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;

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

        /// <summary>
        /// 开始滑动事件
        /// </summary>
        public Action StartScrollAction;
        /// <summary>
        /// 结束滑动事件
        /// </summary>
        public Action EndScrollAction ;

        /// <summary>
        /// 没有更多提示Action，已经是最后一个
        /// </summary>
        public Action NoMoreAction;

       //ImageView LeftImageView = new ImageView() { ImagePath = "RoomIcon/1.jpg" };
       //ImageView RightImageView = new ImageView() { ImagePath = "RoomIcon/2.jpg" };

      

     
        /// <summary>
        /// 构造函数
        /// </summary>
        public HorizontalPages()
        {
            viewGroup = new UIView();
            iosUIScrolView = new MyHorizontalPages(this) { };
            iosUIScrolView.Bounces = false;
            InitMyHorizontalPagesEvent();
            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);
            mTCBJ = Application.GetRealWidth(50);

        }

        ImageView LeftImageView;
        ImageView RightImageView;
        /// <summary>
        /// 是否设置了虚假背景View 设置了才显示
        /// </summary>
        bool IsSetLeftAndRightImageView = false;
        /// <summary>
        /// 设置控制最左和最右2边，填充的假背景View，不设置不显示，需要在AddChidren 前调用该方法
        /// </summary>
        /// <param name="mLeftImageView"></param>
        /// <param name="mRightImageView"></param>
        public void SetLeftAndRightImageView(ImageView mLeftImageView, ImageView mRightImageView)
        {
            if (mLeftImageView == null) return;

            if (mRightImageView == null) return;

            //设置之前先清空一次
            foreach (var view in iosUIScrolView.Subviews)
            {
                view.RemoveFromSuperview();
            }

            LeftImageView = mLeftImageView;
            iosUIScrolView.AddSubview(LeftImageView.RealView);
            LeftImageView.Parent = this;
            LeftImageView.Refresh();

            RightImageView = mRightImageView;
            iosUIScrolView.AddSubview(RightImageView.RealView);
            RightImageView.Parent = this;
            RightImageView.Refresh();

            IsSetLeftAndRightImageView = true;

        }

        bool isNoMore;
        bool isStart;
        int mTouchSlop = 20;
        nfloat beforeXScrollX;
        nfloat moveX;
        void InitMyHorizontalPagesEvent()
        {
           

            iosUIScrolView.Scrolled += (s, e) =>
            {
                //Shared.HDLUtils.WriteLine($"HorizontalPages Scrolled ContentOffsetX:{iosUIScrolView.ContentOffset.X}");
                moveX = iosUIScrolView.ContentOffset.X - beforeXScrollX;
                RefreshPageView();

                if (mTouchSlop < Math.Abs(moveX))
                {
                    if (!isStart)
                    {

                        //当前索引为，不是第一个或者最后一个，滑动距离大于触发距离并且没执行过则 执行一次StartScrollAction
                        if ((moveX > 0 && PageIndex < ChildrenCount - 1) || (moveX < 0 && PageIndex > 0))
                        {
                            isStart = true;
                            StartScrollAction?.Invoke();
                        }

                    }

                    
                    if (!isNoMore && !bSendPageChange)
                    {
                        //当前索引为第一个或者最后一个，滑动距离大于触发距离、没执行过、PageIndex没变化、则执行一次NoMoreAction
                        if ((moveX > 0 && PageIndex == ChildrenCount - 1 && iosUIScrolView.ContentOffset.X > iosUIScrolView.ContentSize.Width - iosUIScrolView.Frame.Width) || (moveX < 0 && PageIndex == 0 && iosUIScrolView.ContentOffset.X < 0))
                        {
                            isNoMore = true;
                            NoMoreAction?.Invoke();
                        }

                    }
                }

              
            };

            iosUIScrolView.DraggingStarted += (sender, e) =>
            {
                //Shared.HDLUtils.WriteLine("HorizontalPages DraggingStarted");
                SetIsScrolling(true);
                beforeXScrollX = iosUIScrolView.ContentOffset.X;
                isStart = false;
                isNoMore = false;
                //StartScrollAction?.Invoke();
            };

            iosUIScrolView.DecelerationStarted += (s, e) =>
            {
                GetMovePageIndex();

            };

            iosUIScrolView.DecelerationEnded += (s, e) =>
            {
               
                if (!bSendPageChange && (PageIndex == ChildrenCount - 1 || PageIndex == 0 )) {
                    //当前索引为，第一个或者最后一个，并且之前执行过开始Action
                    SendEndScrollAction();

                  
                }

            };

            iosUIScrolView.DraggingEnded += (s, e) =>
            {
                if (!e.Decelerate)
                {
                    GetMovePageIndex();
                }
            };

            iosUIScrolView.ScrollAnimationEnded += (s, e) =>
            {
                //Shared.HDLUtils.WriteLine("HorizontalPages ScrollAnimationEnded");
                SendIfPageChange();
                SetIsScrolling(false);
            };
        }


        private void GetMovePageIndex()
        {

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

            }

        }

        //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 = mTCBJ + 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 mTCBJ;
        public int TCBJ
        {
            get
            {
                return mTCBJ;
            }
            set
            {
                mTCBJ = value;
                rowPadding = mTCBJ + 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;
        }

        /// <summary>
        /// 自动计算刷新所有View的高度，实现缩放效果
        /// </summary>
        private void RefreshPageView()
        {
            //RefreshView();
            //RefreshViewWithTransform3D();
            //RefreshViewWithChangeHeight();
            RefreshViewWithChangeHeightNew();
            //RefreshViewWithChangeHeightSF();
        }

        //********************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);
            }
        }

        ///// <summary>
        ///// 旋转效果
        ///// </summary>
        //public void RefreshViewWithTransform3D()
        //{
        //    if (ChildrenCount <= 0) return;

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




        //}

        /// <summary>
        /// 刷新最大距离值
        /// </summary>
        double MaxDistance;
    

        private void RefreshViewWithChangeHeight()
        {
            if (ChildrenCount <= 0) return;

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

            MaxDistance = Width - 2 * TCBJ - JMBJ;
            double centerX = iosUIScrolView.ContentOffset.X + iosUIScrolView.Frame.Width * 0.5;

            foreach (UIView mSubview in iosUIScrolView.Subviews)
            {

                double distance = Math.Abs(mSubview.Center.X - centerX);
                var HH = 0;
                if (distance <= 0)
                {
                    HH = 0;
                }
                else if (distance >= MaxDistance)
                {
                    HH = JMBJ;
                }
                else
                {
                    HH = (int)((distance / MaxDistance) * JMBJ);

                }
                var mFrame = mSubview.Frame;
                mFrame.Height = Height - HH * 2;
                mFrame.Y = HH;
                mSubview.Frame = mFrame;

                //mSubview.MaskView


                //double distance = Math.Abs(mSubview.Center.X - centerX);
                //double factor = 0.01;
                //float scale = (float)(1.0 / (1 + distance * factor));

                ////var mFrame = mSubview.Frame;
                ////mFrame.Height = Height * scale;
                ////mFrame.Y = (Height - mFrame.Height) / 2;
                ////mSubview.Frame = mFrame;

                //var mFrame = mSubview.Frame;
                //var HH = (int)(MaxChangeHeight - MaxChangeHeight * scale);
                //mFrame.Height = Height - HH;
                //mFrame.Y = HH / 2;
                //mSubview.Frame = mFrame;

            }
        }

        /// <summary>
        /// 同时刷新子view 和ImageView的高度，暂时解决底部圆角失效问题
        /// </summary>
        /// <param name="mView"></param>
        /// <param name="height"></param>
        void RefreshSubviewHeight(View mView, nfloat height)
        {
            try
            {
                if (mView is ViewGroup)
                {
                    var tempViewGroup = (ViewGroup)mView;
                    for (int i = 0; i < tempViewGroup.ChildrenCount; i++)
                    {
                        if (tempViewGroup.GetChildren(i) is ViewGroup)
                        {
                            var tempViewGroup2 = (ViewGroup)tempViewGroup.GetChildren(i);
                            for (int j = 0; j < tempViewGroup2.ChildrenCount; j++)
                            {
                                if (tempViewGroup2.GetChildren(j) is ImageView && tempViewGroup2.GetChildren(j).Tag.ToString() == "R")
                                {

                                    tempViewGroup2.GetChildren(j).Height = (int)height;
                                    break;
                                }
                            }
                            if (tempViewGroup2.Tag.ToString() == "R")
                            {
                                tempViewGroup2.Height = (int)height;
                                break;
                            }
                        }
                       
                    }
                }
            }
            catch { }
        }

        /// <summary>
        /// 计算滑动缩放高度的方法
        /// </summary>
        private void RefreshViewWithChangeHeightNew()
        {
            if (ChildrenCount <= 0) return;

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

            MaxDistance = Width - 2 * TCBJ - JMBJ;
            double centerX = iosUIScrolView.ContentOffset.X + iosUIScrolView.Frame.Width * 0.5;

            for (int i = 0; i < ChildrenCount; i++)
            {
                var mSubview = GetChildren(i).RealView;
                var view = GetChildren(i);
                double distance = Math.Abs(mSubview.Center.X - centerX);
                var HH = 0;
                if (distance <= 0)
                {
                    HH = 0;
                }
                else if (distance >= MaxDistance)
                {
                    HH = JMBJ;
                }
                else
                {
                    HH = (int)((distance / MaxDistance) * JMBJ);

                }
                var mFrame = mSubview.Frame;
                mFrame.Height = Height - HH * 2;
                mFrame.Y = HH;
                mSubview.Frame = mFrame;

                RefreshSubviewHeight(view, mFrame.Height);
            }
        }

        //private void RefreshViewWithChangeHeightSF()
        //{
        //    if (ChildrenCount <= 0) return;

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

        //    MaxDistance = Width - 2 * TCBJ - JMBJ;
        //    double centerX = iosUIScrolView.ContentOffset.X + iosUIScrolView.Frame.Width * 0.5;

        //    foreach (UIView mSubview in iosUIScrolView.Subviews)
        //    {

        //        double distance = Math.Abs(mSubview.Center.X - centerX);
        //        nfloat HH = 1;
        //        if (distance <= 0)
        //        {
        //            mSubview.Transform = CGAffineTransform.MakeScale(1.0f, 1.0f);
        //        }
        //        else if (distance >= MaxDistance)
        //        {
        //            mSubview.Transform = CGAffineTransform.MakeScale(1.0f, 0.8f);
        //        }
        //        else
        //        {
        //            HH = (nfloat)((1-distance / MaxDistance) * 0.2f) + 0.8f;
        //            mSubview.Transform = CGAffineTransform.MakeScale(1.0f, 0.8f);
        //        }

        //    }
        //}

        /// <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 = GetChildren(pageIndex).RealView.Frame;
                    var w = frame.X - rowPadding;

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

                //Shared.HDLUtils.WriteLine($"pageIndex xx-------{pageIndex}");
                iosUIScrolView.ScrollRectToVisible(rect, true);

                if (beforePageIndex != pageIndex)
                {
                    bSendPageChange = true;//发送改变标志
                    if (!isStart)
                    {
                        isStart = true;
                        StartScrollAction?.Invoke();
                    }
                }
                else
                {
                    SendEndScrollAction();
                }


            }
        }

        /// <summary>
        /// 判断是否需要发送结束滑动事件
        /// </summary>
        void SendEndScrollAction() {
            if (isStart)
            {
                isStart = false;
                EndScrollAction?.Invoke();
            }
        }

        bool bSendPageChange = false;
        /// <summary>
        /// 判断是否要发送改变事件
        /// </summary>
        private void SendIfPageChange()
        {
            if (bSendPageChange)
            {
                bSendPageChange = false;
                PageChange?.Invoke(this, pageIndex);
            }

            //判断是否需要发送结束滑动事件
            SendEndScrollAction();
        }

        bool isScrolling;
        /// <summary>
        /// 是否正在滑动
        /// </summary>
        public bool ISScrolling
        {
            get
            {
                return isScrolling;
            }
        }

        private void SetIsScrolling(bool bSctolling)
        {
            if (isScrolling == bSctolling) return;

            Shared.HDLUtils.WriteLine($"HorizontalPages StartScroll: {bSctolling}");
            isScrolling = bSctolling;
        }

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

        //public void DelayPageChange()
        //{
        //    PageChange?.Invoke(this, pageIndex);

        //    //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)
        {
            base.AddChidren(view);
            ReLocation();
        }

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


                var frame0 = GetChildren(0).RealView.Frame;
                frame0.X = rowPadding;
                frame0.Y = 0;
                frame0.Width = mPageWidth;
                frame0.Height = iosUIScrolView.Frame.Height;
                GetChildren(0).RealView.Frame = frame0;



                for (int i = 1; i < ChildrenCount; i++)
                {
                    var frame = GetChildren(i).RealView.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;
                    GetChildren(i).RealView.Frame = frame;
                }
                iosUIScrolView.ContentSize = new CoreGraphics.CGSize(GetChildren(ChildrenCount - 1).RealView.Frame.Right + rowPadding, iosUIScrolView.Frame.Height);

                //iosUIScrolView.ContentSize = new CoreGraphics.CGSize(iosUIScrolView.Subviews[ChildrenCount - 1].Frame.Right + rowPadding, iosUIScrolView.Frame.Height);

                if (IsSetLeftAndRightImageView)
                {
                    var leftFrame = iosUIScrolView.Subviews[0].Frame;
                    leftFrame.X = TCBJ - mPageWidth;
                    leftFrame.Y = JMBJ;
                    leftFrame.Width = mPageWidth;
                    leftFrame.Height = Height - JMBJ * 2;
                    iosUIScrolView.Subviews[0].Frame = leftFrame;


                    var rightFrame = iosUIScrolView.Subviews[1].Frame;
                    rightFrame.X = rowPadding + (mPageWidth + pagePadding) * (ChildrenCount);
                    rightFrame.Y = JMBJ;
                    rightFrame.Width = mPageWidth;
                    rightFrame.Height = Height - JMBJ * 2;
                    iosUIScrolView.Subviews[1].Frame = rightFrame;
                }

                RefreshPageView();
            }
            catch { }
        }



        /// <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>
        /// Bounces 
        /// </summary>
        public bool Bounces
        {
            get
            {
                return iosUIScrolView.Bounces;
            }
            set
            {
                iosUIScrolView.Bounces = value;
            }
        }


        

        /// <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]);
        }


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

            [Weak] HorizontalPages HorizontalPages;
            public MyHorizontalPages(HorizontalPages HorizontalPages)
            {

                this.HorizontalPages = HorizontalPages;
            }

            ///// <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));

            //}

            //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));

            //}
            ///// <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));
            //}

            //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);
            }
        }
    }
}