using System;
using System.Windows;

namespace Hardcodet.Wpf.TaskbarNotification
{
    /// <summary>
    /// Helper class used by routed events of the
    /// <see cref="TaskbarIcon"/> class.
    /// </summary>
    internal static class RoutedEventHelper
    {
        #region RoutedEvent Helper Methods

        /// <summary>
        /// A static helper method to raise a routed event on a target UIElement or ContentElement.
        /// </summary>
        /// <param name="target">UIElement or ContentElement on which to raise the event</param>
        /// <param name="args">RoutedEventArgs to use when raising the event</param>
        internal static void RaiseEvent(DependencyObject target, RoutedEventArgs args)
        {
            var uiElement = target as UIElement;
            if (uiElement != null)
            {
                uiElement.RaiseEvent(args);
            }
            else
            {
                var contentElement = target as ContentElement;
                if (contentElement != null)
                {
                    contentElement.RaiseEvent(args);
                }
            }
        }

        /// <summary>
        /// A static helper method that adds a handler for a routed event 
        /// to a target UIElement or ContentElement.
        /// </summary>
        /// <param name="element">UIElement or ContentElement that listens to the event</param>
        /// <param name="routedEvent">Event that will be handled</param>
        /// <param name="handler">Event handler to be added</param>
        internal static void AddHandler(DependencyObject element, RoutedEvent routedEvent, Delegate handler)
        {
            var uie = element as UIElement;
            if (element != null && uie != null)
            {
                uie.AddHandler(routedEvent, handler);
            }
            else
            {
                var ce = element as ContentElement;
                if (element != null && ce != null)
                {
                    ce.AddHandler(routedEvent, handler);
                }
            }
        }

        /// <summary>
        /// A static helper method that removes a handler for a routed event 
        /// from a target UIElement or ContentElement.
        /// </summary>
        /// <param name="element">UIElement or ContentElement that listens to the event</param>
        /// <param name="routedEvent">Event that will no longer be handled</param>
        /// <param name="handler">Event handler to be removed</param>
        internal static void RemoveHandler(DependencyObject element, RoutedEvent routedEvent, Delegate handler)
        {
            var uie = element as UIElement;
            if (uie != null)
            {
                uie.RemoveHandler(routedEvent, handler);
            }
            else
            {
                var ce = element as ContentElement;
                if (ce != null)
                {
                    ce.RemoveHandler(routedEvent, handler);
                }
            }
        }

        #endregion
    }
}