using System.Collections;
using System.Windows;
using Caliburn.Messaging;
using Caliburn.Services;

namespace Caliburn.Views
{
    public class View
    {
        public static readonly DependencyProperty MessagesProperty
            = DependencyProperty.RegisterAttached("Messages", typeof(object), typeof(View),
                                                  new PropertyMetadata(OnMessagesChanged));

        public static void SetMessages(DependencyObject dependencyObject, object value)
        {
            AddMessages(dependencyObject, value);
        }

        private static void OnMessagesChanged(DependencyObject dependencyObject,
                                              DependencyPropertyChangedEventArgs e)
        {
            if (e.NewValue != e.OldValue) AddMessages(dependencyObject, e.NewValue);
        }

        private static void AddMessages(DependencyObject source, object value)
        {
            IViewManager viewManager = DI.Resolve<IViewManager>();
            MessageBase message = value as MessageBase;

            if (message != null) viewManager.AddMessageSource(source, message);
            else
            {
                string actionName = value as string;

                if (actionName != null)
                {
                    ActionMessage actionMessage = new ActionMessage();
                    actionMessage.Action = actionName;
                    viewManager.AddMessageSource(source, actionMessage);
                }
                else
                {
                    IEnumerable messages = value as IEnumerable;

                    if (messages != null)
                    {
                        foreach (MessageBase m in messages)
                        {
                            viewManager.AddMessageSource(source, m);
                        }
                    }
                }
            }
        }
    }
}