using System;
using CoreGraphics;
using Foundation;
using UIKit;

namespace Shared
{
    public class MusicVerticalScrolViewLayout:ViewGroup
    {
		/// <summary>
		/// 构造函数
		/// </summary>
		public MusicVerticalScrolViewLayout()
		{
			viewGroup = new MyMusicVerticalScrolViewLayout(this) { };
            
			viewGroup.AddGestureRecognizer(new MyUILongPressGestureRecognizer(sender =>
                {
                    (sender as MyUILongPressGestureRecognizer).musicVerticalScrolViewLayout?.uiViewLongPressed(sender);
                })
            { MinimumPressDuration = 1.0f,musicVerticalScrolViewLayout=this });
			realViewGroup = viewGroup;
		}

        class MyUILongPressGestureRecognizer : UILongPressGestureRecognizer
        {
            [Weak] internal MusicVerticalScrolViewLayout musicVerticalScrolViewLayout;
            public MyUILongPressGestureRecognizer(Action<UILongPressGestureRecognizer> action) : base(action)
            {
                
            }
        }

        public override void AddChidren(View view)
        {
            base.AddChidren(view);
            int maxHeight = 0;
            foreach (View tempView in viewList)
            {
                if (maxHeight < tempView.Bottom)
                {
                    maxHeight = tempView.Bottom;
                }
            }
            (realViewGroup as MyMusicVerticalScrolViewLayout).ContentSize = new CGSize(Width, maxHeight < realViewGroup.Frame.Height ? (realViewGroup.Frame.Height + 1) : maxHeight);
        }

		/// <summary>
		/// 根据点击位置找出点击到的视图
		/// </summary>
		/// <returns>The view of point.</returns>
		/// <param name="point">Point.</param>
		/// <param name="uiview">Uiview.</param>
		UIView replaceUIViewOfPoint(CGPoint point, UIView uiview)
		{
            //第一个是背景图
            for (int i = 1; i < realViewGroup.Subviews.Length; i++)
			{
                var tempUIView = realViewGroup.Subviews[i];
				if (tempUIView != uiview)
				{
					if (tempUIView.Frame.Contains(point))
					{
                        return tempUIView;
					}
				}
			}
            return null;
		}

        /// <summary>
        /// 
        /// </summary>
        public Action<View, View> ReplaceChanged;
		/// <summary>
        /// 长按事件
        /// </summary>
        public Action<View> LongPressAction;

        /// <summary>
        /// 根据点击位置找出点击到的视图
        /// </summary>
        /// <returns>返回点击到的视图</returns>
        /// <param name="point">当前点击位置</param>
        UIView selectedUIViewOfPoint(CGPoint point)
        {
            foreach (UIView uiView in realViewGroup.Subviews)
            {
                if (uiView.GetType() != typeof(UIImageView) && uiView.Frame.Contains(point))
                {
                    return uiView;
                }
            }
            return null;
        }
		CGPoint originPoint;
		UIView selectedUIView,replaceUIView;
        bool isFirst;
        void uiViewLongPressed(UILongPressGestureRecognizer sender)
        {
            //长按开始
            if (sender.State == UIGestureRecognizerState.Began)
            {
                //找出当前点击位置的视图
                selectedUIView = selectedUIViewOfPoint(sender.LocationInView(sender.View));
                if (selectedUIView == null)
                {
                    return;
                }
                viewGroup.BringSubviewToFront(selectedUIView);
                originPoint = selectedUIView.Center;
                isFirst = false;
                UIView.Animate(1.0f, () =>
                {
                    selectedUIView.Transform = CGAffineTransform.MakeScale(0.8f, 0.8f);
                    selectedUIView.Alpha = 0.7f;
                });
            }
            else if (sender.State == UIGestureRecognizerState.Changed)
            {
                if (selectedUIView == null)
                {
                    return;
                }
                //移动当前视图
                selectedUIView.Center = sender.LocationInView(sender.View);
                //获取当前视图进入了哪个视图的区域
                var temReplaceUIView = replaceUIViewOfPoint(selectedUIView.Center, selectedUIView);
                replaceUIView = temReplaceUIView;
                if (temReplaceUIView != null)
                {
                    if (isFirst)
                    {
                        return;
                    }
                    isFirst = true;
                    ////进入区域后切换位置
                    UIView.Animate(1.0f, () =>
                    {
                        temReplaceUIView.Transform = CGAffineTransform.MakeScale(1.1f, 1.1f);
                    }, () =>
                    {
                        temReplaceUIView.Transform = CGAffineTransform.MakeScale(1.0f, 1.0f);
                    });

                }
            }
            else if (sender.State == UIGestureRecognizerState.Ended)
            {
                if (selectedUIView == null)
                {
                    return;
                }
                View selectedView = null;
                foreach (View view in viewList)
                {
                    if (view.RealView == selectedUIView)
                    {
                        selectedView = view;
                        break;
                    }
                }

                if(selectedUIView!=null&&selectedUIView.Frame.Contains(originPoint)){
                    UIView.Animate(1.0f, () =>
                    {
                        selectedUIView.Transform = CGAffineTransform.MakeIdentity();
                        selectedUIView.Alpha = 1.0f;
                        selectedUIView.Center = originPoint;
                    });
                    return;
                }
                UIView.Animate(1.0f, () =>
                   {
                       selectedUIView.Transform = CGAffineTransform.MakeIdentity();
                       selectedUIView.Alpha = 1.0f;
                       selectedUIView.Center = originPoint;
                });

                if (replaceUIView == null)
                {
                    if (LongPressAction != null)
                    {
                        LongPressAction(selectedView);
                    }
                    return;
                }

                View replaceView = null;
                foreach (View view in viewList)
                {
                    if (view.RealView == replaceUIView)
                    {
                        replaceView = view;
                        break;
                    }
                }
                if (ReplaceChanged != null)
                {
                    ReplaceChanged(replaceView, selectedView);
                }
            }
        }

        /// <summary>
        /// 垂直方向滚动视图
        /// </summary>
        class MyMusicVerticalScrolViewLayout : UIScrollView
        {
            [Weak] View view;
            public MyMusicVerticalScrolViewLayout(View view)
            {
                this.view = view;
            }
            /// <summary>
            /// 点击开始
            /// </summary>
            /// <param name="touches">Touches.</param>
            /// <param name="evt">Evt.</param>
            public override void TouchesBegan(NSSet touches, UIEvent evt)
            {
                view?.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)
            {
                view?.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)
            {
                view?.TouchEvent(EventActions.Up, (touches.AnyObject as UITouch).LocationInView(this));
            }

            public override void TouchesCancelled(NSSet touches, UIEvent evt)
            {
                view?.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);
            }
        }
    }
}