/* === This file is part of Calamares - <https://github.com/calamares> ===
 *
 *   Copyright 2019, Adriaan de Groot <groot@kde.org>
 *
 *   Calamares 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.
 *
 *   Calamares 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 Calamares. If not, see <http://www.gnu.org/licenses/>.
 */

#include "LuksBootKeyFileJob.h"

#include "utils/CalamaresUtilsSystem.h"
#include "utils/Logger.h"
#include "utils/Variant.h"

#include "GlobalStorage.h"
#include "JobQueue.h"

LuksBootKeyFileJob::LuksBootKeyFileJob( QObject* parent )
    : Calamares::CppJob( parent )
{
}

LuksBootKeyFileJob::~LuksBootKeyFileJob() {}

QString
LuksBootKeyFileJob::prettyName() const
{
    return tr( "Configuring LUKS key file." );
}

struct LuksDevice
{
    LuksDevice( const QMap< QString, QVariant >& pinfo )
        : isValid( false )
        , isRoot( false )
    {
        if ( pinfo.contains( "luksMapperName" ) )
        {
            QString fs = pinfo[ "fs" ].toString();
            QString mountPoint = pinfo[ "mountPoint" ].toString();

            if ( !mountPoint.isEmpty() || fs == QStringLiteral( "linuxswap" ) )
            {
                isValid = true;
                isRoot = mountPoint == '/';
                device = pinfo[ "device" ].toString();
                passphrase = pinfo[ "luksPassphrase" ].toString();
            }
        }
    }

    bool isValid;
    bool isRoot;
    QString device;
    QString passphrase;
};

struct LuksDeviceList
{
    LuksDeviceList( const QVariant& partitions )
        : valid( false )
    {
        if ( partitions.canConvert< QVariantList >() )
        {
            devices = getLuksDevices( partitions.toList() );
            valid = true;
        }
    }

    /** @brief Extract the luks passphrases setup.
     *
     * Given a list of partitions (as set up by the partitioning module,
     * so there's maps with keys inside), returns just the list of
     * luks passphrases for each device.
     */
    static QList< LuksDevice >
    getLuksDevices( const QVariantList& list )
    {
        QList< LuksDevice > luksItems;

        for ( const auto& p : list )
        {
            if ( p.canConvert< QVariantMap >() )
            {
                LuksDevice d( p.toMap() );
                if ( d.isValid )
                {
                    luksItems.append( d );
                }
            }
        }
        return luksItems;
    }

    QList< LuksDevice > devices;
    bool valid;
};

static const char keyfile[] = "/crypto_keyfile.bin";

static bool
generateTargetKeyfile()
{
    auto r = CalamaresUtils::System::instance()->targetEnvCommand(
        { "dd", "bs=512", "count=4", "if=/dev/urandom", QString( "of=%1" ).arg( keyfile ) } );
    if ( r.getExitCode() != 0 )
    {
        cWarning() << "Could not create LUKS keyfile:" << r.getOutput() << "(exit code" << r.getExitCode() << ')';
        return false;
    }
    return true;
}

static bool
setupLuks( const LuksDevice& d )
{
    auto r = CalamaresUtils::System::instance()->targetEnvCommand(
        { "cryptsetup", "luksAddKey", d.device, keyfile }, QString(), d.passphrase, 15 );
    if ( r.getExitCode() != 0 )
    {
        cWarning() << "Could not configure LUKS keyfile on" << d.device << ':' << r.getOutput() << "(exit code"
                   << r.getExitCode() << ')';
        return false;
    }
    return true;
}

Calamares::JobResult
LuksBootKeyFileJob::exec()
{
    const auto* gs = Calamares::JobQueue::instance()->globalStorage();
    if ( !gs )
    {
        return Calamares::JobResult::internalError(
            "LukeBootKeyFile", "No GlobalStorage defined.", Calamares::JobResult::InvalidConfiguration );
    }
    if ( !gs->contains( "partitions" ) )
    {
        cError() << "No GS[partitions] key.";
        return Calamares::JobResult::internalError(
            "LukeBootKeyFile", tr( "No partitions are defined." ), Calamares::JobResult::InvalidConfiguration );
    }

    LuksDeviceList s( gs->value( "partitions" ) );
    if ( !s.valid )
    {
        cError() << "GS[partitions] is invalid";
        return Calamares::JobResult::internalError(
            "LukeBootKeyFile", tr( "No partitions are defined." ), Calamares::JobResult::InvalidConfiguration );
    }

    cDebug() << "There are" << s.devices.count() << "LUKS partitions";
    if ( s.devices.count() < 1 )
    {
        cDebug() << Logger::SubEntry << "Nothing to do for LUKS.";
        return Calamares::JobResult::ok();
    }

    auto it = std::partition( s.devices.begin(), s.devices.end(), []( const LuksDevice& d ) { return d.isRoot; } );
    for ( const auto& d : s.devices )
    {
        cDebug() << Logger::SubEntry << d.isRoot << d.device << d.passphrase;
    }

    if ( it == s.devices.begin() )
    {
        // Then there was no root partition
        cDebug() << Logger::SubEntry << "No root partition.";
        return Calamares::JobResult::ok();
    }

    if ( s.devices.first().passphrase.isEmpty() )
    {
        cDebug() << Logger::SubEntry << "No root passphrase.";
        return Calamares::JobResult::error(
            tr( "Encrypted rootfs setup error" ),
            tr( "Root partition %1 is LUKS but no passphrase has been set." ).arg( s.devices.first().device ) );
    }

    if ( !generateTargetKeyfile() )
    {
        return Calamares::JobResult::error(
            tr( "Encrypted rootfs setup error" ),
            tr( "Could not create LUKS key file for root partition %1." ).arg( s.devices.first().device ) );
    }

    for ( const auto& d : s.devices )
    {
        if ( !setupLuks( d ) )
            return Calamares::JobResult::error(
                tr( "Encrypted rootfs setup error" ),
                tr( "Could configure LUKS key file on partition %1." ).arg( d.device ) );
    }

    return Calamares::JobResult::ok();
}

CALAMARES_PLUGIN_FACTORY_DEFINITION( LuksBootKeyFileJobFactory, registerPlugin< LuksBootKeyFileJob >(); )