/*************************************************************************
 *  Copyright (C) 2008, 2009, 2010 by Volker Lanz <vl@fidra.de>          *
 *                                                                       *
 *  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 3 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, see <http://www.gnu.org/licenses/>.*
 *************************************************************************/

#include "util/guihelpers.h"

#include <kpmcore/backend/corebackendmanager.h>

#include <QApplication>
#include <QFileInfo>
#include <QProcess>
#include <QStandardPaths>
#include <QString>

#include <KLocalizedString>
#include <KMessageBox>

#include <unistd.h>
#include <signal.h>

#include <config.h>

bool checkPermissions()
{
	if (geteuid() != 0)
	{
		// only try to gain root privileges if we have a valid (kde|gk)su(do) command and
		// we did not try so before: the dontsu-option is there to make sure there are no
		// endless loops of calling the same non-working (kde|gk)su(do) binary again and again.
		if (!suCommand().isEmpty() && !QCoreApplication::arguments().contains(QLatin1String("--dontsu")))
		{
			QString argList;

			const QString suCmd = suCommand();

			// kdesu broke backward compatibility at some point and now only works with "-c";
			// kdesudo accepts either (with or without "-c"), but the gk* helpers only work
			// without. kdesu maintainers won't fix their app, so we need to work around that here.
			if (suCmd.indexOf(QStringLiteral("kdesu")) != -1)
				argList = QStringLiteral("-c ");

			argList += QCoreApplication::arguments().join(QStringLiteral(" ")) + QStringLiteral(" --dontsu");

			if (QProcess::execute(suCmd, QStringList(argList)) == 0)
				return false;
		}

		return KMessageBox::warningContinueCancel(NULL, xi18nc("@info",
				"<para><warning>You do not have administrative privileges.</warning></para>"
				"<para>It is possible to run <application>%1</application> without these privileges. "
				"You will, however, <emphasis>not</emphasis> be allowed to apply operations.</para>"
				"<para>Do you want to continue running <application>%1</application>?</para>",
				QGuiApplication::applicationDisplayName()),
	 		i18nc("@title:window", "No administrative privileges"),
			KGuiItem(i18nc("@action:button", "Run without administrative privileges"), QStringLiteral("arrow-right")),
			KStandardGuiItem::cancel(),
			QStringLiteral("runWithoutRootPrivileges")) == KMessageBox::Continue;
	}

	return true;
}

bool loadBackend()
{
	if (CoreBackendManager::self()->load(Config::backend()) == false)
	{
		if (CoreBackendManager::self()->load(CoreBackendManager::defaultBackendName()))
		{
			KMessageBox::sorry(NULL,
				xi18nc("@info", "<para>The configured backend plugin \"%1\" could not be loaded.</para>"
					"<para>Loading the default backend plugin \"%2\" instead.</para>",
				Config::backend(), CoreBackendManager::defaultBackendName()),
				i18nc("@title:window", "Error: Could Not Load Backend Plugin"));
			Config::setBackend(CoreBackendManager::defaultBackendName());
		}
		else
		{
			KMessageBox::error(NULL,
				xi18nc("@info", "<para>Neither the configured (\"%1\") nor the default (\"%2\") backend "
					"plugin could be loaded.</para><para>Please check your installation.</para>",
				Config::backend(), CoreBackendManager::defaultBackendName()),
				i18nc("@title:window", "Error: Could Not Load Backend Plugin"));
			return false;
		}
	}

	return true;
}

QString suCommand()
{
	const QString candidates[] = { QStringLiteral("kdesu"), QStringLiteral("kdesudo"), QStringLiteral("gksudo"), QStringLiteral("gksu") };
	QString rval;

	for (quint32 i = 0; i < sizeof(candidates) / sizeof(candidates[0]); i++)
	{
		rval = QStandardPaths::findExecutable(candidates[i]);
		if (QFileInfo(rval).isExecutable())
			return rval;
	}

	return QString();
}