//

// Copyright (C) 2014-2015 Stéphane Lenclud.

//

// This file is part of SharpLibHid.

//

// SharpDisplayManager is free software: you can redistribute it and/or modify

// it under the terms of the GNU General Public License as published by

// the Free Software Foundation, either version 3 of the License, or

// (at your option) any later version.

//

// SharpDisplayManager 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.

//

// You should have received a copy of the GNU General Public License

// along with SharpDisplayManager.  If not, see <http://www.gnu.org/licenses/>.

//

using System;

using System.Windows.Forms;

using System.Runtime.InteropServices;

using System.Diagnostics;

using System.Text;

using Microsoft.Win32.SafeHandles;

using SharpLib.Win32;

using System.Collections.Generic;

namespace SharpLib.Hid

{

    /// <summary>

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

    /// </summary>

    public class Handler : IDisposable

    {

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

        public event HidEventHandler OnHidEvent;

        List<Event> iHidEvents;

        RAWINPUTDEVICE[] iRawInputDevices;

        public bool IsRegistered { get; private set; }

        public bool ManageRepeats { get; private set; }

        public Handler(RAWINPUTDEVICE[] aRawInputDevices, bool aManageRepeats=false)

        {

            iRawInputDevices = aRawInputDevices;

            iHidEvents = new List<Event>();

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

            ManageRepeats = aManageRepeats;

        }

        /// <summary>

        /// Will de-register devices.

        /// </summary>

        public void Dispose()

        {

            //Setup device removal

            for (int i=0; i<iRawInputDevices.Length; i++)

            {

                iRawInputDevices[i].dwFlags = Const.RIDEV_REMOVE;

                iRawInputDevices[i].hwndTarget = IntPtr.Zero;

            }

            //De-register

            Function.RegisterRawInputDevices(iRawInputDevices, (uint)iRawInputDevices.Length, (uint)Marshal.SizeOf(iRawInputDevices[0]));

            IsRegistered = false;

        }

        /// <summary>

        /// Process a WM_INPUT message.

        /// </summary>

        /// <param name="aMessage"></param>

        public void ProcessInput(ref Message aMessage)

        {

            if (aMessage.Msg != Const.WM_INPUT)

            {

                //We only process WM_INPUT messages

                return;

            }

            Event hidEvent = new Event(aMessage, OnHidEventRepeat, ManageRepeats);

            hidEvent.DebugWrite();

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

            {

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

                return;

            }

            //We want to repeat only a single event at a time.

            //Any other event will interrupt the current repeat.

            if (ManageRepeats)

            {

                //Discard all outstanding repeats, though we should only ever have only one

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

                {

                        iHidEvents[i].Dispose();

                        iHidEvents.RemoveAt(i);

                }

                //Add our newly created event in our repeat list

                //TODO: instead of a list we could now have a single event since we only support one repeat at a time

                iHidEvents.Add(hidEvent);

            }

            //Broadcast our events

            OnHidEvent(this, hidEvent);    

        }

        public void OnHidEventRepeat(Event aHidEvent)

        {

            //Broadcast our events

            OnHidEvent(this, aHidEvent);    

        }

    }

}