using System;

using System.IO;

using System.Collections.Generic;

using System.Linq;

using System.Text;

using System.Threading.Tasks;

using System.Diagnostics;

using System.Runtime.InteropServices;

using System.Windows.Forms;

using Microsoft.Win32.SafeHandles;

//

using Hid = SharpLib.Hid;

using SharpLib.Win32;

namespace SharpDisplayManager

{

    /// <summary>

    /// Implement handling of HID input reports notably to be able to launch an application using the Green Start button from IR remotes.

    /// </summary>

    [System.ComponentModel.DesignerCategory("Code")]

    public class MainFormHid : Form

    {

        [System.Runtime.InteropServices.DllImportAttribute("user32.dll", EntryPoint = "SwitchToThisWindow")]

        public static extern void SwitchToThisWindow([System.Runtime.InteropServices.InAttribute()] System.IntPtr hwnd, [System.Runtime.InteropServices.MarshalAsAttribute(System.Runtime.InteropServices.UnmanagedType.Bool)] bool fUnknown);

        //

        public delegate void OnHidEventDelegate(object aSender, Hid.Event aHidEvent);

        /// <summary>

        /// Use notably to handle green start key from IR remote control

        /// </summary>

        private Hid.Handler iHidHandler;

        /// <summary>

        /// Register HID devices so that we receive corresponding WM_INPUT messages.

        /// </summary>

        protected void RegisterHidDevices()

        {

            // Register the input device to receive the commands from the

            // remote device. See http://msdn.microsoft.com/library/default.asp?url=/library/en-us/dnwmt/html/remote_control.asp

            // for the vendor defined usage page.

            RAWINPUTDEVICE[] rid = new RAWINPUTDEVICE[5];

            int i = 0;

            rid[i].usUsagePage = (ushort)SharpLib.Hid.UsagePage.WindowsMediaCenterRemoteControl;

            rid[i].usUsage = (ushort)SharpLib.Hid.UsageCollection.WindowsMediaCenter.WindowsMediaCenterRemoteControl;

            rid[i].dwFlags = Const.RIDEV_INPUTSINK;

            rid[i].hwndTarget = Handle;

            i++;

            rid[i].usUsagePage = (ushort)SharpLib.Hid.UsagePage.Consumer;

            rid[i].usUsage = (ushort)SharpLib.Hid.UsageCollection.Consumer.ConsumerControl;

            rid[i].dwFlags = Const.RIDEV_INPUTSINK;

            rid[i].hwndTarget = Handle;

            i++;

            rid[i].usUsagePage = (ushort)SharpLib.Hid.UsagePage.Consumer;

            rid[i].usUsage = (ushort)SharpLib.Hid.UsageCollection.Consumer.Selection;

            rid[i].dwFlags = Const.RIDEV_INPUTSINK;

            rid[i].hwndTarget = Handle;

            i++;

            rid[i].usUsagePage = (ushort)SharpLib.Hid.UsagePage.GenericDesktopControls;

            rid[i].usUsage = (ushort)SharpLib.Hid.UsageCollection.GenericDesktop.SystemControl;

            rid[i].dwFlags = Const.RIDEV_INPUTSINK;

            rid[i].hwndTarget = Handle;

            i++;

            rid[i].usUsagePage = (ushort)SharpLib.Hid.UsagePage.GenericDesktopControls;

            rid[i].usUsage = (ushort)SharpLib.Hid.UsageCollection.GenericDesktop.GamePad;

            rid[i].dwFlags = Const.RIDEV_INPUTSINK;

            rid[i].hwndTarget = Handle;

            //i++;

            //rid[i].usUsagePage = (ushort)SharpLib.Hid.UsagePage.GenericDesktopControls;

            //rid[i].usUsage = (ushort)SharpLib.Hid.UsageCollection.GenericDesktop.Keyboard;

            //rid[i].dwFlags = Const.RIDEV_EXINPUTSINK;

            //rid[i].hwndTarget = Handle;

            //i++;

            //rid[i].usUsagePage = (ushort)Hid.UsagePage.GenericDesktopControls;

            //rid[i].usUsage = (ushort)Hid.UsageCollection.GenericDesktop.Mouse;

            //rid[i].dwFlags = Const.RIDEV_EXINPUTSINK;

            //rid[i].hwndTarget = aHWND;

            iHidHandler = new SharpLib.Hid.Handler(rid);

            if (!iHidHandler.IsRegistered)

            {

                Debug.WriteLine("Failed to register raw input devices: " + Marshal.GetLastWin32Error().ToString());

            }

            iHidHandler.OnHidEvent += HandleHidEventThreadSafe;

        }

        /// <summary>

        /// Here we receive HID events from our HID library.

        /// </summary>

        /// <param name="aSender"></param>

        /// <param name="aHidEvent"></param>

        public void HandleHidEventThreadSafe(object aSender, SharpLib.Hid.Event aHidEvent)

        {

            if (aHidEvent.IsStray)

            {

                //Stray event just ignore it

                return;

            }

            if (this.InvokeRequired)

            {

                //Not in the proper thread, invoke ourselves

                OnHidEventDelegate d = new OnHidEventDelegate(HandleHidEventThreadSafe);

                this.Invoke(d, new object[] { aSender, aHidEvent });

            }

            else

            {

                if (aHidEvent.Usages.Count == 0)

                {

                    //No usage, nothing to do then

                    return;

                }

                //We are in the proper thread

                if (aHidEvent.UsagePage == (ushort) Hid.UsagePage.WindowsMediaCenterRemoteControl)

                {

                    switch (aHidEvent.Usages[0])

                    {

                        case (ushort)Hid.Usage.WindowsMediaCenterRemoteControl.GreenStart:

                            HandleGreenStart();

                            break;

                        case (ushort)Hid.Usage.WindowsMediaCenterRemoteControl.Eject:

                        case (ushort)Hid.Usage.WindowsMediaCenterRemoteControl.Ext2:

                            HandleEject();

                            break;

                    }

                }

                //Keep this for debug when only ThinkPad keyboard is available

                if (aHidEvent.UsagePage == (ushort)Hid.UsagePage.Consumer && aHidEvent.Usages[0] == (ushort)Hid.Usage.ConsumerControl.ThinkPadFullscreenMagnifier)

                {

                    HandleEject();

                }

            }

        }

        /// <summary>

        /// 

        /// </summary>

        /// <param name="data"></param>

        /// <returns></returns>

        private IntPtr MarshalToPointer(object data)

        {

            IntPtr buf = Marshal.AllocHGlobal(

                Marshal.SizeOf(data));

            Marshal.StructureToPtr(data,

                buf, false);

            return buf;

        }

        /// <summary>

        /// 

        /// </summary>

        /// <returns></returns>

        private SafeFileHandle OpenVolume(string aDriveName)

        {

            return Function.CreateFile("\\\\.\\" + aDriveName,

                               SharpLib.Win32.FileAccess.GENERIC_READ,

                               SharpLib.Win32.FileShare.FILE_SHARE_READ | SharpLib.Win32.FileShare.FILE_SHARE_WRITE,

                               IntPtr.Zero,

                               CreationDisposition.OPEN_EXISTING,

                               0,

                               IntPtr.Zero);

        }

        /// <summary>

        /// 

        /// </summary>

        /// <param name="aVolume"></param>

        /// <returns></returns>

        private bool LockVolume(SafeFileHandle aVolume)

        {

            //Hope that's doing what I think it does

            IntPtr dwBytesReturned=new IntPtr();

            //Should not be needed but I'm not sure how to pass NULL in there.

            OVERLAPPED overlapped=new OVERLAPPED();

            int tries = 0;

            const int KMaxTries = 100;

            const int KSleepTime = 10;

            bool success = false;

            while (!success && tries < KMaxTries)

            {

                success = Function.DeviceIoControl(aVolume, Const.FSCTL_LOCK_VOLUME, IntPtr.Zero, 0, IntPtr.Zero, 0, dwBytesReturned, ref overlapped);

                System.Threading.Thread.Sleep(KSleepTime);

                tries++;

            }

            return success;

        }

        /// <summary>

        /// 

        /// </summary>

        /// <param name="aVolume"></param>

        /// <returns></returns>

        private bool DismountVolume(SafeFileHandle aVolume)

        {

            //Hope that's doing what I think it does

            IntPtr dwBytesReturned = new IntPtr();

            //Should not be needed but I'm not sure how to pass NULL in there.

            OVERLAPPED overlapped=new OVERLAPPED();

            return Function.DeviceIoControl(aVolume, Const.FSCTL_DISMOUNT_VOLUME, IntPtr.Zero, 0, IntPtr.Zero, 0, dwBytesReturned, ref overlapped);

        }

        /// <summary>

        /// 

        /// </summary>

        /// <param name="aVolume"></param>

        /// <param name="aPreventRemoval"></param>

        /// <returns></returns>

        private bool PreventRemovalOfVolume(SafeFileHandle aVolume, bool aPreventRemoval)

        {

            //Hope that's doing what I think it does

            IntPtr dwBytesReturned = new IntPtr();

            //Should not be needed but I'm not sure how to pass NULL in there.

            OVERLAPPED overlapped = new OVERLAPPED();

            //

            PREVENT_MEDIA_REMOVAL preventMediaRemoval = new PREVENT_MEDIA_REMOVAL();

            preventMediaRemoval.PreventMediaRemoval = Convert.ToByte(aPreventRemoval);

            IntPtr preventMediaRemovalParam = MarshalToPointer(preventMediaRemoval);

            bool result = Function.DeviceIoControl(aVolume, Const.IOCTL_STORAGE_MEDIA_REMOVAL, preventMediaRemovalParam, Convert.ToUInt32(Marshal.SizeOf(preventMediaRemoval)), IntPtr.Zero, 0, dwBytesReturned, ref overlapped);

            Marshal.FreeHGlobal(preventMediaRemovalParam);

            return result;

        }

        /// <summary>

        /// 

        /// </summary>

        /// <param name="aVolume"></param>

        /// <returns></returns>

        private bool AutoEjectVolume(SafeFileHandle aVolume)

        {

            //Hope that's doing what I think it does

            IntPtr dwBytesReturned = new IntPtr();

            //Should not be needed but I'm not sure how to pass NULL in there.

            OVERLAPPED overlapped=new OVERLAPPED();

            return Function.DeviceIoControl(aVolume, Const.IOCTL_STORAGE_EJECT_MEDIA, IntPtr.Zero, 0, IntPtr.Zero, 0, dwBytesReturned, ref overlapped);

        }

        /// <summary>

        /// Not working.

        /// </summary>

        /// <param name="aVolume"></param>

        /// <returns></returns>

        private bool CloseTray(SafeFileHandle aVolume)

        {

            //Hope that's doing what I think it does

            IntPtr dwBytesReturned = new IntPtr();

            //Should not be needed but I'm not sure how to pass NULL in there.

            OVERLAPPED overlapped=new OVERLAPPED();

            return Function.DeviceIoControl(aVolume, Const.IOCTL_STORAGE_LOAD_MEDIA, IntPtr.Zero, 0, IntPtr.Zero, 0, dwBytesReturned, ref overlapped);

        }

        /// <summary>

        /// Perform media ejection.

        /// </summary>

        private void HandleEject()

        {

            string drive = ((MainForm)this).OpticalDriveToEject();

            if (drive.Length!=2)

            {

                //Not a proper drive spec.

                //Probably 'None' selected.

                return;

            }

            SafeFileHandle handle = OpenVolume(drive);

            if (handle.IsInvalid)

            {

                return;

            }

            if (LockVolume(handle) && DismountVolume(handle))

            {

                Debug.Write("Volume was dismounted.");

                if (PreventRemovalOfVolume(handle,false))

                {

                    if (AutoEjectVolume(handle))

                    {

                        Debug.Write("Media was ejected");

                    }

                    //else if (CloseTray(handle))

                    //{

                    //    Debug.Write("Media was loaded");

                    //}                    

                }

            }

        }

        /// <summary>

        /// 

        /// </summary>

        private void HandleGreenStart()

        {

            //First check if the process we want to launch already exists

            string procName = Path.GetFileNameWithoutExtension(Properties.Settings.Default.StartFileName);

            Process[] existingProcesses = Process.GetProcessesByName(procName);

            if (existingProcesses == null || existingProcesses.Length == 0)

            {

                // Process do not exists just try to launch it

                ProcessStartInfo start = new ProcessStartInfo();

                // Enter in the command line arguments, everything you would enter after the executable name itself

                //start.Arguments = arguments; 

                // Enter the executable to run, including the complete path

                start.FileName = Properties.Settings.Default.StartFileName;

                start.WindowStyle = ProcessWindowStyle.Normal;

                start.CreateNoWindow = true;

                start.UseShellExecute = true;

                // Run the external process & wait for it to finish

                Process proc = Process.Start(start);

                //SL: We could have used that too

                //Shell32.Shell shell = new Shell32.Shell();

                //shell.ShellExecute(Properties.Settings.Default.StartFileName);

            }

            else

            {

                //This won't work properly until we have a manifest that enables uiAccess.

                //However uiAccess just won't work with ClickOnce so we will have to use a different deployment system.

                SwitchToThisWindow(existingProcesses[0].MainWindowHandle, true);

            }            

        }

        /// <summary>

        /// We need to handle WM_INPUT.

        /// </summary>

        /// <param name="message"></param>

        protected override void WndProc(ref Message message)

        {

            switch (message.Msg)

            {

                case Const.WM_INPUT:

                    //Returning zero means we processed that message.

                    message.Result = new IntPtr(0);

                    iHidHandler.ProcessInput(ref message);

                    break;

            }

            //Is that needed? Check the docs.

            base.WndProc(ref message);

        }

    }

}