using System;
using System.Runtime.InteropServices;

namespace VisualStudioMock
{
    [ComVisible(true)]
    [Guid("177F0C4A-1CD3-4DE7-A32C-71DBBB9FA36D")]
    [ClassInterface(ClassInterfaceType.None)]
    public sealed class SetupConfiguration : ISetupConfiguration, ISetupConfiguration2
    {
        private readonly SetupInstance _singleInstance;

        public SetupConfiguration()
        {
            Ext.LogCall(nameof(SetupConfiguration), ".ctor");

            ComProxy proxy = new ComProxy(new SetupConfiguration(false));
            object proxyCcw = proxy.GetIUnknown();

            // Copy managed object
            GCHandle hThis = GCHandle.Alloc(this, GCHandleType.WeakTrackResurrection);
            IntPtr pThis = Marshal.ReadIntPtr(GCHandle.ToIntPtr(hThis));
            GCHandle hProxy = GCHandle.Alloc(proxyCcw, GCHandleType.WeakTrackResurrection);
            IntPtr pProxy = Marshal.ReadIntPtr(GCHandle.ToIntPtr(hProxy));
            byte[] buffer = new byte[IntPtr.Size * 3];
            Marshal.Copy(pProxy - IntPtr.Size, buffer, 0, buffer.Length);
            Marshal.Copy(buffer, 0, pThis - IntPtr.Size, buffer.Length);

            /*
            Ext.Log("Casting to ISetupConfiguration");
            proxyCcw = this;
            ISetupConfigurationTest wrapper = (ISetupConfigurationTest)proxyCcw;
            GC.KeepAlive(wrapper.GetInstanceForCurrentProcess());
            */

            Ext.LogExit(nameof(SetupConfiguration), ".ctor");
        }

        private SetupConfiguration(bool any)
        {
            this._singleInstance = new SetupInstance();
        }

        #region ISetupConfiguration Members

        public IEnumSetupInstances EnumInstances()
        {
            Ext.LogCall(nameof(SetupConfiguration), nameof(EnumInstances));
            return new Enum(this).ComBarrier<Enum, IEnumSetupInstances>();
        }

        public ISetupInstance GetInstanceForCurrentProcess()
        {
            Ext.LogCall(nameof(SetupConfiguration), nameof(GetInstanceForCurrentProcess));
            return _singleInstance.ComBarrier<SetupInstance, ISetupInstance>();
        }

        public ISetupInstance GetInstanceForPath([In, MarshalAs(UnmanagedType.LPWStr)] string path)
        {
            Ext.LogCall(nameof(SetupConfiguration), nameof(GetInstanceForPath));
            throw new NotImplementedException();
        }

        #endregion

        #region ISetupConfiguration2 Members

        public IEnumSetupInstances EnumAllInstances()
        {
            Ext.LogEnter(nameof(SetupConfiguration), nameof(EnumAllInstances));
            IEnumSetupInstances result = new Enum(this).ComBarrier<Enum, IEnumSetupInstances>();
            Ext.LogExit(nameof(SetupConfiguration), nameof(EnumAllInstances));
            return result;
        }

        #endregion

        sealed class Enum : IEnumSetupInstances
        {
            private readonly SetupConfiguration _owner;
            private int _idx;

            internal Enum(SetupConfiguration owner)
            {
                this._owner = owner;
            }

            public IEnumSetupInstances Clone()
            {
                Ext.LogCall(nameof(Enum), nameof(Clone));
                return ((Enum)MemberwiseClone()).ComBarrier<Enum, IEnumSetupInstances>();
            }

            public void Next([In, MarshalAs(UnmanagedType.U4)] int celt, [MarshalAs(UnmanagedType.LPArray, ArraySubType = UnmanagedType.Interface), Out] ISetupInstance[] rgelt, [MarshalAs(UnmanagedType.U4)] out int pceltFetched)
            {
                Ext.LogEnter(nameof(Enum), nameof(Next));
                if (_idx == 0 && celt > 0)
                {
                    rgelt[0] = _owner._singleInstance.ComBarrier<SetupInstance, ISetupInstance>();
                    pceltFetched = 1;
                }
                else
                {
                    pceltFetched = 0;
                }
                Ext.LogExit(nameof(Enum), nameof(Next));
            }

            public void Reset()
            {
                Ext.LogCall(nameof(Enum), nameof(Reset));
                _idx = 0;
            }

            public void Skip([In, MarshalAs(UnmanagedType.U4)] int celt)
            {
                Ext.LogEnter(nameof(Enum), nameof(Skip));
                if (celt < 0)
                    throw new ArgumentOutOfRangeException();
                _idx += celt;
                Ext.LogExit(nameof(Enum), nameof(Skip));
            }
        }

        /*
                [ComImport]
                [Guid("42843719-DB4C-46C2-8E7C-64F1816EFD5B")]
                [InterfaceType(ComInterfaceType.InterfaceIsIUnknown)]
                public interface ISetupConfigurationTest
                {
                  [return: MarshalAs(UnmanagedType.Interface)]
                    IEnumSetupInstances EnumInstances();
                    [return: MarshalAs(UnmanagedType.Interface)]
                    ISetupInstance GetInstanceForCurrentProcess();
                    [return: MarshalAs(UnmanagedType.Interface)]
                    ISetupInstance GetInstanceForPath([In] [MarshalAs(UnmanagedType.LPWStr)] string path);
                }
        */
    }
}