﻿using System;
using System.Diagnostics;
using Windows.ApplicationModel;
using Windows.ApplicationModel.Activation;
using Windows.UI.ViewManagement;
using Windows.UI.Xaml;
using Windows.UI.Xaml.Controls;
using Windows.UI.Xaml.Media.Animation;
using Windows.UI.Xaml.Navigation;
using GalaSoft.MvvmLight.Threading;
using VkPeopleSearchApp.Domain;
using VkPeopleSearchApp.Services;
using VkPeopleSearchApp.View;

// The Blank Application template is documented at http://go.microsoft.com/fwlink/?LinkId=391641

namespace VkPeopleSearchApp
{
    /// <summary>
    /// Provides application-specific behavior to supplement the default Application class.
    /// </summary>
    public sealed partial class App : Application
    {
        private TransitionCollection _transitions;

        /// <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()
        {
            InitializeComponent();
            Suspending += OnSuspending;
        }

        /// <summary>
        /// Invoked when the application is launched normally by the end user.  Other entry points
        /// will be used when the application is launched to open a specific file, to display
        /// search results, and so forth.
        /// </summary>
        /// <param name="e">Details about the launch request and process.</param>
        protected override void OnLaunched(LaunchActivatedEventArgs e)
        {
#if DEBUG
            if (Debugger.IsAttached)
            {
                DebugSettings.EnableFrameRateCounter = true;
            }
#endif

            ApplicationView.GetForCurrentView().SetDesiredBoundsMode(ApplicationViewBoundsMode.UseCoreWindow);

            Settings.Instance.Load();

            ServiceLocator.Vkontakte.AccessToken = Settings.Instance.AccessToken;

            Frame rootFrame = Window.Current.Content as Frame;

            // 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();

                // TODO: change this value to a cache size that is appropriate for your application
                rootFrame.CacheSize = 1;

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

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

            if (rootFrame.Content == null)
            {
                // Removes the turnstile navigation for startup.
                if (rootFrame.ContentTransitions != null)
                {
                    _transitions = new TransitionCollection();
                    foreach (var c in rootFrame.ContentTransitions)
                    {
                        _transitions.Add(c);
                    }
                }

                rootFrame.ContentTransitions = null;
                rootFrame.Navigated += RootFrame_FirstNavigated;

                Type startPage = null;
                if (Settings.Instance.AccessToken != null && !Settings.Instance.AccessToken.HasExpired)
                    startPage = typeof (MainPage);
                else
                    startPage = typeof (LoginView);

                // When the navigation stack isn't restored navigate to the first page,
                // configuring the new page by passing required information as a navigation
                // parameter
                if (!rootFrame.Navigate(startPage, e.Arguments))
                {
                    throw new Exception("Failed to create initial page");
                }
            }

            DispatcherHelper.Initialize();
            // Ensure the current window is active
            Window.Current.Activate();
        }

        /// <summary>
        /// Restores the content transitions after the app has launched.
        /// </summary>
        /// <param name="sender">The object where the handler is attached.</param>
        /// <param name="e">Details about the navigation event.</param>
        private void RootFrame_FirstNavigated(object sender, NavigationEventArgs e)
        {
            var rootFrame = sender as Frame;
            rootFrame.ContentTransitions = _transitions ?? new TransitionCollection { new NavigationThemeTransition() };
            rootFrame.Navigated -= RootFrame_FirstNavigated;
        }

        /// <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)
        {
            Settings.Instance.Save();

            var deferral = e.SuspendingOperation.GetDeferral();

            // TODO: Save application state and stop any background activity
            deferral.Complete();
        }
    }
}