source: smplayer/trunk/src/youtube/sig.cpp

/*  smplayer, GUI front-end for mplayer.
    Copyright (C) 2006-2017 Ricardo Villalba <rvm@users.sourceforge.net>

    This program is free software; you can redistribute it and/or modify
    it under the terms of the GNU General Public License as published by
    the Free Software Foundation; either version 2 of the License, or
    (at your option) any later version.

    This program is distributed in the hope that it will be useful,
    but WITHOUT ANY WARRANTY; without even the implied warranty of
    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
    GNU General Public License for more details.

    You should have received a copy of the GNU General Public License
    along with this program; if not, write to the Free Software
    Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
*/

#include "sig.h"
#include <QRegExp>
#include <QStringList>
#include <QtScript>
#include <QSettings>
#include <QDebug>

//#define ULTRAVERBOSE

QString Sig::findText(const QString & text, const QString & begin, const QString & end) {
        QString res;

        int pos = text.indexOf(begin);
        if (pos > -1) {
                int pos2 = text.indexOf(end, pos);
                if (pos2 > -1) {
                        pos = pos + begin.length();
                        res = text.mid(pos, pos2 - pos);
                }
        }

        return res;
}

QString Sig::findFunctions(const QString & text) {
        QString res;

        //QString sts;
        QRegExp rx_sts("sts:(\\d+)");
        if (rx_sts.indexIn(text) != -1) {
                sts = rx_sts.cap(1);
        }
        qDebug() << "Sig::findFunctions: sts:" << sts;

        QString sig_name;
        QRegExp rx_sig("\\.sig\\|\\|([a-zA-Z0-9\\$]+)\\(");
        if (rx_sig.indexIn(text) != -1) {
                sig_name = rx_sig.cap(1);
        }
        qDebug() << "Sig::findFunctions: sig_name:" << sig_name;

        QString sig_code;
        if (!sig_name.isEmpty()) {
                //int pos = text.indexOf("function " + sig_name);
                int pos = text.indexOf("var " + sig_name + "=function");
                if (pos == -1) pos = text.indexOf("," + sig_name + "=function");
                if (pos == -1) pos = text.indexOf(sig_name + "=function");
                if (pos > -1) {
                        int endpos = text.indexOf("}", pos);
                        #ifdef ULTRAVERBOSE
                        qDebug() << "Sig::findFunctions: pos:" << pos << "endpos:" << endpos;
                        #endif
                        if (endpos > -1) {
                                sig_code = text.mid(pos, (endpos-pos)+1);
                                if (sig_code.startsWith("var ")) sig_code.replace("var " + sig_name + "=function", "function " + sig_name);
                                else
                                if (sig_code.startsWith(",")) sig_code.replace("," + sig_name + "=function", "function " + sig_name);
                                else
                                if (sig_code.startsWith(sig_name+"=")) sig_code.replace(sig_name + "=function", "function " + sig_name);
                        }
                }
        }
        qDebug() << "Sig::findFunctions: sig_code:" << sig_code;

        // Find the 2nd function
        QString function2;
        if (!sig_code.isEmpty()) {
                QStringList parts = sig_code.split(";");
                #ifdef ULTRAVERBOSE
                qDebug() << "Sig::findFunctions: parts:" << parts;
                #endif
                foreach(QString part, parts) {
                        //qDebug() << "Sig::findFunctions: part:" << part;
                        QRegExp rx("([a-zA-Z\\$]+)\\.([a-zA-Z0-9]+)\\(");
                        if (rx.indexIn(part) != -1) {
                                QString possible_var = rx.cap(1);
                                #ifdef ULTRAVERBOSE
                                qDebug() << "Sig::findFunctions: possible var:" << possible_var;
                                #endif
                                if ((possible_var != "a") && (possible_var != "")) {
                                        QString s = findText(text, "var "+ possible_var +"=", "};");
                                        #ifdef ULTRAVERBOSE
                                        qDebug() << "Sig::findFunctions: s:" << s;
                                        #endif
                                        if (!s.isEmpty()) {
                                                function2 = "var "+ possible_var +" = "+ s +" };";
                                                break;
                                        }
                                }
                        }
                }
        }
        qDebug() << "Sig::findFunctions: function2:" << function2;

        if (!sig_code.isEmpty()) {
                //sig_code = sig_code.replace("function "+ sig_name + "(", "function aclara(");
                function_name = sig_name;
                #ifdef ULTRAVERBOSE
                qDebug() << "Sig::findFunctions: sig_code:" << sig_code;
                #endif
                res = sig_code + " " + function2;
        }

        qDebug() << "Sig::findFunctions: res:" << res;

        decrypt_function = res;
        return res;
}

QString Sig::aclara(const QString & text) {
        int dot = text.indexOf('.');
        qDebug("Sig::aclara: length: %d (%d.%d)", text.size(), dot, text.size()-dot-1);

        QString res;

        if (!decrypt_function.isEmpty()) {
                QString fname = function_name;
                QScriptEngine engine;
                engine.evaluate(decrypt_function);

                QScriptValueList args;
                args << text;
                QScriptValue aclarar = engine.globalObject().property(fname);
                res = aclarar.call(QScriptValue(), args).toString();
        }

        qDebug() << "Sig::aclara: res:" << res;

        if (res.isEmpty()) {
                qDebug() << "Sig::aclara: signature length not supported:" << text.size() << ":" << text;
        }

        return res;
}

void Sig::save(QSettings * set) {
        qDebug() << "Sig::save";

        set->beginGroup("sig");
        set->setValue("player", html5_player);
        set->setValue("sts", sts);
        set->setValue("function_name", function_name);
        set->setValue("function", decrypt_function);
        set->endGroup();
}

void Sig::load(QSettings * set) {
        qDebug() << "Sig::load";

        set->beginGroup("sig");
        html5_player = set->value("player", "").toString();
        sts = set->value("sts", "").toString();
        function_name = set->value("function_name", "").toString();
        decrypt_function = set->value("function", "").toString();
        set->endGroup();
}