// SPDX-License-Identifier: MIT

#include "info.h"

#include <stdio.h>
#include <stdlib.h>
#include <sys/stat.h>
#ifdef Q_OS_WIN
#include <process.h>
#define getpid _getpid
#define popen _popen
#define pclose _pclose
#else
#include <unistd.h> // getpid()
#endif

#include <QCoreApplication>
#include <QFile>
#include <QStandardPaths>
#include <QUrl>

#include <KLocalizedString>
#include <KShell>

using namespace KIO;

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

InfoProtocol::InfoProtocol(const QByteArray &pool, const QByteArray &app)
    : WorkerBase("info", pool, app)
{
    qCDebug(LOG_KIO_INFO);

    m_perl = QStandardPaths::findExecutable("perl");
    if (m_perl.isEmpty())
        m_missingFiles.append("perl");
    m_infoScript = QStandardPaths::locate(QStandardPaths::GenericDataLocation, "kio_info/kde-info2html");
    if (m_infoScript.isEmpty())
        m_missingFiles.append("kio_info/kde-info2html");
    m_infoConf = QStandardPaths::locate(QStandardPaths::GenericDataLocation, "kio_info/kde-info2html.conf");
    if (m_infoConf.isEmpty())
        m_missingFiles.append("kio_info/kde-info2html.conf");

    if (!m_missingFiles.isEmpty()) {
        qCCritical(LOG_KIO_INFO) << "Cannot locate files for HTML conversion," << qPrintable(m_missingFiles.join(' '));
    }

    qCDebug(LOG_KIO_INFO) << "done";
}

KIO::WorkerResult InfoProtocol::missingFilesResult() const
{
    const QString errorStr = i18n(
        "Unable to locate files which are necessary to run this service:<br>%1<br>"
        "Please check your software installation.",
        m_missingFiles.join(' '));
    return KIO::WorkerResult::fail(KIO::ERR_WORKER_DEFINED, errorStr);
}

KIO::WorkerResult InfoProtocol::get(const QUrl &url)
{
    qCDebug(LOG_KIO_INFO) << "URL" << url.toDisplayString() << "path" << url.path();

    if (!m_missingFiles.isEmpty()) {
        return missingFilesResult();
    }

    if (url.path() == "/") {
        QUrl newUrl("info:/dir");
        redirection(newUrl);
        return KIO::WorkerResult::pass();
        ;
    };

    // some people write info://autoconf instead of info:/autoconf
    if (!url.host().isEmpty()) {
        QUrl newURl(url);
        newURl.setPath(url.host() + url.path());
        newURl.setHost(QString());
        redirection(newURl);
        return KIO::WorkerResult::pass();
        ;
    }

    if (url.path().right(1) == "/") {
        // Trailing / are not supported, so we need to remove them.
        QUrl newUrl(url);
        QString newPath(url.path());
        newPath.chop(1);
        newUrl.setPath(newPath);
        redirection(newUrl);
        return KIO::WorkerResult::pass();
        ;
    }

    // '<' in the path looks suspicious, someone is trying info:/dir/<script>alert('xss')</script>
    if (url.path().contains('<')) {
        return KIO::WorkerResult::fail(KIO::ERR_MALFORMED_URL, url.url());
    }

    mimeType("text/html");
    // extract the path and node from url
    decodeURL(url);

    QString cmd = KShell::quoteArg(m_perl);
    cmd += ' ';
    cmd += KShell::quoteArg(m_infoScript);
    cmd += ' ';
    cmd += KShell::quoteArg(m_infoConf);
    cmd += ' ';
    cmd += KShell::quoteArg(m_page);
    cmd += ' ';
    cmd += KShell::quoteArg(m_node);

    qCDebug(LOG_KIO_INFO) << "cmd" << cmd;

    FILE *file = popen(QFile::encodeName(cmd).constData(), "r");
    if (!file) {
        qCDebug(LOG_KIO_INFO) << "popen failed";
        return KIO::WorkerResult::fail(ERR_CANNOT_LAUNCH_PROCESS, cmd);
    }

    auto fileCloser = [](FILE* f) { if(f) pclose(f); };
    std::unique_ptr<FILE, decltype(fileCloser)> fileGuard(file);

    char buffer[4096];
    bool empty = true;
    while (!feof(file)) {
        int n = fread(buffer, 1, sizeof(buffer), file);
        if (!n && feof(file) && empty) {
            return KIO::WorkerResult::fail(ERR_CANNOT_LAUNCH_PROCESS, cmd);
        }
        if (n < 0) {
            // ERROR
            qCWarning(LOG_KIO_INFO) << "read error!";
            return KIO::WorkerResult::fail();
        }

        empty = false;
        data(QByteArray::fromRawData(buffer, n));
    }

    qCDebug(LOG_KIO_INFO) << "done";
    return KIO::WorkerResult::pass();
}

KIO::WorkerResult InfoProtocol::mimetype(const QUrl & /* url */)
{
    qCDebug(LOG_KIO_INFO);

    if (!m_missingFiles.isEmpty()) {
        return missingFilesResult();
    }

    // to get rid of those "Open with" dialogs...
    mimeType("text/html");

    // finish action
    return KIO::WorkerResult::pass();
}

void InfoProtocol::decodeURL(const QUrl &url)
{
    qCDebug(LOG_KIO_INFO) << url;

    /* Notes:
     *
     * I cleaned up the URL decoding and chose not to support URLs in the
     * form "info:/usr/local/share/info/libc.info.gz" or similar which the
     * older code attempted (and failed, maybe it had worked once) to do.
     *
     * The reason is that an obvious use such as viewing a info file off your
     * infopath would work for the first page, but then all the links would be
     * wrong. Of course, one could change kde-info2html to make it work, but I don't
     * think it worthy, others are free to disagree and write the necessary code ;)
     *
     * luis pedro
     */

    if (url == QUrl("info:/browse_by_file?special=yes")) {
        m_page = "#special#";
        m_node = "browse_by_file";
        qCDebug(LOG_KIO_INFO) << "InfoProtocol::decodeURL - special - browse by file";
        return;
    }

    decodePath(url.path());
}

void InfoProtocol::decodePath(QString path)
{
    qCDebug(LOG_KIO_INFO) << path;

    m_page = "dir"; // default
    m_node = "";

    // remove leading slash
    if ('/' == path[0]) {
        path = path.mid(1);
    }
    // qCDebug(LOG_KIO_INFO) << "Path: " << path;

    int slashPos = path.indexOf("/");

    if (slashPos < 0) {
        m_page = path;
        m_node = "Top";
        return;
    }

    m_page = path.left(slashPos);

    // remove leading+trailing whitespace
    m_node = path.right(path.length() - slashPos - 1).trimmed();

    qCDebug(LOG_KIO_INFO) << "-> page" << m_page << "node" << m_node;
}

// A minimalistic stat with only the file type
// This seems to be enough for konqueror
KIO::WorkerResult InfoProtocol::stat(const QUrl &)
{
    if (!m_missingFiles.isEmpty()) {
        return missingFilesResult();
    }

    UDSEntry uds_entry;

#ifdef Q_OS_WIN
    // Regular file with rwx permission for all
    uds_entry.fastInsert(KIO::UDSEntry::UDS_FILE_TYPE, S_IFREG);
#else
    // Regular file with rwx permission for all
    uds_entry.fastInsert(KIO::UDSEntry::UDS_FILE_TYPE, S_IFREG | S_IRWXU | S_IRWXG | S_IRWXO);
#endif

    statEntry(uds_entry);
    return KIO::WorkerResult::pass();
}

extern "C" {
int Q_DECL_EXPORT kdemain(int argc, char **argv);
}

int kdemain(int argc, char **argv)
{
    QCoreApplication app(argc, argv); // needed for QSocketNotifier
    app.setApplicationName(QLatin1String("kio_info"));

    qCDebug(LOG_KIO_INFO) << "kio_info starting" << getpid();

    if (argc != 4) {
        fprintf(stderr, "Usage: kio_info protocol domain-socket1 domain-socket2\n");
        exit(-1);
    }

    InfoProtocol worker(argv[2], argv[3]);
    worker.dispatchLoop();

    return 0;
}

#include "info.moc"