// SPDX-License-Identifier: GPL-3.0-or-later
// Copyright (C) 2026 Dany Thinnes

#include "xdftool.h"

#include <QPair>
#include <QProcess>
#include <QProcessEnvironment>
#include <QRegularExpression>
#include <QVector>

XdfTool::XdfTool(const QString &program) : m_program(program) {}

XdfTool::Result XdfTool::runBatch(const QString &image, const QList<QStringList> &commands) const
{
    Result r;

    QStringList args;
    args << image;
    for (int i = 0; i < commands.size(); ++i) {
        if (i > 0)
            args << QStringLiteral("+");
        args << commands.at(i);
    }

    QStringList shown;
    for (const QString &a : args)
        shown << (a.contains(' ') ? QStringLiteral("\"%1\"").arg(a) : a);
    r.commandLine = m_program + ' ' + shown.join(' ');

    QProcess p;
#ifdef Q_OS_WIN
    // Python-Ausgabe unter Windows auf UTF-8 zwingen (sonst Umlaute in Dateinamen kaputt)
    QProcessEnvironment env = QProcessEnvironment::systemEnvironment();
    env.insert(QStringLiteral("PYTHONUTF8"), QStringLiteral("1"));
    env.insert(QStringLiteral("PYTHONIOENCODING"), QStringLiteral("utf-8"));
    p.setProcessEnvironment(env);
#endif
    p.start(m_program, args);
    if (!p.waitForStarted(5000)) {
        r.err = QStringLiteral("Konnte '%1' nicht starten: %2").arg(m_program, p.errorString());
        return r;
    }
    p.waitForFinished(-1);

    r.out = QString::fromUtf8(p.readAllStandardOutput());
    r.err = QString::fromUtf8(p.readAllStandardError());
    r.ok = (p.exitStatus() == QProcess::NormalExit && p.exitCode() == 0);
    return r;
}

XdfTool::Result XdfTool::list(const QString &image, QList<AdfEntry> &entries) const
{
    Result r = runBatch(image, { { QStringLiteral("list") } });
    if (r.ok)
        entries = parseList(r.out);
    return r;
}

// Erwartet das typische Ausgabeformat von "xdftool <img> list":
// pro Zeile ein Eintrag, Unterverzeichnisse um je 2 Leerzeichen eingerueckt,
// danach eine Spalte mit "DIR" bzw. der Dateigroesse in Bytes.
QList<AdfEntry> XdfTool::parseList(const QString &text)
{
    static const QRegularExpression reWide(
        QStringLiteral(R"(^( *)(.*?)\s{2,}(DIR|\d+)(?:\s.*)?$)"));
    static const QRegularExpression reNarrow(
        QStringLiteral(R"(^( *)(.*?)\s+(DIR|\d+)(?:\s.*)?$)"));

    QList<AdfEntry> result;
    QVector<QPair<int, QString>> stack; // (Einrueckung, Pfad) offener Verzeichnisse

    const QStringList lines = text.split('\n');
    for (QString line : lines) {
        if (line.endsWith('\r'))
            line.chop(1);
        if (line.trimmed().isEmpty())
            continue;

        QRegularExpressionMatch m = reWide.match(line);
        if (!m.hasMatch())
            m = reNarrow.match(line);
        if (!m.hasMatch())
            continue;

        const int indent = m.captured(1).size();
        const QString name = m.captured(2).trimmed();
        if (name.isEmpty())
            continue;

        while (!stack.isEmpty() && stack.last().first >= indent)
            stack.removeLast();

        const QString parent = stack.isEmpty() ? QString() : stack.last().second;

        AdfEntry e;
        e.name = name;
        e.path = parent.isEmpty() ? name : parent + QLatin1Char('/') + name;
        e.isDir = (m.captured(3) == QLatin1String("DIR"));
        e.size = e.isDir ? 0 : m.captured(3).toLongLong();
        result << e;

        if (e.isDir)
            stack.append({ indent, e.path });
    }
    return result;
}