/* -*- mode: js2; js2-basic-offset: 4; indent-tabs-mode: nil -*- */

const DBus = imports.dbus;
const GConf = imports.gi.GConf;
const Gio = imports.gi.Gio;
const Gtk = imports.gi.Gtk;
const Lang = imports.lang;
const Mainloop = imports.mainloop;
const Shell = imports.gi.Shell;
const Signals = imports.signals;
const St = imports.gi.St;

const PanelMenu = imports.ui.panelMenu;
const PopupMenu = imports.ui.popupMenu;
const Util = imports.misc.util;

const Gettext = imports.gettext.domain('gnome-shell');
const _ = Gettext.gettext;

const A11Y_SCHEMA = 'org.gnome.desktop.a11y.keyboard';
const KEY_STICKY_KEYS_ENABLED = 'stickykeys-enable';
const KEY_BOUNCE_KEYS_ENABLED = 'bouncekeys-enable';
const KEY_SLOW_KEYS_ENABLED   = 'slowkeys-enable';
const KEY_MOUSE_KEYS_ENABLED  = 'mousekeys-enable';

const APPLICATIONS_SCHEMA = 'org.gnome.desktop.a11y.applications';

const XSETTINGS_SCHEMA = 'org.gnome.settings-daemon.plugins.xsettings';
const KEY_DPI = 'dpi';

const DPI_LOW_REASONABLE_VALUE  = 50;
const DPI_HIGH_REASONABLE_VALUE = 500;

const DPI_FACTOR_LARGE   = 1.25;
const DPI_FACTOR_LARGER  = 1.5;
const DPI_FACTOR_LARGEST = 2.0;
const DPI_DEFAULT        = 96;

const KEY_META_DIR       = '/apps/metacity/general';
const KEY_VISUAL_BELL = KEY_META_DIR + '/visual_bell';

const DESKTOP_INTERFACE_SCHEMA = 'org.gnome.desktop.interface';
const KEY_GTK_THEME      = 'gtk-theme';
const KEY_ICON_THEME     = 'icon-theme';

const HIGH_CONTRAST_THEME = 'HighContrast';

function getDPIFromX() {
    let screen = global.get_gdk_screen();
    if (screen) {
        let width_dpi = (screen.get_width() / (screen.get_width_mm() / 25.4));
        let height_dpi = (screen.get_height() / (screen.get_height_mm() / 25.4));
        if (width_dpi < DPI_LOW_REASONABLE_VALUE
            || width_dpi > DPI_HIGH_REASONABLE_VALUE
            || height_dpi < DPI_LOW_REASONABLE_VALUE
            || height_dpi > DPI_HIGH_REASONABLE_VALUE)
            return DPI_DEFAULT;
        else
            return (width_dpi + height_dpi) / 2;
    }
    return DPI_DEFAULT;
}

function ATIndicator() {
    this._init.apply(this, arguments);
}

ATIndicator.prototype = {
    __proto__: PanelMenu.SystemStatusButton.prototype,

    _init: function() {
        PanelMenu.SystemStatusButton.prototype._init.call(this, 'preferences-desktop-accessibility', null);

        let client = GConf.Client.get_default();
        client.add_dir(KEY_META_DIR, GConf.ClientPreloadType.PRELOAD_ONELEVEL, null);
        client.notify_add(KEY_META_DIR, Lang.bind(this, this._keyChanged), null, null);

        let highContrast = this._buildHCItem();
        this.menu.addMenuItem(highContrast);

        let magnifier = this._buildItem(_("Zoom"), APPLICATIONS_SCHEMA,
                                                   'screen-magnifier-enabled');
        this.menu.addMenuItem(magnifier);

        let textZoom = this._buildFontItem();
        this.menu.addMenuItem(textZoom);

        let screenReader = this._buildItem(_("Screen Reader"), APPLICATIONS_SCHEMA,
                                                               'screen-reader-enabled');
        this.menu.addMenuItem(screenReader);

        let screenKeyboard = this._buildItem(_("Screen Keyboard"), APPLICATIONS_SCHEMA,
                                                                   'screen-keyboard-enabled');
        this.menu.addMenuItem(screenKeyboard);

        let visualBell = this._buildItemGConf(_("Visual Alerts"), client, KEY_VISUAL_BELL);
        this.menu.addMenuItem(visualBell);

        let stickyKeys = this._buildItem(_("Sticky Keys"), A11Y_SCHEMA, KEY_STICKY_KEYS_ENABLED);
        this.menu.addMenuItem(stickyKeys);

        let slowKeys = this._buildItem(_("Slow Keys"), A11Y_SCHEMA, KEY_SLOW_KEYS_ENABLED);
        this.menu.addMenuItem(slowKeys);

        let bounceKeys = this._buildItem(_("Bounce Keys"), A11Y_SCHEMA, KEY_BOUNCE_KEYS_ENABLED);
        this.menu.addMenuItem(bounceKeys);

        let mouseKeys = this._buildItem(_("Mouse Keys"), A11Y_SCHEMA, KEY_MOUSE_KEYS_ENABLED);
        this.menu.addMenuItem(mouseKeys);

        this.menu.addMenuItem(new PopupMenu.PopupSeparatorMenuItem());
        this.menu.addAction(_("Universal Access Settings"), function() {
            Util.spawnDesktop('gnome-universal-access-panel');
        });
    },

    _buildItemExtended: function(string, initial_value, writable, on_set) {
        let widget = new PopupMenu.PopupSwitchMenuItem(string, initial_value);
        if (!writable)
            widget.actor.reactive = false;
        else
            widget.connect('toggled', function(item) {
                on_set(item.state);
            });
        return widget;
    },

    _buildItemGConf: function(string, client, key) {
        function on_get() {
            return client.get_bool(key);
        }
        let widget = this._buildItemExtended(string,
            client.get_bool(key),
            client.key_is_writable(key),
            function(enabled) {
                client.set_bool(key, enabled);
            });
        this.connect('gconf-changed', function() {
            widget.setToggleState(client.get_bool(key));
        });
        return widget;
    },

    _buildItem: function(string, schema, key) {
        let settings = new Gio.Settings({ schema: schema });
        let widget = this._buildItemExtended(string,
            settings.get_boolean(key),
            settings.is_writable(key),
            function(enabled) {
                return settings.set_boolean(key, enabled);
            });
        settings.connect('changed::'+key, function() {
            widget.setToggleState(settings.get_boolean(key));
        });
        return widget;
    },

    _buildHCItem: function() {
        let settings = new Gio.Settings({ schema: DESKTOP_INTERFACE_SCHEMA });
        let gtkTheme = settings.get_string(KEY_GTK_THEME);
        let iconTheme = settings.get_string(KEY_ICON_THEME);
        let hasHC = (gtkTheme == HIGH_CONTRAST_THEME);
        let highContrast = this._buildItemExtended(
            _("High Contrast"),
            hasHC,
            settings.is_writable(KEY_GTK_THEME) && settings.is_writable(KEY_ICON_THEME),
            function (enabled) {
                if (enabled) {
                    settings.set_string(KEY_GTK_THEME, HIGH_CONTRAST_THEME);
                    settings.set_string(KEY_ICON_THEME, HIGH_CONTRAST_THEME);
                } else if(!hasHC) {
                    settings.set_string(KEY_GTK_THEME, gtkTheme);
                    settings.set_string(KEY_ICON_THEME, iconTheme);
                } else {
                    settings.reset(KEY_GTK_THEME);
                    settings.reset(KEY_ICON_THEME);
                }
            });
        settings.connect('changed::' + KEY_GTK_THEME, function() {
            let value = settings.get_string(KEY_GTK_THEME);
            if (value == HIGH_CONTRAST_THEME) {
                highContrast.setToggleState(true);
            } else {
                highContrast.setToggleState(false);
                gtkTheme = value;
            }
        });
        settings.connect('changed::' + KEY_ICON_THEME, function() {
            let value = settings.get_string(KEY_ICON_THEME);
            if (value != HIGH_CONTRAST_THEME)
                iconTheme = value;
        });
        return highContrast;
    },

    _buildFontItem: function() {
        let settings = new Gio.Settings({ schema: XSETTINGS_SCHEMA });

        // we assume this never changes (which is not true if resolution
        // is changed, but we would need XRandR events for that)
        let x_value = getDPIFromX();
        let user_value;
        function on_get() {
            user_value = settings.get_double(KEY_DPI);
            return (user_value - (DPI_FACTOR_LARGE * x_value) > -1);
        }
        let initial_setting = on_get();
        let default_value = initial_setting ? x_value : user_value;
        let widget = this._buildItemExtended(_("Large Text"),
            initial_setting,
            settings.is_writable(KEY_DPI),
            function (enabled) {
                if (enabled)
                    settings.set_double(KEY_DPI, DPI_FACTOR_LARGE * default_value);
                else
                    settings.set_double(KEY_DPI, default_value);
            });
        settings.connect('changed::' + KEY_DPI, function() {
            let active = on_get();
            default_value = active ? x_value : user_value;
            widget.setToggleState(active);
        });
        return widget;
    },

    _keyChanged: function() {
        this.emit('gconf-changed');
    }
};
Signals.addSignalMethods(ATIndicator.prototype);