/*  SPDX-License-Identifier: LGPL-2.0-or-later
 */

#include <stdio.h>
#include <stdlib.h>
#include <sys/stat.h>

#include "kio_mits_debug.h"
#include <QCoreApplication>
#include <QMimeDatabase>
#include <QMimeType>

#include <QBitArray>
#include <QDir>
#include <QFile>
#include <QVector>

#include "libchmurlfactory.h"
#include "msits.h"

using namespace KIO;

// Pseudo plugin class to embed meta data
class KIOPluginForMetaData : public QObject
{
    Q_OBJECT
    Q_PLUGIN_METADATA(IID "org.kde.kio.slave.ms-its.json" FILE "ms-its.json")
};

extern "C" {
int Q_DECL_EXPORT kdemain(int argc, char **argv)
{
    qCDebug(KIO_MITS_LOG) << "*** kio_msits Init";

    QCoreApplication app(argc, argv);
    app.setApplicationName(QStringLiteral("kio_msits"));

    if (argc != 4) {
        qCDebug(KIO_MITS_LOG) << "Usage: kio_msits protocol domain-socket1 domain-socket2";
        exit(-1);
    }

    ProtocolMSITS slave(argv[2], argv[3]);
    slave.dispatchLoop();

    qCDebug(KIO_MITS_LOG) << "*** kio_msits Done";
    return 0;
}
}

ProtocolMSITS::ProtocolMSITS(const QByteArray &pool_socket, const QByteArray &app_socket)
    : SlaveBase("kio_msits", pool_socket, app_socket)
{
    m_chmFile = nullptr;
}

ProtocolMSITS::~ProtocolMSITS()
{
    if (!m_chmFile) {
        return;
    }

    chm_close(m_chmFile);
    m_chmFile = nullptr;
}

// A simple stat() wrapper
static bool isDirectory(const QString &filename)
{
    return filename.endsWith(QLatin1Char('/'));
}

void ProtocolMSITS::get(const QUrl &url)
{
    QString htmdata, fileName;
    chmUnitInfo ui;
    QByteArray buf;

    qCDebug(KIO_MITS_LOG) << "kio_msits::get() " << url.path();

    if (!parseLoadAndLookup(url, fileName)) {
        return; // error() has been called by parseLoadAndLookup
    }

    qCDebug(KIO_MITS_LOG) << "kio_msits::get: parseLoadAndLookup returned " << fileName;

    if (LCHMUrlFactory::handleFileType(url.path(), htmdata)) {
        buf = htmdata.toUtf8();
        qCDebug(KIO_MITS_LOG) << "Using special handling for image pages: " << htmdata;
    } else {
        if (isDirectory(fileName)) {
            error(KIO::ERR_IS_DIRECTORY, url.toString());
            return;
        }

        if (!ResolveObject(fileName, &ui)) {
            qCDebug(KIO_MITS_LOG) << "kio_msits::get: could not resolve filename " << fileName;
            error(KIO::ERR_DOES_NOT_EXIST, url.toString());
            return;
        }

        buf.resize(ui.length);

        if (RetrieveObject(&ui, (unsigned char *)buf.data(), 0, ui.length) == 0) {
            qCDebug(KIO_MITS_LOG) << "kio_msits::get: could not retrieve filename " << fileName;
            error(KIO::ERR_NO_CONTENT, url.toString());
            return;
        }
    }

    totalSize(buf.size());

    QMimeDatabase db;
    QMimeType result = db.mimeTypeForFileNameAndData(fileName, buf);
    qCDebug(KIO_MITS_LOG) << "Emitting mimetype " << result.name();

    mimeType(result.name());

    data(buf);
    processedSize(buf.size());

    finished();
}

bool ProtocolMSITS::parseLoadAndLookup(const QUrl &url, QString &abspath)
{
    qCDebug(KIO_MITS_LOG) << "ProtocolMSITS::parseLoadAndLookup (const KUrl&) " << url.path();

    int pos = url.path().indexOf(QStringLiteral("::"));

    if (pos == -1) {
        error(KIO::ERR_MALFORMED_URL, url.toString());
        return false;
    }

    QString filename = url.path().left(pos);
    abspath = url.path().mid(pos + 2); // skip ::

    // Some buggy apps add ms-its:/ to the path as well
    if (abspath.startsWith(QLatin1String("ms-its:"))) {
        abspath = abspath.mid(7);
    }

    qCDebug(KIO_MITS_LOG) << "ProtocolMSITS::parseLoadAndLookup: filename " << filename << ", path " << abspath;

    if (filename.isEmpty()) {
        error(KIO::ERR_MALFORMED_URL, url.toString());
        return false;
    }

    // If the file has been already loaded, nothing to do.
    if (m_chmFile && filename == m_openedFile) {
        return true;
    }

    qCDebug(KIO_MITS_LOG) << "Opening a new CHM file " << QFile::encodeName(QDir::toNativeSeparators(filename));

    // First try to open a temporary file
    chmFile *tmpchm;

    if ((tmpchm = chm_open(QFile::encodeName(QDir::toNativeSeparators(filename)).constData())) == nullptr) {
        error(KIO::ERR_CANNOT_READ, url.toString());
        return false;
    }

    // Replace an existing file by a new one
    if (m_chmFile) {
        chm_close(m_chmFile);
    }

    m_chmFile = tmpchm;
    m_openedFile = filename;

    qCDebug(KIO_MITS_LOG) << "A CHM file " << filename << " has beed opened successfully";
    return true;
}

/*
 * Shamelessly stolen from a KDE KIO tutorial
 */
static void app_entry(UDSEntry &e, unsigned int uds, const QString &str)
{
    e.fastInsert(uds, str);
}

// appends an int with the UDS-ID uds
static void app_entry(UDSEntry &e, unsigned int uds, long l)
{
    e.fastInsert(uds, l);
}

// internal function
// fills a directory item with its name and size
static void app_dir(UDSEntry &e, const QString &name)
{
    e.clear();
    app_entry(e, KIO::UDSEntry::UDS_NAME, name);
    app_entry(e, KIO::UDSEntry::UDS_FILE_TYPE, S_IFDIR);
    app_entry(e, KIO::UDSEntry::UDS_SIZE, 1);
}

// internal function
// fills a file item with its name and size
static void app_file(UDSEntry &e, const QString &name, size_t size)
{
    e.clear();
    app_entry(e, KIO::UDSEntry::UDS_NAME, name);
    app_entry(e, KIO::UDSEntry::UDS_FILE_TYPE, S_IFREG);
    app_entry(e, KIO::UDSEntry::UDS_SIZE, size);
}

void ProtocolMSITS::stat(const QUrl &url)
{
    QString fileName;
    chmUnitInfo ui;

    qCDebug(KIO_MITS_LOG) << "kio_msits::stat (const KUrl& url) " << url.path();

    if (!parseLoadAndLookup(url, fileName)) {
        return; // error() has been called by parseLoadAndLookup
    }

    if (!ResolveObject(fileName, &ui)) {
        error(KIO::ERR_DOES_NOT_EXIST, url.toString());
        return;
    }

    qCDebug(KIO_MITS_LOG) << "kio_msits::stat: adding an entry for " << fileName;
    UDSEntry entry;

    if (isDirectory(fileName)) {
        app_dir(entry, fileName);
    } else {
        app_file(entry, fileName, ui.length);
    }

    statEntry(entry);

    finished();
}

// A local CHMLIB enumerator
static int chmlib_enumerator(struct chmFile *, struct chmUnitInfo *ui, void *context)
{
    ((QVector<QString> *)context)->push_back(QString::fromLocal8Bit(ui->path));
    return CHM_ENUMERATOR_CONTINUE;
}

void ProtocolMSITS::listDir(const QUrl &url)
{
    QString filepath;

    qCDebug(KIO_MITS_LOG) << "kio_msits::listDir (const KUrl& url) " << url.path();

    if (!parseLoadAndLookup(url, filepath)) {
        return; // error() has been called by parseLoadAndLookup
    }

    filepath += QLatin1Char('/');

    if (!isDirectory(filepath)) {
        error(KIO::ERR_CANNOT_ENTER_DIRECTORY, url.path());
        return;
    }

    qCDebug(KIO_MITS_LOG) << "kio_msits::listDir: enumerating directory " << filepath;

    QVector<QString> listing;

    if (chm_enumerate_dir(m_chmFile, filepath.toLocal8Bit().constData(), CHM_ENUMERATE_NORMAL | CHM_ENUMERATE_FILES | CHM_ENUMERATE_DIRS, chmlib_enumerator, &listing) != 1) {
        error(KIO::ERR_CANNOT_ENTER_DIRECTORY, url.path());
        return;
    }

    UDSEntry entry;
    int striplength = filepath.length();

    for (const QString &iListing : qAsConst(listing)) {
        // Strip the directory name
        const QString ename = iListing.mid(striplength);

        if (isDirectory(ename)) {
            app_dir(entry, ename);
        } else {
            app_file(entry, ename, 0);
        }
    }

    finished();
}

#include "msits.moc"
