C.B.R.

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using CBR.Core.Helpers;
using System.Windows.Input;
using System.Net;
using System.Xml;
using System.Windows;
using System.Collections.ObjectModel;
using System.ComponentModel;
using System.Windows.Data;
using System.Windows.Markup;
using System.Windows.Controls;
using System.Reflection;
using System.IO;

namespace CBR.ViewModels
{
    public class HomeViewModel : ViewModelBase
    {
        #region ----------------CONSTRUCTOR----------------

        public HomeViewModel()
		{
		}

		#endregion

        private List<Headline> _Items = null;
        public ICollectionView ItemsSource
        {
            get
            {
                if (_Items != null)
                {
                    return CollectionViewSource.GetDefaultView(_Items);
                }
                else
                    return null;
            }
        }

        /// <summary>
        /// Gets or sets whether the view is loading headlines.
        /// </summary>
        private bool _IsLoading = false;

        public bool IsLoading
        {
            get { return _IsLoading; }
            set
            {
                if (_IsLoading != value)
                {
                    _IsLoading = value;
                    RaisePropertyChanged("IsLoading");
                }
            }
        }

        /// <summary>
        /// Gets or sets whether the view has got error.
        /// </summary>
        private bool _HasError = true;

        public bool HasError
        {
            get { return _HasError; }
            set
            {
                if (_HasError != value)
                {
                    _HasError = value;
                    RaisePropertyChanged("HasError");
                }
            }
        }

        public string ApplicationVersion
        {
            get { return Assembly.GetEntryAssembly().GetName().Version.ToString(); }
        }

        #region ---------------- COMMANDS ----------------

        #region forward command
        private ICommand forwardCommand;
        public ICommand ForwardCommand
        {
            get
            {
                if (forwardCommand == null)
                    forwardCommand = new DelegateCommand<string>(
                        delegate(string param)
                        {
                            Mediator.Instance.NotifyColleagues(ViewModelMessages.ContextCommand,
                                new CommandContext() { CommandName = param, CommandParameter = null });
                        },
                        delegate(string param)
                        {
                            return true;
                        });
                return forwardCommand;
            }
        }
        #endregion
        #endregion

        #region --------------------METHODS--------------------

        /// <summary>
        /// Load the feed.
        /// </summary>
        public void LoadFeed()
        {
			if (_Items == null)
			{
				Uri uri = null;

				if (!string.IsNullOrEmpty(CBR.Properties.Settings.Default.HeadlineUrl) &&
					Uri.TryCreate(CBR.Properties.Settings.Default.HeadlineUrl, UriKind.Absolute, out uri))
				{
					this.GetFeed(new Uri(CBR.Properties.Settings.Default.HeadlineUrl, UriKind.Absolute));
				}
			}
			else IsLoading = false;
        }

        /// <summary>
        /// Gets a feed from a Uri.
        /// </summary>
        /// <param name="uri">The Uri of the feed.</param>
        private void GetFeed(Uri uri)
        {
            IsLoading = true;
            WebClient client = new WebClient();
            client.OpenReadCompleted += new OpenReadCompletedEventHandler(this.Client_OpenReadCompleted);
            client.OpenReadAsync(uri);
            //Stream test = null;

            //try
            //{
            //    test = client.OpenRead(uri);

            //    if (test != null)
            //    {
            //        try
            //        {
            //            _Items = new List<Headline>();

            //            HeadlineCollection col = (HeadlineCollection)XmlHelper.Deserialize(test, typeof(HeadlineCollection));
            //            _Items.AddRange(col.HeadlineItems);

            //            RaisePropertyChanged("ItemsSource");

            //            HasError = false;
            //        }
            //        catch (XmlException exception)
            //        {
            //            HasError = true;
            //        }
            //    }
            //    else HasError = true;
            //}
            //catch( Exception err ) 
            //{
            //    HasError = true;
            //}

            //IsLoading = false;
        }

        /// <summary>
        /// Gets the response, and parses as a feed.
        /// </summary>
        /// <param name="sender">The web client.</param>
        /// <param name="e">Open Read Completed Event Args</param>
        private void Client_OpenReadCompleted(object sender, OpenReadCompletedEventArgs e)
        {
            if (e.Error == null && e.Result != null)
            {
                try
                {
                    _Items = new List<Headline>();

                    HeadlineCollection col = (HeadlineCollection)XmlHelper.Deserialize(e.Result, typeof(HeadlineCollection));
                    _Items.AddRange(col.HeadlineItems);

                    RaisePropertyChanged("ItemsSource");

                    HasError = false;
                }
                catch (XmlException exception)
                {
                    StringBuilder errorMessage = new StringBuilder();
                    errorMessage.AppendLine("An error occured:");
                    errorMessage.AppendLine("   " + exception.Message);
                    errorMessage.AppendLine("       " + exception.StackTrace);
                    HasError = true;
                }
            }
            else if (e.Error != null)
            {
                StringBuilder errorMessage = new StringBuilder();
                errorMessage.AppendLine("An error occured:");
                errorMessage.AppendLine("   " + e.Error.Message);
                errorMessage.AppendLine("       " + e.Error.StackTrace);
                HasError = true;
            }

            IsLoading = false;
        }
        
        #endregion
    }
}