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

namespace Shared
{
    /// <summary>
    /// 位置布局
    /// </summary>
    public class HorizontalPages : ViewGroup
    {
        readonly MyHorizontalPages iosUIScrolView;

        //readonly UIPageControl iosUIPageControl;

   
        /// <summary>
        /// 页面变化事件
        /// </summary>
        public Action<HorizontalPages,int> PageChange;

        /// <summary>
        /// 垂直方向滚动视图
        /// </summary>
        class MyHorizontalPages : UIScrollView
        {
            nfloat beforeXScrollX;
            nfloat moveX;

            [Weak]  HorizontalPages HorizontalPages;
            //nfloat mLastX, mLastY, deltaX;
            public MyHorizontalPages(HorizontalPages HorizontalPages)
            {

                this.HorizontalPages = HorizontalPages;
                //this.ScrollEnabled = false;
                Scrolled += (s, e) =>
                {
                    moveX = this.ContentOffset.X - beforeXScrollX;              
                };

                DraggingStarted += (sender, e) =>
                {
                    beforeXScrollX = this.ContentOffset.X;
                };

                DecelerationStarted += (s, e) =>
                {
                    //var tempUIScrolView = s as MyHorizontalPages;
                    ////获取当前界面的索引
                    ////System.Console.WriteLine($"DecelerationStarted-------{tempUIScrolView.ContentOffset.X}");
                    //var tempPageIndex = Convert.ToInt32(tempUIScrolView.ContentOffset.X / (this.HorizontalPages.mScrollWidth));
                    //this.HorizontalPages.PageIndex = tempPageIndex;
                    GetMovePageIndex();

                };

                //DecelerationEnded += (s, e) =>
                //{
                //    Console.WriteLine("HorizontalPages DecelerationEnded");

                //};

                 DraggingEnded += (s, e) =>
                {
                 
                    var tempUIScrolView = s as MyHorizontalPages;
                    if (!e.Decelerate)
                    {
                        GetMovePageIndex();
                        ////System.Console.WriteLine($"DraggingEnded-------{tempUIScrolView.ContentOffset.X}");
                        //var tempPageIndex = Convert.ToInt32(tempUIScrolView.ContentOffset.X / (this.HorizontalPages.mScrollWidth));
                        //this.HorizontalPages.PageIndex = tempPageIndex;
                    }
                };
            }

            private void GetMovePageIndex() {

                if (mTouchSlop < Math.Abs(moveX))
                {
                    if (moveX < 0)
                    {
                        this.HorizontalPages.PageIndex -= 1;
                    }
                    else if (moveX > 0)
                    {
                        this.HorizontalPages.PageIndex += 1;
                    }
                }
                else
                {
                    this.HorizontalPages.PageIndex = this.HorizontalPages.PageIndex;
                }

            }


            /// <summary>
            /// 点击开始
            /// </summary>
            /// <param name="touches">Touches.</param>
            /// <param name="evt">Evt.</param>
            public override void TouchesBegan(NSSet touches, UIEvent evt)
            {
          
                HorizontalPages?.TouchEvent(EventActions.Down, (touches.AnyObject as UITouch).LocationInView(this));

                //CGPoint point = (touches.AnyObject as UITouch).LocationInView(this);
                ////记录点击的最新X坐标
                //mLastX = point.X;
                //bMove = false;
                //System.Console.WriteLine($"TouchesBegan-------{mLastX}");
            }

            int mTouchSlop = 20;
            bool bMove;
            /// <summary>
            ///  移动
            /// </summary>
            /// <param name="touches">Touches.</param>
            /// <param name="evt">Evt.</param>
            public override void TouchesMoved(NSSet touches, UIEvent evt)
            {


                HorizontalPages?.TouchEvent(EventActions.Move, (touches.AnyObject as UITouch).LocationInView(this));

                //CGPoint point = (touches.AnyObject as UITouch).LocationInView(this);
                //deltaX = point.X - mLastX;
                //if (Math.Abs(deltaX) >= mTouchSlop) {
                //    bMove = true;
                //}
                //System.Console.WriteLine($"deltaX-------{deltaX}");
        
            }
            /// <summary>
            /// 点击弹起
            /// </summary>
            /// <param name="touches">Touches.</param>
            /// <param name="evt">Evt.</param>
            public override void TouchesEnded(NSSet touches, UIEvent evt)
            {
                HorizontalPages?.TouchEvent(EventActions.Up, (touches.AnyObject as UITouch).LocationInView(this));

                //if (bMove)
                //{
                //    if (deltaX < 0)//左滑
                //    {
                //        this.HorizontalPages.PageIndex--;
                //    }
                //    else
                //    {
                //        this.HorizontalPages.PageIndex++;

                //    }
                //}
            }

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

                if (view.ToString().Contains("UIScrollViewScrollIndicator"))
                {
                    return;
                }
                base.AddSubview(view);
            }
        }

        /// <summary>
        /// 构造函数
        /// </summary>
        public HorizontalPages()
        {
            viewGroup = new UIView();
            iosUIScrolView = new MyHorizontalPages(this) {  };  
            realViewGroup = iosUIScrolView;
            //启动翻页功能
            //iosUIScrolView.PagingEnabled = true;
            iosUIScrolView.ShowsHorizontalScrollIndicator = false;
            viewGroup.AddSubview(iosUIScrolView);
            _PagePadding = Application.GetRealWidth(50);
            _RowPadding = Application.GetRealWidth(100);
            _TCBJ = Application.GetRealWidth(50);

        }

   

        // //两个Page之间的距离
        //int _PagePadding;
        //public int PagePadding
        //{
        //    get
        //    {
        //        return _PagePadding;
        //    }
        //    set
        //    {
        //        _PagePadding = value;
        //        ReLocation();
        //    }
        //}
        ////page的外边距
        //int _RowPadding;
        //public int RowPadding
        //{
        //    get
        //    {
        //        return _RowPadding;
        //    }
        //    set
        //    {
        //        _RowPadding = value;
        //        ReLocation();
        //    }
        //}
        /// <summary>
        /// 突出宽度
        /// </summary>
        //public int JMBJ


        //两个Page界面之间的距离
        int _PagePadding;
        /// <summary>
        /// 界面之间的边距
        /// </summary>
        public int JMBJ
        {
            get
            {
                return _PagePadding;
            }
            set
            {
                _PagePadding = value;
                _RowPadding = _TCBJ + _PagePadding;
                RefreshScrollWidth();
                ReLocation();
            }
        }

        //page的与手机屏幕的边距 = 突出宽度 + 两个Page之间的距离
        int _RowPadding;
        /// <summary>
        /// 突出宽度
        /// </summary>
        int _TCBJ;
        public int TCBJ
        {
            get
            {
                return _TCBJ;
            }
            set
            {
                _TCBJ = value;
                _RowPadding = _TCBJ + _PagePadding;
                RefreshScrollWidth();
                ReLocation();
            }
        }

        int mScrollWidth;
        int mPageWidth;
        private void RefreshScrollWidth()
        {
            mScrollWidth = (int)this.RealView.Frame.Width - 2 * _RowPadding + _PagePadding;
            mPageWidth = (int)this.RealView.Frame.Width - 2 * _RowPadding;

        }



        private void RefreshPageView() {
            //RefreshView();
            RefreshViewWithTransform3D();
        }

        //********************Transform3D 旋转效果方法**********************
        //默认25度
        nfloat transformAngle = (nfloat)(25 * Math.PI / 180.0);
        //旋转角度
        public int TransformAngle
        {
            set
            {
                transformAngle = (nfloat)(value * Math.PI / 180.0);
            }
        }

        //
        public void RefreshViewWithTransform3D()
        {
            if (iosUIScrolView.Subviews.Length <= 0) return;

            if (PageIndex > iosUIScrolView.Subviews.Length - 1)
            {
                PageIndex = iosUIScrolView.Subviews.Length - 1;
            }

            // - 单位矩阵
            CATransform3D transform = CATransform3D.Identity;
            // - 增加透视效果
            transform.m34 = (nfloat)(-1.0 / 500);
            var mRotate = transform.Rotate(0, 0f, 1f, 0f);
            iosUIScrolView.Subviews[PageIndex].Layer.Transform = mRotate;


            //判断PageIndex 前后是否有view，并旋转
            if (PageIndex - 1 >= 0)
            {
                var mRotate1 = transform.Rotate(transformAngle, 0f, 1f, 0f);
                iosUIScrolView.Subviews[PageIndex - 1].Layer.Transform = mRotate1;
            }

            if (PageIndex <= iosUIScrolView.Subviews.Length - 2)
            {
                var mRotate2 = transform.Rotate(-1 * transformAngle, 0f, 1f, 0f);
                iosUIScrolView.Subviews[PageIndex + 1].Layer.Transform = mRotate2;
            }



    
        }

        int PaddingHeight = 20;
        //********************普通高度改变方法**********************
        private void RefreshView()
        {
            if (iosUIScrolView.Subviews.Length <= 0) return;

            if (PageIndex > iosUIScrolView.Subviews.Length - 1)
            {
                PageIndex = iosUIScrolView.Subviews.Length - 1;
            }

            //System.Console.WriteLine($" tempPageIndex:{PageIndex}");
            if (PageIndex == 0)
            {
                var frame0 = iosUIScrolView.Subviews[0].Frame;
                frame0.Height = iosUIScrolView.Frame.Height;
                frame0.Y = 0;
                iosUIScrolView.Subviews[0].Frame = frame0;

                if (iosUIScrolView.Subviews.Length > 1)
                {
                    var frame1 = iosUIScrolView.Subviews[1].Frame;
                    frame1.Height = iosUIScrolView.Frame.Height - PaddingHeight;
                    frame1.Y = PaddingHeight/2;
                    iosUIScrolView.Subviews[1].Frame = frame1;
                }
             


            }
            else
            {
                var frame0 = iosUIScrolView.Subviews[PageIndex].Frame;
                frame0.Height = iosUIScrolView.Frame.Height;
                frame0.Y = 0;
                iosUIScrolView.Subviews[PageIndex].Frame = frame0;

                var frame = iosUIScrolView.Subviews[PageIndex - 1].Frame;
                frame.Height = iosUIScrolView.Frame.Height - PaddingHeight;
                frame.Y = PaddingHeight/2;
                iosUIScrolView.Subviews[PageIndex - 1].Frame = frame;
                if (PageIndex <= iosUIScrolView.Subviews.Length - 2)
                {
                    var frame1 = iosUIScrolView.Subviews[PageIndex + 1].Frame;
                    frame1.Height = iosUIScrolView.Frame.Height - PaddingHeight;
                    frame1.Y = PaddingHeight/2;
                    iosUIScrolView.Subviews[PageIndex + 1].Frame = frame1;
                }
            }

        }

        /// <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 (iosUIScrolView as MyHorizontalPages).ScrollEnabled;
            }
            set
            {
                (iosUIScrolView as MyHorizontalPages).ScrollEnabled = value;
            }
        }

		int pageIndex;
		/// <summary>
		/// 设置或者获取当前的界面索引
		/// </summary>
		/// <value>The index of the page.</value>
		public int PageIndex
		{
			get
			{
				return pageIndex;
			}
			set
			{
                if (value < 0 || ChildrenCount <= value)
                {
                    return;
                }
                int beforePageIndex = pageIndex;
				pageIndex = value;
				if (!IsCanRefresh)
				{
					return;
				}
              
				var viewSize = iosUIScrolView.Frame.Size;

                RefreshPageView();
                var rect = new CGRect(pageIndex * viewSize.Width, 0, viewSize.Width, viewSize.Height);
                if (pageIndex != 0) {
                    var frame = iosUIScrolView.Subviews[pageIndex].Frame;
                    var w = frame.X - _RowPadding;

                    rect = new CGRect(w, 0, viewSize.Width, viewSize.Height);
                    //System.Console.WriteLine($"CGRect xx-------{w}");
                }

                //System.Console.WriteLine($"pageIndex xx-------{pageIndex}");

                //Console.WriteLine("HorizontalPages ScrollRectToVisible");
                iosUIScrolView.ScrollRectToVisible(rect, true);

                if (beforePageIndex != pageIndex)
                {
                    //Console.WriteLine("HorizontalPages DelayPageChange");
                    DelayPageChange();
                    //PageChange?.Invoke(this, pageIndex);
                }
			}
		}



        public void DelayPageChange()
        {
            new System.Threading.Thread(async () =>
            {
                System.Threading.Thread.Sleep(500);
                Application.RunOnMainThread(() =>
                {
                    PageChange?.Invoke(this, pageIndex);
                });
            })
            { IsBackground = true }.Start();
        }

        /// <summary>
        /// 增加子控件
        /// </summary>
        /// <param name="view">View.</param>
        public override void AddChidren(View view)
		{
            //var v = Application.AverageScale;
            //var vv = Application.CurrentHeight;
            //var dddd = Application.DesignWidth;
			base.AddChidren(view);
			ReLocation();
		}

		/// <summary>
		/// 重新排位置及设备内容大小
		/// </summary>
		public virtual void ReLocation()
		{
			if (iosUIScrolView.Subviews.Length == 0)
			{
				return;
			}

            var frame0 = iosUIScrolView.Subviews[0].Frame;
            frame0.X = _RowPadding;
            frame0.Y = 0;
            frame0.Width = mPageWidth;
            frame0.Height = iosUIScrolView.Frame.Height;
            iosUIScrolView.Subviews[0].Frame = frame0;



            for (int i = 1; i < iosUIScrolView.Subviews.Length; i++)
			{
				var frame = iosUIScrolView.Subviews[i].Frame;
			
                frame.Width = mPageWidth;
                frame.Height = iosUIScrolView.Frame.Height;
                frame.Y = 0;
                //frame.X = iosUIScrolView.Subviews[i - 1].Frame.Right + _PagePadding;
                frame.X = _RowPadding + (mPageWidth + _PagePadding)*i;
                iosUIScrolView.Subviews[i].Frame = frame;
			}

			iosUIScrolView.ContentSize = new CoreGraphics.CGSize(iosUIScrolView.Subviews[iosUIScrolView.Subviews.Length - 1].Frame.Right+_RowPadding, iosUIScrolView.Frame.Height);
            RefreshPageView();
        }



		/// <summary>
		/// 控件宽度
		/// </summary>
		/// <value>The width.</value>
		public override int Width
		{
			get
			{
				return base.Width;
			}
			set
			{
				base.Width = value;
     
                if (!IsCanRefresh)
					return;
			}
		}

		/// <summary>
		/// 控件的高度
		/// </summary>
		/// <value>The height.</value>
		public override int Height
		{
			get
			{
				return base.Height;
			}
			set
			{
				base.Height = value;
				if (!IsCanRefresh)
					return;

			}
		}

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

            if (PageIndex > ChildrenCount - 1)
            {
                PageIndex = ChildrenCount - 1;
            }
 
        }

		/// <summary>
		/// 移除所有的控件
		/// </summary>
		public override void RemoveAll()
		{
			base.RemoveAll();
			ReLocation();
            PageIndex = 0;
		}

		/// <summary>
		/// 根据索引移除控件
		/// </summary>
		/// <param name="index">Index.</param>
		public override void RemoveAt(int index)
		{
            if (viewList.Count - 1 < index || index < 0)
            {
                return;
            }
            Remove(viewList[index]);
		}
    }
}