/********************************************************************
 KWin - the KDE window manager
 This file is part of the KDE project.

Copyright (C) 1999, 2000 Matthias Ettrich <ettrich@kde.org>
Copyright (C) 2003 Lubos Lunak <l.lunak@kde.org>

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, see <http://www.gnu.org/licenses/>.
*********************************************************************/

#include "sm.h"

#include <unistd.h>
#include <cstdlib>
#include <pwd.h>
#include <kconfig.h>

#include "workspace.h"
#include "x11client.h"
#include <QDebug>
#include <QSessionManager>

#include <QDBusConnection>
#include "sessionadaptor.h"

namespace KWin
{

static KConfig *sessionConfig(QString id, QString key)
{
    static KConfig *config = nullptr;
    static QString lastId;
    static QString lastKey;
    static QString pattern = QString(QLatin1String("session/%1_%2_%3")).arg(qApp->applicationName());
    if (id != lastId || key != lastKey) {
        delete config;
        config = nullptr;
    }
    lastId = id;
    lastKey = key;
    if (!config) {
        config = new KConfig(pattern.arg(id).arg(key), KConfig::SimpleConfig);
    }
    return config;
}

static const char* const window_type_names[] = {
    "Unknown", "Normal" , "Desktop", "Dock", "Toolbar", "Menu", "Dialog",
    "Override", "TopMenu", "Utility", "Splash"
};
// change also the two functions below when adding new entries

static const char* windowTypeToTxt(NET::WindowType type)
{
    if (type >= NET::Unknown && type <= NET::Splash)
        return window_type_names[ type + 1 ]; // +1 (unknown==-1)
    if (type == -2)   // undefined (not really part of NET::WindowType)
        return "Undefined";
    qFatal("Unknown Window Type");
    return nullptr;
}

static NET::WindowType txtToWindowType(const char* txt)
{
    for (int i = NET::Unknown;
            i <= NET::Splash;
            ++i)
        if (qstrcmp(txt, window_type_names[ i + 1 ]) == 0)     // +1
            return static_cast< NET::WindowType >(i);
    return static_cast< NET::WindowType >(-2);   // undefined
}

void Workspace::saveState(QSessionManager &sm)
{
    bool sessionManagerIsKSMServer = QDBusConnection::sessionBus().interface()->isServiceRegistered("org.kde.ksmserver").value();

    // If the session manager is ksmserver, save stacking
    // order, active window, active desktop etc. in phase 1,
    // as ksmserver assures no interaction will be done
    // before the WM finishes phase 1. Saving in phase 2 is
    // too late, as possible user interaction may change some things.
    // Phase2 is still needed though (ICCCM 5.2)
    KConfig *config = sessionConfig(sm.sessionId(), sm.sessionKey());
    if (!sm.isPhase2()) {
        KConfigGroup cg(config, "Session");
        cg.writeEntry("AllowsInteraction", sm.allowsInteraction());
        if (sessionManagerIsKSMServer)   // save stacking order etc. before "save file?" etc. dialogs change it
            storeSession(config, SMSavePhase0);
        config->markAsClean(); // don't write Phase #1 data to disk
        sm.release(); // Qt doesn't automatically release in this case (bug?)
        sm.requestPhase2();
        return;
    }
    storeSession(config, sessionManagerIsKSMServer ? SMSavePhase2 : SMSavePhase2Full);
    config->sync();

    // inform the smserver on how to clean-up after us
    const QString localFilePath = QStandardPaths::writableLocation(QStandardPaths::GenericConfigLocation) + QLatin1Char('/') + config->name();
    if (QFile::exists(localFilePath)) { // expectable for the sync
        sm.setDiscardCommand(QStringList() << QStringLiteral("rm") << localFilePath);
    }
}

// Workspace

/**
 * Stores the current session in the config file
 *
 * @see loadSessionInfo
 */
void Workspace::storeSession(KConfig* config, SMSavePhase phase)
{
    KConfigGroup cg(config, "Session");
    int count =  0;
    int active_client = -1;

    for (auto it = clients.begin(); it != clients.end(); ++it) {
        X11Client *c = (*it);
        if (c->windowType() > NET::Splash) {
            //window types outside this are not tooltips/menus/OSDs
            //typically these will be unmanaged and not in this list anyway, but that is not enforced
            continue;
        }
        QByteArray sessionId = c->sessionId();
        QByteArray wmCommand = c->wmCommand();
        if (sessionId.isEmpty())
            // remember also applications that are not XSMP capable
            // and use the obsolete WM_COMMAND / WM_SAVE_YOURSELF
            if (wmCommand.isEmpty())
                continue;
        count++;
        if (c->isActive())
            active_client = count;
        if (phase == SMSavePhase2 || phase == SMSavePhase2Full)
            storeClient(cg, count, c);
    }
    if (phase == SMSavePhase0) {
        // it would be much simpler to save these values to the config file,
        // but both Qt and KDE treat phase1 and phase2 separately,
        // which results in different sessionkey and different config file :(
        session_active_client = active_client;
        session_desktop = VirtualDesktopManager::self()->current();
    } else if (phase == SMSavePhase2) {
        cg.writeEntry("count", count);
        cg.writeEntry("active", session_active_client);
        cg.writeEntry("desktop", session_desktop);
    } else { // SMSavePhase2Full
        cg.writeEntry("count", count);
        cg.writeEntry("active", session_active_client);
        cg.writeEntry("desktop", VirtualDesktopManager::self()->current());
    }
}

void Workspace::storeClient(KConfigGroup &cg, int num, X11Client *c)
{
    c->setSessionActivityOverride(false); //make sure we get the real values
    QString n = QString::number(num);
    cg.writeEntry(QLatin1String("sessionId") + n, c->sessionId().constData());
    cg.writeEntry(QLatin1String("windowRole") + n, c->windowRole().constData());
    cg.writeEntry(QLatin1String("wmCommand") + n, c->wmCommand().constData());
    cg.writeEntry(QLatin1String("resourceName") + n, c->resourceName().constData());
    cg.writeEntry(QLatin1String("resourceClass") + n, c->resourceClass().constData());
    cg.writeEntry(QLatin1String("geometry") + n, QRect(c->calculateGravitation(true), c->clientSize()));   // FRAME
    cg.writeEntry(QLatin1String("restore") + n, c->geometryRestore());
    cg.writeEntry(QLatin1String("fsrestore") + n, c->geometryFSRestore());
    cg.writeEntry(QLatin1String("maximize") + n, (int) c->maximizeMode());
    cg.writeEntry(QLatin1String("fullscreen") + n, (int) c->fullScreenMode());
    cg.writeEntry(QLatin1String("desktop") + n, c->desktop());
    // the config entry is called "iconified" for back. comp. reasons
    // (kconf_update script for updating session files would be too complicated)
    cg.writeEntry(QLatin1String("iconified") + n, c->isMinimized());
    cg.writeEntry(QLatin1String("opacity") + n, c->opacity());
    // the config entry is called "sticky" for back. comp. reasons
    cg.writeEntry(QLatin1String("sticky") + n, c->isOnAllDesktops());
    cg.writeEntry(QLatin1String("shaded") + n, c->isShade());
    // the config entry is called "staysOnTop" for back. comp. reasons
    cg.writeEntry(QLatin1String("staysOnTop") + n, c->keepAbove());
    cg.writeEntry(QLatin1String("keepBelow") + n, c->keepBelow());
    cg.writeEntry(QLatin1String("skipTaskbar") + n, c->originalSkipTaskbar());
    cg.writeEntry(QLatin1String("skipPager") + n, c->skipPager());
    cg.writeEntry(QLatin1String("skipSwitcher") + n, c->skipSwitcher());
    // not really just set by user, but name kept for back. comp. reasons
    cg.writeEntry(QLatin1String("userNoBorder") + n, c->userNoBorder());
    cg.writeEntry(QLatin1String("windowType") + n, windowTypeToTxt(c->windowType()));
    cg.writeEntry(QLatin1String("shortcut") + n, c->shortcut().toString());
    cg.writeEntry(QLatin1String("stackingOrder") + n, unconstrained_stacking_order.indexOf(c));
    cg.writeEntry(QLatin1String("activities") + n, c->activities());
}

void Workspace::storeSubSession(const QString &name, QSet<QByteArray> sessionIds)
{
    //TODO clear it first
    KConfigGroup cg(KSharedConfig::openConfig(), QLatin1String("SubSession: ") + name);
    int count =  0;
    int active_client = -1;
    for (auto it = clients.begin(); it != clients.end(); ++it) {
        X11Client *c = (*it);
        if (c->windowType() > NET::Splash) {
            continue;
        }
        QByteArray sessionId = c->sessionId();
        QByteArray wmCommand = c->wmCommand();
        if (sessionId.isEmpty())
            // remember also applications that are not XSMP capable
            // and use the obsolete WM_COMMAND / WM_SAVE_YOURSELF
            if (wmCommand.isEmpty())
                continue;
        if (!sessionIds.contains(sessionId))
            continue;

        qCDebug(KWIN_CORE) << "storing" << sessionId;
        count++;
        if (c->isActive())
            active_client = count;
        storeClient(cg, count, c);
    }
    cg.writeEntry("count", count);
    cg.writeEntry("active", active_client);
    //cg.writeEntry( "desktop", currentDesktop());
}

/**
 * Loads the session information from the config file.
 *
 * @see storeSession
 */
void Workspace::loadSessionInfo(const QString &key)
{
    // NOTICE: qApp->sessionKey() is outdated when this gets invoked
    // the key parameter is cached from the application constructor.
    session.clear();
    KConfigGroup cg(sessionConfig(qApp->sessionId(), key), "Session");
    addSessionInfo(cg);
}

void Workspace::addSessionInfo(KConfigGroup &cg)
{
    m_initialDesktop = cg.readEntry("desktop", 1);
    int count =  cg.readEntry("count", 0);
    int active_client = cg.readEntry("active", 0);
    for (int i = 1; i <= count; i++) {
        QString n = QString::number(i);
        SessionInfo* info = new SessionInfo;
        session.append(info);
        info->sessionId = cg.readEntry(QLatin1String("sessionId") + n, QString()).toLatin1();
        info->windowRole = cg.readEntry(QLatin1String("windowRole") + n, QString()).toLatin1();
        info->wmCommand = cg.readEntry(QLatin1String("wmCommand") + n, QString()).toLatin1();
        info->resourceName = cg.readEntry(QLatin1String("resourceName") + n, QString()).toLatin1();
        info->resourceClass = cg.readEntry(QLatin1String("resourceClass") + n, QString()).toLower().toLatin1();
        info->geometry = cg.readEntry(QLatin1String("geometry") + n, QRect());
        info->restore = cg.readEntry(QLatin1String("restore") + n, QRect());
        info->fsrestore = cg.readEntry(QLatin1String("fsrestore") + n, QRect());
        info->maximized = cg.readEntry(QLatin1String("maximize") + n, 0);
        info->fullscreen = cg.readEntry(QLatin1String("fullscreen") + n, 0);
        info->desktop = cg.readEntry(QLatin1String("desktop") + n, 0);
        info->minimized = cg.readEntry(QLatin1String("iconified") + n, false);
        info->opacity = cg.readEntry(QLatin1String("opacity") + n, 1.0);
        info->onAllDesktops = cg.readEntry(QLatin1String("sticky") + n, false);
        info->shaded = cg.readEntry(QLatin1String("shaded") + n, false);
        info->keepAbove = cg.readEntry(QLatin1String("staysOnTop") + n, false);
        info->keepBelow = cg.readEntry(QLatin1String("keepBelow") + n, false);
        info->skipTaskbar = cg.readEntry(QLatin1String("skipTaskbar") + n, false);
        info->skipPager = cg.readEntry(QLatin1String("skipPager") + n, false);
        info->skipSwitcher = cg.readEntry(QLatin1String("skipSwitcher") + n, false);
        info->noBorder = cg.readEntry(QLatin1String("userNoBorder") + n, false);
        info->windowType = txtToWindowType(cg.readEntry(QLatin1String("windowType") + n, QString()).toLatin1().constData());
        info->shortcut = cg.readEntry(QLatin1String("shortcut") + n, QString());
        info->active = (active_client == i);
        info->stackingOrder = cg.readEntry(QLatin1String("stackingOrder") + n, -1);
        info->activities = cg.readEntry(QLatin1String("activities") + n, QStringList());
    }
}

void Workspace::loadSubSessionInfo(const QString &name)
{
    KConfigGroup cg(KSharedConfig::openConfig(), QLatin1String("SubSession: ") + name);
    addSessionInfo(cg);
}

static bool sessionInfoWindowTypeMatch(X11Client *c, SessionInfo* info)
{
    if (info->windowType == -2) {
        // undefined (not really part of NET::WindowType)
        return !c->isSpecialWindow();
    }
    return info->windowType == c->windowType();
}

/**
 * Returns a SessionInfo for client \a c. The returned session
 * info is removed from the storage. It's up to the caller to delete it.
 *
 * This function is called when a new window is mapped and must be managed.
 * We try to find a matching entry in the session.
 *
 * May return 0 if there's no session info for the client.
 */
SessionInfo* Workspace::takeSessionInfo(X11Client *c)
{
    SessionInfo *realInfo = nullptr;
    QByteArray sessionId = c->sessionId();
    QByteArray windowRole = c->windowRole();
    QByteArray wmCommand = c->wmCommand();
    QByteArray resourceName = c->resourceName();
    QByteArray resourceClass = c->resourceClass();

    // First search ``session''
    if (! sessionId.isEmpty()) {
        // look for a real session managed client (algorithm suggested by ICCCM)
        foreach (SessionInfo * info, session) {
            if (realInfo)
                break;
            if (info->sessionId == sessionId && sessionInfoWindowTypeMatch(c, info)) {
                if (! windowRole.isEmpty()) {
                    if (info->windowRole == windowRole) {
                        realInfo = info;
                        session.removeAll(info);
                    }
                } else {
                    if (info->windowRole.isEmpty()
                            && info->resourceName == resourceName
                            && info->resourceClass == resourceClass) {
                        realInfo = info;
                        session.removeAll(info);
                    }
                }
            }
        }
    } else {
        // look for a sessioninfo with matching features.
        foreach (SessionInfo * info, session) {
            if (realInfo)
                break;
            if (info->resourceName == resourceName
                    && info->resourceClass == resourceClass
                    && sessionInfoWindowTypeMatch(c, info)) {
                if (wmCommand.isEmpty() || info->wmCommand == wmCommand) {
                    realInfo = info;
                    session.removeAll(info);
                }
            }
        }
    }
    return realInfo;
}

SessionManager::SessionManager(QObject *parent)
    : QObject(parent)
{
    new SessionAdaptor(this);
    QDBusConnection::sessionBus().registerObject(QStringLiteral("/Session"), this);
}

SessionManager::~SessionManager()
{
}

SessionState SessionManager::state() const
{
    return m_sessionState;
}

void SessionManager::setState(uint state)
{
    switch (state) {
    case 0:
        setState(SessionState::Saving);
        break;
    case 1:
        setState(SessionState::Quitting);
        break;
    default:
        setState(SessionState::Normal);
    }
}

void SessionManager::setState(SessionState state)
{
    if (state == m_sessionState) {
        return;
    }
    // If we're starting to save a session
    if (state == SessionState::Saving) {
        RuleBook::self()->setUpdatesDisabled(true);
    }
    // If we're ending a save session due to either completion or cancellation
    if (m_sessionState == SessionState::Saving) {
        RuleBook::self()->setUpdatesDisabled(false);
        Workspace::self()->forEachClient([](X11Client *client) {
            client->setSessionActivityOverride(false);
        });
    }
    m_sessionState = state;
    emit stateChanged();
}

} // namespace