/*
    Copyright 2000 Matthias Hölzer-Klüpfel <hoelzer@kde.org>
    Copyright 2014 Frederik Gladhorn <gladhorn@kde.org>

    This library is free software; you can redistribute it and/or
    modify it under the terms of the GNU Lesser General Public
    License as published by the Free Software Foundation; either
    version 2.1 of the License, or (at your option) version 3, or any
    later version accepted by the membership of KDE e.V. (or its
    successor approved by the membership of KDE e.V.), which shall
    act as a proxy defined in Section 6 of version 3 of the license.

    This library 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
    Lesser General Public License for more details.

    You should have received a copy of the GNU Lesser General Public
    License along with this library.  If not, see <http://www.gnu.org/licenses/>.
*/

#include "kcmaccess.h"

#include <math.h>
#include <stdlib.h>

#include <QFileDialog>
#include <QProcess>
#include <QQuickItem>
#include <QQuickRenderControl>
#include <QStandardPaths>
#include <QWindow>
#include <QX11Info>

#include <KAboutData>
#include <KConfigGroup>
#include <KKeyServer>
#include <KLocalizedString>
#include <KNotifyConfigWidget>
#include <KPluginFactory>
#include <KSharedConfig>
#include <X11/XKBlib.h>
#include <X11/Xlib.h>

#define XK_MISCELLANY
#define XK_XKB_KEYS
#include <X11/keysymdef.h>

#include "kcmaccessibilitybell.h"
#include "kcmaccessibilitydata.h"
#include "kcmaccessibilitykeyboard.h"
#include "kcmaccessibilitykeyboardfilters.h"
#include "kcmaccessibilitymouse.h"
#include "kcmaccessibilityscreenreader.h"

K_PLUGIN_FACTORY_WITH_JSON(KCMAccessFactory, "kcm_access.json", registerPlugin<KAccessConfig>(); registerPlugin<AccessibilityData>();)

QString mouseKeysShortcut(Display *display)
{
    // Calculate the keycode
    KeySym sym = XK_MouseKeys_Enable;
    KeyCode code = XKeysymToKeycode(display, sym);
    if (code == 0) {
        sym = XK_Pointer_EnableKeys;
        code = XKeysymToKeycode(display, sym);
        if (code == 0)
            return QString(); // No shortcut available?
    }

    // Calculate the modifiers by searching the keysym in the X keyboard mapping
    XkbDescPtr xkbdesc = XkbGetMap(display, XkbKeyTypesMask | XkbKeySymsMask, XkbUseCoreKbd);
    if (!xkbdesc)
        return QString(); // Failed to obtain the mapping from server

    bool found = false;
    unsigned char modifiers = 0;
    int groups = XkbKeyNumGroups(xkbdesc, code);
    for (int grp = 0; grp < groups && !found; grp++) {
        int levels = XkbKeyGroupWidth(xkbdesc, code, grp);
        for (int level = 0; level < levels && !found; level++) {
            if (sym == XkbKeySymEntry(xkbdesc, code, level, grp)) {
                // keysym found => determine modifiers
                int typeIdx = xkbdesc->map->key_sym_map[code].kt_index[grp];
                XkbKeyTypePtr type = &(xkbdesc->map->types[typeIdx]);
                for (int i = 0; i < type->map_count && !found; i++) {
                    if (type->map[i].active && (type->map[i].level == level)) {
                        modifiers = type->map[i].mods.mask;
                        found = true;
                    }
                }
            }
        }
    }
    XkbFreeClientMap(xkbdesc, 0, true);

    if (!found)
        return QString(); // Somehow the keycode -> keysym mapping is flawed

    XEvent ev;
    ev.type = KeyPress;
    ev.xkey.display = display;
    ev.xkey.keycode = code;
    ev.xkey.state = 0;
    int key;
    KKeyServer::xEventToQt(&ev, &key);
    QString keyname = QKeySequence(key).toString();

    unsigned int AltMask = KKeyServer::modXAlt();
    unsigned int WinMask = KKeyServer::modXMeta();
    unsigned int NumMask = KKeyServer::modXNumLock();
    unsigned int ScrollMask = KKeyServer::modXScrollLock();

    unsigned int MetaMask = XkbKeysymToModifiers(display, XK_Meta_L);
    unsigned int SuperMask = XkbKeysymToModifiers(display, XK_Super_L);
    unsigned int HyperMask = XkbKeysymToModifiers(display, XK_Hyper_L);
    unsigned int AltGrMask = XkbKeysymToModifiers(display, XK_Mode_switch) | XkbKeysymToModifiers(display, XK_ISO_Level3_Shift)
        | XkbKeysymToModifiers(display, XK_ISO_Level3_Latch) | XkbKeysymToModifiers(display, XK_ISO_Level3_Lock);

    unsigned int mods = ShiftMask | ControlMask | AltMask | WinMask | LockMask | NumMask | ScrollMask;

    AltGrMask &= ~mods;
    MetaMask &= ~(mods | AltGrMask);
    SuperMask &= ~(mods | AltGrMask | MetaMask);
    HyperMask &= ~(mods | AltGrMask | MetaMask | SuperMask);

    if ((modifiers & AltGrMask) != 0)
        keyname = i18n("AltGraph") + QLatin1Char('+') + keyname;
    if ((modifiers & HyperMask) != 0)
        keyname = i18n("Hyper") + QLatin1Char('+') + keyname;
    if ((modifiers & SuperMask) != 0)
        keyname = i18n("Super") + QLatin1Char('+') + keyname;
    if ((modifiers & WinMask) != 0)
        keyname = QKeySequence(Qt::META).toString() + QLatin1Char('+') + keyname;
    if ((modifiers & AltMask) != 0)
        keyname = QKeySequence(Qt::ALT).toString() + QLatin1Char('+') + keyname;
    if ((modifiers & ControlMask) != 0)
        keyname = QKeySequence(Qt::CTRL).toString() + QLatin1Char('+') + keyname;
    if ((modifiers & ShiftMask) != 0)
        keyname = QKeySequence(Qt::SHIFT).toString() + QLatin1Char('+') + keyname;

    return modifiers & ScrollMask & LockMask & NumMask ? i18n("Press %1 while NumLock, CapsLock and ScrollLock are active", keyname)
        : modifiers & ScrollMask & LockMask            ? i18n("Press %1 while CapsLock and ScrollLock are active", keyname)
        : modifiers & ScrollMask & NumMask             ? i18n("Press %1 while NumLock and ScrollLock are active", keyname)
        : modifiers & ScrollMask                       ? i18n("Press %1 while ScrollLock is active", keyname)
        : modifiers & LockMask & NumMask               ? i18n("Press %1 while NumLock and CapsLock are active", keyname)
        : modifiers & LockMask                         ? i18n("Press %1 while CapsLock is active", keyname)
        : modifiers & NumMask                          ? i18n("Press %1 while NumLock is active", keyname)
                                                       : i18n("Press %1", keyname);
}

KAccessConfig::KAccessConfig(QObject *parent, const QVariantList &args)
    : KQuickAddons::ManagedConfigModule(parent, args)
    , m_data(new AccessibilityData(this))
    , m_desktopShortcutInfo(QX11Info::isPlatformX11() ? mouseKeysShortcut(QX11Info::display()) : QString())
{
    qmlRegisterType<MouseSettings>();
    qmlRegisterType<BellSettings>();
    qmlRegisterType<KeyboardSettings>();
    qmlRegisterType<KeyboardFiltersSettings>();
    qmlRegisterType<ScreenReaderSettings>();

    KAboutData *about = new KAboutData(QStringLiteral("kcmaccess"),
                                       i18n("Accessibility"),
                                       QStringLiteral("1.0"),
                                       QString(),
                                       KAboutLicense::GPL,
                                       i18n("(c) 2000, Matthias Hoelzer-Kluepfel"));

    about->addAuthor(i18n("Matthias Hoelzer-Kluepfel"), i18n("Author"), QStringLiteral("hoelzer@kde.org"));

    int tryOrcaRun = QProcess::execute(QStringLiteral("orca"), {QStringLiteral("--version")});
    m_screenReaderInstalled = tryOrcaRun != -2;

    setButtons(ConfigModule::Apply | ConfigModule::Default | ConfigModule::Help);
    setAboutData(about);

    connect(m_data->bellSettings(), &BellSettings::configChanged, this, &KAccessConfig::bellIsDefaultsChanged);
    connect(m_data->mouseSettings(), &MouseSettings::configChanged, this, &KAccessConfig::mouseIsDefaultsChanged);
    connect(m_data->keyboardFiltersSettings(), &ScreenReaderSettings::configChanged, this, &KAccessConfig::keyboardFiltersIsDefaultsChanged);
    connect(m_data->keyboardSettings(), &ScreenReaderSettings::configChanged, this, &KAccessConfig::keyboardModifiersIsDefaultsChanged);
    connect(m_data->screenReaderSettings(), &ScreenReaderSettings::configChanged, this, &KAccessConfig::screenReaderIsDefaultsChanged);
}

KAccessConfig::~KAccessConfig()
{
}

void KAccessConfig::configureKNotify(QQuickItem *parent)
{
    auto dialog = KNotifyConfigWidget::configure(nullptr, QStringLiteral("kaccess"));
    if (parent && parent->window()) {
        dialog->winId();
        dialog->windowHandle()->setTransientParent(QQuickRenderControl::renderWindowFor(parent->window()));
    }
}

void KAccessConfig::launchOrcaConfiguration()
{
    const QStringList gsettingArgs = {QStringLiteral("set"),
                                      QStringLiteral("org.gnome.desktop.a11y.applications"),
                                      QStringLiteral("screen-reader-enabled"),
                                      QStringLiteral("true")};

    int ret = QProcess::execute(QStringLiteral("gsettings"), gsettingArgs);
    if (ret) {
        const QString errorStr = QLatin1String("gsettings ") + gsettingArgs.join(QLatin1Char(' '));
        setOrcaLaunchFeedback(i18n("Could not set gsettings for Orca: \"%1\" failed", errorStr));
        return;
    }

    qint64 pid = 0;
    bool started = QProcess::startDetached(QStringLiteral("orca"), {QStringLiteral("--setup")}, QString(), &pid);
    if (!started) {
        setOrcaLaunchFeedback(i18n("Error: Could not launch \"orca --setup\""));
    }
}

void KAccessConfig::save()
{
    ManagedConfigModule::save();

    if (bellSettings()->systemBell() || bellSettings()->customBell() || bellSettings()->visibleBell()) {
        KConfig _cfg(QStringLiteral("kdeglobals"), KConfig::NoGlobals);
        KConfigGroup cfg(&_cfg, "General");
        cfg.writeEntry("UseSystemBell", true);
        cfg.sync();
    }

    // make kaccess reread the configuration
    // turning a11y features off needs to be done by kaccess
    // so run it to clear any enabled features and it will exit if it should
    QProcess::startDetached(QStringLiteral("kaccess"), {});
}

QString KAccessConfig::orcaLaunchFeedback() const
{
    return m_orcaLaunchFeedback;
}

void KAccessConfig::setOrcaLaunchFeedback(const QString &value)
{
    if (m_orcaLaunchFeedback != value) {
        m_orcaLaunchFeedback = value;
        Q_EMIT orcaLaunchFeedbackChanged();
    }
}

bool KAccessConfig::orcaInstalled()
{
    int tryOrcaRun = QProcess::execute(QStringLiteral("orca"), {QStringLiteral("--version")});
    // If the process cannot be started, -2 is returned.
    return tryOrcaRun != -2;
}

MouseSettings *KAccessConfig::mouseSettings() const
{
    return m_data->mouseSettings();
}

BellSettings *KAccessConfig::bellSettings() const
{
    return m_data->bellSettings();
}

KeyboardSettings *KAccessConfig::keyboardSettings() const
{
    return m_data->keyboardSettings();
}

KeyboardFiltersSettings *KAccessConfig::keyboardFiltersSettings() const
{
    return m_data->keyboardFiltersSettings();
}

ScreenReaderSettings *KAccessConfig::screenReaderSettings() const
{
    return m_data->screenReaderSettings();
}

bool KAccessConfig::bellIsDefaults() const
{
    return bellSettings()->isDefaults();
}

bool KAccessConfig::mouseIsDefaults() const
{
    return mouseSettings()->isDefaults();
}

bool KAccessConfig::keyboardFiltersIsDefaults() const
{
    return keyboardFiltersSettings()->isDefaults();
}

bool KAccessConfig::keyboardModifiersIsDefaults() const
{
    return keyboardSettings()->isDefaults();
}

bool KAccessConfig::screenReaderIsDefaults() const
{
    return screenReaderSettings()->isDefaults();
}

#include "kcmaccess.moc"