using System;
using System.ComponentModel;
using Caliburn.Services;
using Caliburn.Views;

namespace Caliburn.Presenters
{
    public interface IHostedPresenter
    {
        object CurrentView { get; set; }
    }

    public abstract class HostedPresenter : IHostedPresenter, INotifyPropertyChanged
    {
        private object _currentView;

        public virtual object CurrentView
        {
            get { return _currentView; }
            set { _currentView = value; OnPropertyChanged("CurrentView"); }
        }

        public virtual void ChangeView(string viewKey)
        {
            DI.Resolve<IViewManager>().ChangeView(this, viewKey);
        }

        public virtual void ChangeView(Type viewType)
        {
            DI.Resolve<IViewManager>().ChangeView(this, viewType);
        }

        #region INotifyPropertyChanged Members

        public event PropertyChangedEventHandler PropertyChanged;

        protected virtual void OnPropertyChanged(string propertyName)
        {
            if (PropertyChanged != null)
                PropertyChanged(this, new PropertyChangedEventArgs(propertyName));
        }

        #endregion
    }
}