCDATA() || domBuilder.preserveSpacingOnlyNodes()

                || !(reader->isWhitespace() || reader->text().trimmed().isEmpty())) {

                if (!domBuilder.characters(reader->text().toString(), reader->isCDATA())) {

                    domBuilder.fatalError(

                            QDomParser::tr("Error occurred while processing the element content"));

                    return false;

                }

            }

            break;

        case QXmlStreamReader::Comment:

            if (!domBuilder.comment(reader->text().toString())) {

                domBuilder.fatalError(QDomParser::tr("Error occurred while processing comments"));

                return false;

            }

            break;

        case QXmlStreamReader::ProcessingInstruction:

            if (!domBuilder.processingInstruction(reader->processingInstructionTarget().toString(),

                                                  reader->processingInstructionData().toString())) {

                domBuilder.fatalError(

                        QDomParser::tr("Error occurred while processing a processing instruction"));

                return false;

            }

            break;

        case QXmlStreamReader::EntityReference:

            if (!domBuilder.skippedEntity(reader->name().toString())) {

                domBuilder.fatalError(

                        QDomParser::tr("Error occurred while processing an entity reference"));

                return false;

            }

            break;

        default:

            domBuilder.fatalError(QDomParser::tr("Unexpected token"));

            return false;

        }

        reader->readNext();

    }

    if (reader->hasError()) {

        domBuilder.fatalError(reader->errorString());

        reader->readNext();

        return false;

    }

    if (!tagStack.empty()) {

        domBuilder.fatalError(QDomParser::tr("Tag mismatch"));

        return false;

    }

    return true;

}

bool QDomParser::parseMarkupDecl()

{

    Q_ASSERT(reader);

    const auto entities = reader->entityDeclarations();

    for (const auto &entityDecl : entities) {

        // Entity declarations are created only for External Entities. Internal Entities

        // are parsed, and QXmlStreamReader handles the parsing itself and returns the

        // parsed result. So we don't need to do anything for the Internal Entities.

        if (!entityDecl.publicId().isEmpty() || !entityDecl.systemId().isEmpty()) {

            // External Entity

            if (!domBuilder.unparsedEntityDecl(entityDecl.name().toString(),

                                               entityDecl.publicId().toString(),

                                               entityDecl.systemId().toString(),

                                               entityDecl.notationName().toString())) {

                domBuilder.fatalError(

                        QDomParser::tr("Error occurred while processing entity declaration"));

                return false;

            }

        }

    }

    const auto notations = reader->notationDeclarations();

    for (const auto &notationDecl : notations) {

        if (!domBuilder.notationDecl(notationDecl.name().toString(),

                                     notationDecl.publicId().toString(),

                                     notationDecl.systemId().toString())) {

            domBuilder.fatalError(

                    QDomParser::tr("Error occurred while processing notation declaration"));

            return false;

        }

    }

    return true;

}

QT_END_NAMESPACE

#endif // feature dom