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

const Clutter = imports.gi.Clutter;
const Mainloop = imports.mainloop;
const Meta = imports.gi.Meta;
const Shell = imports.gi.Shell;
const Tidy = imports.gi.Tidy;

const Button = imports.ui.button;
const Main = imports.ui.main;

const PANEL_HEIGHT = 32;
const TRAY_HEIGHT = 24;
const PANEL_BACKGROUND_COLOR = new Clutter.Color();
PANEL_BACKGROUND_COLOR.from_pixel(0xeeddccff);
const PRESSED_BUTTON_BACKGROUND_COLOR = new Clutter.Color();
PRESSED_BUTTON_BACKGROUND_COLOR.from_pixel(0xccbbaaff);

function Panel() {
    this._init();
}

Panel.prototype = {
    _init : function() {
        let global = Shell.Global.get();

        this._group = new Clutter.Group();

        let background = new Clutter.Rectangle({ color: PANEL_BACKGROUND_COLOR,
                                                 reactive: true,
                                                 width: global.screen_width+2,
                                                 height: PANEL_HEIGHT+1,
                                                 border_width: 1});
        background.set_position(-1, -1);
        this._group.add_actor(background);

        this.button = new Button.Button("Activities", PANEL_BACKGROUND_COLOR, PRESSED_BUTTON_BACKGROUND_COLOR, true, null, PANEL_HEIGHT-1);

        this._group.add_actor(this.button.button);

        this._grid = new Tidy.Grid({ height: TRAY_HEIGHT,
                                     valign: 0.5,
                                     end_align: true,
                                     column_gap: 2 })
        this._group.add_actor(this._grid);

        this._clock = new Clutter.Label({ font_name: "Sans Bold 16px",
                                          text: "" });
        this._grid.add_actor(this._clock);

        // Setting the anchor point at top right (north east) makes that portion of the
        // grid positioned at the position specified below.
        this._grid.set_anchor_point_from_gravity(Clutter.Gravity.NORTH_EAST);
        this._grid.set_position(global.screen_width - 2, (PANEL_HEIGHT - TRAY_HEIGHT) / 2);

        this._traymanager = new Shell.TrayManager({ bg_color: PANEL_BACKGROUND_COLOR });
        let me = this;
        // the anchor point needs to be updated each time the height/width of the content might have changed, because
        // it doesn't get updated on its own
        this._traymanager.connect('tray-icon-added',
            function(o, icon) {
                me._grid.add_actor(icon);
                /* bump the clock back to the end */
                me._grid.remove_actor(me._clock);
                me._grid.add_actor(me._clock);
                me._grid.move_anchor_point_from_gravity(Clutter.Gravity.NORTH_EAST);
            });
        this._traymanager.connect('tray-icon-removed',
            function(o, icon) {
                me._grid.remove_actor(icon);
                me._grid.move_anchor_point_from_gravity(Clutter.Gravity.NORTH_EAST);
            });
        this._traymanager.manage_stage(global.stage);

        // TODO: decide what to do with the rest of the panel in the overlay mode (make it fade-out, become non-reactive, etc.)
        // We get into the overlay mode on button-press-event as opposed to button-release-event because eventually we'll probably
        // have the overlay act like a menu that allows the user to release the mouse on the activity the user wants
        // to switch to.
        this.button.button.connect('button-press-event',
            function(o, event) {
                if (Main.overlay.visible)
                    Main.hide_overlay();
                else
                    Main.show_overlay();

                return true;
            });

        this._setStruts();
        global.screen.connect('notify::n-workspaces',
            function() {
                me._setStruts();
            });

        global.stage.add_actor(this._group);

        // Start the clock
        this._updateClock();
    },

    // Struts determine the area along each side of the screen that is reserved
    // and not available to applications
    _setStruts: function() {
        let global = Shell.Global.get();

        let struts = [
            new Meta.Strut({
                rect: {
                    x: 0,
                    y: 0,
                    width: global.screen_width,
                    height: PANEL_HEIGHT
                },
                side: Meta.Direction.TOP
            })
        ];

        let screen = global.screen;
        for (let i = 0; i < screen.n_workspaces; i++) {
            let workspace = screen.get_workspace_by_index(i);
            workspace.set_builtin_struts(struts);
        }
    },

    _updateClock: function() {
        let me = this;
        let display_date = new Date();
        let msec_remaining = 60000 - (1000 * display_date.getSeconds() +
                                      display_date.getMilliseconds());
        if (msec_remaining < 500) {
            display_date.setMinutes(display_date.getMinutes() + 1);
            msec_remaining += 60000;
        }
        this._clock.set_text(display_date.toLocaleFormat("%H:%M"));
        Mainloop.timeout_add(msec_remaining, function() {
            me._updateClock();
            return false;
        });
    },

    overlayHidden: function() {
        this.button.release();
    }
};