#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

#region --- Using directives ---

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

#endregion

namespace OpenTK.Platform.Windows
{
    internal class WinRawKeyboard : IKeyboardDriver, IDisposable
    {
        readonly List<KeyboardState> keyboards = new List<KeyboardState>();
        // ContextHandle instead of IntPtr for fast dictionary access
        readonly Dictionary<ContextHandle, int> rawids = new Dictionary<ContextHandle, int>();
        private List<KeyboardDevice> keyboards_old = new List<KeyboardDevice>();
        private IntPtr window;

        #region --- Constructors ---

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

        internal WinRawKeyboard(IntPtr windowHandle)
        {
            Debug.WriteLine("Initializing keyboard driver (WinRawKeyboard).");
            Debug.Indent();

            this.window = windowHandle;

            UpdateKeyboardList();

            Debug.Unindent();
        }

        #endregion

        #region internal static void UpdateKeyboardList()

        internal void UpdateKeyboardList()
        {
            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 keyboard devices:
            for (int i = 0; i < count; i++)
            {
                uint size = 0;
                Functions.GetRawInputDeviceInfo(ridl[i].Device, RawInputDeviceInfoEnum.DEVICENAME, IntPtr.Zero, ref size);
                IntPtr name_ptr = Marshal.AllocHGlobal((IntPtr)size);
                Functions.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.KEYBOARD || ridl[i].Type == RawInputDeviceType.HID)
                {
                    // This is a keyboard or USB keyboard device. In the latter case, discover if it really is a
                    // keyboard 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");
                    string deviceClass =
                        (string)regkey.GetValue("Class");
                    if (!String.IsNullOrEmpty(deviceClass) && deviceClass.ToLower().Equals("keyboard"))
                    {
                        KeyboardDevice kb = new KeyboardDevice();
                        kb.Description = deviceDesc;

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

                        kb.NumberOfLeds = info.Device.Keyboard.NumberOfIndicators;
                        kb.NumberOfFunctionKeys = info.Device.Keyboard.NumberOfFunctionKeys;
                        kb.NumberOfKeys = info.Device.Keyboard.NumberOfKeysTotal;
                        //kb.DeviceID = (info.Device.Keyboard.Type << 32) + info.Device.Keyboard.SubType;
                        kb.DeviceID = ridl[i].Device;

                        //if (!keyboards.Contains(kb))
                        //{
                            this.RegisterKeyboardDevice(kb);
                            keyboards_old.Add(kb);
                        //}

                        keyboards.Add(new KeyboardState());
                        rawids.Add(new ContextHandle(ridl[i].Device), keyboards.Count - 1);
                    }
                }
            }
        }

        #endregion

        #region internal void RegisterKeyboardDevice(Keyboard kb)

        internal void RegisterKeyboardDevice(KeyboardDevice kb)
        {
            RawInputDevice[] rid = new RawInputDevice[1];
            // Keyboard is 1/6 (page/id). See http://www.microsoft.com/whdc/device/input/HID_HWID.mspx
            rid[0] = new RawInputDevice();
            rid[0].UsagePage = 1;
            rid[0].Usage = 6;
            rid[0].Flags = RawInputDeviceFlags.INPUTSINK;
            rid[0].Target = window;

            if (!Functions.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 keyboard {0}", kb.ToString());
            }
        }

        #endregion

        #region internal bool ProcessKeyboardEvent(API.RawInput rin)

        /// <summary>
        /// Processes raw input events.
        /// </summary>
        /// <param name="rin"></param>
        /// <returns></returns>
        internal bool ProcessKeyboardEvent(RawInput rin)
        {
            bool processed = false;

            bool pressed =
                rin.Data.Keyboard.Message == (int)WindowMessage.KEYDOWN ||
                rin.Data.Keyboard.Message == (int)WindowMessage.SYSKEYDOWN;

            ContextHandle handle = new ContextHandle(rin.Header.Device);
            KeyboardState keyboard;
            if (!rawids.ContainsKey(handle))
            {
                keyboards.Add(new KeyboardState());
                rawids.Add(handle, keyboards.Count - 1);
            }
            keyboard = keyboards[rawids[handle]];

            // Generic control, shift, alt keys may be sent instead of left/right.
            // It seems you have to explicitly register left/right events.
            switch (rin.Data.Keyboard.VKey)
            {
                case VirtualKeys.SHIFT:
                    keyboard[Input.Key.ShiftLeft] = keyboard[Input.Key.ShiftRight] = pressed;
                    processed = true;
                    break;

                case VirtualKeys.CONTROL:
                    keyboard[Input.Key.ControlLeft] = keyboard[Input.Key.ControlRight] = pressed;
                    processed = true;
                    break;

                case VirtualKeys.MENU:
                    keyboard[Input.Key.AltLeft] = keyboard[Input.Key.AltRight] = pressed;
                    processed = true;
                    break;

                default:
                    if (!WMInput.KeyMap.ContainsKey(rin.Data.Keyboard.VKey))
                    {
                        Debug.Print("Virtual key {0} ({1}) not mapped.",
                                    rin.Data.Keyboard.VKey, (int)rin.Data.Keyboard.VKey);
                    }
                    else
                    {
                        keyboard[WMInput.KeyMap[rin.Data.Keyboard.VKey]] = pressed;
                        processed = true;
                    }
                    break;
            }

            keyboards[rawids[handle]] = keyboard;
            return processed;
        }

        #endregion

        #region --- IInputDevice Members ---

        public string Description
        {
            get { throw new Exception("The method or operation is not implemented."); }
        }

        public Input.InputDeviceType DeviceType
        {
            get { return Input.InputDeviceType.Keyboard; }
        }

        #endregion

        #region --- IKeyboardDriver Members ---

        public IList<KeyboardDevice> Keyboard
        {
            get { return keyboards_old; }
        }

        public KeyboardState GetState()
        {
            if (keyboards.Count > 0)
                return keyboards[0];
            else
                return new KeyboardState();
        }

        public KeyboardState GetState(int index)
        {
            if (keyboards.Count > index)
                return keyboards[index];
            else
                return new KeyboardState();
        }

        #endregion

        #region --- IDisposable Members ---

        private bool disposed;

        public void Dispose()
        {
            Dispose(true);
            GC.SuppressFinalize(this);
        }

        private void Dispose(bool manual)
        {
            if (!disposed)
            {
                if (manual)
                {
                    keyboards_old.Clear();
                }
                disposed = true;
            }
        }

        ~WinRawKeyboard()
        {
            Dispose(false);
        }

        #endregion
    }
}