/*
 * Copyright (c) 2010-2020 Belledonne Communications SARL.
 *
 * This file is part of Linphone TutorialCS.
 *
 * 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/>.
 */

using _05_FileTransfer.Service;
using _05_FileTransfer.Views;
using Linphone;
using System;
using System.Diagnostics;
using System.Text;
using Windows.ApplicationModel;
using Windows.ApplicationModel.Activation;
using Windows.UI.Xaml;
using Windows.UI.Xaml.Controls;
using Windows.UI.Xaml.Navigation;

namespace _05_FileTransfer
{
	/// <summary>
	/// Provides application-specific behavior to supplement the default Application class.
	/// </summary>
	sealed partial class App : Application
	{
		private CoreService CoreService { get; } = CoreService.Instance;

		/// <summary>
		/// Initializes the singleton application object.  This is the first line of authored code
		/// executed, and as such is the logical equivalent of main() or WinMain().
		/// </summary>
		public App()
		{
			this.InitializeComponent();
			this.Suspending += OnSuspending;
		}

		/// <summary>
		/// Invoked when the application is launched normally by the end user.  Other entry points
		/// will be used such as when the application is launched to open a specific file.
		/// </summary>
		/// <param name="e">Details about the launch request and process.</param>
		protected override void OnLaunched(LaunchActivatedEventArgs e)
		{
			Frame rootFrame = Window.Current.Content as Frame;

			// Start Linphone
			LoggingService.Instance.LogLevel = LogLevel.Debug;
			LoggingService.Instance.Listener.OnLogMessageWritten = OnLog;

			CoreService.CoreStart(Windows.ApplicationModel.Core.CoreApplication.GetCurrentView().CoreWindow.Dispatcher);

			// Do not repeat app initialization when the Window already has content,
			// just ensure that the window is active
			if (rootFrame == null)
			{
				// Create a Frame to act as the navigation context and navigate to the first page
				rootFrame = new Frame();

				rootFrame.NavigationFailed += OnNavigationFailed;

				if (e.PreviousExecutionState == ApplicationExecutionState.Terminated)
				{
					//TODO: Load state from previously suspended application
				}

				// Place the frame in the current Window
				Window.Current.Content = rootFrame;
			}

			if (e.PrelaunchActivated == false)
			{
				if (rootFrame.Content == null)
				{
					// When the navigation stack isn't restored navigate to the first page,
					// configuring the new page by passing required information as a navigation
					// parameter
					rootFrame.Navigate(typeof(LoginPage), e.Arguments);
				}
				// Ensure the current window is active
				Window.Current.Activate();
			}
		}

		private void OnLog(LoggingService logService, string domain, LogLevel lev, string message)
		{
			StringBuilder builder = new StringBuilder();
			_ = builder.Append("Linphone-[").Append(lev.ToString()).Append("](").Append(domain).Append(")").Append(message);
			Debug.WriteLine(builder.ToString());
		}

		/// <summary>
		/// Invoked when Navigation to a certain page fails
		/// </summary>
		/// <param name="sender">The Frame which failed navigation</param>
		/// <param name="e">Details about the navigation failure</param>
		private void OnNavigationFailed(object sender, NavigationFailedEventArgs e)
		{
			throw new Exception("Failed to load Page " + e.SourcePageType.FullName);
		}

		/// <summary>
		/// Invoked when application execution is being suspended.  Application state is saved
		/// without knowing whether the application will be terminated or resumed with the contents
		/// of memory still intact.
		/// </summary>
		/// <param name="sender">The source of the suspend request.</param>
		/// <param name="e">Details about the suspend request.</param>
		private void OnSuspending(object sender, SuspendingEventArgs e)
		{
			var deferral = e.SuspendingOperation.GetDeferral();
			//TODO: Save application state and stop any background activity
			deferral.Complete();
		}
	}
}