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#include <QCoreApplication>
#include <QFile>
#include <QTextStream>

#include <QtQml/private/qqmljslexer_p.h>
#include <QtQml/private/qqmljsparser_p.h>
#include <QtQml/private/qqmljsengine_p.h>
#include <QtQml/private/qqmljsastvisitor_p.h>
#include <QtQml/private/qqmljsast_p.h>

#if QT_CONFIG(commandlineparser)
#include <QCommandLineParser>
#endif

#include "commentastvisitor.h"
#include "dumpastvisitor.h"
#include "restructureastvisitor.h"

struct Options
{
    bool verbose = false;
    bool inplace = false;
    bool force = false;
    bool tabs = false;
    bool valid = false;

    int indentWidth = 4;
    bool indentWidthSet = false;
    QString newline = "native";

    QStringList files;
    QStringList arguments;
    QStringList errors;
};

bool parseFile(const QString &filename, const Options &options)
{
    QFile file(filename);

    if (!file.open(QIODevice::Text | QIODevice::ReadOnly)) {
        qWarning().noquote() << "Failed to open" << filename << "for reading.";
        return false;
    }

    QString code = QString::fromUtf8(file.readAll());
    file.close();

    QQmlJS::Engine engine;
    QQmlJS::Lexer lexer(&engine);

    lexer.setCode(code, 1, true);
    QQmlJS::Parser parser(&engine);

    bool success = parser.parse();

    if (!success) {
        const auto diagnosticMessages = parser.diagnosticMessages();
        for (const QQmlJS::DiagnosticMessage &m : diagnosticMessages) {
            qWarning().noquote() << QString::fromLatin1("%1:%2 : %3")
                                    .arg(filename).arg(m.loc.startLine).arg(m.message);
        }

        qWarning().noquote() << "Failed to parse" << filename;
        return false;
    }

    // Try to attach comments to AST nodes
    CommentAstVisitor comment(&engine, parser.rootNode());

    if (options.verbose)
        qWarning().noquote() << comment.attachedComments().size() << "comment(s) attached.";

    if (options.verbose) {
        int orphaned = 0;

        for (const auto& orphanList : comment.orphanComments().values())
            orphaned += orphanList.size();

        qWarning().noquote() << orphaned << "comments are orphans.";
    }

    // Do the actual restructuring
    RestructureAstVisitor restructure(parser.rootNode());

    // Turn AST back into source code
    if (options.verbose)
        qWarning().noquote() << "Dumping" << filename;

    DumpAstVisitor dump(
            &engine, parser.rootNode(), &comment, options.tabs ? 1 : options.indentWidth,
            options.tabs ? DumpAstVisitor::Indentation::Tabs : DumpAstVisitor::Indentation::Spaces);

    QString dumpCode = dump.toString();

    lexer.setCode(dumpCode, 1, true);

    bool dumpSuccess = parser.parse();

    if (!dumpSuccess) {
        if (options.verbose) {
            const auto diagnosticMessages = parser.diagnosticMessages();
            for (const QQmlJS::DiagnosticMessage &m : diagnosticMessages) {
              qWarning().noquote() << QString::fromLatin1("<formatted>:%2 : %3")
                                      .arg(m.loc.startLine).arg(m.message);
            }
        }

        qWarning().noquote() << "Failed to parse formatted code.";
    }

    if (dump.error() || !dumpSuccess) {
        if (options.force) {
            qWarning().noquote() << "An error has occurred. The output may not be reliable.";
        } else {
            qWarning().noquote() << "An error has occurred. Aborting.";
            return false;
        }
   }

   const bool native = options.newline == "native";

   if (!native) {
       if (options.newline == "macos") {
           dumpCode = dumpCode.replace("\n", "\r");
       } else if (options.newline == "windows") {
           dumpCode = dumpCode.replace("\n", "\r\n");
       } else if (options.newline == "unix") {
           // Nothing needs to be done for unix line-endings
       } else {
           qWarning().noquote() << "Unknown line ending type" << options.newline;
           return false;
       }
   }

   if (options.inplace) {
       if (options.verbose)
           qWarning().noquote() << "Writing to file" << filename;

       if (!file.open(native ? QIODevice::WriteOnly | QIODevice::Text : QIODevice::WriteOnly)) {
           qWarning().noquote() << "Failed to open" << filename << "for writing";
           return false;
       }

       file.write(dumpCode.toUtf8());
       file.close();
   } else {
       QFile out;
       out.open(stdout, QIODevice::WriteOnly);
       out.write(dumpCode.toUtf8());
   }

    return true;
}

Options buildCommandLineOptions(const QCoreApplication &app)
{
#if QT_CONFIG(commandlineparser)
    QCommandLineParser parser;
    parser.setApplicationDescription("Formats QML files according to the QML Coding Conventions.");
    parser.addHelpOption();
    parser.addVersionOption();

    parser.addOption(QCommandLineOption({"V", "verbose"},
                     QStringLiteral("Verbose mode. Outputs more detailed information.")));

    parser.addOption(QCommandLineOption({"i", "inplace"},
                     QStringLiteral("Edit file in-place instead of outputting to stdout.")));

    parser.addOption(QCommandLineOption({"f", "force"},
                     QStringLiteral("Continue even if an error has occurred.")));

    parser.addOption(
            QCommandLineOption({ "t", "tabs" }, QStringLiteral("Use tabs instead of spaces.")));

    parser.addOption(QCommandLineOption({ "w", "indent-width" },
                                        QStringLiteral("How many spaces are used when indenting."),
                                        "width", "4"));

    parser.addOption(QCommandLineOption(
            { "F", "files" }, QStringLiteral("Format all files listed in file, in-place"), "file"));

    parser.addOption(QCommandLineOption({"l", "newline"},
                     QStringLiteral("Override the new line format to use (native macos unix windows)."),
                     "newline", "native"));

    parser.addPositionalArgument("filenames", "files to be processed by qmlformat");

    parser.process(app);

    bool indentWidthOkay = false;
    const int indentWidth = parser.value("indent-width").toInt(&indentWidthOkay);
    if (!indentWidthOkay) {
        Options options;
        options.errors.push_back("Error: Invalid value passed to -w");
        return options;
    }

    QStringList files;
    QFile file(parser.value("files"));
    file.open(QIODevice::Text | QIODevice::ReadOnly);
    if (file.isOpen()) {
        QTextStream in(&file);
        while (!in.atEnd()) {
            QString file = in.readLine();

            if (file.isEmpty())
                continue;

            files.push_back(file);
        }
    }

    Options options;
    options.verbose = parser.isSet("verbose");
    options.inplace = parser.isSet("inplace");
    options.force = parser.isSet("force");
    options.tabs = parser.isSet("tabs");
    options.valid = true;

    options.indentWidth = indentWidth;
    options.indentWidthSet = parser.isSet("indent-width");
    options.newline = parser.value("newline");
    options.files = files;
    options.arguments = parser.positionalArguments();
    return options;
#else
    return Options {};
#endif
}

int main(int argc, char *argv[])
{
    QCoreApplication app(argc, argv);
    QCoreApplication::setApplicationName("qmlformat");
    QCoreApplication::setApplicationVersion("1.0");

    const auto options = buildCommandLineOptions(app);
    if (!options.valid) {
        for (const auto &error : options.errors) {
            qWarning().noquote() << error;
        }

        return -1;
    }

    bool success = true;
    if (!options.files.isEmpty()) {
        if (!options.arguments.isEmpty())
            qWarning() << "Warning: Positional arguments are ignored when -F is used";

        for (const QString &file : options.files) {
            Q_ASSERT(!file.isEmpty());

            if (!parseFile(file, options))
                success = false;
        }
    } else {
        for (const QString &file : options.arguments) {
            if (!parseFile(file, options))
                success = false;
        }
    }

    return success ? 0 : 1;
}