using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using VastPark.Horde3D;
using VastPark.Data.EventArg;
using VastPark.Data;
using VastPark.Data.Collections;

namespace Client
{
    /// <summary>
    /// Detects input from a WPF based input source
    /// </summary>
    public class WpfInputSource : IInputSource, IDisposable
    {
        #region Events

        public event Event<System.Windows.Input.Key, System.Windows.Input.ModifierKeys> KeyDown;
        public event Event<System.Windows.Input.Key, System.Windows.Input.ModifierKeys> KeyUp;
        public event Event<MouseState> MouseDown;
        public event Event<MouseState> MouseUp;
        public event Event<MouseState> MouseMove;
        public event Event<MouseState> MouseClick;
        public event Event<MouseState> MouseDoubleClick;
        public event Event<MouseState> MouseWheel;

        #endregion

        public bool MouseWrapEnabled { get; set; }

        private MouseState _MouseState;
        private KeyboardState _KeyboardState;

        private System.Windows.DependencyObject _Control;
        private System.Timers.Timer _ResetMouseRelativePositionTimer;
        private System.Timers.Timer _ResetMouseWheelTimer;
        private bool _IsMouseMoveEventExecuting;

        public WpfInputSource(System.Windows.DependencyObject control)
        {
            _Control = control;
            _RelativePositionLock = new object();
            _MouseWheelLock = new object();

            _MouseState.AbsX = -1;
            _MouseState.AbsY = -1;
            _KeyboardState.Initialise(new ThreadSafeDictionary<System.Windows.Input.Key, bool>());

            this.MouseWrapEnabled = true;

            Array keys = Enum.GetValues(typeof(System.Windows.Input.Key));

            foreach (System.Windows.Input.Key key in keys)
            {
                if (!_KeyboardState.Keys.ContainsKey(key))
                    _KeyboardState.Keys.Add(key, false);
            }

            System.Windows.Input.Keyboard.AddKeyDownHandler(_Control, new System.Windows.Input.KeyEventHandler(_KeyDownHandler));
            System.Windows.Input.Keyboard.AddKeyUpHandler(_Control, new System.Windows.Input.KeyEventHandler(_KeyUpHandler));

            if (_Control is System.Windows.Forms.Integration.WindowsFormsHost)
            {
                (_Control as System.Windows.Forms.Integration.WindowsFormsHost).Child.MouseMove += new System.Windows.Forms.MouseEventHandler(Child_MouseMove);

                (_Control as System.Windows.Forms.Integration.WindowsFormsHost).Child.MouseDown += new System.Windows.Forms.MouseEventHandler(Child_MouseDown);
                (_Control as System.Windows.Forms.Integration.WindowsFormsHost).Child.MouseUp += new System.Windows.Forms.MouseEventHandler(Child_MouseUp);
                (_Control as System.Windows.Forms.Integration.WindowsFormsHost).Child.MouseClick += new System.Windows.Forms.MouseEventHandler(Child_MouseClick);
                (_Control as System.Windows.Forms.Integration.WindowsFormsHost).Child.MouseDoubleClick += new System.Windows.Forms.MouseEventHandler(Child_MouseDoubleClick);
                (_Control as System.Windows.Forms.Integration.WindowsFormsHost).Child.LostFocus += new EventHandler(Child_LostFocus);
                (_Control as System.Windows.Forms.Integration.WindowsFormsHost).Child.DragOver += new System.Windows.Forms.DragEventHandler(Child_DragOver);
                (_Control as System.Windows.Forms.Integration.WindowsFormsHost).Child.MouseWheel += new System.Windows.Forms.MouseEventHandler(Child_MouseWheel);
            }

            _ResetMouseRelativePositionTimer = new System.Timers.Timer(10);
            _ResetMouseRelativePositionTimer.Elapsed += new System.Timers.ElapsedEventHandler(_ResetMouseRelativePositionTimer_Elapsed);

            _ResetMouseWheelTimer = new System.Timers.Timer(10);
            _ResetMouseWheelTimer.Elapsed += new System.Timers.ElapsedEventHandler(_ResetMouseWheelTimer_Elapsed);
        }

        public KeyboardState GetKeyboardState()
        {
            return _KeyboardState;
        }

        public MouseState GetMouseState()
        {
            return _MouseState;
        }

        void Child_LostFocus(object sender, EventArgs e)
        {
            //when losing focus, need to release mouse button states to false
            _MouseState[MouseInput.LeftButton] = false;
            _MouseState[MouseInput.RightButton] = false;
            _MouseState[MouseInput.MiddleButton] = false;
            _MouseState[MouseInput.WheelDown] = false;
            _MouseState[MouseInput.WheelUp] = false;
        }

        void Child_MouseWheel(object sender, System.Windows.Forms.MouseEventArgs e)
        {
            _ResetMouseWheelTimer.Stop();
            _IsMouseWheelEventExecuting = true;

            lock (_MouseWheelLock)
            {
                if (e.Delta > 0)
                {
                    _MouseState[MouseInput.WheelUp] = true;
                    _MouseState[MouseInput.WheelDown] = false;
                }
                else
                {
                    _MouseState[MouseInput.WheelDown] = true;
                    _MouseState[MouseInput.WheelUp] = false;
                }
            }

            MouseWheel.Raise(this, _MouseState);

            _IsMouseWheelEventExecuting = false;
            _ResetMouseWheelTimer.Start();
        }

        void Child_MouseClick(object sender, System.Windows.Forms.MouseEventArgs e)
        {
            _MouseState.Button = _GetMouseInput(e.Button);

            MouseClick.Raise(this, _MouseState);
        }

        void Child_MouseDoubleClick(object sender, System.Windows.Forms.MouseEventArgs e)
        {
            _MouseState.Button = _GetMouseInput(e.Button);

            MouseDoubleClick.Raise(this, _MouseState);
        }

        private MouseInput _GetMouseInput(System.Windows.Forms.MouseButtons mouseButton)
        {
            switch (mouseButton)
            {
                case System.Windows.Forms.MouseButtons.Left:
                    {
                        return MouseInput.LeftButton;
                    }
                case System.Windows.Forms.MouseButtons.Right:
                    {
                        return MouseInput.RightButton;
                    }
                case System.Windows.Forms.MouseButtons.Middle:
                    {
                        return MouseInput.MiddleButton;
                    }
                default:
                    {
                        return MouseInput.None;
                    }
            }
        }

        void Child_MouseUp(object sender, System.Windows.Forms.MouseEventArgs e)
        {
            switch (e.Button)
            {
                case System.Windows.Forms.MouseButtons.Left:
                    {
                        _MouseState[VastPark.Data.MouseInput.LeftButton] = false;
                        break;
                    }
                case System.Windows.Forms.MouseButtons.Right:
                    {
                        _MouseState[VastPark.Data.MouseInput.RightButton] = false;
                        break;
                    }
                case System.Windows.Forms.MouseButtons.Middle:
                    {
                        _MouseState[VastPark.Data.MouseInput.MiddleButton] = false;
                        break;
                    }
                case System.Windows.Forms.MouseButtons.XButton1:
                    {
                        _MouseState[VastPark.Data.MouseInput.FourthButton] = false;
                        break;
                    }
            }

            MouseUp.Raise(this, _MouseState);
        }

        void Child_MouseDown(object sender, System.Windows.Forms.MouseEventArgs e)
        {
            switch (e.Button)
            {
                case System.Windows.Forms.MouseButtons.Left:
                    {
                        _MouseState[VastPark.Data.MouseInput.LeftButton] = true;
                        break;
                    }
                case System.Windows.Forms.MouseButtons.Right:
                    {
                        _MouseState[VastPark.Data.MouseInput.RightButton] = true;
                        break;
                    }
                case System.Windows.Forms.MouseButtons.Middle:
                    {
                        _MouseState[VastPark.Data.MouseInput.MiddleButton] = true;
                        break;
                    }
                case System.Windows.Forms.MouseButtons.XButton1:
                    {
                        _MouseState[VastPark.Data.MouseInput.FourthButton] = true;
                        break;
                    }
            }

            //manipulate the focus to the control in order to allow mousewheel events to be raised
            ((System.Windows.Interop.IKeyboardInputSink)_Control).TabInto(new System.Windows.Input.TraversalRequest(System.Windows.Input.FocusNavigationDirection.First));
            (sender as System.Windows.Forms.Control).Focus();

            MouseDown.Raise(this, _MouseState);
        }

        void Child_DragOver(object sender, System.Windows.Forms.DragEventArgs e)
        {
            //MouseMove events are not raised during a drag operation, so we make use of the DragOver event which in essence does the same thing as the move, but only during a drag
            var normalisedPoint = (_Control as System.Windows.Forms.Integration.WindowsFormsHost).Child.PointToClient(new System.Drawing.Point(e.X, e.Y));
            _HandleMouseMove(normalisedPoint.X, normalisedPoint.Y);
        }

        void Child_MouseMove(object sender, System.Windows.Forms.MouseEventArgs e)
        {
            _HandleMouseMove(e.X, e.Y);
        }

        //private int _LastX = -1;
        //private int _LastY = -1;

        private void _HandleMouseMove(int x, int y)
        {
            //Note: Exploiting the fact that MouseMove appears to fire continuously, consumers of this InputSource can test for changes to the previous mouse move position and fire either a move or hover based on this
            //if (_LastX == x && _LastY == y)
            //{
            //    return;
            //}

            //System.Diagnostics.Debug.WriteLine(HighResClock.Now.ToString() + string.Format(" MouseMove {0},{1}", x, y));

            //_LastX = x;
            //_LastY = y;

            _ResetMouseRelativePositionTimer.Stop();
            _IsMouseMoveEventExecuting = true;

            System.Windows.Point absolutePoint = new System.Windows.Point(x, y);
            System.Windows.Point relativePoint = new System.Windows.Point();

            if (_MouseState.AbsX == -1 && _MouseState.AbsY == -1) //need to initialise
            {
                _MouseState.AbsX = (int)absolutePoint.X;
                _MouseState.AbsY = (int)absolutePoint.Y;

                MouseMove.Raise(this, _MouseState);

                _IsMouseMoveEventExecuting = false;

                return;
            }

            //relative point is the difference between the new position and the old position
            relativePoint.X = absolutePoint.X - _MouseState.AbsX;
            relativePoint.Y = absolutePoint.Y - _MouseState.AbsY;

            lock (_RelativePositionLock)
            {
                _MouseState.RelX = (int)relativePoint.X;
                _MouseState.RelY = (int)relativePoint.Y;
            }

            _MouseState.AbsX = (int)absolutePoint.X;
            _MouseState.AbsY = (int)absolutePoint.Y;

            MouseMove.Raise(this, _MouseState);

            _IsMouseMoveEventExecuting = false;
            _ResetMouseRelativePositionTimer.Start();
        }

        private object _MouseWheelLock;
        private bool _IsMouseWheelEventExecuting;

        void _ResetMouseWheelTimer_Elapsed(object sender, System.Timers.ElapsedEventArgs e)
        {
            if (_IsMouseWheelEventExecuting)
                return;

            //also update the mouse wheel if needed
            lock (_MouseWheelLock)
            {
                if (_MouseState[MouseInput.WheelDown] || _MouseState[MouseInput.WheelUp])
                {
                    _MouseState[MouseInput.WheelDown] = false;
                    _MouseState[MouseInput.WheelUp] = false;

                    MouseWheel.Raise(this, _MouseState);
                }
            }
        }

        private object _RelativePositionLock;

        void _ResetMouseRelativePositionTimer_Elapsed(object sender, System.Timers.ElapsedEventArgs e)
        {
            if (_IsMouseMoveEventExecuting)
                return;

            _ResetMouseRelativePositionTimer.Stop();

            lock (_RelativePositionLock)
            {
                _MouseState.RelX = 0;
                _MouseState.RelY = 0;

                MouseMove.Raise(this, _MouseState);
            }
        }

        private void _KeyDownHandler(object sender, System.Windows.Input.KeyEventArgs e)
        {
            if (_KeyboardState.IsKeyPressed(e.Key))
                return;

            _KeyboardState.Keys[e.Key] = e.IsDown;
            KeyDown.Raise(this, e.Key, System.Windows.Input.Keyboard.Modifiers);
        }

        private void _KeyUpHandler(object sender, System.Windows.Input.KeyEventArgs e)
        {
            if (!_KeyboardState.IsKeyPressed(e.Key))
                return;

            _KeyboardState.Keys[e.Key] = e.IsDown;
            KeyUp.Raise(this, e.Key, System.Windows.Input.Keyboard.Modifiers);
        }

        #region IDisposable Members

        public void Dispose()
        {
            if (_ResetMouseRelativePositionTimer != null)
                _ResetMouseRelativePositionTimer.Stop();

            if (_ResetMouseWheelTimer != null)
                _ResetMouseWheelTimer.Stop();

            System.Windows.Input.Keyboard.RemoveKeyDownHandler(_Control, _KeyDownHandler);
            System.Windows.Input.Keyboard.RemoveKeyUpHandler(_Control, _KeyUpHandler);

            if (_Control is System.Windows.Forms.Integration.WindowsFormsHost)
            {
                (_Control as System.Windows.Forms.Integration.WindowsFormsHost).Child.MouseMove -= new System.Windows.Forms.MouseEventHandler(Child_MouseMove);

                (_Control as System.Windows.Forms.Integration.WindowsFormsHost).Child.MouseDown -= new System.Windows.Forms.MouseEventHandler(Child_MouseDown);
                (_Control as System.Windows.Forms.Integration.WindowsFormsHost).Child.MouseUp -= new System.Windows.Forms.MouseEventHandler(Child_MouseUp);
                (_Control as System.Windows.Forms.Integration.WindowsFormsHost).Child.MouseClick -= new System.Windows.Forms.MouseEventHandler(Child_MouseClick);
                (_Control as System.Windows.Forms.Integration.WindowsFormsHost).Child.MouseDoubleClick -= new System.Windows.Forms.MouseEventHandler(Child_MouseDoubleClick);
                (_Control as System.Windows.Forms.Integration.WindowsFormsHost).Child.LostFocus -= new EventHandler(Child_LostFocus);
                (_Control as System.Windows.Forms.Integration.WindowsFormsHost).Child.DragOver -= new System.Windows.Forms.DragEventHandler(Child_DragOver);
                (_Control as System.Windows.Forms.Integration.WindowsFormsHost).Child.MouseWheel -= new System.Windows.Forms.MouseEventHandler(Child_MouseWheel);
            }
        }

        #endregion        
    }
}