/* extension.js
 *
 * 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 3 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/>.
 *
 * SPDX-License-Identifier: GPL-3.0-or-later
 */

/* Based on https://stackoverflow.com/questions/33001192/how-to-send-a-string-to-a-gnome-shell-extension */

/*
  Some useful documentation :

  https://github.com/bananenfisch/RecentItems/blob/master/extension.js
  https://github.com/julio641742/gnome-shell-extension-reference/blob/master/tutorials/POPUPMENU-EXTENSION.md
  https://gjs-docs.gnome.org/st10~1.0_api/st.widget
  https://gitlab.gnome.org/GNOME/gnome-shell/-/blob/master/js/ui/panelMenu.js
  https://gitlab.gnome.org/GNOME/gnome-shell/-/blob/master/js/ui/popupMenu.js
  https://gitlab.gnome.org/GNOME/gnome-shell/-/blob/master/js/ui/panel.js
*/

const St = imports.gi.St;
const Gio = imports.gi.Gio;
const Lang = imports.lang;
const GLib = imports.gi.GLib
const Main = imports.ui.main;
const Mainloop = imports.mainloop;
const Clutter = imports.gi.Clutter;
const PanelMenu = imports.ui.panelMenu;
const PopupMenu = imports.ui.popupMenu;
const GObject = imports.gi.GObject;
const Pixbuf = imports.gi.GdkPixbuf;
const Cogl = imports.gi.Cogl;


function hashGet(hash, key, defaultValue) {
    if (hash.hasOwnProperty(key))
        return hash[key];

    return defaultValue;
}

function log(message) {
    global.log('[GenericMontior]', message);
}


class SignalMgt {

    constructor(item, name, group, dbus, menu) {
        this.name = name;
        this.group = group;
        this.fullname = this.name + '@' + this.group;
        this.dbus = dbus;
        this.menu = menu;
        this.signals = {}

        this.nbClicks = 0;
        this.button = -1;

        this.onClick         = hashGet(item, 'on-click', '');
        this.onDblClick      = hashGet(item, 'on-dblclick', '');
        this.onRightClick    = hashGet(item, 'on-rightclick', '');
        this.onRightDblClick = hashGet(item, 'on-rightdblclick', '');
        this.onEnter         = hashGet(item, 'on-enter',  '');
        this.onLeave         = hashGet(item, 'on-leave',  '');
        this.onScroll        = hashGet(item, 'on-scroll', '');
    }

    destructor() {
        for(let widgetIdx in this.signals)
            this.disconnectWidgetSignals(this.signals[widgetIdx]);
    }
    
    updateSignals(item) {
        this.onClick         = hashGet(item, 'on-click', this.onClick);
        this.onDblClick      = hashGet(item, 'on-dblclick', this.onDblClick);
        this.onRightClick    = hashGet(item, 'on-rightclick', this.onRightClick);
        this.onRightDblClick = hashGet(item, 'on-rightdblclick', this.onRightDblClick);
        this.onEnter         = hashGet(item, 'on-enter',  this.onEnter);
        this.onLeave         = hashGet(item, 'on-leave',  this.onLeave);
        this.onScroll        = hashGet(item, 'on-scroll', this.onScroll);
    }

    connectWidgetSignals(widget) {
        this.signals[widget] = [];
        let id;
        id = widget.connect('enter-event', this._onEnter.bind(this));
        this.signals[widget].push(id);
        id = widget.connect('leave-event', this._onLeave.bind(this));
        this.signals[widget].push(id);
        id = widget.connect('scroll-event', this._onScroll.bind(this));
        this.signals[widget].push(id);
        widget.set_reactive(true);
        id = widget.connect('button-release-event', Lang.bind(this, this._clicked));
        this.signals[widget].push(id);
    }

    disconnectWidgetSignals(widget) {
        for(let idx in this.signals[widget])
            widget.disconnect(this.signals[widget][idx]);
        this.signals[widget] = null;
    }

    _manageEventAction(action, signalName) {
        if (action === 'open-popup')
            this.menu.open(true);
        else if (action === 'close-popup')
            this.menu.close();
        else if (action === 'toggle-popup')
            this.menu.toggle();
        else if (action == 'delete')
            this.dbus.deleteItem(this, this.group);
        else if (action === 'signal')
            this.dbus.emitSignal(signalName, this.fullname);

        return Clutter.EVENT_PROPAGATE;
    }
    
    _manageLeaveEvent() {
        this._manageEventAction(this.onLeave);
    }
    
    _doClickCallback() {
        let right = '';
        let nbClicks = '';
    
        if (this.button == 3)
            right = 'Right';
        if (this.nbClicks > 1)
            nbClicks = 'Dbl';

        const signalName = 'on' + right + nbClicks + 'Click';

        let action = 'signal';
        switch(signalName) {
        case 'onClick':         action = this.onClick; break;
        case 'onDblClick':      action = this.onDblClick; break;
        case 'onRightClick':    action = this.onRightClick; break;
        case 'onRightDblClick': action = this.onRightDblClick; break;
        }

        this._manageEventAction(action, signalName);

        this.nbClicks = 0;
        this.button = -1;

        return false;
    }

    _clicked(actor, event) {
        if (event.get_button() == this.button) {
            this.nbClicks++;
        } else {
            this.button = event.get_button();
            this.nbClicks = 1;

            Mainloop.timeout_add(this.dbus.ClutterSettings['double-click-time'],
                                 Lang.bind(this, this._doClickCallback));
        }

        return Clutter.EVENT_PROPAGATE;
    }
    
    _onEnter(/*actor, event*/) {
        return this._manageEventAction(this.onEnter, 'onEnter');
    }

    _onLeave(/*actor, event*/) {
        return this._manageEventAction(this.onLeave, 'onLeave');
    }

    _onScroll(actor, event) {
        let signalName = '';
        const direction = event.get_scroll_direction ();
        if (direction ==  Clutter.ScrollDirection.UP)
            signalName = 'onScrollUp';
        else if (direction ==  Clutter.ScrollDirection.DOWN)
            signalName = 'onScrollDown';

        return this._manageEventAction(this.onScroll, signalName);
    }
}

var MyPopupMenuItem = GObject.registerClass({
    GTypeName: 'MyPopupMenuItem'
},
class MyPopupMenuItem extends PopupMenu.PopupBaseMenuItem {
    _init(widgets, params) {
        super._init(params);

        this.box = new St.BoxLayout({ style_class: 'popup-combobox-item' });
        this.box.set_vertical(true);

        for (let widgetIndex in widgets)
            this.box.add(widgets[widgetIndex]);
        
        this.add_child(this.box);
    }
});


var MonitorWidget = GObject.registerClass({
    GTypeName: 'MonitorWidget'
},
class MonitorWidget extends PanelMenu.Button {

    _init(item, group, dbus, position) {    
        super._init(0.0);
        
        this.name = item['name'];
        this.group = group;
        this.fullname = this.name + '@' + this.group;
        this.dbus = dbus;
        this.signals = new SignalMgt(item, this.name, group, dbus, this.menu);
        this.popup_signals = {};
        
        if (item.hasOwnProperty('icon'))
        {
            if (typeof(item['icon']) === 'string')
                this.icon = this._createIconOld(item);
            else
                this.icon = this._createIcon(item['icon']);
            if (this.icon !== null) {
                this.signals.connectWidgetSignals(this.icon);
                this.add_child(this.icon);
            }
        } else
            this.icon = null;
        
        if (item.hasOwnProperty('text'))
        {
            if (typeof(item['text']) === 'string')
                this.widget = this._createTextOld(item);
            else
                this.widget = this._createText(item['text']);

            if (this.widget !== null) {
                this.signals.connectWidgetSignals(this.widget);
                this.add_child(this.widget);
            }
        } else
            this.widget = null;
        
        if (item.hasOwnProperty('popup'))
            this._createPopup(item['popup']);

        const box = hashGet(item, 'box', 'center');

        if (box === 'right' && position == -1)
            position = 0;
        
        this.connect('style-changed', this._onStyleChanged.bind(this));
        
        Main.panel.addToStatusArea(this.fullname, this, position, box);
    }

    update(item) {
        const prevWidget = this.widget;
        const prevIcon = this.icon;

        if (item.hasOwnProperty('text'))
        {
            let text = '';
            let style = '';
            if (typeof(item['text']) === 'string') {
                text = hashGet(item, 'text', '');
                style = hashGet(item, 'style', '');
            } else {
                const textValues = item['text'];
                text = hashGet(textValues, 'text', '');
                style = hashGet(textValues, 'style', '');
            }
            
            if (text !== '') {
                if (!this.widget) {
                    if (typeof(item['text']) === 'string')
                        this.widget = this._createTextOld(item);
                    else
                        this.widget = this._createText(item['text']);
                    this.insert_child_above(this.widget, this.icon);
                } else {
                    this.widget.label = text;
                }
            }

            if (style !== '' && this.widget) {
                this.widget.set_style(style);
            }
        }

        if (item.hasOwnProperty('icon'))
        {
            let icon = '';
            let style = '';
            if (typeof(item['icon']) === 'string') {
                icon = hashGet(item, 'icon', '');
                style = hashGet(item, 'iconStyle', '');
            } else {
                const iconValues = item['icon'];
                icon = hashGet(iconValues, 'path', '');
                style = hashGet(iconValues, 'style', '');
            }
            
            if (icon !== '') {
                if (typeof(item['icon']) === 'string')
                    this.icon = this._createIconOld(item);
                else
                    this.icon = this._createIcon(item['icon']);
            }
            
            if (prevIcon) {
                this.signals.disconnectWidgetSignals(prevIcon);
                this.insert_child_above(this.icon, prevIcon);
                this.remove_child(prevIcon);
                //delete prevIcon;
            } else
                this.insert_child_before(this.icon, prevWidget);

            if (style !== '' && this.icon) {
                this.icon.set_style(style);
            }
        }

        if (item.hasOwnProperty('popup'))
        {
            const menuOpen = this.menu.isOpen;
            if (this.menuItem) {
                if (menuOpen)
                    this.menu.close();
                for(let widgetIdx in this.popup_signals)
                    this.signals.disconnectWidgetSignals(this.popup_signals[widgetIdx]);
                this.menu.removeAll();
                //delete this.menuItem;
            }

            const popup = this._createPopup(item['popup']);
            if (popup !== null && menuOpen)
                this.menu.open(true);
        }

        this.signals.updateSignals(item);
    }

    openPopup() {
        this.menu.open(true);
    }
    
    closePopup() {
        this.menu.close();
    }

    togglePopup() {
        this.menu.toggle();
    }

    destroy() {
        this.menu.close();
        super.destroy();
    }

    _onStyleChanged() {
        // Force these values to avoid big spaces between each widgets
        this._minHPadding = 1;
        this._natHPadding = 1;
    }
    
    _createPopup(item) {
        if (!item.hasOwnProperty('items')) {
            return null;
        }

        let widgets = [];
        for (let itemIndex in item['items']) {
            let widget = null;
            let widgetDict = item['items'][itemIndex];

            let nestedItem = null;
            if (widgetDict.hasOwnProperty('text')) {
                nestedItem = widgetDict['text'];
                widget = this._createLabel(nestedItem);
            } else if (widgetDict.hasOwnProperty('picture')) {
                nestedItem = widgetDict['picture'];
                widget = this._createPicture(nestedItem);
            } else {
                log('No known widget defined in popup');
            }
            
            if (nestedItem === null) {
                continue;
            }
            
            widgets.push(widget);
            const name = hashGet(nestedItem, 'name', '');
            this.popup_signals[widget] = new SignalMgt(nestedItem, name,
                                                       this.fullname, this.dbus,
                                                       this.menu);
            this.popup_signals[widget].connectWidgetSignals(widget);
        }

        if (widgets.length > 0) {
            this.menuItem = new MyPopupMenuItem(widgets, {});    
            this.menu.addMenuItem(this.menuItem);
            this.menu.setSensitive(false);
            return this.menuItem;
        }

        return null;
    }
    
    _createTextOld(item) {
        var itemValues = {};
        itemValues = { 'text':item['text'] };
        if (item.hasOwnProperty('style'))
            itemValues['style'] = item['style'];
        return this._createText(itemValues);
    }
    
    __createText(item, isLabel) {
        if (!item.hasOwnProperty('text')) {
            log('Text must have a \'text\' value');
            return null;
        }

        const style = hashGet(item, 'style', '');

        this.textProperties = item;

        if (item['text'] === '') {
            return null;
        } else {
            let widget = null;
            if (isLabel)
                widget = new St.Label({ text: item['text'] });
            else
                widget = new St.Button({ label: item['text'] });
            widget.set_style(style);

            return widget;
        }
    }

    _createText(item) {
        return this.__createText(item, false);
    }

    _createLabel(item) {
        return this.__createText(item, true);
    }

    _createIconOld(item) {
        var itemValues = {};
        itemValues = { 'path':item['icon'] };
        if (item.hasOwnProperty('iconStyle'))
            itemValues['style'] = item['iconStyle'];
        return this._createIcon(itemValues);
    }

    _createIcon(item) {
        if (!item.hasOwnProperty('path')) {
            log('Icon must have a \'path\' value');
            return null;
        }

        const style = hashGet(item, 'style', '');

        this.iconProperties = item;

        if (item['path'] === '') {
            return null;
        } else {
            let gicon = Gio.icon_new_for_string(item['path']);
            gicon = new St.Icon({ gicon });
            gicon.set_style(style);

            return gicon;
        }
    }

    _createPicture(item) {
        if (!item.hasOwnProperty('path')) {
            log('Picture must have a \'path\' value');
            return null;
        }

        let width = hashGet(item, 'width', -1);
        let height = hashGet(item, 'height', -1);

        if (typeof(width) === 'string')
            width = parseInt(width, 10);

        if (typeof(height) === 'string')
            height = parseInt(height, 10);

        const img = new Clutter.Image();
        const initialPixbuf = Pixbuf.Pixbuf.new_from_file(item['path']);
        img.set_data(initialPixbuf.get_pixels(),
                     initialPixbuf.get_has_alpha() ? Cogl.PixelFormat.RGBA_8888
                     : Cogl.PixelFormat.RGB_888,
                     initialPixbuf.get_width(),
                     initialPixbuf.get_height(),
                     initialPixbuf.get_rowstride());
        const picture = new Clutter.Actor();
        picture.set_content(img);
        picture.set_size((width != -1)?width:initialPixbuf.get_width(),
                         (height != -1)?height:initialPixbuf.get_height());

        // Pack it in a box to avoid picture resize
        const box = new St.BoxLayout({});
        box.add_child(picture);

        return box;
    }
});

// From https://github.com/ubuntu/gnome-shell-extension-appindicator/blob/master/interfaces.js
// loads a xml file into an in-memory string
function loadInterfaceXml(filename) {
    const extension = imports.misc.extensionUtils.getCurrentExtension();

    const interfacesDir = extension.dir.get_child('.');

    const file = interfacesDir.get_child(filename);

    let [result, contents] = imports.gi.GLib.file_get_contents(file.get_path());

    if (result) {
        // HACK: The "" + trick is important as hell because file_get_contents returns
        // an object (WTF?) but Gio.makeProxyWrapper requires `typeof() == "string"`
        // Otherwise, it will try to check `instanceof XML` and fail miserably because there
        // is no `XML` on very recent SpiderMonkey releases (or, if SpiderMonkey is old enough,
        // will spit out a TypeError soon).
        if (contents instanceof Uint8Array)
            contents = imports.byteArray.toString(contents);
        const res = `<node>${contents}</node>`;
        return res;
    } else {
        throw new Error(`Generic monitor: Could not load file: ${filename}`);
    }
}

class GenericMonitorDBUS {
    constructor() {
        this.monitor_groups = {};
        this.actor_clicked = {};
        this.ClutterSettings = Clutter.Settings.get_default();
        this._dbusImpl = Gio.DBusExportedObject.wrapJSObject(loadInterfaceXml('dbus.xml'), this);
        this._dbusImpl.export(Gio.DBus.session, '/com/soutade/GenericMonitor');
        this._dbusImpl.emit_signal('onActivate', null);
    }

    emitSignal(name, value) {
        this._dbusImpl.emit_signal(name, GLib.Variant.new('(s)',[value]));
    }

    _checkParameters(parameters) {
        if (!parameters.hasOwnProperty('group')) {
            log('No group defined');
            return false;
        }

        if (!parameters.hasOwnProperty('items')) {
            log('No items defined');
            return false;
        }

        for (let itemIndex in parameters['items']) {
            const item = parameters['items'][itemIndex];
            if (!item.hasOwnProperty('name')) {
                log('No name defined for item');
                return false;
            }
        }

        return true;
    }

    _getItemFromGroup(group, name) {
        for (let groupItemIndex in group) {
            const groupItem = group[groupItemIndex];
            if (groupItem.name === name)
                return groupItem;
        }

        return null;
    }

    _getItemFromFullName(fullname) {
        const splitName = fullname.split('@');
        if (splitName.length !== 2) {
            log(`Invalid name ${fullname}`);
            return null;
        }
        if (!this.monitor_groups.hasOwnProperty(splitName[1]))
            return null;
        return this._getItemFromGroup(this.monitor_groups[splitName[1]], splitName[0]);
    }
    
    _removeFromArray(array, value) {
        for(let i=0; i<array.length; i++) {
            if (array[i] === value) {
                array.splice(i, 1);
                if (array === null)
                    array = [];
                break;
            }
        }
        return array;
    }
    
    notify(str) {
        const parameters = JSON.parse(str);
        if (!this._checkParameters(parameters))
            return;

        const groupName = parameters['group'];
        let group;
        if (!this.monitor_groups.hasOwnProperty(groupName)) {
            group = [];
            this.monitor_groups[groupName] = group;
        } else {
            group = this.monitor_groups[groupName];
        }

        for (let itemIndex in parameters['items']) {
            const item = parameters['items'][itemIndex];
            let monitorWidget = this._getItemFromGroup(group, item['name']);

            // New widget
            if (monitorWidget === null) {
                let position = group.length - 1;
                // Find real position
                if (position != -1) {
                    const lastWidget = group[position].container;
                    const childrens = lastWidget.get_parent().get_children();
                    for(;position < childrens.length; position++)
                    {
                        if (childrens[position] == lastWidget) {
                            position++;
                            break;
                        }
                    }
                    if (position >= childrens.length)
                        position = -1;
                }
                monitorWidget = new MonitorWidget(item, groupName, this, position);
                group.push(monitorWidget);
            } else {
                monitorWidget.update(item);
            }
        }
    }

    deleteItem(item, groupName) {
        let group = this.monitor_groups[groupName];
        group = this._removeFromArray(group, item);
        item.destroy();
        if (group.length === 0)
            delete this.monitor_groups[groupName];
        else
            this.monitor_groups = group;
    }
    
    deleteItems(str) {
        const parameters = JSON.parse(str);

        if (!parameters.hasOwnProperty('items')) {
            log('No items defined');
            return false;
        }

        for (let itemIndex in parameters['items']) {
            let itemName = parameters['items'][itemIndex];
            const splitName = itemName.split('@');
            if (splitName.length !== 2) {
                log(`Invalid name ${itemName}`);
                return false;
            }
            itemName = splitName[0];
            let groupName = splitName[1];
            if (!this.monitor_groups.hasOwnProperty(groupName))
                continue;
            let group = this.monitor_groups[groupName];
            let item = this._getItemFromGroup(group, itemName);
            if (item !== null) {
                this.deleteItem(item, groupName);
            }
        }
    }

    deleteGroups(str) {
        const parameters = JSON.parse(str);

        if (!parameters.hasOwnProperty('groups')) {
            log('No groups defined');
            return false;
        }

        let groupsToDelete = [];
        for (let groupIndex in parameters['groups']) {
            const groupName = parameters['groups'][groupIndex];
            if (!this.monitor_groups.hasOwnProperty(groupName))
                continue;
            const group = this.monitor_groups[groupName];
            for (let itemIndex in group)
                group[itemIndex].destroy();
            groupsToDelete.push(groupName);
        }
        for (let groupDeleteIndex in groupsToDelete) {
            const groupName = groupsToDelete[groupDeleteIndex];
            delete this.monitor_groups[groupName];
        }
    }

    _popupFunction(str) {
        const parameters = JSON.parse(str);

        if (!parameters.hasOwnProperty('item')) {
            log('No item defined');
            return false;
        }

        const monitorWidget = this._getItemFromFullName(parameters['item']);
        if (monitorWidget !== null)
            return monitorWidget;
        else
            log(`Item ${str} not found`);

        return null;
    }
    
    openPopup(str) {
        const monitorWidget = this._popupFunction(str)
        if (monitorWidget !== null)
            monitorWidget.openPopup();
    }

    closePopup(str) {
        const monitorWidget = this._popupFunction(str)
        if (monitorWidget !== null)
            monitorWidget.closePopup();
    }

    togglePopup(str) {
        const monitorWidget = this._popupFunction(str)
        if (monitorWidget !== null)
            monitorWidget.togglePopup();
    }

    destructor() {
        this._dbusImpl.emit_signal('onDeactivate', null);
        for (let groupIndex in this.monitor_groups) {
            const group = this.monitor_groups[groupIndex];
            for (let itemIndex in group)
                group[itemIndex].destroy();
        }
        this.monitor_groups = {};
        this._dbusImpl.unexport();
    }
}

class Extension {
    enable() {
        this.textDBusService = new GenericMonitorDBUS();
    }

    disable() {
        this.textDBusService.destructor();
        delete this.textDBusService;
    }
}

const extension = new Extension();

function init() {
}

function enable() {
    extension.enable();
}

function disable() {
    extension.disable();
}