#region ================== Copyright (c) 2007 Pascal vd Heiden

/*
 * Copyright (c) 2007 Pascal vd Heiden, www.codeimp.com
 * This program is released under GNU General Public License
 * 
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 * 
 */

#endregion

#region ================== Namespaces

using System;
using System.Windows.Forms;
using CodeImp.DoomBuilder.Geometry;
using System.Runtime.InteropServices;
using System.Drawing;

#endregion

namespace CodeImp.DoomBuilder.Actions
{
	internal class MouseInput : IDisposable
	{
		#region ================== Variables

		// Mouse input
		private RawMouse mouse;
		private bool firstProcess = true;
		private Point lastPos = new Point();
		private Control source;
		
		#endregion

		#region ================== Constructor / Disposer

		// Constructor
		public MouseInput(Control source)
		{
			this.source = source;

			// Start mouse input
			try
			{
				mouse = new RawMouse(source);
			}
			catch
			{
				mouse = null;
			}

			// We have no destructor
			GC.SuppressFinalize(this);
		}

		// Disposer
		public void Dispose()
		{
			if(mouse != null)
			{
				mouse.Dispose();
				mouse = null;
			}
		}

		#endregion

		#region ================== Methods

		#endregion

		#region ================== Processing

		// This processes the input
		public Vector2D Process()
		{
			float msX, msY;
			if (mouse != null) // Windows version where RawInput is available
			{
				MouseState ms = mouse.Poll();
				msX = ms.X;
				msY = ms.Y;
			}
			else // Fallback implementation for unix
			{
				Point pos = Cursor.Position;

				Rectangle clipBox = source.RectangleToScreen(source.ClientRectangle); //Cursor.Clip;
				Cursor.Position = new Point(clipBox.X + clipBox.Width / 2, clipBox.Y + clipBox.Height / 2);

				if (firstProcess)
				{
					lastPos = Cursor.Position;
					firstProcess = false;
				}

				msX = (float)(pos.X - lastPos.X);
				msY = (float)(pos.Y - lastPos.Y);
				lastPos = Cursor.Position;
			}

			// Calculate changes depending on sensitivity
			float changex = msX * General.Settings.VisualMouseSensX * General.Settings.MouseSpeed * 0.01f;
			float changey = msY * General.Settings.VisualMouseSensY * General.Settings.MouseSpeed * 0.01f;

			return new Vector2D(changex, changey);
		}

		#endregion
	}

	public struct MouseState
	{
		public MouseState(float x, float y) { X = x; Y = y; }
		public float X { get; }
		public float Y { get; }
	}

	public class RawMouse
	{
		public RawMouse(System.Windows.Forms.Control control)
		{
			Handle = RawMouse_New(control.Handle);
			if (Handle == IntPtr.Zero)
				throw new Exception("RawMouse_New failed");
		}

		~RawMouse()
		{
			Dispose();
		}

		public MouseState Poll()
		{
			return new MouseState(RawMouse_GetX(Handle), RawMouse_GetY(Handle));
		}

		public bool Disposed { get { return Handle == IntPtr.Zero; } }

		public void Dispose()
		{
			if (!Disposed)
			{
				RawMouse_Delete(Handle);
				Handle = IntPtr.Zero;
			}
		}

		internal IntPtr Handle;

		[DllImport("BuilderNative.dll", CallingConvention = CallingConvention.Cdecl)]
		static extern IntPtr RawMouse_New(IntPtr windowHandle);

		[DllImport("BuilderNative.dll", CallingConvention = CallingConvention.Cdecl)]
		static extern void RawMouse_Delete(IntPtr handle);

		[DllImport("BuilderNative.dll", CallingConvention = CallingConvention.Cdecl)]
		static extern float RawMouse_GetX(IntPtr handle);

		[DllImport("BuilderNative.dll", CallingConvention = CallingConvention.Cdecl)]
		static extern float RawMouse_GetY(IntPtr handle);
	}
}