using System;
using System.Runtime.InteropServices;
using System.Text;
using FILETIME = System.Runtime.InteropServices.ComTypes.FILETIME;

namespace Vanara.PInvoke
{
	public static partial class Shell32
	{
		[Flags]
		public enum IEIFLAG
		{
			/// <summary>
			/// Used to ask the object to use the supplied aspect ratio. If this flag is set, a rectangle with the desired aspect ratio will
			/// be passed in prgSize. This flag cannot be used with IEIFLAG_SCREEN.
			/// </summary>
			IEIFLAG_ASPECT = 0x0004,

			/// <summary>
			/// Not used. The thumbnail is always extracted on a background thread. Microsoft Windows XP and earlier. Used to ask if this
			/// instance supports asynchronous (free-threaded) extraction. If this flag is set by the calling applications,
			/// IExtractImage::GetLocation may return E_PENDING, indicating to the calling application to extract the image on another
			/// thread. If E_PENDING is returned, the priority of the item is returned in pdwPriority.
			/// </summary>
			IEIFLAG_ASYNC = 0x0001,

			/// <summary>
			/// Not supported. Windows XP and earlier: Set by the object to indicate that it will not cache the image. If this flag is
			/// returned, the Shell will cache a copy of the image.
			/// </summary>
			IEIFLAG_CACHE = 0x0002,

			/// <summary>Not supported.</summary>
			IEIFLAG_GLEAM = 0x0010,

			/// <summary>Not supported.</summary>
			IEIFLAG_NOBORDER = 0x0100,

			/// <summary>Not supported.</summary>
			IEIFLAG_NOSTAMP = 0x0080,

			/// <summary>Used to tell the object to use only local content for rendering.</summary>
			IEIFLAG_OFFLINE = 0x0008,

			/// <summary>
			/// Version 5.0. Used to tell the object to render the image to the approximate size passed in prgSize, but crop it if necessary.
			/// </summary>
			IEIFLAG_ORIGSIZE = 0x0040,

			/// <summary>
			/// Passed to the IExtractImage::Extract method to indicate that a higher quality image is requested. If this flag is not set,
			/// IExtractImage retrieves an embedded thumbnail if the file has one, no matter what size the user requests. For example, if
			/// the file is 2000x2000 pixels but the embedded thumbnail is only 100x100 pixels and the user does not set this flag, yet
			/// requests a 1000x1000 pixel thumbnail, IExtractImage always returns the 100x100 pixel thumbnail. This is by design, since
			/// IExtractImage does not scale up. If a larger thumbnail is desired (usually embedded thumbnails are 160x160), this flag must
			/// be set.
			/// </summary>
			IEIFLAG_QUALITY = 0x0200,

			/// <summary>Returned by the object to indicate that Refresh Thumbnail should be displayed on the item's shortcut menu.</summary>
			IEIFLAG_REFRESH = 0x0400,

			/// <summary>Used to tell the object to render as if for the screen. This flag cannot be used with IEIFLAG_ASPECT.</summary>
			IEIFLAG_SCREEN = 0x0020,
		}

		/// <summary>Exposes methods that request a thumbnail image from a Shell folder.</summary>
		[ComImport, Guid("BB2E617C-0920-11d1-9A0B-00C04FC2D6C1"), InterfaceType(ComInterfaceType.InterfaceIsIUnknown)]
		[PInvokeData("Shobjidl.h", MSDNShortId = "bb761848")]
		public interface IExtractImage
		{
			/// <summary>Gets a path to the image that is to be extracted.</summary>
			/// <param name="pszPathBuffer">
			/// The buffer used to return the path description. This value identifies the image so you can avoid loading the same one more
			/// than once.
			/// </param>
			/// <param name="cchMax">The size of pszPathBuffer in characters.</param>
			/// <param name="pdwPriority">Not used.</param>
			/// <param name="prgSize">A pointer to a SIZE structure with the desired width and height of the image. Must not be NULL.</param>
			/// <param name="dwRecClrDepth">The recommended color depth in units of bits per pixel. Must not be NULL.</param>
			/// <param name="pdwFlags">Flags that specify how the image is to be handled.</param>
			/// <returns>
			/// This method may return a COM-defined error code or one of the following:
			/// <list type="table">
			/// <listheader>
			/// <term>Return code</term>
			/// <term>Description</term>
			/// </listheader>
			/// <item>
			/// <term>S_OK</term>
			/// <definition>Success</definition>
			/// </item>
			/// <item>
			/// <term>E_PENDING</term>
			/// <definition>Windows XP and earlier: If the IEIFLAG_ASYNC flag is set, this return value is used to indicate to the Shell
			/// that the object is free-threaded.</definition>
			/// </item>
			/// </list>
			/// </returns>
			[PreserveSig]
			HRESULT GetLocation([Out, MarshalAs(UnmanagedType.LPWStr)] StringBuilder pszPathBuffer, uint cchMax, [Optional] IntPtr pdwPriority, ref SIZE prgSize, uint dwRecClrDepth, ref IEIFLAG pdwFlags);

			/// <summary>Requests an image from an object, such as an item in a Shell folder.</summary>
			/// <returns>The HBITMAP of the image.</returns>
			HBITMAP Extract();
		}

		/// <summary>Extends the capabilities of IExtractImage.</summary>
		/// <remarks>
		/// <para>Implement <c>IExtractImage2</c> to provide date stamps for your thumbnail images.</para>
		/// <para>
		/// You do not call this interface directly. <c>IExtractImage2</c> is used by the operating system only when it has confirmed that
		/// your application is aware of this interface.
		/// </para>
		/// <para>
		/// <c>IExtractImage2</c> implements all the IExtractImage methods as well as <c>IUnknown</c>. The listed method is specific to <c>IExtractImage2</c>.
		/// </para>
		/// </remarks>
		// https://docs.microsoft.com/en-us/windows/win32/api/shobjidl_core/nn-shobjidl_core-iextractimage2
		[PInvokeData("shobjidl_core.h", MSDNShortId = "NN:shobjidl_core.IExtractImage2")]
		[ComImport, Guid("953BB1EE-93B4-11d1-98A3-00C04FB687DA"), InterfaceType(ComInterfaceType.InterfaceIsIUnknown)]
		public interface IExtractImage2 : IExtractImage
		{
			/// <summary>Gets a path to the image that is to be extracted.</summary>
			/// <param name="pszPathBuffer">
			/// The buffer used to return the path description. This value identifies the image so you can avoid loading the same one more
			/// than once.
			/// </param>
			/// <param name="cchMax">The size of pszPathBuffer in characters.</param>
			/// <param name="pdwPriority">Not used.</param>
			/// <param name="prgSize">A pointer to a SIZE structure with the desired width and height of the image. Must not be NULL.</param>
			/// <param name="dwRecClrDepth">The recommended color depth in units of bits per pixel. Must not be NULL.</param>
			/// <param name="pdwFlags">Flags that specify how the image is to be handled.</param>
			/// <returns>
			/// This method may return a COM-defined error code or one of the following:
			/// <list type="table">
			/// <listheader>
			/// <term>Return code</term>
			/// <term>Description</term>
			/// </listheader>
			/// <item>
			/// <term>S_OK</term>
			/// <definition>Success</definition>
			/// </item>
			/// <item>
			/// <term>E_PENDING</term>
			/// <definition>Windows XP and earlier: If the IEIFLAG_ASYNC flag is set, this return value is used to indicate to the Shell
			/// that the object is free-threaded.</definition>
			/// </item>
			/// </list>
			/// </returns>
			[PreserveSig]
			new HRESULT GetLocation([Out, MarshalAs(UnmanagedType.LPWStr)] StringBuilder pszPathBuffer, uint cchMax, [Optional] IntPtr pdwPriority, ref SIZE prgSize, uint dwRecClrDepth, ref IEIFLAG pdwFlags);

			/// <summary>Requests an image from an object, such as an item in a Shell folder.</summary>
			/// <returns>The HBITMAP of the image.</returns>
			new HBITMAP Extract();

			/// <summary>
			/// Requests the date the image was last modified. This method allows the Shell to determine whether cached images are out-of-date.
			/// </summary>
			/// <returns>
			/// <para>Type: <c>FILETIME*</c></para>
			/// <para>A pointer to a FILETIME structure used to return the last time the image was modified.</para>
			/// </returns>
			// https://docs.microsoft.com/en-us/windows/win32/api/shobjidl_core/nf-shobjidl_core-iextractimage2-getdatestamp HRESULT
			// GetDateStamp( FILETIME *pDateStamp );
			FILETIME GetDateStamp();
		}
	}
}