// Licensed to the .NET Foundation under one or more agreements.
// The .NET Foundation licenses this file to you under the MIT license.
 
using System.Runtime.CompilerServices;
using System.Runtime.InteropServices;
using System.Runtime.InteropServices.ComTypes;
using Com = Windows.Win32.System.Com;
 
namespace System.Private.Windows.Ole;
 
internal unsafe partial class Composition<TRuntime, TDataFormat>
{
    /// <summary>
    ///  Maps native pointer <see cref="Com.IDataObject"/> to the .NET Runtime <see cref="IDataObject"/>.
    /// </summary>
    private class NativeToRuntimeAdapter : IDataObject
    {
        private readonly AgileComPointer<Com.IDataObject> _nativeDataObject;
 
        public NativeToRuntimeAdapter(Com.IDataObject* dataObject)
        {
#if DEBUG
            _nativeDataObject = new(dataObject, takeOwnership: true, trackDisposal: false);
#else
            _nativeDataObject = new(dataObject, takeOwnership: true);
#endif
        }
 
        public int DAdvise(ref FORMATETC pFormatetc, ADVF advf, IAdviseSink adviseSink, out int connection)
        {
            using var nativeAdviseSink = ComHelpers.TryGetComScope<Com.IAdviseSink>(adviseSink);
            fixed (Com.FORMATETC* nativeFormat = &Unsafe.As<FORMATETC, Com.FORMATETC>(ref pFormatetc))
            fixed (int* pConnection = &connection)
            {
                using var nativeDataObject = _nativeDataObject.GetInterface();
                return nativeDataObject.Value->DAdvise(nativeFormat, (uint)advf, nativeAdviseSink, (uint*)pConnection);
            }
        }
 
        public void DUnadvise(int connection)
        {
            using var nativeDataObject = _nativeDataObject.GetInterface();
            nativeDataObject.Value->DUnadvise((uint)connection).ThrowOnFailure();
        }
 
        public int EnumDAdvise(out IEnumSTATDATA? enumAdvise)
        {
            using ComScope<Com.IEnumSTATDATA> nativeStatData = new(null);
            using var nativeDataObject = _nativeDataObject.GetInterface();
            HRESULT result = nativeDataObject.Value->EnumDAdvise(nativeStatData);
            ComHelpers.TryGetObjectForIUnknown(nativeStatData.AsUnknown, out enumAdvise);
            return result;
        }
 
        public IEnumFORMATETC EnumFormatEtc(DATADIR direction)
        {
            using ComScope<Com.IEnumFORMATETC> nativeFormat = new(null);
            using var nativeDataObject = _nativeDataObject.GetInterface();
            if (nativeDataObject.Value->EnumFormatEtc((uint)direction, nativeFormat).Failed)
            {
                throw new ExternalException(SR.ExternalException, (int)HRESULT.E_NOTIMPL);
            }
 
            return (IEnumFORMATETC)ComHelpers.GetObjectForIUnknown(nativeFormat);
        }
 
        public int GetCanonicalFormatEtc(ref FORMATETC formatIn, out FORMATETC formatOut)
        {
            using var nativeDataObject = _nativeDataObject.GetInterface();
            HRESULT result = nativeDataObject.Value->GetCanonicalFormatEtc(Unsafe.As<FORMATETC, Com.FORMATETC>(ref formatIn), out Com.FORMATETC nativeFormat);
            formatOut = Unsafe.As<Com.FORMATETC, FORMATETC>(ref nativeFormat);
            return result;
        }
 
        public void GetData(ref FORMATETC format, out STGMEDIUM medium)
        {
            Com.FORMATETC nativeFormat = Unsafe.As<FORMATETC, Com.FORMATETC>(ref format);
            Com.STGMEDIUM nativeMedium = default;
            using var nativeDataObject = _nativeDataObject.GetInterface();
            nativeDataObject.Value->GetData(&nativeFormat, &nativeMedium).ThrowOnFailure();
            medium = (STGMEDIUM)nativeMedium;
            nativeMedium.ReleaseUnknown();
        }
 
        public void GetDataHere(ref FORMATETC format, ref STGMEDIUM medium)
        {
            Com.FORMATETC nativeFormat = Unsafe.As<FORMATETC, Com.FORMATETC>(ref format);
            Com.STGMEDIUM nativeMedium = (Com.STGMEDIUM)medium;
            using var nativeDataObject = _nativeDataObject.GetInterface();
            nativeDataObject.Value->GetDataHere(&nativeFormat, &nativeMedium).ThrowOnFailure();
            medium = (STGMEDIUM)nativeMedium;
            nativeMedium.ReleaseUnknown();
        }
 
        public int QueryGetData(ref FORMATETC format)
        {
            using var nativeDataObject = _nativeDataObject.GetInterface();
            return nativeDataObject.Value->QueryGetData(Unsafe.As<FORMATETC, Com.FORMATETC>(ref format));
        }
 
        public void SetData(ref FORMATETC formatIn, ref STGMEDIUM medium, bool release)
        {
            Com.STGMEDIUM nativeMedium = (Com.STGMEDIUM)medium;
            Com.FORMATETC nativeFormat = Unsafe.As<FORMATETC, Com.FORMATETC>(ref formatIn);
            using var nativeDataObject = _nativeDataObject.GetInterface();
            HRESULT result = nativeDataObject.Value->SetData(&nativeFormat, &nativeMedium, release);
            medium = (STGMEDIUM)nativeMedium;
            nativeMedium.ReleaseUnknown();
            result.ThrowOnFailure();
        }
    }
}