using System;
using System.Windows;
using Chronos.Authentication;
using Chronos.Model;
using Chronos.Presentation.Core.VirtualDesktops;
using Chronos.Presentation.Core.Windows;
using Chronos.Presentation.ViewModel;
using nRoute.Components.Messaging;
using nRoute.Services;

namespace Chronos.ViewModel
{
  /// <summary>
  /// Login view view model class
  /// </summary>
  public sealed class LoginViewModel
      : WindowViewModel<UserLogin>
  {
    #region · Data Properties ·

    /// <summary>
    /// Gets or sets the user name
    /// </summary>
    public string UserId
    {
      get { return this.Entity.UserId; }
      set
      {
        if (this.Entity.UserId != value)
        {
          this.Entity.UserId = value;
          this.NotifyPropertyChanged(() => UserId);

          this.InquiryCommand.RequeryCanExecute();
        }
      }
    }

    /// <summary>
    /// Gets or sets the password
    /// </summary>
    public string Password
    {
      get { return this.Entity.Password; }
      set
      {
        if (this.Entity.Password != value)
        {
          this.Entity.Password = value;
          this.NotifyPropertyChanged(() => Password);

          this.InquiryCommand.RequeryCanExecute();
        }
      }
    }

    #endregion

    #region · Constructors ·

    /// <summary>
    /// Initializes a new instance of the <see cref="LoginViewModel"/> class
    /// </summary>
    public LoginViewModel()
      : base()
    {
    }

    #endregion

    #region · Overriden Methods ·

    public override bool CanClose()
    {
      return (this.ViewMode != ViewModeType.Busy);
    }

    public override void Close()
    {
      this.GetService<IVirtualDesktopManager>().CloseDialog();
      Application.Current.Shutdown();
    }

    protected override void InitializePropertyStates()
    {
      this.PropertyStates.Add(e => e.UserId);
      this.PropertyStates.Add(e => e.Password);
    }

    protected override void OnViewModeChanged()
    {
      base.OnViewModeChanged();

      if (this.PropertyStates.Count > 0)
      {
        this.PropertyStates[x => x.UserId].IsEditable = (this.ViewMode != ViewModeType.Busy);
        this.PropertyStates[x => x.Password].IsEditable = (this.ViewMode != ViewModeType.Busy);
      }
    }

    #endregion

    #region · Command Actions ·

    protected override bool CanInquiryData()
    {
      return (!String.IsNullOrEmpty(this.UserId) &&
              !String.IsNullOrEmpty(this.Password) &&
              this.ViewMode != ViewModeType.Busy);
    }

    protected override void OnInquiryAction(InquiryActionResult<UserLogin> result)
    {
      result.Data = this.Entity;
      result.Result = InquiryActionResultType.DataFetched;
    }

    protected override void OnInquiryActionComplete(InquiryActionResult<UserLogin> result)
    {
      if (result.Result == InquiryActionResultType.DataFetched)
      {
        Channel<AuthenticationInfo>.Public.OnNext(
            new AuthenticationInfo
            {
              Action = AuthenticationAction.LoggedIn,
              UserId = this.UserId
            }, true);

        ServiceLocator.GetService<IVirtualDesktopManager>().CloseDialog();
      }
      else if (result.Result == InquiryActionResultType.DataNotFound)
      {
        this.NotificationMessage = "Username and password do not match.";

        this.ViewMode = ViewModeType.Default;
      }
    }

    #endregion
  }
}