using StockPortfolio.Common;
using System;
using System.Collections.Generic;
using System.Text;
using Windows.UI.Xaml.Controls;
using Windows.UI.Xaml.Navigation;

namespace StockPortfolio
{
    public interface PageBase
    {
        //private readonly NavigationHelper navigationHelper;
       // private readonly ObservableDictionary defaultViewModel = new ObservableDictionary();
        public readonly NavigationHelper NavigationHelper { get; private set; }
        public PageBase(Page page)
        {

            this.NavigationHelper = new NavigationHelper(page);
            this.NavigationHelper.LoadState += this.NavigationHelper_LoadState;
            this.NavigationHelper.SaveState += this.NavigationHelper_SaveState;
        } 

        /// <summary>
        /// Gets the <see cref="NavigationHelper"/> associated with this <see cref="Page"/>.
        /// </summary>
        //public NavigationHelper NavigationHelper
        //{
        //    get { return this.navigationHelper; }
        //}


        /// <summary>
        /// Populates the page with content passed during navigation.  Any saved state is also
        /// provided when recreating a page from a prior session.
        /// </summary>
        /// <param name="sender">
        /// The source of the event; typically <see cref="NavigationHelper"/>
        /// </param>
        /// <param name="e">Event data that provides both the navigation parameter passed to
        /// <see cref="Frame.Navigate(Type, object)"/> when this page was initially requested and
        /// a dictionary of state preserved by this page during an earlier
        /// session.  The state will be null the first time a page is visited.</param>
        private  async void NavigationHelper_LoadState(object sender, LoadStateEventArgs e)
        {
            // TODO: Create an appropriate data model for your problem domain to replace the sample data
            //var item = await SampleDataSource.GetItemAsync((string)e.NavigationParameter);
            //this.DefaultViewModel["Item"] = item;
        }

        /// <summary>
        /// Preserves state associated with this page in case the application is suspended or the
        /// page is discarded from the navigation cache.  Values must conform to the serialization
        /// requirements of <see cref="SuspensionManager.SessionState"/>.
        /// </summary>
        /// <param name="sender">The source of the event; typically <see cref="NavigationHelper"/></param>
        /// <param name="e">Event data that provides an empty dictionary to be populated with
        /// serializable state.</param>
        private  void NavigationHelper_SaveState(object sender, SaveStateEventArgs e)
        {
            // TODO: Save the unique state of the page here.
        }

        #region NavigationHelper registration

        /// <summary>
        /// The methods provided in this section are simply used to allow
        /// NavigationHelper to respond to the page's navigation methods.
        /// <para>
        /// Page specific logic should be placed in event handlers for the
        /// <see cref="NavigationHelper.LoadState"/>
        /// and <see cref="NavigationHelper.SaveState"/>.
        /// The navigation parameter is available in the LoadState method
        /// in addition to page state preserved during an earlier session.
        /// </para>
        /// </summary>
        /// <param name="e">Event data that describes how this page was reached.</param>
        protected virtual void OnNavigatedTo(NavigationEventArgs e)
        {
            this.NavigationHelper.OnNavigatedTo(e);
        }

        protected virtual void OnNavigatedFrom(NavigationEventArgs e)
        {
            this.NavigationHelper.OnNavigatedFrom(e);
        }
        
        #endregion
    }
}