using System;
using UIKit;
using CoreGraphics;
using Shared.IO;
using Foundation;

namespace Shared
{
	/// <summary>
	/// 位置布局，已经全面检查
	/// </summary>
	public class VerticalScrolViewLayout : ViewGroup
	{
		/// <summary>
		/// 构造函数
		/// </summary>
		public VerticalScrolViewLayout()
		{
			viewGroup = new MyVerticalScrolViewLayout(this) { };
           
			realViewGroup = viewGroup;
		}

        /// <summary>
        /// 垂直方向滚动视图
        /// </summary>
        class MyVerticalScrolViewLayout : UIScrollView
        {
            [Weak] VerticalScrolViewLayout verticalScrolViewLayout;
            public MyVerticalScrolViewLayout(VerticalScrolViewLayout verticalScrolViewLayout)
            {
                this.verticalScrolViewLayout = verticalScrolViewLayout;
                Scrolled += (sender, e) =>
                {
                   this.verticalScrolViewLayout?.ScrolledEventHandler?.Invoke(this, new MouseEventArgs { X = (float)(sender as MyVerticalScrolViewLayout).ContentOffset.X, Y = (float)(sender as MyVerticalScrolViewLayout).ContentOffset.Y });
                };
            }
            /// <summary>
            /// 点击开始
            /// </summary>
            /// <param name="touches">Touches.</param>
            /// <param name="evt">Evt.</param>
            public override void TouchesBegan(NSSet touches, UIEvent evt)
            {
                verticalScrolViewLayout?.TouchEvent(EventActions.Down, (touches.AnyObject as UITouch).LocationInView(this));
            }
            /// <summary>
            ///  移动
            /// </summary>
            /// <param name="touches">Touches.</param>
            /// <param name="evt">Evt.</param>
            public override void TouchesMoved(NSSet touches, UIEvent evt)
            {
                verticalScrolViewLayout?.TouchEvent(EventActions.Move, (touches.AnyObject as UITouch).LocationInView(this));
            }

            /// <summary>
            /// 点击弹起
            /// </summary>
            /// <param name="touches">Touches.</param>
            /// <param name="evt">Evt.</param>
            public override void TouchesEnded(NSSet touches, UIEvent evt)
            {
                verticalScrolViewLayout?.TouchEvent(EventActions.Up, (touches.AnyObject as UITouch).LocationInView(this));
            }

            public override void TouchesCancelled(NSSet touches, UIEvent evt)
            {
                verticalScrolViewLayout?.TouchEvent(EventActions.Cancel, (touches.AnyObject as UITouch).LocationInView(this));
            }
            /// <summary>
            /// 框架默认加了两个UIImageView ，这样可以去掉默认添加
            /// </summary>
            /// <param name="view">View.</param>
            public override void AddSubview(UIView view)
            {
                if (view.GetType() == typeof(UIImageView) && view.Tag != int.MinValue)
                {
                    return;
                }
                base.AddSubview(view);
            }
        }

        /// <summary>
        /// 增加控件
        /// </summary>
        /// <param name="view">子控件</param>
        public override void AddChidren(View view)
		{
			base.AddChidren(view);
			ReLocation();
		}

		/// <summary>
		/// 重新排位置及设备内容大小
		/// </summary>
		public virtual void ReLocation()
		{
			if (0 == viewList.Count)
			{
				return;
			}
            var frame1 = viewList[0].RealView.Frame;
			frame1.Y = 0;
			viewList[0].RealView.Frame = frame1;

			for (int i = 1; i < viewList.Count; i++)
			{
				var frame = viewList[i].RealView.Frame;
				frame.Y = viewList[i - 1].RealView.Frame.Bottom;
				viewList[i].RealView.Frame = frame;
			}

			(realViewGroup as MyVerticalScrolViewLayout).ContentSize = new CoreGraphics.CGSize(0, viewList[viewList.Count - 1].Bottom <= Height ? Height + 1 : viewList[viewList.Count - 1].Bottom);
		}

		/// <summary>
		/// 移除所有的视图
		/// </summary>
		public override void RemoveAll()
		{
			base.RemoveAll();

			ReLocation();
		}

		/// <summary>
		/// 移除当前视图
		/// </summary>
		/// <param name="view">当前视图</param>
		internal override void Remove(View view)
		{
			base.Remove(view);

			ReLocation();
		}

		/// <summary>
		/// 移除指定索引
		/// </summary>
		/// <param name="index">索引</param>
		public override void RemoveAt(int index)
		{
			base.RemoveAt(index);
			ReLocation();
		}

		/// <summary>
		/// 是否允许滑动
		/// </summary>
		/// <value><c>true</c> if scroll enabled; otherwise, <c>false</c>.</value>
		public bool ScrollEnabled
		{
			get
			{
				return (viewGroup as MyVerticalScrolViewLayout).ScrollEnabled;
			}
			set
			{
				(viewGroup as MyVerticalScrolViewLayout).ScrollEnabled = value;
			}
		}

		/// <summary>
		/// 是否正在滑动
		/// </summary>
		/// <value><c>true</c> if decelerating; otherwise, <c>false</c>.</value>
		public bool Decelerating
		{
			get
			{
				return (viewGroup as MyVerticalScrolViewLayout).Decelerating;
			}
		}

		/// <summary>
		/// 滑动事件
		/// </summary>
		public  EventHandler<MouseEventArgs> ScrolledEventHandler;

        /// <summary>
        /// 是否显示垂直滚动条
        /// </summary>

        public bool VerticalScrollBarEnabled
        {
            get
            {
                return (viewGroup as MyVerticalScrolViewLayout).ShowsVerticalScrollIndicator;
            }
            set
            {
                (viewGroup as MyVerticalScrolViewLayout).ShowsVerticalScrollIndicator = value;

            }
        }

    }




}