#region License
//
// The Open Toolkit Library License
//
// Copyright (c) 2006 - 2010 the Open Toolkit library.
//
// Permission is hereby granted, free of charge, to any person obtaining a copy
// of this software and associated documentation files (the "Software"), to deal
// in the Software without restriction, including without limitation the rights to 
// use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of
// the Software, and to permit persons to whom the Software is furnished to do
// so, subject to the following conditions:
//
// The above copyright notice and this permission notice shall be included in all
// copies or substantial portions of the Software.
//
// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
// EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES
// OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
// NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT
// HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY,
// WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
// FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
// OTHER DEALINGS IN THE SOFTWARE.
//
#endregion

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

namespace OpenTK.Platform.Windows
{
    /// \internal
    /// <summary>
    /// Contains methods to register for and process mouse WM_INPUT messages.
    /// </summary>
    sealed class WinRawMouse : IMouseDriver2
    {
        readonly List<MouseState> mice = new List<MouseState>();
        readonly List<string> names = new List<string>(); 
        readonly Dictionary<ContextHandle, int> rawids = new Dictionary<ContextHandle, int>();
        readonly IntPtr Window;
        readonly object UpdateLock = new object();

        #region Constructors

        public WinRawMouse(IntPtr window)
        {
            Debug.WriteLine("Initializing mouse driver (WinRawMouse).");
            Debug.Indent();

            if (window == IntPtr.Zero)
                throw new ArgumentNullException("window");

            Window = window;
            RefreshDevices();

            Debug.Unindent();
        }

        #endregion

        #region Public Members

        public void RefreshDevices()
        {
            lock (UpdateLock)
            {
                // Mark all devices as disconnected. We will check which of those
                // are connected later on.
                for (int i = 0; i < mice.Count; i++)
                {
                    MouseState state = mice[i];
                    state.IsConnected = false;
                    mice[i] = state;
                }

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

                // Discover mouse devices
                foreach (RawInputDeviceList dev in ridl)
                {
                    ContextHandle id = new ContextHandle(dev.Device);
                    if (rawids.ContainsKey(id))
                    {
                        // Device already registered, mark as connected
                        MouseState state = mice[rawids[id]];
                        state.IsConnected = true;
                        mice[rawids[id]] = state;
                        continue;
                    }

                    // Unregistered device, find what it is
                    string name = GetDeviceName(dev);
                    if (name.ToLower().Contains("root"))
                    {
                        // This is a terminal services device, skip it.
                        continue;
                    }
                    else if (dev.Type == RawInputDeviceType.MOUSE || dev.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.
                        RegistryKey regkey = FindRegistryKey(name);
                        string deviceDesc = (string)regkey.GetValue("DeviceDesc");
                        string deviceClass = (string)regkey.GetValue("Class");
                        deviceDesc = deviceDesc.Substring(deviceDesc.LastIndexOf(';') + 1);

                        if (!String.IsNullOrEmpty(deviceClass) && deviceClass.ToLower().Equals("mouse"))
                        {
                            if (!rawids.ContainsKey(new ContextHandle(dev.Device)))
                            {
                                // Register the device:
                                RawInputDeviceInfo info = new RawInputDeviceInfo();
                                int devInfoSize = API.RawInputDeviceInfoSize;
                                Functions.GetRawInputDeviceInfo(dev.Device, RawInputDeviceInfoEnum.DEVICEINFO,
                                        info, ref devInfoSize);

                                RegisterRawDevice(Window, deviceDesc);
                                MouseState state = new MouseState();
                                state.IsConnected = true;
                                mice.Add(state);
                                names.Add(deviceDesc);
                                rawids.Add(new ContextHandle(dev.Device), mice.Count - 1);
                            }
                        }
                    }
                }
            }
        }

        public bool ProcessMouseEvent(RawInput rin)
        {
            RawMouse raw = rin.Data.Mouse;
            ContextHandle handle = new ContextHandle(rin.Header.Device);

            MouseState mouse;
            if (!rawids.ContainsKey(handle))
            {
                RefreshDevices();
            }
            mouse = mice[rawids[handle]];

            if ((raw.ButtonFlags & RawInputMouseState.LEFT_BUTTON_DOWN) != 0) mouse.EnableBit((int)MouseButton.Left);
            if ((raw.ButtonFlags & RawInputMouseState.LEFT_BUTTON_UP) != 0) mouse.DisableBit((int)MouseButton.Left);
            if ((raw.ButtonFlags & RawInputMouseState.RIGHT_BUTTON_DOWN) != 0) mouse.EnableBit((int)MouseButton.Right);
            if ((raw.ButtonFlags & RawInputMouseState.RIGHT_BUTTON_UP) != 0) mouse.DisableBit((int)MouseButton.Right);
            if ((raw.ButtonFlags & RawInputMouseState.MIDDLE_BUTTON_DOWN) != 0) mouse.EnableBit((int)MouseButton.Middle);
            if ((raw.ButtonFlags & RawInputMouseState.MIDDLE_BUTTON_UP) != 0) mouse.DisableBit((int)MouseButton.Middle);
            if ((raw.ButtonFlags & RawInputMouseState.BUTTON_4_DOWN) != 0) mouse.EnableBit((int)MouseButton.Button1);
            if ((raw.ButtonFlags & RawInputMouseState.BUTTON_4_UP) != 0) mouse.DisableBit((int)MouseButton.Button1);
            if ((raw.ButtonFlags & RawInputMouseState.BUTTON_5_DOWN) != 0) mouse.EnableBit((int)MouseButton.Button2);
            if ((raw.ButtonFlags & RawInputMouseState.BUTTON_5_UP) != 0) mouse.DisableBit((int)MouseButton.Button2);

            if ((raw.ButtonFlags & RawInputMouseState.WHEEL) != 0)
                mouse.WheelPrecise += (short)raw.ButtonData / 120.0f;

            if ((raw.Flags & RawMouseFlags.MOUSE_MOVE_ABSOLUTE) != 0)
            {
                mouse.X = raw.LastX;
                mouse.Y = raw.LastY;
            }
            else
            {   // Seems like MOUSE_MOVE_RELATIVE is the default, unless otherwise noted.
                mouse.X += raw.LastX;
                mouse.Y += raw.LastY;
            }

            lock (UpdateLock)
            {
                mice[rawids[handle]] = mouse;
                return true;
            }
        }

        #endregion

        #region Private Members

        static string GetDeviceName(RawInputDeviceList dev)
        {
            // get name size
            uint size = 0;
            Functions.GetRawInputDeviceInfo(dev.Device, RawInputDeviceInfoEnum.DEVICENAME, IntPtr.Zero, ref size);

            // get actual name
            IntPtr name_ptr = Marshal.AllocHGlobal((IntPtr)size);
            Functions.GetRawInputDeviceInfo(dev.Device, RawInputDeviceInfoEnum.DEVICENAME, name_ptr, ref size);
            string name = Marshal.PtrToStringAnsi(name_ptr);
            Marshal.FreeHGlobal(name_ptr);

            return name;
        }

        static RegistryKey FindRegistryKey(string name)
        {
            // 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);
            return regkey;
        }

        static void RegisterRawDevice(IntPtr window, string device)
        {
            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 (!Functions.RegisterRawInputDevices(rid, 1, API.RawInputDeviceSize))
            {
                Debug.Print("[Warning] Raw input registration failed with error: {0}. Device: {1}",
                    Marshal.GetLastWin32Error(), rid[0].ToString());
            }
            else
            {
                Debug.Print("Registered mouse {0}", device);
            }
        }

        #endregion

        #region IMouseDriver2 Members

        public MouseState GetState()
        {
            lock (UpdateLock)
            {
                MouseState master = new MouseState();
                foreach (MouseState ms in mice)
                {
                    master.MergeBits(ms);
                }
                return master;
            }
        }

        public MouseState GetState(int index)
        {
            lock (UpdateLock)
            {
                if (mice.Count > index)
                    return mice[index];
                else
                    return new MouseState();
            }
        }

        #endregion
    }
}