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

/* exported init enable disable */

const {

    Atk, Clutter, Gio, GLib, GMenu, GObject, Gtk, Meta, Shell, St

} = imports.gi;

const DND = imports.ui.dnd;

const Main = imports.ui.main;

const PanelMenu = imports.ui.panelMenu;

const PopupMenu = imports.ui.popupMenu;

const Signals = imports.signals;

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

const _ = Gettext.gettext;

const ExtensionUtils = imports.misc.extensionUtils;

const appSys = Shell.AppSystem.get_default();

const APPLICATION_ICON_SIZE = 32;

const HORIZ_FACTOR = 5;

const MENU_HEIGHT_OFFSET = 132;

const NAVIGATION_REGION_OVERSHOOT = 50;

Gio._promisify(Gio._LocalFilePrototype, 'query_info_async', 'query_info_finish');

Gio._promisify(Gio._LocalFilePrototype, 'set_attributes_async', 'set_attributes_finish');

class ApplicationMenuItem extends PopupMenu.PopupBaseMenuItem {

    constructor(button, app) {

        super();

        this._app = app;

        this._button = button;

        this._iconBin = new St.Bin();

        this.actor.add_child(this._iconBin);

        let appLabel = new St.Label({

            text: app.get_name(),

            y_expand: true,

            y_align: Clutter.ActorAlign.CENTER

        });

        this.actor.add_child(appLabel);

        this.actor.label_actor = appLabel;

        let textureCache = St.TextureCache.get_default();

        let iconThemeChangedId = textureCache.connect('icon-theme-changed',

                                                      this._updateIcon.bind(this));

        this.actor.connect('destroy', () => {

            textureCache.disconnect(iconThemeChangedId);

        });

        this._updateIcon();

        this.actor._delegate = this;

        let draggable = DND.makeDraggable(this.actor);

        let maybeStartDrag = draggable._maybeStartDrag;

        draggable._maybeStartDrag = (event) => {

            if (this._dragEnabled)

                return maybeStartDrag.call(draggable, event);

            return false;

        };

    }

    activate(event) {

        this._app.open_new_window(-1);

        this._button.selectCategory(null);

        this._button.menu.toggle();

        super.activate(event);

        Main.overview.hide();

    }

    setActive(active, params) {

        if (active)

            this._button.scrollToButton(this);

        super.setActive(active, params);

    }

    setDragEnabled(enable) {

        this._dragEnabled = enable;

    }

    getDragActor() {

        return this._app.create_icon_texture(APPLICATION_ICON_SIZE);

    }

    getDragActorSource() {

        return this._iconBin;

    }

    _updateIcon() {

        let icon = this.getDragActor();

        icon.style_class = 'icon-dropshadow';

        this._iconBin.set_child(icon);

    }

}

class CategoryMenuItem extends PopupMenu.PopupBaseMenuItem {

    constructor(button, category) {

        super();

        this._category = category;

        this._button = button;

        this._oldX = -1;

        this._oldY = -1;

        let name;

        if (this._category)

            name = this._category.get_name();

        else

            name = _('Favorites');

        let label = new St.Label({ text: name });

        this.actor.add_child(label);

        this.actor.label_actor = label;

        this.actor.connect('motion-event', this._onMotionEvent.bind(this));

    }

    activate(event) {

        this._button.selectCategory(this._category);

        this._button.scrollToCatButton(this);

        super.activate(event);

    }

    _isNavigatingSubmenu([x, y]) {

        let [posX, posY] = this.actor.get_transformed_position();

        if (this._oldX == -1) {

            this._oldX = x;

            this._oldY = y;

            return true;

        }

        let deltaX = Math.abs(x - this._oldX);

        let deltaY = Math.abs(y - this._oldY);

        this._oldX = x;

        this._oldY = y;

        // If it lies outside the x-coordinates then it is definitely outside.

        if (posX > x || posX + this.actor.width < x)

            return false;

        // If it lies inside the menu item then it is definitely inside.

        if (posY <= y && posY + this.actor.height >= y)

            return true;

        // We want the keep-up triangle only if the movement is more

        // horizontal than vertical.

        if (deltaX * HORIZ_FACTOR < deltaY)

            return false;

        // Check whether the point lies inside triangle ABC, and a similar

        // triangle on the other side of the menu item.

        //

        //   +---------------------+

        //   | menu item           |

        // A +---------------------+ C

        //              P          |

        //                         B

        // Ensure that the point P always lies below line AC so that we can

        // only check for triangle ABC.

        if (posY > y) {

            let offset = posY - y;

            y = posY + this.actor.height + offset;

        }

        // Ensure that A is (0, 0).

        x -= posX;

        y -= posY + this.actor.height;

        // Check which side of line AB the point P lies on by taking the

        // cross-product of AB and AP. See:

        // http://stackoverflow.com/questions/3461453/determine-which-side-of-a-line-a-point-lies

        if (((this.actor.width * y) - (NAVIGATION_REGION_OVERSHOOT * x)) <= 0)

            return true;

        return false;

    }

    _onMotionEvent(actor, event) {

        if (!Clutter.get_pointer_grab()) {

            this._oldX = -1;

            this._oldY = -1;

            Clutter.grab_pointer(this.actor);

        }

        this.actor.hover = true;

        if (this._isNavigatingSubmenu(event.get_coords()))

            return true;

        this._oldX = -1;

        this._oldY = -1;

        this.actor.hover = false;

        Clutter.ungrab_pointer();

        let source = event.get_source();

        if (source instanceof St.Widget)

            source.sync_hover();

        return false;

    }

    setActive(active, params) {

        if (active) {

            this._button.selectCategory(this._category);

            this._button.scrollToCatButton(this);

        }

        super.setActive(active, params);

    }

}

class ApplicationsMenu extends PopupMenu.PopupMenu {

    constructor(sourceActor, arrowAlignment, arrowSide, button) {

        super(sourceActor, arrowAlignment, arrowSide);

        this._button = button;

    }

    isEmpty() {

        return false;

    }

    toggle() {

        if (this.isOpen)

            this._button.selectCategory(null);

        super.toggle();

    }

}

class DesktopTarget {

    constructor() {

        this._desktop = null;

        this._desktopDestroyedId = 0;

        this._windowAddedId =

            global.window_group.connect('actor-added',

                                        this._onWindowAdded.bind(this));

        global.get_window_actors().forEach(a => {

            this._onWindowAdded(a.get_parent(), a);

        });

    }

    get hasDesktop() {

        return this._desktop != null;

    }

    _onWindowAdded(group, actor) {

        if (!(actor instanceof Meta.WindowActor))

            return;

        if (actor.meta_window.get_window_type() == Meta.WindowType.DESKTOP)

            this._setDesktop(actor);

    }

    _setDesktop(desktop) {

        if (this._desktop) {

            this._desktop.disconnect(this._desktopDestroyedId);

            this._desktopDestroyedId = 0;

            delete this._desktop._delegate;

        }

        this._desktop = desktop;

        this.emit('desktop-changed');

        if (this._desktop) {

            this._desktopDestroyedId = this._desktop.connect('destroy', () => {

                this._setDesktop(null);

            });

            this._desktop._delegate = this;

        }

    }

    _getSourceAppInfo(source) {

        if (!(source instanceof ApplicationMenuItem))

            return null;

        return source._app.app_info;

    }

    async _markTrusted(file) {

        let modeAttr = Gio.FILE_ATTRIBUTE_UNIX_MODE;

        let trustedAttr = 'metadata::trusted';

        let queryFlags = Gio.FileQueryInfoFlags.NONE;

        let ioPriority = GLib.PRIORITY_DEFAULT;

        try {

            let info = await file.query_info_async(modeAttr, queryFlags, ioPriority, null);

            let mode = info.get_attribute_uint32(modeAttr) | 0o100;

            info.set_attribute_uint32(modeAttr, mode);

            info.set_attribute_string(trustedAttr, 'yes');

            await file.set_attributes_async(info, queryFlags, ioPriority, null);

            // Hack: force nautilus to reload file info

            info = new Gio.FileInfo();

            info.set_attribute_uint64(Gio.FILE_ATTRIBUTE_TIME_ACCESS,

                                      GLib.get_real_time());

            try {

                await file.set_attributes_async(info, queryFlags, ioPriority, null);

            } catch (e) {

                log(`Failed to update access time: ${e.message}`);

            }

        } catch (e) {

            log(`Failed to mark file as trusted: ${e.message}`);

        }

    }

    destroy() {

        if (this._windowAddedId)

            global.window_group.disconnect(this._windowAddedId);

        this._windowAddedId = 0;

        this._setDesktop(null);

    }

    handleDragOver(source, _actor, _x, _y, _time) {

        let appInfo = this._getSourceAppInfo(source);

        if (!appInfo)

            return DND.DragMotionResult.CONTINUE;

        return DND.DragMotionResult.COPY_DROP;

    }

    acceptDrop(source, _actor, _x, _y, _time) {

        let appInfo = this._getSourceAppInfo(source);

        if (!appInfo)

            return false;

        this.emit('app-dropped');

        let desktop = GLib.get_user_special_dir(GLib.UserDirectory.DIRECTORY_DESKTOP);

        let src = Gio.File.new_for_path(appInfo.get_filename());

        let dst = Gio.File.new_for_path(GLib.build_filenamev([desktop, src.get_basename()]));

        try {

            // copy_async() isn't introspectable :-(

            src.copy(dst, Gio.FileCopyFlags.OVERWRITE, null, null);

            this._markTrusted(dst);

        } catch (e) {

            log(`Failed to copy to desktop: ${e.message}`);

        }

        return true;

    }

}

Signals.addSignalMethods(DesktopTarget.prototype);

let ApplicationsButton = GObject.registerClass(

class ApplicationsButton extends PanelMenu.Button {

    _init(includeIcon) {

        super._init(1.0, null, false);

        this.setMenu(new ApplicationsMenu(this, 1.0, St.Side.TOP, this));

        Main.panel.menuManager.addMenu(this.menu);

        // At this moment applications menu is not keyboard navigable at

        // all (so not accessible), so it doesn't make sense to set as

        // role ATK_ROLE_MENU like other elements of the panel.

        this.accessible_role = Atk.Role.LABEL;

        let hbox = new St.BoxLayout({ style_class: 'panel-status-menu-box' });

        let iconFile = Gio.File.new_for_path(

            '/usr/share/icons/hicolor/scalable/apps/start-here.svg');

        this._icon = new St.Icon({

            gicon: new Gio.FileIcon({ file: iconFile }),

            style_class: 'panel-logo-icon',

            visible: includeIcon

        });

        hbox.add_actor(this._icon);

        this._label = new St.Label({

            text: _('Applications'),

            y_expand: true,

            y_align: Clutter.ActorAlign.CENTER

        });

        hbox.add_child(this._label);

        hbox.add_child(PopupMenu.arrowIcon(St.Side.BOTTOM));

        this.add_actor(hbox);

        this.name = 'panelApplications';

        this.label_actor = this._label;

        this._showingId = Main.overview.connect('showing', () => {

            this.add_accessible_state (Atk.StateType.CHECKED);

        });

        this._hidingId = Main.overview.connect('hiding', () => {

            this.remove_accessible_state (Atk.StateType.CHECKED);

        });

        Main.layoutManager.connect('startup-complete',

                                   this._setKeybinding.bind(this));

        this._setKeybinding();

        this._desktopTarget = new DesktopTarget();

        this._desktopTarget.connect('app-dropped', () => {

            this.menu.close();

        });

        this._desktopTarget.connect('desktop-changed', () => {

            this._applicationsButtons.forEach(item => {

                item.setDragEnabled(this._desktopTarget.hasDesktop);

            });

        });

        this._tree = new GMenu.Tree({ menu_basename: 'applications.menu' });

        this._treeChangedId = this._tree.connect('changed',

                                                 this._onTreeChanged.bind(this));

        this._applicationsButtons = new Map();

        this.reloadFlag = false;

        this._createLayout();

        this._display();

        this._installedChangedId = appSys.connect('installed-changed',

                                                  this._onTreeChanged.bind(this));

    }

    _onTreeChanged() {

        if (this.menu.isOpen) {

            this._redisplay();

            this.mainBox.show();

        } else {

            this.reloadFlag = true;

        }

    }

    _createVertSeparator() {

        let separator = new St.DrawingArea({

            style_class: 'calendar-vertical-separator',

            pseudo_class: 'highlighted'

        });

        separator.connect('repaint', this._onVertSepRepaint.bind(this));

        return separator;

    }

    _onDestroy() {

        super._onDestroy();

        Main.overview.disconnect(this._showingId);

        Main.overview.disconnect(this._hidingId);

        appSys.disconnect(this._installedChangedId);

        this._tree.disconnect(this._treeChangedId);

        this._tree = null;

        let handler = Main.sessionMode.hasOverview ?

            Main.overview.toggle.bind(Main.overview) : null;

        Main.wm.setCustomKeybindingHandler('panel-main-menu',

                                           Shell.ActionMode.NORMAL |

                                           Shell.ActionMode.OVERVIEW,

                                           handler);

        this._desktopTarget.destroy();

    }

    _onMenuKeyPress(actor, event) {

        let symbol = event.get_key_symbol();

        if (symbol == Clutter.KEY_Left || symbol == Clutter.KEY_Right) {

            let direction = symbol == Clutter.KEY_Left ?

                Gtk.DirectionType.LEFT : Gtk.DirectionType.RIGHT;

            if (this.menu.actor.navigate_focus(global.stage.key_focus, direction, false))

                return true;

        }

        return super._onMenuKeyPress(actor, event);

    }

    _onVertSepRepaint(area) {

        let cr = area.get_context();

        let themeNode = area.get_theme_node();

        let [width, height] = area.get_surface_size();

        let stippleColor = themeNode.get_color('-stipple-color');

        let stippleWidth = themeNode.get_length('-stipple-width');

        let x = Math.floor(width / 2) + 0.5;

        cr.moveTo(x, 0);

        cr.lineTo(x, height);

        Clutter.cairo_set_source_color(cr, stippleColor);

        cr.setDash([1, 3], 1); // Hard-code for now

        cr.setLineWidth(stippleWidth);

        cr.stroke();

    }

    _onOpenStateChanged(menu, open) {

        if (open) {

            if (this.reloadFlag) {

                this._redisplay();

                this.reloadFlag = false;

            }

            this.mainBox.show();

        }

        super._onOpenStateChanged(menu, open);

    }

    _setKeybinding() {

        Main.wm.setCustomKeybindingHandler('panel-main-menu',

                                           Shell.ActionMode.NORMAL |

                                           Shell.ActionMode.OVERVIEW,

                                           () => this.menu.toggle());

    }

    _redisplay() {

        this.applicationsBox.destroy_all_children();

        this.categoriesBox.destroy_all_children();

        this._display();

    }

    _loadCategory(categoryId, dir) {

        let iter = dir.iter();

        let nextType;

        while ((nextType = iter.next()) != GMenu.TreeItemType.INVALID) {

            if (nextType == GMenu.TreeItemType.ENTRY) {

                let entry = iter.get_entry();

                let id;

                try {

                    id = entry.get_desktop_file_id(); // catch non-UTF8 filenames

                } catch (e) {

                    continue;

                }

                let app = appSys.lookup_app(id);

                if (!app)

                    app = new Shell.App({ app_info: entry.get_app_info() });

                if (app.get_app_info().should_show())

                    this.applicationsByCategory[categoryId].push(app);

            } else if (nextType == GMenu.TreeItemType.SEPARATOR) {

                this.applicationsByCategory[categoryId].push('separator');

            } else if (nextType == GMenu.TreeItemType.DIRECTORY) {

                let subdir = iter.get_directory();

                if (!subdir.get_is_nodisplay())

                    this._loadCategory(categoryId, subdir);

            }

        }

    }

    scrollToButton(button) {

        let appsScrollBoxAdj = this.applicationsScrollBox.get_vscroll_bar().get_adjustment();

        let appsScrollBoxAlloc = this.applicationsScrollBox.get_allocation_box();

        let currentScrollValue = appsScrollBoxAdj.get_value();

        let boxHeight = appsScrollBoxAlloc.y2 - appsScrollBoxAlloc.y1;

        let buttonAlloc = button.actor.get_allocation_box();

        let newScrollValue = currentScrollValue;

        if (currentScrollValue > buttonAlloc.y1 - 10)

            newScrollValue = buttonAlloc.y1 - 10;

        if (boxHeight + currentScrollValue < buttonAlloc.y2 + 10)

            newScrollValue = buttonAlloc.y2 - boxHeight + 10;

        if (newScrollValue != currentScrollValue)

            appsScrollBoxAdj.set_value(newScrollValue);

    }

    scrollToCatButton(button) {

        let catsScrollBoxAdj = this.categoriesScrollBox.get_vscroll_bar().get_adjustment();

        let catsScrollBoxAlloc = this.categoriesScrollBox.get_allocation_box();

        let currentScrollValue = catsScrollBoxAdj.get_value();

        let boxHeight = catsScrollBoxAlloc.y2 - catsScrollBoxAlloc.y1;

        let buttonAlloc = button.actor.get_allocation_box();

        let newScrollValue = currentScrollValue;

        if (currentScrollValue > buttonAlloc.y1 - 10)

            newScrollValue = buttonAlloc.y1 - 10;

        if (boxHeight + currentScrollValue < buttonAlloc.y2 + 10)

            newScrollValue = buttonAlloc.y2 - boxHeight + 10;

        if (newScrollValue != currentScrollValue)

            catsScrollBoxAdj.set_value(newScrollValue);

    }

    _createLayout() {

        let section = new PopupMenu.PopupMenuSection();

        this.menu.addMenuItem(section);

        this.mainBox = new St.BoxLayout({ vertical: false });

        this.leftBox = new St.BoxLayout({ vertical: true });

        this.applicationsScrollBox = new St.ScrollView({

            x_fill: true,

            y_fill: false,

            y_align: St.Align.START,

            style_class: 'apps-menu vfade'

        });

        this.applicationsScrollBox.set_policy(Gtk.PolicyType.NEVER, Gtk.PolicyType.AUTOMATIC);

        let vscroll = this.applicationsScrollBox.get_vscroll_bar();

        vscroll.connect('scroll-start', () => {

            this.menu.passEvents = true;

        });

        vscroll.connect('scroll-stop', () => {

            this.menu.passEvents = false;

        });

        this.categoriesScrollBox = new St.ScrollView({

            x_fill: true,

            y_fill: false,

            y_align: St.Align.START,

            style_class: 'vfade'

        });

        this.categoriesScrollBox.set_policy(Gtk.PolicyType.NEVER, Gtk.PolicyType.AUTOMATIC);

        vscroll = this.categoriesScrollBox.get_vscroll_bar();

        vscroll.connect('scroll-start', () => this.menu.passEvents = true);

        vscroll.connect('scroll-stop', () => this.menu.passEvents = false);

        this.leftBox.add(this.categoriesScrollBox, {

            expand: true,

            x_fill: true,

            y_fill: true,

            y_align: St.Align.START

        });

        this.applicationsBox = new St.BoxLayout({ vertical: true });

        this.applicationsScrollBox.add_actor(this.applicationsBox);

        this.categoriesBox = new St.BoxLayout({ vertical: true });

        this.categoriesScrollBox.add_actor(this.categoriesBox);

        this.mainBox.add(this.leftBox);

        this.mainBox.add(this._createVertSeparator(), {

            expand: false,

            x_fill: false,

            y_fill: true

        });

        this.mainBox.add(this.applicationsScrollBox, {

            expand: true,

            x_fill: true,

            y_fill: true

        });

        section.actor.add_actor(this.mainBox);

    }

    _display() {

        this._applicationsButtons.clear();

        this.mainBox.style = 'width: 35em;';

        this.mainBox.hide();

        //Load categories

        this.applicationsByCategory = {};

        this._tree.load_sync();

        let root = this._tree.get_root_directory();

        let categoryMenuItem = new CategoryMenuItem(this, null);

        this.categoriesBox.add_actor(categoryMenuItem.actor);

        let iter = root.iter();

        let nextType;

        while ((nextType = iter.next()) != GMenu.TreeItemType.INVALID) {

            if (nextType != GMenu.TreeItemType.DIRECTORY)

                continue;

            let dir = iter.get_directory();

            if (dir.get_is_nodisplay())

                continue;

            let categoryId = dir.get_menu_id();

            this.applicationsByCategory[categoryId] = [];

            this._loadCategory(categoryId, dir);

            if (this.applicationsByCategory[categoryId].length > 0) {

                let categoryMenuItem = new CategoryMenuItem(this, dir);

                this.categoriesBox.add_actor(categoryMenuItem.actor);

            }

        }

        //Load applications

        this._displayButtons(this._listApplications(null));

        let themeContext = St.ThemeContext.get_for_stage(global.stage);

        let scaleFactor = themeContext.scale_factor;

        let categoriesHeight = this.categoriesBox.height / scaleFactor;

        let height = Math.round(categoriesHeight) + MENU_HEIGHT_OFFSET;

        this.mainBox.style += `height: ${height}px`;

    }

    selectCategory(dir) {

        this.applicationsBox.get_children().forEach(c => {

            if (c._delegate instanceof PopupMenu.PopupSeparatorMenuItem)

                c._delegate.destroy();

            else

                this.applicationsBox.remove_actor(c);

        });

        if (dir)

            this._displayButtons(this._listApplications(dir.get_menu_id()));

        else

            this._displayButtons(this._listApplications(null));

    }

    _displayButtons(apps) {

        for (let i = 0; i < apps.length; i++) {

            let app = apps[i];

            let item;

            if (app instanceof Shell.App)

                item = this._applicationsButtons.get(app);

            else

                item = new PopupMenu.PopupSeparatorMenuItem();

            if (!item) {

                item = new ApplicationMenuItem(this, app);

                item.setDragEnabled(this._desktopTarget.hasDesktop);

                this._applicationsButtons.set(app, item);

            }

            if (!item.actor.get_parent())

                this.applicationsBox.add_actor(item.actor);

        }

    }

    _listApplications(categoryMenuId) {

        let applist;

        if (categoryMenuId) {

            applist = this.applicationsByCategory[categoryMenuId];

        } else {

            applist = new Array();

            let favorites = global.settings.get_strv('favorite-apps');

            for (let i = 0; i < favorites.length; i++) {

                let app = appSys.lookup_app(favorites[i]);

                if (app)

                    applist.push(app);

            }

        }

        return applist;

    }

});

let appsMenuButton;

function enable() {

    let index = Main.sessionMode.panel.left.indexOf('activities') + 1;

    appsMenuButton = new ApplicationsButton(index == 0);

    Main.panel.addToStatusArea('apps-menu', appsMenuButton, index, 'left');

}

function disable() {

    Main.panel.menuManager.removeMenu(appsMenuButton.menu);

    appsMenuButton.destroy();

}

function init() {

    ExtensionUtils.initTranslations();

}