/* Mailnag - GNOME-Shell extension frontend
*
* Copyright 2013 - 2019 Patrick Ulbrich <zulu99@gmx.net>
*
* 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 2 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, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston,
* MA 02110-1301, USA.
*/

const Main = imports.ui.main;
const Gio = imports.gi.Gio;
const GLib = imports.gi.GLib;
const ExtensionUtils = imports.misc.extensionUtils;
const Me = ExtensionUtils.getCurrentExtension();
const Convenience = Me.imports.convenience;
const Indicator = Me.imports.indicator;
const Opts = Me.imports.opts;

const AVATAR_ICON_SIZE = 38;

const SHOW_AVATARS_KEY					= 'show-avatars';
const MAX_VISIBLE_MAILS_KEY				= 'max-visible-mails';
const SHOW_DATES_KEY					= 'show-dates';
const SHOW_MARK_ALL_AS_READ_BUTTON_KEY	= 'show-mark-all-as-read-button';
const SHOW_CHECK_FOR_MAIL_BUTTON_KEY	= 'show-check-for-mail-button';
const SHOW_SETTINGS_BUTTON_KEY			= 'show-settings-button';
const SHOW_QUIT_BUTTON_KEY				= 'show-quit-button';
const GROUP_BY_ACCOUNT_KEY				= 'group-by-account';
const REMOVE_INDICATOR_KEY				= 'remove-indicator';

const KeyActionMap = new Map([
	[ SHOW_MARK_ALL_AS_READ_BUTTON_KEY,	Opts.ACTION_FLAGS.MARK_ALL_AS_READ ],
	[ SHOW_CHECK_FOR_MAIL_BUTTON_KEY,	Opts.ACTION_FLAGS.CHECK_FOR_MAIL ],
	[ SHOW_SETTINGS_BUTTON_KEY,			Opts.ACTION_FLAGS.SETTINGS ],
	[ SHOW_QUIT_BUTTON_KEY,				Opts.ACTION_FLAGS.QUIT ]
]);

const MailnagIface =
'<node>\
	<interface name="mailnag.MailnagService">\
		<method name="GetMails">\
			<arg type="aa{sv}" direction="out" />\
		</method>\
		<method name="GetMailCount">\
			<arg type="u" direction="out" />\
		</method>\
		<method name="Shutdown" />\
		<method name="CheckForMails" />\
		<method name="MarkMailAsRead">\
			<arg type="s" direction="in" />\
		</method>\
		<signal name="MailsAdded">\
			<arg type="aa{sv}" />\
			<arg type="aa{sv}" />\
		</signal>\
		<signal name="MailsRemoved">\
			<arg type="aa{sv}" />\
		</signal>\
	</interface>\
</node>';

const MailnagDbus = Gio.DBusProxy.makeProxyWrapper(MailnagIface);

var MailnagExtension = class {
	constructor(options) {
		
		this._mails = [];
		this._opts = options;
		this._indicator = null;
		
		this._proxy = new MailnagDbus(Gio.DBus.session,
			'mailnag.MailnagService', '/mailnag/MailnagService');
			
		this._onMailsAddedId = this._proxy.connectSignal('MailsAdded', this._onMailsAdded.bind(this));
		this._onMailsRemovedId = this._proxy.connectSignal('MailsRemoved', this._onMailsRemoved.bind(this));
		
		// TODO : what if Mailnag sends a MailsAdded signal here or after GetMailsRemote()
		// (should happen *extremely* rarely)?
		// Is it possible to prevent the extension from notifying twice?
		
		// Mailnag possibly fired a 'MailsAdded' signal before this extension was started,
		// so check if Mailnag fetched mails already and pull them manually.
		this._proxy.GetMailsRemote(([mails], error) => {
				if (!error) {
					if ((mails.length > 0) || !this._opts.removeIndicator) {
						this._handle_new_mails(mails, mails);
					}
				}
			});
	}
	
	_onMailsAdded(proxy, sender, [new_mails, all_mails]) {
		this._handle_new_mails(new_mails, all_mails);
	}
	
	_onMailsRemoved(proxy, sender, [remaining_mails]) {
		// TODO : not only support removal of *all* mails
		if (remaining_mails.length == 0) {
			this._mails = [];
			
			if (this._indicator != null) {
				if ((this._mails.length == 0) && this._opts.removeIndicator) {
					this._destroyIndicator();
				} else {
					this._indicator.setMails(this._mails);
				}
			}
		}
	}
	
	_handle_new_mails(new_mails, all_mails) {
		this._mails = all_mails;
		
		if (this._indicator == null) {
			this._createIndicator();
		} else {
			this._indicator.setMails(all_mails);
		}
	}
	
	_createIndicator() {
		this._indicator = new Indicator.MailnagIndicator(this._opts, this);
		this._indicator.setMails(this._mails);
		Main.panel.addToStatusArea('mailnag-indicator', this._indicator, 0);
	}
	
	_destroyIndicator() {
		if (this._indicator != null) {
			this._indicator.destroy();
			this._indicator = null;
		}
	}
	
	markMailAsRead(mail_id) {
		// Find the mail object with the specified mail_id
		let idx = -1;
		for (let i = 0; i < this._mails.length; i++) {
			let [id, size] = this._mails[i]['id'].get_string();
			if (id == mail_id) {
				idx = i;
				break;
			}
		}
		
		// There is no mail object with the specified mail_id -> return
		if (idx == -1)
			return;
		
		// Remove mail from local mail list
		this._mails.splice(idx, 1);
		
		// Notify the Mailnag daemon to mark the mail as read
		this._proxy.MarkMailAsReadRemote(mail_id, (result, error) => {
			if (error) {
				log("Error: markMailAsReadRemote() failed.");
			}
		});
		
		// Update Panel Indicator		
		if ((this._mails.length == 0) && this._opts.removeIndicator) {
			this._destroyIndicator();
		} else {
			if (this._indicator != null)
				this._indicator.setMails(this._mails);
		}
	}
	
	markAllMailsAsRead() {
		// TODO: add a markAllMailsAsRead() method to the DBus interface
		for (let i = 0; i < this._mails.length; i++) {
			let [id, size] = this._mails[i]['id'].get_string();
		
			// Notify the Mailnag daemon to mark the mail as read
			this._proxy.MarkMailAsReadRemote(id, (result, error) => {
				if (error) {
					log("Error: markMailAsReadRemote() failed.");
				}
			});
		}
		
		this._mails = [];
		
		if (this._opts.removeIndicator) {
			this._destroyIndicator();
		} else {
			if (this._indicator != null)
				this._indicator.setMails(this._mails);
		}
	}
	
	checkForMails() {
		this._proxy.CheckForMailsRemote((result, error) => {
			if (error) {
				log("Error: checkForMailsRemote() failed.");
			}
		});
	}
	
	shutdown() {
		this._proxy.ShutdownRemote((result, error) => {
			if (error) {
				log("Error: shutdownRemote() failed.");
			}
		});
	}
	
	dispose() {
		if (this._onMailsAddedId > -1) {
			this._proxy.disconnectSignal(this._onMailsAddedId);
			this._onMailsAddedId = -1;
		}
		
		if (this._onMailsRemovedId > -1) {
			this._proxy.disconnectSignal(this._onMailsRemovedId);
			this._onMailsRemovedId = -1;
		}
		
		this._destroyIndicator();
	}
};

function aggregateAvatarsAsync(completedCallback) {
	let aggregator = "aggregate-avatars";
	let result = null;
	let avatars = {};

	try {
		result = GLib.spawn_async_with_pipes(
			null, [aggregator], 
			null, GLib.SpawnFlags.SEARCH_PATH | 
					GLib.SpawnFlags.DO_NOT_REAP_CHILD, null);
	} catch (ex) {
		try {
			result = GLib.spawn_async_with_pipes(
				Me.path, [aggregator], 
				null, GLib.SpawnFlags.DO_NOT_REAP_CHILD, null);
		} catch (ex) {
			logError(ex, "Failed to spawn '%s'".format(aggregator));
		}
	}

	if (result == null) {
		completedCallback(avatars);
	} else {
		let [res, pid, stdin_fd, stdout_fd, stderr_fd] = result;		
		let stdout = new Gio.DataInputStream({ 
				base_stream: new Gio.UnixInputStream({ fd: stdout_fd, close_fd: true })});

		GLib.close(stdin_fd);
		GLib.close(stderr_fd);

		let childWatch = GLib.child_watch_add(GLib.PRIORITY_DEFAULT, pid, 
			(pid, status, requestObject) => {
				let [out, size] = stdout.read_line(null);

				if (size > 0) {
					let lst = out.toString().split(";");
					for (let i = 0; i < lst.length; i += 2) {
						let email = lst[i].toLowerCase();
						let avatarFile = lst[i + 1];
						avatars[email] = avatarFile;
					}
				}

				stdout.close(null);
				GLib.source_remove(childWatch);
				completedCallback(avatars);
			});
	}
}

function createExt(s, avatars) {
	let opts = new Opts.Options();
	
	opts.maxVisibleMails 		= s.get_int(MAX_VISIBLE_MAILS_KEY);
	opts.showDates				= s.get_boolean(SHOW_DATES_KEY);
	opts.groupMailsByAccount	= s.get_boolean(GROUP_BY_ACCOUNT_KEY);
	opts.removeIndicator		= s.get_boolean(REMOVE_INDICATOR_KEY);
	opts.avatars				= avatars;
	opts.avatarSize				= AVATAR_ICON_SIZE;
	opts.menuActions			= Opts.ACTION_FLAGS.NONE;
	
	for ([k, v] of KeyActionMap) {
		if (s.get_boolean(k))
			opts.menuActions |= v;
	}
	
	return new MailnagExtension(opts);
}

let ext = null;
let watch_id = -1;
let settings = null;
let cachedAvatars = null;
let reloadInProgress = false;

function init() {
}

function enable() {	
	settings = Convenience.getSettings();
	
	// Register changed handler for gsettings.
	// (Restarts the extension if settings
	// have been changed, e.g. via prefs.js)
	settings.connect('changed', (settings, key) => {
		if ((ext != null) && !reloadInProgress) {
			ext.dispose();

			if ((cachedAvatars == null) && (key == SHOW_AVATARS_KEY) && settings.get_boolean(key)) {
				reloadInProgress = true;
				aggregateAvatarsAsync((avatars) => {
						cachedAvatars = avatars;
						ext = createExt(settings, avatars);
						reloadInProgress = false;
					});
			} else {							
				ext = createExt(settings, settings.get_boolean(SHOW_AVATARS_KEY) ? cachedAvatars : {});
			}
		}
	});

	// Register dbus watch handlers - create the extension 
	// if the Mailnag daemon is running / remove it if the daemon is gone.
	watch_id = Gio.DBus.session.watch_name('mailnag.MailnagService', Gio.BusNameWatcherFlags.NONE,
		(owner) => {
			if (settings.get_boolean(SHOW_AVATARS_KEY)) {
				aggregateAvatarsAsync((avatars) => {
						cachedAvatars = avatars;
						ext = createExt(settings, avatars);
					});
			} else {
				ext = createExt(settings, {});
			}
		},
		(owner) => {
			if (ext != null) {
				ext.dispose();
				ext = null;
			}
		});
}

function disable() {
	if (watch_id > -1) {
		// TODO : test: does this call the function (owner) callback, so ext.dispose() is called twice?
		Gio.DBus.session.unwatch_name(watch_id);
		watch_id = -1;
	}
	
	cachedAvatars = null;
	reloadInProgress = false;
	
	if (settings != null) {
		settings.run_dispose();
		settings = null;
	}
	
	if (ext != null) {
		ext.dispose();
		ext = null;
	}
}
