extension.js

const St = imports.gi.St;
const Main = imports.ui.main;
const Soup = imports.gi.Soup;
const Lang = imports.lang;
const Mainloop = imports.mainloop;
const Clutter = imports.gi.Clutter;
const PanelMenu = imports.ui.panelMenu;
const GLib = imports.gi.GLib;
const Gio = imports.gi.Gio;
const ExtensionUtils = imports.misc.extensionUtils;
const Me = ExtensionUtils.getCurrentExtension();

//"User-defined" constants. If you've stumbled upon this extension, these values are the most likely you'd like to change.
let LEFT_PADDING, RIGHT_PADDING, MAX_STRING_LENGTH, REFRESH_RATE, FRIENDLY_GREETING, ARTIST_FIRST, EXTENSION_PLACE, EXTENSION_INDEX, TOGGLE_WINDOW, gschema, lastExtensionPlace, lastExtensionIndex;
var settings, onLeftPaddingChanged, onRightPaddingChanged, onExtensionPlaceChanged, onExtensionIndexChanged, onToggleModeChanged;
let _httpSession;
let spMenu;

const SpotifyLabel = new Lang.Class({
	Name: 'SpotifyLabel',
	Extends: PanelMenu.Button,

	_init: function (settings) {
		this.parent(0.0, "Spotify Label", false);

		this.settings = settings;

		this.buttonText = new St.Label({
			text: _("Loading..."),
			style: "padding-left: " + this.settings.get_int('left-padding') + "px;"
				 + "padding-right: " + this.settings.get_int('right-padding') + "px; ",
			y_align: Clutter.ActorAlign.CENTER,
			x_align: Clutter.ActorAlign.FILL
		});

		// Listen for update of padding in settings
		onLeftPaddingChanged = this.settings.connect(
			'changed::left-padding',
			this._leftPaddingChanged.bind(this)
		);
		onRightPaddingChanged = this.settings.connect(
			'changed::right-padding',
			this._rightPaddingChanged.bind(this)
		);

		// Listen for changes in the toggle feature
		onToggleModeChanged = this.settings.connect(
			'changed::toggle-window',
			this._toggleModeChanged.bind(this)
		);
		this._toggleModeChanged(); // checks and connects the toggle button

		// Create a new layout, add the text and add the actor to the layout
		let topBox = new St.BoxLayout();
		topBox.add(this.buttonText);
		this.actor.add_actor(topBox);

		//Place the actor/label at the "end" (rightmost) position within the left box
		children = Main.panel._leftBox.get_children();
		Main.panel._leftBox.insert_child_at_index(this.actor, children.length)

		this._refresh();
	},

	// Update padding of this.buttonText according to new value set in settings
	_leftPaddingChanged: function() {
		this.buttonText.set_style("padding-left: " + this.settings.get_int('left-padding') + "px; "
				    			+ "padding-right: " + this.settings.get_int('right-padding') + "px; ");
	},
	_rightPaddingChanged: function() {
		this.buttonText.set_style("padding-left: " + this.settings.get_int('left-padding') + "px; "
				    			+ "padding-right: " + this.settings.get_int('right-padding') + "px; ");
	},

	// Update labelEventListener if toggle mode changes
	_toggleModeChanged: function () {
		spotifyWindow = nonSpotifyWindow = null;
		if (settings.get_boolean('toggle-window')) {
			this.toggleModeID = this.actor.connect('button-press-event', toggleWindow);
		} else {
			this.actor.disconnect(this.toggleModeID);
		}
	},

	//Defind the refreshing function and set the timeout in seconds
	_refresh: function () {
		this._loadData(this._refreshUI);
		this._removeTimeout();
		this._timeout = Mainloop.timeout_add_seconds(this.settings.get_int('refresh-rate'), Lang.bind(this, this._refresh));
		return true;
	},

	_loadData: function () {

		let [res, out, err, status] = [];
		try {
			//Use GLib to send a dbus request with the expectation of receiving an MPRIS v2 response.
			[res, out, err, status] = GLib.spawn_command_line_sync("dbus-send --print-reply --dest=org.mpris.MediaPlayer2.spotify /org/mpris/MediaPlayer2 org.freedesktop.DBus.Properties.Get string:org.mpris.MediaPlayer2.Player string:Metadata");
		}
		catch(err) {
			this._refreshUI("Error. Please check system logs.");
			global.log("spotifylabel: res: " + res + " -- status: " + status + " -- err:" + err);
			return;
		}

		var labelstring = parseSpotifyData(out.toString());
		this._refreshUI(labelstring);
	},

	_refreshUI: function (data) {
		let txt = data.toString();
		this.buttonText.set_text(txt);
	},

	_removeTimeout: function () {
		if (this._timeout) {
			Mainloop.source_remove(this._timeout);
			this._timeout = null;
		}
	},

	stop: function () {
		if (_httpSession !== undefined)
			_httpSession.abort();
		_httpSession = undefined;

		if (this._timeout)
			Mainloop.source_remove(this._timeout);
		this._timeout = undefined;

		this.menu.removeAll();
	}
}
);

function init() {
}

function enable() {

	// Load schema
	gschema = Gio.SettingsSchemaSource.new_from_directory(
        Me.dir.get_child('schemas').get_path(),
        Gio.SettingsSchemaSource.get_default(),
        false
    );

	// Load settings
    settings = new Gio.Settings({
        settings_schema: gschema.lookup('org.gnome.shell.extensions.spotifylabel', true)
	});

	// Mandatory for removing the spMenu from the correct location
	this.lastExtensionPlace = settings.get_string('extension-place');
	this.lastExtensionIndex = settings.get_int('extension-index');

	onExtensionPlaceChanged = this.settings.connect(
		'changed::extension-place',
		this.onExtensionLocationChanged.bind(this)
	);

	onExtensionIndexChanged = this.settings.connect(
		'changed::extension-index',
		this.onExtensionLocationChanged.bind(this)
	);

	let spotifyWindow, nonSpotifyWindow; // used by the switcher - greyed out in most editors

	spMenu = new SpotifyLabel(settings);
	Main.panel.addToStatusArea('sp-indicator', spMenu, settings.get_int('extension-index'), settings.get_string('extension-place'));
}

function disable() {
	this.settings.disconnect(onLeftPaddingChanged);
	this.settings.disconnect(onRightPaddingChanged);
	this.settings.disconnect(onExtensionPlaceChanged);
	this.settings.disconnect(onExtensionIndexChanged);
	this.settings.disconnect(onToggleModeChanged);

	spMenu.stop();
	spMenu.destroy();
}

// Removes spMenu from correct location and then adds it to new one
function onExtensionLocationChanged (settings, key) {
	const newExtensionPlace = this.settings.get_string('extension-place');
	const newExtensionIndex = this.settings.get_int('extension-index');

	if (this.lastExtensionPlace !== newExtensionPlace
			|| this.lastExtensionIndex !== newExtensionIndex) {

		switch (this.lastExtensionPlace) {
			case 'left':
				Main.panel._leftBox.remove_actor(spMenu.container);
				break;
			case 'center':
				Main.panel._centerBox.remove_actor(spMenu.container);
				break;
			default:
				Main.panel._rightBox.remove_actor(spMenu.container);
		}

		this.lastExtensionPlace = newExtensionPlace;
		this.lastExtensionIndex = newExtensionIndex;

		switch (newExtensionPlace) {
			case 'left':
				Main.panel._leftBox.insert_child_at_index(spMenu.container, newExtensionIndex);
				break;
			case 'center':
				Main.panel._centerBox.insert_child_at_index(spMenu.container, newExtensionIndex);
				break;
			default:
				Main.panel._rightBox.insert_child_at_index(spMenu.container, newExtensionIndex);
		}
	}
}

//Spotify uses MIPRIS v2, and as such the metadata fields are prefixed by 'xesam'
//We use this info to set our limits,and assume the data is properly escaped within quotes.
function parseSpotifyData(data) {
	if(!data)
		return createGreeting()

	var titleBlock = data.substring(data.indexOf("xesam:title"));
	var title = titleBlock.split("\"")[2]

	var artistBlock = data.substring(data.indexOf("xesam:artist"));
	var artist = artistBlock.split("\"")[2]

	//If the delimited '-' is in the title, we assume that it's remix, and encapsulate the end in brackets.
	if(title.includes("-"))
		title = title.replace("- ", "(") + ")";

	//If the name of either string is too long, cut off and add '...'
	if (artist.length > this.settings.get_int('max-string-length'))
		artist = artist.substring(0, this.settings.get_int('max-string-length')) + "...";

	if (title.length > this.settings.get_int('max-string-length'))
		title = title.substring(0, this.settings.get_int('max-string-length')) + "...";

	if (title.includes("xesam") || artist.includes("xesam"))
		return "Loading..."

	if (this.settings.get_boolean('artist-first')) {
    	return (artist + " - " + title);
  	}
  	return (title + " - " + artist);
}

function toggleWindow() {
	if (spotifyWindow && spotifyWindow.has_focus()){ // Spotify is focused
		if (nonSpotifyWindow)
			Main.activateWindow(nonSpotifyWindow);
		// else do nothing

	} else { // Spotify not focused, first press, multiple Spotify windows - all cases
		nonSpotifyWindow = spotifyWindow = null; // nonSpotifyWindow changes OR another spotifyWindow is active
		let windowActors = global.get_window_actors();
		for (let windowActor of windowActors) {
			if (typeof windowActor.get_meta_window === "function") {
				if (windowActor.get_meta_window().get_wm_class() === 'Spotify')
					spotifyWindow = windowActor.get_meta_window();
				else if (windowActor.get_meta_window().has_focus())
					nonSpotifyWindow = windowActor.get_meta_window();

				if (spotifyWindow && nonSpotifyWindow) // both found
					break;
			}
		}
		Main.activateWindow(spotifyWindow); // switch to Spotify
	}
}

let genres = ["DnB", "Synthwave", "Dubstep", "Pop", "House", "Hardstyle", "Rock", "8-bit", "Classical", "Electro"]
let currentGenre = genres[Math.floor(Math.random() * genres.length)];
let genreChanged = false;

function createGreeting() {
	if (!this.settings.get_boolean('friendly-greeting'))
		return ""

	var current_hour = new Date().getHours();

	if(new Date().getMinutes() % 5 == 0 && !genreChanged) {
		currentGenre = genres[Math.floor(Math.random() * genres.length)];
		genreChanged = true;
	}
	else if(new Date().getMinutes() % 5 != 0)
		genreChanged = false;

	if (current_hour < 4)
		return "A bit of late night coding and " + currentGenre + " music?";

	else if (current_hour < 7)
		return "You're up early, get at 'em!"

	else if (current_hour < 10)
		return "Start the day properly with some " + currentGenre + " music?";

	else if (current_hour < 12)
		return "What's todays soundtrack? A bit of " + currentGenre + "?";

	else if (current_hour == 12)
		return "" + currentGenre + " music and bit of lunch?";

	else if (current_hour < 15)
		return "Is that " + currentGenre + " music on the radio? Let's go!";

	else if (current_hour < 18)
		return "Isn't work progressing nicely with some " + currentGenre + " music?";

	else if (current_hour < 21)
		return "Free time and " + currentGenre + "? Name a better duo.";

	else
		return "Can " + currentGenre + " be considered a lullaby? Sure!"


}