using System;
using System.Runtime.InteropServices;

namespace Windows7Taskbar
{
    #region Interop ITaskbarList3

    internal enum TBPFLAG
    {
        TBPF_NOPROGRESS = 0,
        TBPF_INDETERMINATE = 0x1,
        TBPF_NORMAL = 0x2,
        TBPF_ERROR = 0x4,
        TBPF_PAUSED = 0x8
    }

    internal enum TBATFLAG
    {
        TBATF_USEMDITHUMBNAIL = 0x1,
        TBATF_USEMDILIVEPREVIEW = 0x2
    }

    [StructLayout(LayoutKind.Sequential, CharSet = CharSet.Auto)]
    internal struct THUMBBUTTON
    {
        [MarshalAs(UnmanagedType.U4)]
        public THBMASK dwMask;
        public uint iId;
        public uint iBitmap;
        public IntPtr hIcon;
        [MarshalAs(UnmanagedType.ByValTStr, SizeConst = 260)]
        public string szTip;
        [MarshalAs(UnmanagedType.U4)]
        public THBFLAGS dwFlags;
    }

    [StructLayout(LayoutKind.Sequential)]
    internal struct RECT
    {
        public int left;
        public int top;
        public int right;
        public int bottom;

        public RECT(int left, int top, int right, int bottom)
        {
            this.left = left;
            this.top = top;
            this.right = right;
            this.bottom = bottom;
        }
    }

    internal enum THBMASK
    {
        THB_BITMAP = 0x1,
        THB_ICON = 0x2,
        THB_TOOLTIP = 0x4,
        THB_FLAGS = 0x8
    }

    internal enum THBFLAGS
    {
        THBF_ENABLED = 0,
        THBF_DISABLED = 0x1,
        THBF_DISMISSONCLICK = 0x2,
        THBF_NOBACKGROUND = 0x4,
        THBF_HIDDEN = 0x8
    }

    [ComImportAttribute()]
    [GuidAttribute("ea1afb91-9e28-4b86-90e9-9e9f8a5eefaf")]
    [InterfaceTypeAttribute(ComInterfaceType.InterfaceIsIUnknown)]
    internal interface ITaskbarList3
    {
        // ITaskbarList
        [PreserveSig]
        void HrInit();
        [PreserveSig]
        void AddTab(IntPtr hwnd);
        [PreserveSig]
        void DeleteTab(IntPtr hwnd);
        [PreserveSig]
        void ActivateTab(IntPtr hwnd);
        [PreserveSig]
        void SetActiveAlt(IntPtr hwnd);

        // ITaskbarList2
        [PreserveSig]
        void MarkFullscreenWindow(
            IntPtr hwnd,
            [MarshalAs(UnmanagedType.Bool)] bool fFullscreen);

        // ITaskbarList3
        void SetProgressValue(IntPtr hwnd, UInt64 ullCompleted, UInt64 ullTotal);
        void SetProgressState(IntPtr hwnd, TBPFLAG tbpFlags);
        void RegisterTab(IntPtr hwndTab, IntPtr hwndMDI);
        void UnregisterTab(IntPtr hwndTab);
        void SetTabOrder(IntPtr hwndTab, IntPtr hwndInsertBefore);
        void SetTabActive(IntPtr hwndTab, IntPtr hwndMDI, TBATFLAG tbatFlags);
        void ThumbBarAddButtons(
            IntPtr hwnd,
            uint cButtons,
            [MarshalAs(UnmanagedType.LPArray)] THUMBBUTTON[] pButtons);
        void ThumbBarUpdateButtons(
            IntPtr hwnd,
            uint cButtons,
            [MarshalAs(UnmanagedType.LPArray)] THUMBBUTTON[] pButtons);
        void ThumbBarSetImageList(IntPtr hwnd, IntPtr himl);
        void SetOverlayIcon(
          IntPtr hwnd,
          IntPtr hIcon,
          [MarshalAs(UnmanagedType.LPWStr)] string pszDescription);
        void SetThumbnailTooltip(
            IntPtr hwnd,
            [MarshalAs(UnmanagedType.LPWStr)] string pszTip);
        void SetThumbnailClip(
            IntPtr hwnd,
            /*[MarshalAs(UnmanagedType.LPStruct)]*/ ref RECT prcClip);
    }

    [GuidAttribute("56FDF344-FD6D-11d0-958A-006097C9A090")]
    [ClassInterfaceAttribute(ClassInterfaceType.None)]
    [ComImportAttribute()]
    internal class CTaskbarList { }

    #endregion

    public static class Windows7Taskbar
    {
        #region Infrastructure

        private static ITaskbarList3 _taskbarList;
        internal static ITaskbarList3 TaskbarList
        {
            get
            {
                if (_taskbarList == null)
                {
                    lock (typeof(Windows7Taskbar))
                    {
                        if (_taskbarList == null)
                        {
                            _taskbarList = (ITaskbarList3)new CTaskbarList();
                            _taskbarList.HrInit();
                        }
                    }
                }
                return _taskbarList;
            }
        }

        #endregion

        #region Taskbar Progress Bar

        /// <summary>
        /// Represents the thumbnail progress bar state.
        /// </summary>
        public enum ThumbnailProgressState
        {
            /// <summary>
            /// No progress is displayed.
            /// </summary>
            NoProgress = 0,
            /// <summary>
            /// The progress is indeterminate (marquee).
            /// </summary>
            Indeterminate = 0x1,
            /// <summary>
            /// Normal progress is displayed.
            /// </summary>
            Normal = 0x2,
            /// <summary>
            /// An error occurred (red).
            /// </summary>
            Error = 0x4,
            /// <summary>
            /// The operation is paused (yellow).
            /// </summary>
            Paused = 0x8
        }

        /// <summary>
        /// Sets the progress state of the specified window's
        /// taskbar button.
        /// </summary>
        /// <param name="hwnd">The window handle.</param>
        /// <param name="state">The progress state.</param>
        public static void SetProgressState(IntPtr hwnd,
            ThumbnailProgressState state)
        {
            TaskbarList.SetProgressState(hwnd, (TBPFLAG)state);
        }
        /// <summary>
        /// Sets the progress value of the specified window's
        /// taskbar button.
        /// </summary>
        /// <param name="hwnd">The window handle.</param>
        /// <param name="current">The current value.</param>
        /// <param name="maximum">The maximum value.</param>
        public static void SetProgressValue(IntPtr hwnd,
            ulong current, ulong maximum)
        {
            TaskbarList.SetProgressValue(hwnd, current, maximum);
        }

        #endregion
    }
}