#region --- License ---
/* Copyright (c) 2006, 2007 Stefanos Apostolopoulos
 * See license.txt for license info
 */
#endregion

using System;
using System.Collections.Generic;
using System.Text;
using OpenTK.Input;
using System.Diagnostics;
using System.Runtime.InteropServices;
using Microsoft.Win32;

namespace OpenTK.Platform.Windows
{
    internal class WinRawMouse : IMouseDriver, IDisposable
    {
        private List<Mouse> mice = new List<Mouse>();
        private IntPtr window;

        #region --- Constructors ---

        internal WinRawMouse()
            : this(IntPtr.Zero)
        {
        }

        internal WinRawMouse(IntPtr windowHandle)
        {
            Debug.WriteLine("Initializing mouse driver (WinRawMouse).");
            Debug.Indent();

            this.window = windowHandle;

            RegisterDevices();

            Debug.Unindent();
        }

        #endregion

        #region --- IMouseDriver Members ---

        public IList<Mouse> Mouse
        {
            get { return mice; }
        }

        public int RegisterDevices()
        {
            int count = WinRawInput.DeviceCount;
            RawInputDeviceList[] ridl = new RawInputDeviceList[count];
            for (int i = 0; i < count; i++)
                ridl[i] = new RawInputDeviceList();
            API.GetRawInputDeviceList(ridl, ref count, API.RawInputDeviceListSize);

            // Discover mouse devices:
            for (int i = 0; i < count; i++)
            {
                uint size = 0;
                API.GetRawInputDeviceInfo(ridl[i].Device, RawInputDeviceInfoEnum.DEVICENAME, IntPtr.Zero, ref size);
                IntPtr name_ptr = Marshal.AllocHGlobal((IntPtr)size);
                API.GetRawInputDeviceInfo(ridl[i].Device, RawInputDeviceInfoEnum.DEVICENAME, name_ptr, ref size);
                string name = Marshal.PtrToStringAnsi(name_ptr);
                Marshal.FreeHGlobal(name_ptr);

                if (name.ToLower().Contains("root"))
                {
                    // This is a terminal services device, skip it.
                    continue;
                }
                else if (ridl[i].Type == RawInputDeviceType.MOUSE || ridl[i].Type == RawInputDeviceType.HID)
                {
                    // This is a mouse or a USB mouse device. In the latter case, discover if it really is a
                    // mouse device by qeurying the registry.

                    // remove the \??\
                    name = name.Substring(4);

                    string[] split = name.Split('#');

                    string id_01 = split[0];    // ACPI (Class code)
                    string id_02 = split[1];    // PNP0303 (SubClass code)
                    string id_03 = split[2];    // 3&13c0b0c5&0 (Protocol code)
                    // The final part is the class GUID and is not needed here

                    string findme = string.Format(
                        @"System\CurrentControlSet\Enum\{0}\{1}\{2}",
                        id_01, id_02, id_03);

                    RegistryKey regkey = Registry.LocalMachine.OpenSubKey(findme);

                    string deviceDesc = (string)regkey.GetValue("DeviceDesc");
                    deviceDesc = deviceDesc.Substring(deviceDesc.LastIndexOf(';') + 1);
                    string deviceClass = (string)regkey.GetValue("Class");

                    if (!String.IsNullOrEmpty(deviceClass) && deviceClass.ToLower().Equals("mouse"))
                    {
                        OpenTK.Input.Mouse mouse = new OpenTK.Input.Mouse();
                        mouse.Description = deviceDesc;

                        // Register the keyboard:
                        RawInputDeviceInfo info = new RawInputDeviceInfo();
                        int devInfoSize = API.RawInputDeviceInfoSize;
                        API.GetRawInputDeviceInfo(ridl[i].Device, RawInputDeviceInfoEnum.DEVICEINFO,
                                info, ref devInfoSize);

                        mouse.NumberOfButtons = info.Device.Mouse.NumberOfButtons;
                        mouse.NumberOfWheels = info.Device.Mouse.HasHorizontalWheel ? 1 : 0;

                        mouse.DeviceID = ridl[i].Device;//(IntPtr)info.Device.Mouse.Id;

                        this.RegisterRawDevice(mouse);
                        mice.Add(mouse);
                    }
                }
            }

            return count;
        }

        #endregion

        #region internal void RegisterRawDevice(OpenTK.Input.Mouse mouse)

        internal void RegisterRawDevice(OpenTK.Input.Mouse mouse)
        {
            RawInputDevice[] rid = new RawInputDevice[1];
            // Mouse is 1/2 (page/id). See http://www.microsoft.com/whdc/device/input/HID_HWID.mspx
            rid[0] = new RawInputDevice();
            rid[0].UsagePage = 1;
            rid[0].Usage = 2;
            rid[0].Flags = RawInputDeviceFlags.INPUTSINK;
            rid[0].Target = window;

            if (!API.RegisterRawInputDevices(rid, 1, API.RawInputDeviceSize))
            {
                throw new ApplicationException(
                    String.Format(
                        "Raw input registration failed with error: {0}. Device: {1}",
                        Marshal.GetLastWin32Error(),
                        rid[0].ToString())
                );
            }
            else
            {
                Debug.Print("Registered mouse {0}", mouse.ToString());
            }
        }

        #endregion

        #region internal bool ProcessEvent(API.RawInput rin)

        /// <summary>
        /// Processes raw input events.
        /// </summary>
        /// <param name="rin"></param>
        /// <returns></returns>
        internal bool ProcessEvent(RawInput rin)
        {
            Mouse mouse = mice.Find(delegate(Mouse m)
            {
                return m.DeviceID == rin.Header.Device;
            });

            switch (rin.Header.Type)
            {
                case RawInputDeviceType.MOUSE:
                    mouse[MouseButton.Left] = rin.Data.Mouse.ButtonFlags == RawInputMouseState.LEFT_BUTTON_DOWN;
                    mouse[MouseButton.Right] = rin.Data.Mouse.ButtonFlags == RawInputMouseState.RIGHT_BUTTON_DOWN;
                    mouse[MouseButton.Middle] = rin.Data.Mouse.ButtonFlags == RawInputMouseState.MIDDLE_BUTTON_DOWN;
                    mouse[MouseButton.Button1] = rin.Data.Mouse.ButtonFlags == RawInputMouseState.BUTTON_4_DOWN;
                    mouse[MouseButton.Button2] = rin.Data.Mouse.ButtonFlags == RawInputMouseState.BUTTON_5_DOWN;

                    if (rin.Data.Mouse.ButtonFlags == RawInputMouseState.WHEEL)
                    {
                        mouse.Wheel += rin.Data.Mouse.ButtonData;
                    }

                    if (rin.Data.Mouse.Flags == RawMouseFlags.MOUSE_MOVE_ABSOLUTE)
                    {
                        mouse.DeltaX = mouse.X - rin.Data.Mouse.LastX;
                        mouse.DeltaY = mouse.Y - rin.Data.Mouse.LastY;
                        mouse.X = rin.Data.Mouse.LastX;
                        mouse.Y = rin.Data.Mouse.LastY;
                    }
                    else if (rin.Data.Mouse.Flags == RawMouseFlags.MOUSE_MOVE_RELATIVE)
                    {
                        mouse.DeltaX = rin.Data.Mouse.LastX;
                        mouse.DeltaY = rin.Data.Mouse.LastY;
                        mouse.X += mouse.DeltaX;
                        mouse.Y += mouse.DeltaY;
                    }

                    return false;

                default:
                    throw new ApplicationException("WinRawMouse driver received keyboard data.");
            }
        }

        #endregion

        #region --- IDisposable Members ---

        public void Dispose()
        {
            //throw new Exception("The method or operation is not implemented.");
        }

        #endregion
    }
}