using System;
using System.Collections;
using System.Runtime.InteropServices;
using System.Runtime.InteropServices.ComTypes;

namespace FaceAI
{
    [ComVisible(false)]
    public class FilterCategory     // uuids.h  :  CLSID_*
    {
        /// <summary> CLSID_AudioInputDeviceCategory, audio capture category </summary>
        public static readonly Guid AudioInputDevice = new Guid(0x33d9a762, 0x90c8, 0x11d0, 0xbd, 0x43, 0x00, 0xa0, 0xc9, 0x11, 0xce, 0x86);

        /// <summary> CLSID_VideoInputDeviceCategory, video capture category </summary>
        public static readonly Guid VideoInputDevice = new Guid(0x860BB310, 0x5D01, 0x11d0, 0xBD, 0x3B, 0x00, 0xA0, 0xC9, 0x11, 0xCE, 0x86);
    }

    [ComVisible(false)]
    public class Clsid      // uuids.h  :  CLSID_*
    {
        /// <summary> CLSID_SystemDeviceEnum for ICreateDevEnum </summary>
        public static readonly Guid SystemDeviceEnum = new Guid(0x62BE5D10, 0x60EB, 0x11d0, 0xBD, 0x3B, 0x00, 0xA0, 0xC9, 0x11, 0xCE, 0x86);

        /// <summary> CLSID_FilterGraph, filter Graph </summary>
        public static readonly Guid FilterGraph = new Guid(0xe436ebb3, 0x524f, 0x11ce, 0x9f, 0x53, 0x00, 0x20, 0xaf, 0x0b, 0xa7, 0x70);

        /// <summary> CLSID_CaptureGraphBuilder2, new Capture graph building </summary>
        public static readonly Guid CaptureGraphBuilder2 = new Guid(0xBF87B6E1, 0x8C27, 0x11d0, 0xB3, 0xF0, 0x0, 0xAA, 0x00, 0x37, 0x61, 0xC5);

        /// <summary> CLSID_SampleGrabber, Sample Grabber filter </summary>
        public static readonly Guid SampleGrabber = new Guid(0xC1F400A0, 0x3F08, 0x11D3, 0x9F, 0x0B, 0x00, 0x60, 0x08, 0x03, 0x9E, 0x37);

        /// <summary> CLSID_DvdGraphBuilder,  DVD graph builder </summary>
        public static readonly Guid DvdGraphBuilder = new Guid(0xFCC152B7, 0xF372, 0x11d0, 0x8E, 0x00, 0x00, 0xC0, 0x4F, 0xD7, 0xC0, 0x8B);

    }

    [ComVisible(false)]
    public class DevEnum
    {
        public static bool GetDevicesOfCat(Guid cat, out ArrayList devs)
        {
            devs = null;
            int hr;
            object comObj = null;
            ICreateDevEnum enumDev = null;
            IEnumMoniker enumMon = null;
            IMoniker[] mon = new IMoniker[1];
            try
            {
                Type srvType = Type.GetTypeFromCLSID(Clsid.SystemDeviceEnum);
                if (srvType == null)
                    throw new NotImplementedException("System Device Enumerator");

                comObj = Activator.CreateInstance(srvType);
                enumDev = (ICreateDevEnum)comObj;
                hr = enumDev.CreateClassEnumerator(ref cat, out enumMon, 0);
                if (hr != 0)
                    throw new NotSupportedException("No devices of the category");

                int /*f, */count = 0;
                IntPtr ptr = new IntPtr();
                do
                {
                    hr = enumMon.Next(1, mon, ptr);
                    if ((hr != 0) || (mon[0] == null))
                        break;
                    DsDevice dev = new DsDevice();
                    GetFriendlyName(mon[0], ref dev.Name, ref dev.Path);
                    if (devs == null)
                        devs = new ArrayList();
                    dev.id = count;
                    dev.Mon = mon[0]; mon[0] = null;
                    devs.Add(dev); dev = null;
                    count++;
                }
                while (true);

                return count > 0;
            }
            catch (Exception)
            {
                if (devs != null)
                {
                    foreach (DsDevice d in devs)
                        d.Dispose();
                    devs = null;
                }
                return false;
            }
            finally
            {
                enumDev = null;
                if (mon[0] != null)
                    Marshal.ReleaseComObject(mon[0]); mon[0] = null;
                if (enumMon != null)
                    Marshal.ReleaseComObject(enumMon); enumMon = null;
                if (comObj != null)
                    Marshal.ReleaseComObject(comObj); comObj = null;
            }

        }

        private static bool GetFriendlyName(IMoniker mon, ref string devname, ref string devpath)
        {
            object bagObj = null;
            IPropertyBag bag = null;
            try
            {
                Guid bagId = typeof(IPropertyBag).GUID;
                mon.BindToStorage(null, null, ref bagId, out bagObj);
                bag = (IPropertyBag)bagObj;
                object val = "";
                int hr = bag.Read("Description", ref val, IntPtr.Zero);
                if(hr != 0)
                    hr = bag.Read("FriendlyName", ref val, IntPtr.Zero);
                if (hr != 0)
                    Marshal.ThrowExceptionForHR(hr);               
                devname = val as string;
                if ((devname == null) || (devname.Length < 1))
                    throw new NotImplementedException("Device FriendlyName");
                val = "";
                hr = bag.Read("DevicePath", ref val, IntPtr.Zero);
                if (hr != 0)
                    Marshal.ThrowExceptionForHR(hr);
                devpath = val as string;
                if((devpath == null) || (devpath.Length < 1))
                    throw new NotImplementedException("Device Path");
                return true;
            }
            catch (Exception)
            {
                return false;
            }
            finally
            {
                bag = null;
                if (bagObj != null)
                    Marshal.ReleaseComObject(bagObj); bagObj = null;
            }
        }
    }


    [ComVisible(false)]
    public class DsDevice : IDisposable
    {
        public int id;
        public string Name;
        public string Path;
        public IMoniker Mon;
        

        public void Dispose()
        {
            if (Mon != null)
                Marshal.ReleaseComObject(Mon); Mon = null;
        }
    }

    [ComVisible(true), ComImport,
    Guid("29840822-5B84-11D0-BD3B-00A0C911CE86"),
    InterfaceType(ComInterfaceType.InterfaceIsIUnknown)]
    public interface ICreateDevEnum
    {
        [PreserveSig]
        int CreateClassEnumerator(
        [In]                                            ref Guid pType,
        [Out]                                       out IEnumMoniker ppEnumMoniker,
        [In]                                            int dwFlags);
    }



    [ComVisible(true), ComImport,
    Guid("55272A00-42CB-11CE-8135-00AA004BB851"),
    InterfaceType(ComInterfaceType.InterfaceIsIUnknown)]
    public interface IPropertyBag
    {
        [PreserveSig]
        int Read(
        [In, MarshalAs(UnmanagedType.LPWStr)]           string pszPropName,
        [In, Out, MarshalAs(UnmanagedType.Struct)]  ref object pVar,
        IntPtr pErrorLog);

        [PreserveSig]
        int Write(
        [In, MarshalAs(UnmanagedType.LPWStr)]           string pszPropName,
        [In, MarshalAs(UnmanagedType.Struct)]       ref object pVar);
    }
}