using System;

using System.Windows.Forms;

using System.Runtime.InteropServices;

using System.Diagnostics;

using System.Text;

using Microsoft.Win32.SafeHandles;

using Win32;

using System.Collections.Generic;

namespace Hid

{

    /// <summary>

    /// Our HID handler manages raw input registrations, processes WM_INPUT messages and broadcasts HID events in return.

    /// </summary>

    public class HidHandler

    {

        public delegate void HidEventHandler(object aSender, HidEvent aHidEvent);

        public event HidEventHandler OnHidEvent;

        List<HidEvent> iHidEvents;

        public bool IsRegistered { get; private set; }

        public HidHandler(RAWINPUTDEVICE[] aRawInputDevices)

        {

            iHidEvents=new List<HidEvent>();

            IsRegistered = Function.RegisterRawInputDevices(aRawInputDevices, (uint)aRawInputDevices.Length, (uint)Marshal.SizeOf(aRawInputDevices[0]));

        }

        public void ProcessInput(Message aMessage)

        {

            Hid.HidEvent hidEvent = new Hid.HidEvent(aMessage, OnHidEventRepeat);

            hidEvent.DebugWrite();

            if (!hidEvent.IsValid || !hidEvent.IsGeneric)

            {

                Debug.WriteLine("Skipping HID message.");

                return;

            }

            //

            if (hidEvent.Usages[0] == 0)

            {

                //This is a key up event

                //We need to discard any events belonging to the same page and collection

                for (int i = (iHidEvents.Count-1); i >= 0; i--)

                {

                    if (iHidEvents[i].UsageId == hidEvent.UsageId)

                    {

                        iHidEvents[i].Dispose();

                        iHidEvents.RemoveAt(i);

                    }

                }

            }

            else

            {

                //Keep that event until we get a key up message

                iHidEvents.Add(hidEvent);

            }

            //Broadcast our events

            OnHidEvent(this, hidEvent);    

        }

        public void OnHidEventRepeat(HidEvent aHidEvent)

        {

            //Broadcast our events

            OnHidEvent(this, aHidEvent);    

        }

    }

}