/*
 * Copyright(C) 2018-2020, Franco Conidi <edmondweblog@gmail.com>
 *
 * This file is part of the Systemback.
 *
 * The Systemback 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 3 of the License, or (at your option) any later
 * version.
 *
 * The Systemback 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 the
 * Systemback. If not, see <http://www.gnu.org/licenses>.
 */

#include "sbscheduler.hpp"
#include <QDir>

void scheduler::main()
{
    {
        QSL args(qApp->arguments());

        uchar rv(args.count() != 2 ? 1
            : sb::schdlr[1] != "false" && (sb::schdlr[1] == "everyone" || sb::right(sb::schdlr[1], -1).split(',').contains(args.at(1))) ? 2
            : getuid() + getgid() ? 3
            : sb::isfile("/cdrom/casper/filesystem.squashfs") || sb::isfile("/lib/live/mount/medium/live/filesystem.squashfs") ? 4
            : ! sb::lock(sb::Schdlrlock) ? 5
            : daemon(0, 0) ? 6
            : [&]() -> uchar {
                    sb::delay(100);
                    return sb::lock(sb::Schdlrlock) && sb::crtfile(*(pfile = new QStr(sb::isdir("/run") ? "/run/sbscheduler.pid" : "/var/run/sbscheduler.pid")), QStr::number(qApp->applicationPid())) ? 0 : 255;
                }());

        if(rv)
        {
            if(rv < 255) sb::error("\n " % sb::tr("Cannot start the Systemback scheduler daemon!") % "\n\n " % [rv] {
                    switch(rv) {
                    case 1:
                        return sb::tr("Missing, wrong or too much argument(s).");
                    case 2:
                        return sb::tr("The process is disabled for this user.");
                    case 3:
                        return sb::tr("Root privileges are required.");
                    case 4:
                        return sb::tr("This system is a Live.");
                    case 5:
                        return sb::tr("Already running.");
                    default:
                        return sb::tr("Unable to daemonize.");
                    }
                }() % "\n\n");

            return qApp->exit(rv);
        }
    }

    QDateTime pflmd(QFileInfo(*pfile).lastModified());
    sleep(290);

    forever
    {
        sleep(10);

        if(! sb::isfile(*pfile) || (pflmd != QFileInfo(*pfile).lastModified() && sb::fload(*pfile) != QBA::number(qApp->applicationPid())))
        {
            sb::unlock(sb::Schdlrlock), sb::exec("sbscheduler " % qApp->arguments().at(1), sb::Silent | sb::Bckgrnd);
            break;
        }

        if(! sb::isfile(cfgfile) || cfglmd != QFileInfo(cfgfile).lastModified()) sb::cfgread(),
                                                                                 cfglmd = QFileInfo(cfgfile).lastModified();

        if(! (sb::isdir(sb::sdir[1]) && sb::access(sb::sdir[1], sb::Write)))
            sleep(50);
        else if(! sb::isfile(sb::sdir[1] % "/.sbschedule"))
            sb::crtfile(sb::sdir[1] % "/.sbschedule");
        else if(! sb::schdle[0])
            sleep(1790);
        else if(QFileInfo(sb::sdir[1] % "/.sbschedule").lastModified().secsTo(QDateTime::currentDateTime()) / 60 >= sb::schdle[1] * 1440 + sb::schdle[2] * 60 + sb::schdle[3] && sb::lock(sb::Sblock))
        {
            if(! sb::lock(sb::Dpkglock) || [] {
                    if(! sb::lock(sb::Aptlock))
                    {
                        sb::unlock(sb::Dpkglock);
                        return true;
                    }

                    return false;
                }())

                sb::unlock(sb::Sblock);
            else
            {
                if(sb::schdle[5] || ! sb::execsrch("systemback"))
                    newrpnt();
                else
                {
                    QStr xauth("/tmp/sbXauthority-" % sb::rndstr()), usrhm(qgetenv("HOME"));

                    if((qEnvironmentVariableIsSet("XAUTHORITY") && QFile(qgetenv("XAUTHORITY")).copy(xauth)) || [&] {
                            QStr path("/home/" % qApp->arguments().at(1) % "/.Xauthority");
                            return (sb::isfile(path) && QFile(path).copy(xauth)) || (sb::isfile(path = usrhm % "/.Xauthority") && QFile(path).copy(xauth));
                        }()) sb::exec("systemback schedule", sb::Wait, "XAUTHORITY=" % xauth),
                             sb::rmfile(xauth);
                }

                sb::unlock(sb::Sblock), sb::unlock(sb::Dpkglock), sb::unlock(sb::Aptlock), sleep(50);
            }
        }
    }

    qApp->quit();
}

void scheduler::newrpnt()
{
    sb::pupgrade();

    for(cQStr &item : QDir(sb::sdir[1]).entryList(QDir::Dirs | QDir::Hidden | QDir::NoSymLinks | QDir::NoDotAndDotDot))
        if(sb::like(item, {"_.DELETED_*", "_.S00_*"}) && ! sb::remove(sb::sdir[1] % '/' % item)) return;

    for(uchar a(9) ; a > 1 ; --a)
        if(! sb::pnames[a].isEmpty() && (a == 9 || a > 2 ? sb::pnumber < a + 2 : sb::pnumber == 3) && ! (QFile::rename(sb::sdir[1] % (a < 9 ? QStr("/S0" % QStr::number(a + 1)) : "/S10") % '_' % sb::pnames[a], sb::sdir[1] % "/.DELETED_" % sb::pnames[a]) && sb::remove(sb::sdir[1] % "/.DELETED_" % sb::pnames[a]))) return;

    QStr dtime(QDateTime().currentDateTime().toString("yyyy-MM-dd,hh.mm.ss"));

    if(sb::crtrpoint(dtime))
    {
        for(uchar a(0) ; a < 9 && sb::isdir(sb::sdir[1] % "/S0" % QStr::number(a + 1) % '_' % sb::pnames[a]) ; ++a)
            if(! QFile::rename(sb::sdir[1] % "/S0" % QStr::number(a + 1) % '_' % sb::pnames[a], sb::sdir[1] % (a < 8 ? "/S0" : "/S") % QStr::number(a + 2) % '_' % sb::pnames[a])) return;

        if(! QFile::rename(sb::sdir[1] % "/.S00_" % dtime, sb::sdir[1] % "/S01_" % dtime)) return;
    }
    else if(sb::dfree(sb::sdir[1]) < 104857600)
        sb::remove(sb::sdir[1] % "/.S00_" % dtime);
    else
        return;

    sb::crtfile(sb::sdir[1] % "/.sbschedule"), sb::fssync();
    if(sb::ecache) sb::crtfile("/proc/sys/vm/drop_caches", "3");
}