// Copyright (C) 2021 The Qt Company Ltd.
// SPDX-License-Identifier: LicenseRef-Qt-Commercial OR GPL-3.0-only WITH Qt-GPL-exception-1.0

#include "qmlcodeparser.h"

#include "node.h"
#include "qmlvisitor.h"

#ifndef QT_NO_DECLARATIVE
#    include <private/qqmljsast_p.h>
#endif
#include <qdebug.h>

QT_BEGIN_NAMESPACE

/*!
  Constructs the QML code parser.
 */
QmlCodeParser::QmlCodeParser()
#ifndef QT_NO_DECLARATIVE
    : m_lexer(nullptr), m_parser(nullptr)
#endif
{
}

/*!
  Initializes the code parser base class.
  Also creates a lexer and parser from QQmlJS.
 */
void QmlCodeParser::initializeParser()
{
    CodeParser::initializeParser();

#ifndef QT_NO_DECLARATIVE
    m_lexer = new QQmlJS::Lexer(&m_engine);
    m_parser = new QQmlJS::Parser(&m_engine);
#endif
}

/*!
  Terminates the QML code parser. Deletes the lexer and parser
  created by the constructor.
 */
void QmlCodeParser::terminateParser()
{
#ifndef QT_NO_DECLARATIVE
    delete m_lexer;
    delete m_parser;
#endif
}

/*!
  Returns "QML".
 */
QString QmlCodeParser::language()
{
    return "QML";
}

/*!
  Returns a string list containing "*.qml". This is the only
  file type parsed by the QMLN parser.
 */
QStringList QmlCodeParser::sourceFileNameFilter()
{
    return QStringList() << "*.qml";
}

/*!
  Parses the source file at \a filePath and inserts the contents
  into the database. The \a location is used for error reporting.

  If it can't open the file at \a filePath, it reports an error
  and returns without doing anything.
 */
void QmlCodeParser::parseSourceFile(const Location &location, const QString &filePath)
{
    QFile in(filePath);
    m_currentFile = filePath;
    if (!in.open(QIODevice::ReadOnly)) {
        location.error(QStringLiteral("Cannot open QML file '%1'").arg(filePath));
        m_currentFile.clear();
        return;
    }

#ifndef QT_NO_DECLARATIVE
    QString document = in.readAll();
    in.close();

    Location fileLocation(filePath);

    QString newCode = document;
    extractPragmas(newCode);
    m_lexer->setCode(newCode, 1);

    if (m_parser->parse()) {
        QQmlJS::AST::UiProgram *ast = m_parser->ast();
        QmlDocVisitor visitor(filePath, newCode, &m_engine, topicCommands() + commonMetaCommands(),
                              topicCommands());
        QQmlJS::AST::Node::accept(ast, &visitor);
        if (visitor.hasError()) {
            qDebug().nospace() << qPrintable(filePath) << ": Could not analyze QML file. "
                               << "The output is incomplete.";
        }
    }
    const auto &messages = m_parser->diagnosticMessages();
    for (const auto &msg : messages) {
        qDebug().nospace() << qPrintable(filePath) << ':'
                           << msg.loc.startLine << ": QML syntax error at col "
                           << msg.loc.startColumn
                           << ": " << qPrintable(msg.message);
    }
    m_currentFile.clear();
#else
    location.warning("QtDeclarative not installed; cannot parse QML or JS.");
#endif
}

static QSet<QString> topicCommands_;
/*!
  Returns the set of strings representing the topic commands.
 */
const QSet<QString> &QmlCodeParser::topicCommands()
{
    if (topicCommands_.isEmpty()) {
        topicCommands_ << COMMAND_VARIABLE << COMMAND_QMLCLASS << COMMAND_QMLTYPE
                       << COMMAND_QMLPROPERTY << COMMAND_QMLPROPERTYGROUP // mws 13/03/2019
                       << COMMAND_QMLATTACHEDPROPERTY << COMMAND_QMLSIGNAL
                       << COMMAND_QMLATTACHEDSIGNAL << COMMAND_QMLMETHOD
                       << COMMAND_QMLATTACHEDMETHOD << COMMAND_QMLVALUETYPE << COMMAND_QMLBASICTYPE;
    }
    return topicCommands_;
}

#ifndef QT_NO_DECLARATIVE
/*!
  Copy and paste from src/declarative/qml/qdeclarativescriptparser.cpp.
  This function blanks out the section of the \a str beginning at \a idx
  and running for \a n characters.
*/
static void replaceWithSpace(QString &str, int idx, int n)
{
    QChar *data = str.data() + idx;
    const QChar space(QLatin1Char(' '));
    for (int ii = 0; ii < n; ++ii)
        *data++ = space;
}

/*!
  Copy & paste from src/declarative/qml/qdeclarativescriptparser.cpp,
  then modified to return no values.

  Searches for ".pragma <value>" declarations within \a script.
  Currently supported pragmas are: library
*/
void QmlCodeParser::extractPragmas(QString &script)
{
    const QString pragma(QLatin1String("pragma"));

    QQmlJS::Lexer l(nullptr);
    l.setCode(script, 0);

    int token = l.lex();

    while (true) {
        if (token != QQmlJSGrammar::T_DOT)
            return;

        int startOffset = l.tokenOffset();
        int startLine = l.tokenStartLine();

        token = l.lex();

        if (token != QQmlJSGrammar::T_IDENTIFIER || l.tokenStartLine() != startLine
            || script.mid(l.tokenOffset(), l.tokenLength()) != pragma)
            return;

        token = l.lex();

        if (token != QQmlJSGrammar::T_IDENTIFIER || l.tokenStartLine() != startLine)
            return;

        QString pragmaValue = script.mid(l.tokenOffset(), l.tokenLength());
        int endOffset = l.tokenLength() + l.tokenOffset();

        token = l.lex();
        if (l.tokenStartLine() == startLine)
            return;

        if (pragmaValue == QLatin1String("library"))
            replaceWithSpace(script, startOffset, endOffset - startOffset);
        else
            return;
    }
}
#endif

QT_END_NAMESPACE
