#include <QtCore>#include <QtNetwork>#include <iostream>#include "spider.h"using namespace std;Spider::Spider(QObject *parent)    : QObject(parent){    connect(&ftp, SIGNAL(done(bool)), this, SLOT(ftpDone(bool)));    connect(&ftp, SIGNAL(listInfo(const QUrlInfo &)),            this, SLOT(ftpListInfo(const QUrlInfo &)));}bool Spider::getDirectory(const QUrl &url){    if (!url.isValid()) {        cerr << "Error: Invalid URL" << endl;        return false;    }    if (url.scheme() != "ftp") {        cerr << "Error: URL must start with 'ftp:'" << endl;        return false;    }    ftp.connectToHost(url.host(), url.port(21));    ftp.login();    QString path = url.path();    if (path.isEmpty())        path = "/";    pendingDirs.append(path);    processNextDirectory();    return true;}void Spider::ftpDone(bool error){    if (error) {        cerr << "Error: " << qPrintable(ftp.errorString()) << endl;    } else {        cout << "Downloaded " << qPrintable(currentDir) << " to "             << qPrintable(QDir::convertSeparators(                               QDir(currentLocalDir).canonicalPath()));    }    qDeleteAll(openedFiles);    openedFiles.clear();    processNextDirectory();}void Spider::ftpListInfo(const QUrlInfo &urlInfo){    if (urlInfo.isFile()) {        if (urlInfo.isReadable()) {            QFile *file = new QFile(currentLocalDir + "/"                                    + urlInfo.name());            if (!file->open(QIODevice::WriteOnly)) {                cerr << "Warning: Cannot open file "                     << qPrintable(                            QDir::convertSeparators(file->fileName()))                     << endl;                return;            }            ftp.get(urlInfo.name(), file);            openedFiles.append(file);        }    } else if (urlInfo.isDir() && !urlInfo.isSymLink()) {        pendingDirs.append(currentDir + "/" + urlInfo.name());    }}void Spider::processNextDirectory(){    if (!pendingDirs.isEmpty()) {        currentDir = pendingDirs.takeFirst();        currentLocalDir = "downloads/" + currentDir;        QDir(".").mkpath(currentLocalDir);        ftp.cd(currentDir);        ftp.list();    } else {        emit done();    }}