/* === This file is part of Calamares - <https://github.com/calamares> ===
 *
 *   Copyright 2014-2015, Teo Mrnjavac <teo@kde.org>
 *   Copyright 2017-2018, 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 "Module.h"

#include "CalamaresConfig.h"
#include "CppJobModule.h"
#include "ProcessJobModule.h"
#include "Settings.h"
#include "ViewModule.h"

#include "utils/Dirs.h"
#include "utils/Logger.h"
#include "utils/Yaml.h"

#ifdef WITH_PYTHON
#include "PythonJobModule.h"
#endif

#ifdef WITH_PYTHONQT
#include "PythonQtViewModule.h"
#endif

#include <QDir>
#include <QFile>
#include <QFileInfo>
#include <QString>


static const char EMERGENCY[] = "emergency";

namespace Calamares
{

Module::~Module()
{}

Module*
Module::fromDescriptor( const QVariantMap& moduleDescriptor,
                        const QString& instanceId,
                        const QString& configFileName,
                        const QString& moduleDirectory )
{
    std::unique_ptr<Module> m;

    QString typeString = moduleDescriptor.value( "type" ).toString();
    QString intfString = moduleDescriptor.value( "interface" ).toString();

    if ( typeString.isEmpty() || intfString.isEmpty() )
    {
        cError() << "Bad module descriptor format" << instanceId;
        return nullptr;
    }
    if ( ( typeString == "view" ) || ( typeString == "viewmodule" ) )
    {
        if ( intfString == "qtplugin" )
            m.reset( new ViewModule() );
        else if ( intfString == "pythonqt" )
        {
#ifdef WITH_PYTHONQT
            m.reset( new PythonQtViewModule() );
#else
            cError() << "PythonQt view modules are not supported in this version of Calamares.";
#endif
        }
        else
            cError() << "Bad interface" << intfString << "for module type" << typeString;
    }
    else if ( typeString == "job" )
    {
        if ( intfString == "qtplugin" )
            m.reset( new CppJobModule() );
        else if ( intfString == "process" )
            m.reset( new ProcessJobModule() );
        else if ( intfString == "python" )
        {
#ifdef WITH_PYTHON
            m.reset( new PythonJobModule() );
#else
            cError() << "Python modules are not supported in this version of Calamares.";
#endif
        }
        else
            cError() << "Bad interface" << intfString << "for module type" << typeString;
    }
    else
        cError() << "Bad module type" << typeString;

    if ( !m )
    {
        cError() << "Bad module type (" << typeString
                 << ") or interface string (" << intfString
                 << ") for module " << instanceId;
        return nullptr;
    }

    QDir moduleDir( moduleDirectory );
    if ( moduleDir.exists() && moduleDir.isReadable() )
        m->m_directory = moduleDir.absolutePath();
    else
    {
        cError() << "Bad module directory" << moduleDirectory << "for" << instanceId;
        return nullptr;
    }

    m->m_instanceId = instanceId;

    m->initFrom( moduleDescriptor );
    try
    {
        m->loadConfigurationFile( configFileName );
    }
    catch ( YAML::Exception& e )
    {
        cError() << "YAML parser error " << e.what();
        return nullptr;
    }
    return m.release();
}


static QStringList
moduleConfigurationCandidates( bool assumeBuildDir, const QString& moduleName, const QString& configFileName )
{
    QStringList paths;

    if ( CalamaresUtils::isAppDataDirOverridden() )
        paths << CalamaresUtils::appDataDir().absoluteFilePath( QString( "modules/%1" ).arg( configFileName ) );
    else
    {
        // If an absolute path is given, in debug mode, look for it
        // first. The case contains('/'), below, will add the absolute
        // path a second time, though.
        if ( assumeBuildDir && configFileName.startsWith( '/' ) )
            paths << configFileName;
        if ( assumeBuildDir )
            paths << QDir().absoluteFilePath(QString( "src/modules/%1/%2" ).arg( moduleName ).arg( configFileName ) );
        if ( assumeBuildDir && configFileName.contains( '/' ) )
            paths << QDir().absoluteFilePath( configFileName );

        if ( CalamaresUtils::haveExtraDirs() )
            for ( auto s : CalamaresUtils::extraConfigDirs() )
                paths << ( s + QString( "modules/%1" ).arg( configFileName ) );

        paths << QString( "/etc/calamares/modules/%1" ).arg( configFileName );
        paths << CalamaresUtils::appDataDir().absoluteFilePath( QString( "modules/%1" ).arg( configFileName ) );
    }

    return paths;
}

void
Module::loadConfigurationFile( const QString& configFileName ) //throws YAML::Exception
{
    QStringList configCandidates = moduleConfigurationCandidates( Settings::instance()->debugMode(), m_name, configFileName );
    for ( const QString& path : configCandidates )
    {
        QFile configFile( path );
        if ( configFile.exists() && configFile.open( QFile::ReadOnly | QFile::Text ) )
        {
            QByteArray ba = configFile.readAll();

            YAML::Node doc = YAML::Load( ba.constData() );
            if ( doc.IsNull() )
            {
                cDebug() << "Found empty module configuration" << path;
                // Special case: empty config files are valid,
                // but aren't a map.
                return;
            }
            if ( !doc.IsMap() )
            {
                cWarning() << "Bad module configuration format" << path;
                return;
            }

            cDebug() << "Loaded module configuration" << path;
            m_configurationMap = CalamaresUtils::yamlMapToVariant( doc ).toMap();
            m_emergency = m_maybe_emergency
                          && m_configurationMap.contains( EMERGENCY )
                          && m_configurationMap[ EMERGENCY ].toBool();
            return;
        }
    }
    cDebug() << "No config file found in" << Logger::DebugList( configCandidates );
}


QString
Module::name() const
{
    return m_name;
}


QString
Module::instanceId() const
{
    return m_instanceId;
}


QString
Module::instanceKey() const
{
    return QString( "%1@%2" ).arg( m_name ).arg( m_instanceId );
}


QString
Module::location() const
{
    return m_directory;
}


QString
Module::typeString() const
{
    switch ( type() )
    {
        case Type::Job:
        return "Job Module";
    case Type::View:
        return "View Module";
    }
    return QString();
}


QString
Module::interfaceString() const
{
    switch ( interface() )
    {
        case Interface::Process:
        return "External process";
    case Interface::Python:
        return "Python (Boost.Python)";
    case Interface::PythonQt:
        return "Python (experimental)";
    case Interface::QtPlugin:
        return "Qt Plugin";
    }
    return QString();
}


QVariantMap
Module::configurationMap()
{
    return m_configurationMap;
}


Module::Module()
    : m_loaded( false )
{}


void
Module::initFrom( const QVariantMap& moduleDescriptor )
{
    m_name = moduleDescriptor.value( "name" ).toString();
    if ( moduleDescriptor.contains( EMERGENCY ) )
        m_maybe_emergency = moduleDescriptor[ EMERGENCY ].toBool();
}

RequirementsList
Module::checkRequirements()
{
    return RequirementsList();
}

} //ns