using System;
using System.Runtime.InteropServices;
using System.Text;

namespace MGdu.WinFormUI.Win32
{
    internal static class WinAPI
    {
        #region const

        public static readonly IntPtr TRUE = new IntPtr(1);
        public static readonly IntPtr FALSE = IntPtr.Zero;

        #endregion

        #region WindowMessages

        public enum WindowMessages
        {            
            WM_MOVE = 0x0003,
            WM_SIZE = 0x0005,
            WM_ACTIVATE = 0x0006,

            WM_ACTIVATEAPP = 0x001C,

            WM_SETCURSOR = 0x0020,
            WM_MOUSEACTIVATE = 0x0021,
            WM_GETMINMAXINFO = 0x24,
            WM_WINDOWPOSCHANGING = 0x0046,
            WM_WINDOWPOSCHANGED = 0x0047,

            // non client area
            WM_NCCREATE = 0x0081,
            WM_NCDESTROY = 0x0082,
            WM_NCCALCSIZE = 0x0083,
            WM_NCHITTEST = 0x84,
            WM_NCPAINT = 0x0085,
            WM_NCACTIVATE = 0x0086,

            // non client mouse
            WM_NCMOUSEMOVE = 0x00A0,
            WM_NCLBUTTONDOWN = 0x00A1,
            WM_NCLBUTTONUP = 0x00A2,
            WM_NCLBUTTONDBLCLK = 0x00A3,
            WM_NCRBUTTONDOWN = 0x00A4,
            WM_NCRBUTTONUP = 0x00A5,
            WM_NCRBUTTONDBLCLK = 0x00A6,
            WM_NCMBUTTONDOWN = 0x00A7,
            WM_NCMBUTTONUP = 0x00A8,
            WM_NCMBUTTONDBLCLK = 0x00A9,

            WM_SYSCOMMAND = 0x0112,
            WM_PARENTNOTIFY = 0x0210,

            WM_MDINEXT = 0x224,
        }

        #endregion        

        #region WindowStyle

        [Flags]
        public enum WindowStyle : uint
        {
            WS_OVERLAPPED = 0x00000000,
            WS_POPUP = 0x80000000,
            WS_CHILD = 0x40000000,
            WS_MINIMIZE = 0x20000000,
            WS_VISIBLE = 0x10000000,
            WS_DISABLED = 0x08000000,
            WS_CLIPSIBLINGS = 0x04000000,
            WS_CLIPCHILDREN = 0x02000000,
            WS_MAXIMIZE = 0x01000000,
            WS_CAPTION = 0x00C00000,
            WS_BORDER = 0x00800000,
            WS_DLGFRAME = 0x00400000,
            WS_VSCROLL = 0x00200000,
            WS_HSCROLL = 0x00100000,
            WS_SYSMENU = 0x00080000,
            WS_THICKFRAME = 0x00040000,
            WS_GROUP = 0x00020000,
            WS_TABSTOP = 0x00010000,
            WS_MINIMIZEBOX = 0x00020000,
            WS_MAXIMIZEBOX = 0x00010000,
            WS_TILED = WS_OVERLAPPED,
            WS_ICONIC = WS_MINIMIZE,
            WS_SIZEBOX = WS_THICKFRAME,
            WS_TILEDWINDOW = WS_OVERLAPPEDWINDOW,
            WS_OVERLAPPEDWINDOW = (WS_OVERLAPPED | WS_CAPTION | WS_SYSMENU |
                                    WS_THICKFRAME | WS_MINIMIZEBOX | WS_MAXIMIZEBOX),
            WS_POPUPWINDOW = (WS_POPUP | WS_BORDER | WS_SYSMENU),
            WS_CHILDWINDOW = (WS_CHILD)
        }

        #endregion

        #region WindowStyleEx

        [Flags]
        public enum WindowStyleEx
        {
            WS_EX_DLGMODALFRAME = 0x00000001,
            WS_EX_NOPARENTNOTIFY = 0x00000004,
            WS_EX_TOPMOST = 0x00000008,
            WS_EX_ACCEPTFILES = 0x00000010,
            WS_EX_TRANSPARENT = 0x00000020,
            WS_EX_MDICHILD = 0x00000040,
            WS_EX_TOOLWINDOW = 0x00000080,
            WS_EX_WINDOWEDGE = 0x00000100,
            WS_EX_CLIENTEDGE = 0x00000200,
            WS_EX_CONTEXTHELP = 0x00000400,
            WS_EX_RIGHT = 0x00001000,
            WS_EX_LEFT = 0x00000000,
            WS_EX_RTLREADING = 0x00002000,
            WS_EX_LTRREADING = 0x00000000,
            WS_EX_LEFTSCROLLBAR = 0x00004000,
            WS_EX_RIGHTSCROLLBAR = 0x00000000,
            WS_EX_CONTROLPARENT = 0x00010000,
            WS_EX_STATICEDGE = 0x00020000,
            WS_EX_APPWINDOW = 0x00040000,
            WS_EX_OVERLAPPEDWINDOW = (WS_EX_WINDOWEDGE | WS_EX_CLIENTEDGE),
            WS_EX_PALETTEWINDOW = (WS_EX_WINDOWEDGE | WS_EX_TOOLWINDOW | WS_EX_TOPMOST),
            WS_EX_LAYERED = 0x00080000,
            WS_EX_NOINHERITLAYOUT = 0x00100000, // Disable inheritence of mirroring by children
            WS_EX_LAYOUTRTL = 0x00400000, // Right to left mirroring
            WS_EX_COMPOSITED = 0x02000000,
            WS_EX_NOACTIVATE = 0x08000000,
        }

        #endregion

        #region Scrollbar

        public enum ScrollBar
        {
            SB_HORZ = 0,
            SB_VERT = 1,
            SB_CTL = 2,
            SB_BOTH = 3,
        }

        #endregion

        #region NCHITTEST
        /// <summary>
        /// Location of cursor hot spot returnet in WM_NCHITTEST.
        /// </summary>
        public enum NCHITTEST
        {
            /// <summary>
            /// On the screen background or on a dividing line between windows 
            /// (same as HTNOWHERE, except that the DefWindowProc function produces a system beep to indicate an error).
            /// </summary>
            HTERROR = (-2),
            /// <summary>
            /// In a window currently covered by another window in the same thread 
            /// (the message will be sent to underlying windows in the same thread until one of them returns a code that is not HTTRANSPARENT).
            /// </summary>
            HTTRANSPARENT = (-1),
            /// <summary>
            /// On the screen background or on a dividing line between windows.
            /// </summary>
            HTNOWHERE = 0,
            /// <summary>In a client area.</summary>
            HTCLIENT = 1,
            /// <summary>In a title bar.</summary>
            HTCAPTION = 2,
            /// <summary>In a window menu or in a Close button in a child window.</summary>
            HTSYSMENU = 3,
            /// <summary>In a size box (same as HTSIZE).</summary>
            HTGROWBOX = 4,
            /// <summary>In a menu.</summary>
            HTMENU = 5,
            /// <summary>In a horizontal scroll bar.</summary>
            HTHSCROLL = 6,
            /// <summary>In the vertical scroll bar.</summary>
            HTVSCROLL = 7,
            /// <summary>In a Minimize button.</summary>
            HTMINBUTTON = 8,
            /// <summary>In a Maximize button.</summary>
            HTMAXBUTTON = 9,
            /// <summary>In the left border of a resizable window 
            /// (the user can click the mouse to resize the window horizontally).</summary>
            HTLEFT = 10,
            /// <summary>
            /// In the right border of a resizable window 
            /// (the user can click the mouse to resize the window horizontally).
            /// </summary>
            HTRIGHT = 11,
            /// <summary>In the upper-horizontal border of a window.</summary>
            HTTOP = 12,
            /// <summary>In the upper-left corner of a window border.</summary>
            HTTOPLEFT = 13,
            /// <summary>In the upper-right corner of a window border.</summary>
            HTTOPRIGHT = 14,
            /// <summary>	In the lower-horizontal border of a resizable window 
            /// (the user can click the mouse to resize the window vertically).</summary>
            HTBOTTOM = 15,
            /// <summary>In the lower-left corner of a border of a resizable window 
            /// (the user can click the mouse to resize the window diagonally).</summary>
            HTBOTTOMLEFT = 16,
            /// <summary>	In the lower-right corner of a border of a resizable window 
            /// (the user can click the mouse to resize the window diagonally).</summary>
            HTBOTTOMRIGHT = 17,
            /// <summary>In the border of a window that does not have a sizing border.</summary>
            HTBORDER = 18,

            HTOBJECT = 19,
            /// <summary>In a Close button.</summary>
            HTCLOSE = 20,
            /// <summary>In a Help button.</summary>
            HTHELP = 21,
        }

        #endregion

        #region struct

        [StructLayout(LayoutKind.Sequential)]
        public 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;
            }

            public override string ToString()
            {
                return "{ Left:" + this.Left + ", Top:" + this.Top
                    + ", Width:" + (this.Right - this.Left).ToString()
                    + ", Height:" + (this.Bottom - this.Top).ToString() + "}";
            }
        }

        [StructLayout(LayoutKind.Sequential)]
        public struct WINDOWPOS
        {
            public IntPtr hwnd;
            public IntPtr hWndInsertAfter;
            public int x;
            public int y;
            public int cx;
            public int cy;
            public uint flags;
        }

        [StructLayout(LayoutKind.Sequential)]
        public struct NCCALCSIZE_PARAMS
        {
            /// <summary>
            /// Contains the new coordinates of a window that has been moved or resized, that is, it is the proposed new window coordinates.
            /// </summary>
            public RECT rectNewForm;
            /// <summary>
            /// Contains the coordinates of the window before it was moved or resized.
            /// </summary>
            public RECT rectOldForm;
            /// <summary>
            /// Contains the coordinates of the window's client area before the window was moved or resized.
            /// </summary>
            public RECT rectOldClient;
            /// <summary>
            /// Pointer to a WINDOWPOS structure that contains the size and position values specified in the operation that moved or resized the window.
            /// </summary>
            public WINDOWPOS lpPos;
        }

        [StructLayout(LayoutKind.Sequential)]
        public struct SIZE
        {
            public Int32 cx;
            public Int32 cy;

            public SIZE(Int32 x, Int32 y)
            {
                cx = x;
                cy = y;
            }
        }

        [StructLayout(LayoutKind.Sequential)]
        public struct BLENDFUNCTION
        {
            byte BlendOp;
            byte BlendFlags;
            byte SourceConstantAlpha;
            byte AlphaFormat;

            public BLENDFUNCTION(byte op, byte flags, byte alpha, byte format)
            {
                BlendOp = op;
                BlendFlags = flags;
                SourceConstantAlpha = alpha;
                AlphaFormat = format;
            }
        }

        public enum BlendOp : byte
        {
            AC_SRC_OVER = 0x00,
            AC_SRC_ALPHA = 0x01,
        }        

        [StructLayout(LayoutKind.Sequential)]
        public struct POINT
        {
            public Int32 x;
            public Int32 y;

            public POINT(Int32 x, Int32 y)
            {
                this.x = x;
                this.y = y;
            }
        }

        #endregion

        // update-layered-window
        public enum ULWPara
        {
            ULW_COLORKEY = 0x00000001,
            ULW_ALPHA = 0x00000002,
            ULW_OPAQUE = 0x00000004,
            ULW_EX_NORESIZE = 0x00000008,
        }

        // get-wondow-long
        public enum GWLPara
        {
            GWL_WNDPROC = -4,
            GWL_HINSTANCE = -6,
            GWL_HWNDPARENT = -8,
            GWL_STYLE = -16,
            GWL_EXSTYLE = -20,
            GWL_USERDATA = -21,
            GWL_ID = -12,
        }

        // set-window-position
        public enum SWPPara : uint
        {
            SWP_NOSIZE = 0x0001,
            SWP_NOMOVE = 0x0002,
            SWP_NOZORDER = 0x0004,
            SWP_NOREDRAW = 0x0008,
            SWP_NOACTIVATE = 0x0010,
            SWP_FRAMECHANGED = 0x0020,
            SWP_SHOWWINDOW = 0x0040,
            SWP_HIDEWINDOW = 0x0080,
            SWP_NOCOPYBITS = 0x0100,
            SWP_NOOWNERZORDER = 0x0200,
            SWP_NOSENDCHANGING = 0x0400,
        }

        #region non-dll method

        public static int LOWORD(int value)
        {
            return value & 0xFFFF;
        }

        public static int HIWORD(int value)
        {
            return value >> 16;
        }

        #endregion

        #region dll-import method

        [DllImport("user32.dll")]
        public static extern int ShowScrollBar(IntPtr hWnd, int wBar, int bShow);

        [DllImport("user32.dll", CharSet = CharSet.Auto)]
        public static extern int GetWindowLong(IntPtr hWnd, int Index);

        [DllImport("user32.dll", CharSet = CharSet.Auto)]
        public static extern int SetWindowLong(IntPtr hWnd, int Index, int Value);

        [DllImport("user32.dll", ExactSpelling = true)]
        public static extern int SetWindowPos(IntPtr hWnd, IntPtr hWndInsertAfter, int X, int Y, int cx, int cy, uint uFlags);

        [DllImport("user32.dll", ExactSpelling = true, SetLastError = true)]
        public static extern IntPtr GetDC(IntPtr hWnd);

        [DllImport("gdi32.dll", ExactSpelling = true, PreserveSig = true, SetLastError = true)]
        public static extern IntPtr SelectObject(IntPtr hdc, IntPtr hgdiobj);

        [DllImport("gdi32.dll")]
        public static extern bool DeleteDC(IntPtr hdc);

        [DllImport("user32.dll", ExactSpelling = true)]
        public static extern int ReleaseDC(IntPtr hWnd, IntPtr hDC);

        [DllImport("gdi32.dll")]
        public static extern bool DeleteObject(IntPtr hObject);

        [DllImport("gdi32.dll", SetLastError = true)]
        public static extern IntPtr CreateCompatibleDC(IntPtr hdc);

        [DllImport("user32.dll", ExactSpelling = true, SetLastError = true)]
        public static extern bool UpdateLayeredWindow(IntPtr hwnd
            , IntPtr hdcDst
            , ref POINT pptDst
            , ref SIZE psize
            , IntPtr hdcSrc
            , ref POINT pptSrc
            , uint crKey
            , [In] ref BLENDFUNCTION pblend
            , uint dwFlags
            );

        [System.Security.SuppressUnmanagedCodeSecurity]
        [DllImport("user32.dll", CharSet = CharSet.Auto)]
        public static extern IntPtr SendMessage(IntPtr hWnd, int msg,
                                    IntPtr wParam, IntPtr lParam);

        #endregion
    }
}