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



namespace Shared
{
    /// <summary>
    /// 右滑抽屉View
    /// </summary>
    public class UIDrawerLayout : ViewGroup
    {
        /// <summary>
        ///  当前视图
        /// </summary>
        /// <value>The UICoverFlowView.</value>
        MyUIDrawerLayout mUIDrawerLayout
        {
            get
            {
                return uiView as MyUIDrawerLayout;
            }
            set
            {
                uiView = value;
            }
        }

        UIView leftView;
        UIView mainView;

        /// <summary>
        /// 构造函数
        /// </summary>
        public UIDrawerLayout()
        {

            mUIDrawerLayout = new MyUIDrawerLayout(this) { };

            viewGroup = mUIDrawerLayout;
            mainView = new UIView();
            realViewGroup = mainView;


            viewGroup.AddSubview(realViewGroup);
            viewGroup.Layer.MasksToBounds = true;

            leftView = new UIView();
            //new UIView(new CGRect(0, 0, Application.CurrentWidth, Application.CurrentHeight));
            var mFrame = leftView.Frame;
            mFrame.Y = 0;
            mFrame.X = 0;
            mFrame.Width = Application.CurrentWidth;
            mFrame.Height = Application.CurrentHeight;
            mFrame.X = -Application.CurrentWidth;
            leftView.Frame = mFrame;
            leftView.BackgroundColor = UIColor.FromRGBA(0, 0, 0, 99);

            viewGroup.AddSubview(leftView);

        }




        View leftChildView;
        /// <summary>
        /// 增加左边视图
        /// </summary>
        /// <param name="view">View.</param>
        public void AddLeftView(View view)
        {
            if (null == view)
            {
                return;
            }
            LeftViewRemoveAllViews();

            view.Parent = this;
            leftChildView = view;
            //view.X = 0;
            //view.Y = 0;
            //view.Width = Width;
            //view.Height = Height;

            //view.Parent = this;
            //view.Refresh();
            var addFrame = leftView.Frame;
            addFrame.X = 0;
            addFrame.Y = 0;
            //addFrame.Height = Height;
            //addFrame.Width = Width;

            leftChildView.RealView.Frame = addFrame;
            leftView.AddSubview(leftChildView.RealView);

        }


        /// <summary>
        /// RemoveLeftView
        /// </summary>
        public void LeftViewRemoveAllViews()
        {
            if (leftChildView == null) return;


            if (leftChildView.RealView.Superview != null)
            {
                leftChildView.RealView.RemoveFromSuperview();
            }
            leftChildView.Parent = null;
        }

        /// <summary>
        /// 是否锁定右滑功能， 锁定后右滑弹出菜单失效
        /// </summary>
        bool _IsDrawerLockMode;
        public bool IsDrawerLockMode
        {
            get
            {
                return _IsDrawerLockMode;
            }
            set
            {
                _IsDrawerLockMode = value;
                mUIDrawerLayout.IsDrawerLockMode = _IsDrawerLockMode;
            }
        }

        bool _IsDrawerOpen = false;

        private bool IsDrawerOpen
        {
            get
            {
                return _IsDrawerOpen;
            }
            set
            {
                _IsDrawerOpen = value;
                mUIDrawerLayout.IsDrawerOpen = _IsDrawerOpen;


            }
        }

        /// <summary>
        /// 打开抽屉view
        /// </summary>
        public void OpenLeftMenu()
        {

            if (!IsDrawerOpen)
            {
                IsDrawerOpen = true;
                ShowLeftView(IsDrawerOpen);
                //System.Console.WriteLine("OpenLeftMenu-------");
            }
       
        }



        /// <summary>
        /// 关闭抽屉view
        /// </summary>
        public void CloseLeftMenu()
        {
            if (IsDrawerOpen)
            {
                IsDrawerOpen = false;
                ShowLeftView(IsDrawerOpen);
                //System.Console.WriteLine("CloseLeftMenu-------");
            }
        }


        //private CABasicAnimation moveX(float X)
        //{
        //    //CABasicAnimation animation = new CABasicAnimation("transform.translation.x");
        //    CABasicAnimation animation = CABasicAnimation.FromKeyPath("transform.translation.x");
        //    animation.To = NSNumber.FromFloat(X);
        //    animation.Duration = 0.2F;
        //    animation.RemovedOnCompletion = false;//yes的话，又返回原位置了。  
        //    animation.RepeatCount = 1;
        //    animation.FillMode = CAFillMode.Forwards;
        //    return animation;
        //}




        /// <summary>
        /// 是否打开显示左边菜单view
        /// </summary>
        private void ShowLeftView(bool bShow)
        {
            var mFrame = leftView.Frame;
            mFrame.X = bShow ? 0 : -mUIDrawerLayout.Frame.Size.Width;
            leftView.Frame = mFrame;
        }

        /// <summary>
        /// 移动左边view
        /// </summary>
        public void MoveLeftView(nfloat XX)
        { 
            if (IsDrawerOpen)
            {
                if (XX < 0)
                {
                    var mFrame = leftView.Frame;
                    mFrame.X = 0 + XX;
                    leftView.Frame = mFrame;
                }
            }
            else
            {
                if(XX > 0)
                {
                    var mFrame = leftView.Frame;
                    mFrame.X = -mUIDrawerLayout.Frame.Size.Width + XX;
                    leftView.Frame = mFrame;
                }

            }
        }


        /// <summary>
        /// 重置左边view
        /// </summary>
        public void ResetView()
        {

            var mFrame = leftView.Frame;
            if (IsDrawerOpen)
            {
                mFrame.X = 0;
                //System.Console.WriteLine($"Reset Open");
            }
            else
            {
                mFrame.X = -mUIDrawerLayout.Frame.Size.Width;
                //System.Console.WriteLine($"Reset CLOSE");
            }

            leftView.Frame = mFrame;
        }


        nfloat mLastX, mLastY, deltaX;
        int mTouchSlop = 3;

        private void MYTouchEvent(EventActions eventAction, CGPoint point)
        {
            if (_IsDrawerLockMode) return;

            switch (eventAction)
            {
                case EventActions.Down:

                    //记录点击的最新X坐标
                    mLastX = point.X;
                    mLastY = point.Y;
                    //System.Console.WriteLine($"DrawerLayout:EventActions.Down XXX{mLastX}");
                    break;
                case EventActions.Move:
                    moveWithPoint(point);
                    //System.Console.WriteLine("DrawerLayout:EventActions.Move");
                    break;
                case EventActions.Up:
                    //System.Console.WriteLine($"DrawerLayout:EventActions.Down deltaX{deltaX}   WWW:{mUIDrawerLayout.Frame.Size.Width} ");
                    if (Math.Abs(deltaX) >= mUIDrawerLayout.Frame.Size.Width / 2)
                    {
                        if (deltaX > 0)
                        {
                            //System.Console.WriteLine("DrawerOpen");
                            IsDrawerOpen = true;
                            ShowLeftView(IsDrawerOpen);
                        }
                        else
                        {
                            //System.Console.WriteLine("Drawer CLOSE");
                            IsDrawerOpen = false;
                            ShowLeftView(IsDrawerOpen);
                        }
                    }
                    else
                    {
                        ResetView();

                    }
                    //System.Console.WriteLine("DrawerLayout:EventActions.Up");
                    break;

            }
        }

        private void moveWithPoint(CGPoint movePoint)
        {
            var x = movePoint.X;
            deltaX = x - mLastX;

            if (deltaX * deltaX > mTouchSlop * mTouchSlop)
            {
                //开始移动视图
                if (IsDrawerOpen)
                {
                    //MoveAction?.Invoke(deltaX);
                    MoveLeftView(deltaX);
                }
                else
                {
                    if (mLastX < 10)
                    {
                        MoveLeftView(deltaX);
                        //从屏幕左侧开始滑动，才触发
                        //MoveAction?.Invoke(deltaX);

                    }


                }

            }

        }


        /// <summary>
        /// 垂直方向滚动视图
        /// </summary>
        class MyUIDrawerLayout : UIView
        {
            public bool IsDrawerOpen = false;
            public bool IsDrawerLockMode = false;

            [Weak] internal UIDrawerLayout mUIDrawerLayout;

            public MyUIDrawerLayout(UIDrawerLayout mUIDrawerLayout)
            {
                this.mUIDrawerLayout = mUIDrawerLayout;


            }


            /// <summary>
            /// 寻找最适合的View
            /// 实现拦截
            /// </summary>
            public override UIView HitTest(CGPoint point, UIEvent uievent)
            {

                if (!IsDrawerLockMode)//不锁定，允许右滑
                {
                    if (PointInside(point, uievent))
                    {
                        if (IsDrawerOpen)//左菜单是否打开
                        {
                            if (point.X > this.Frame.Size.Width - 10)
                            {
                                //System.Console.WriteLine($"MyUIDrawerLayout:HitTest{point.X}   uievent{uievent.ToString()}");
                                return this;//拦截
                            }

                        }
                        else
                        {
                            if (point.X < 10)
                            {
                                //System.Console.WriteLine($"MyUIDrawerLayout:HitTest{point.X}   uievent{uievent.ToString()}");
                                return this; return this;//拦截
                            }
                        }

                    }
                }

                return base.HitTest(point, uievent);//不拦截
            }


            /// <summary>
            /// 点击开始
            /// </summary>
            /// <param name="touches">Touches.</param>
            /// <param name="evt">Evt.</param>
            public override void TouchesBegan(NSSet touches, UIEvent evt)
            {
                //System.Console.WriteLine("MyUIDrawerLayout:TouchesBegan");
                mUIDrawerLayout?.TouchEvent(EventActions.Down, (touches.AnyObject as UITouch).LocationInView(this));
                mUIDrawerLayout?.MYTouchEvent(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)
            {
                mUIDrawerLayout?.TouchEvent(EventActions.Move, (touches.AnyObject as UITouch).LocationInView(this));
                mUIDrawerLayout?.MYTouchEvent(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)
            {
                mUIDrawerLayout?.TouchEvent(EventActions.Up, (touches.AnyObject as UITouch).LocationInView(this));
                mUIDrawerLayout?.MYTouchEvent(EventActions.Up, (touches.AnyObject as UITouch).LocationInView(this));
                //System.Console.WriteLine("MyUIDrawerLayout:TouchesEnded");
            }

            public override void TouchesCancelled(NSSet touches, UIEvent evt)
            {
                mUIDrawerLayout?.TouchEvent(EventActions.Cancel, (touches.AnyObject as UITouch).LocationInView(this));
                mUIDrawerLayout?.MYTouchEvent(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);
            }



        }
    }
}