using Prism.Regions;
using Syncfusion.UI.Xaml.NavigationDrawer;
using System;
using System.Collections.Generic;
using System.Collections.Specialized;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.Windows;

namespace FATrace.WPLApp.RegionAdapter
{
    public class SfNavigationDrawerRegionAdapter : RegionAdapterBase<SfNavigationDrawer>
    {
        public SfNavigationDrawerRegionAdapter(IRegionBehaviorFactory regionBehaviorFactory)
        : base(regionBehaviorFactory)
        {
        }

        protected override void Adapt(IRegion region, SfNavigationDrawer regionTarget)
        {
            {
                //////Old Version

                //if (regionTarget == null)
                //    throw new ArgumentNullException(nameof(regionTarget));

                //bool contentIsSet = regionTarget.ContentView != null;
                //contentIsSet = contentIsSet || null != BindingOperations.GetBinding(regionTarget, ContentControl.ContentProperty);

                //if (contentIsSet)
                //    throw new InvalidOperationException("ContentControlHasContentException");

                //region.ActiveViews.CollectionChanged += delegate
                //{
                //    regionTarget.ContentView = region.ActiveViews.FirstOrDefault();
                //};

                //region.Views.CollectionChanged +=
                //(sender, e) =>
                //{
                //    if (e.Action == NotifyCollectionChangedAction.Add && region.ActiveViews.Count() == 0)
                //    {
                //        region.Activate(e.NewItems[0]);
                //    }
                //};
            }


            //New Version
            if (region == null)
            {
                throw new ArgumentNullException(nameof(region));
            }

            if (regionTarget == null)
            {
                throw new ArgumentNullException(nameof(regionTarget));
            }

            // 处理活动视图变化 - 这是界面切换的关键
            region.ActiveViews.CollectionChanged += (s, e) =>
            {
                // 当有视图被激活时，将其设置为ContentView
                if (e.Action == NotifyCollectionChangedAction.Add && e.NewItems != null && e.NewItems.Count > 0)
                {
                    regionTarget.ContentView = e.NewItems[0] as FrameworkElement;
                }
            };

            // 处理视图集合变化
            region.Views.CollectionChanged += (s, e) =>
            {
                // 当添加新视图且没有活动视图时，自动激活它
                if (e.Action == NotifyCollectionChangedAction.Add &&
                    e.NewItems != null &&
                    e.NewItems.Count > 0 &&
                    region.ActiveViews.Count() == 0)
                {
                    region.Activate(e.NewItems[0]);
                }
            };


        }

        protected override IRegion CreateRegion()
        {
            return new SingleActiveRegion();
            //return new Region();
        }
    }
}