/*
 *  Copyright (C) 2014 Weng Xuetian <wengxt@gmail.com>
 *
 *  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) 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 14 of version 3 of the license.
 *
 *  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 "xkblayoutmanager.h"
#include <QStringList>
#include <QProcess>
#include <QDir>

const char* XKB_COMMAND = "setxkbmap";
const char* XKB_QUERY_ARG = "-query";
const char* XKB_LAYOUT_ARG = "-layout";
const char* XMODMAP_COMMAND = "xmodmap";
const char* XMODMAP_KNOWN_FILES[] = {".xmodmap", ".xmodmaprc",
                                     ".Xmodmap", ".Xmodmaprc"};

XkbLayoutManager::XkbLayoutManager() :
    m_useXkbModmap(false)
{

}

void XkbLayoutManager::setLatinLayouts(const gchar** variants, gsize length)
{
    m_latinLayouts.clear();
    for (gsize i = 0; i < length; i ++ ) {
        m_latinLayouts.insert(QString::fromUtf8(variants[i]));
    }
}

void XkbLayoutManager::getLayout()
{
    QProcess process;
    process.start(XKB_COMMAND, QStringList(XKB_QUERY_ARG));
    process.waitForFinished();
    QByteArray output = process.readAllStandardOutput();
    QList< QByteArray > lines = output.split('\n');
    Q_FOREACH(const QByteArray& line, lines) {
        QByteArray element("layout:");
        if (line.startsWith(element)) {
            m_defaultLayout = QString::fromLatin1(line.mid(element.length(), line.length())).trimmed();
        }

        element = "variant:";
        if (line.startsWith(element)) {
            m_defaultVariant = QString::fromLatin1(line.mid(element.length(), line.length())).trimmed();
        }

        element = "options:";
        if (line.startsWith(element)) {
            m_defaultOption = QString::fromLatin1(line.mid(element.length(), line.length())).trimmed();
        }
    }
}

void XkbLayoutManager::setLayout(IBusEngineDesc* desc)
{
    const gchar* clayout = ibus_engine_desc_get_layout(desc);
    const gchar* cvariant = ibus_engine_desc_get_layout_variant(desc);
    const gchar* coption = ibus_engine_desc_get_layout_option(desc);

    QString layout = QString::fromUtf8(clayout ? clayout : "");
    QString variant = QString::fromUtf8(cvariant ? cvariant : "");
    QString option = QString::fromUtf8(coption ? coption : "");

    if (layout == "default" &&
        (variant == "default" || variant == "") &&
        (option == "default" || option == "")) {
        return;
    }

    bool need_us_layout = false;
    if (variant != "eng") {
        need_us_layout = m_latinLayouts.contains(layout);
    }
    if (!need_us_layout && variant != "") {
        need_us_layout = m_latinLayouts.contains(QString("%1(%2)").arg(layout, variant));
    }

    if (m_defaultLayout == "") {
        getLayout();
    }

    if (layout == "default" || layout == "") {
        layout = m_defaultLayout;
        variant = m_defaultVariant;
    }

    if (layout == "") {
        g_warning("Could not get the correct layout");
        return;
    }

    if (option == "default" || option == "") {
        option = m_defaultOption;
    } else {
        if (!(m_defaultOption.split(",").contains(option))) {
            option = QString("%1,%2").arg(m_defaultOption, option);
        } else {
            option = m_defaultOption;
        }
    }

    if (need_us_layout) {
        layout += ",us";
        if (variant != "") {
            variant += ",";
        }
    }

    QStringList args;
    args << XKB_LAYOUT_ARG;
    args << layout;
    if (variant != "" && variant != "default") {
        args << "-variant";
        args << variant;
    }
    if (option != "" && option != "default") {
        /*TODO: Need to get the session XKB options */
        args << "-option";
        args << option;
    }

    int exit_status = QProcess::execute(XKB_COMMAND, args);

    if (exit_status != 0) {
        g_warning("Execute setxkbmap failed.");
    }

    runXmodmap();
}

void XkbLayoutManager::runXmodmap()
{
    if (!m_useXkbModmap) {
        return;
    }

    QDir home = QDir::home();
    for (size_t i = 0; i < sizeof(XMODMAP_KNOWN_FILES) / sizeof(XMODMAP_KNOWN_FILES[0]); i ++ ) {
        if (home.exists(XMODMAP_KNOWN_FILES[i])) {
            QProcess::startDetached(XMODMAP_COMMAND, QStringList(home.filePath(XMODMAP_KNOWN_FILES[i])));
            break;
        }
    }
}

void XkbLayoutManager::setUseXkbModmap(bool use)
{
    m_useXkbModmap = use;
}