// 8 february 2014
package main

import (
//	"syscall"
	"unsafe"
)

// Window styles.
const (
	_WS_BORDER = 0x00800000
	_WS_CAPTION = 0x00C00000
	_WS_CHILD = 0x40000000
	_WS_CHILDWINDOW = 0x40000000
	_WS_CLIPCHILDREN = 0x02000000
	_WS_CLIPSIBLINGS = 0x04000000
	_WS_DISABLED = 0x08000000
	_WS_DLGFRAME = 0x00400000
	_WS_GROUP = 0x00020000
	_WS_HSCROLL = 0x00100000
	_WS_ICONIC = 0x20000000
	_WS_MAXIMIZE = 0x01000000
	_WS_MAXIMIZEBOX = 0x00010000
	_WS_MINIMIZE = 0x20000000
	_WS_MINIMIZEBOX = 0x00020000
	_WS_OVERLAPPED = 0x00000000
	_WS_OVERLAPPEDWINDOW = (_WS_OVERLAPPED | _WS_CAPTION | _WS_SYSMENU | _WS_THICKFRAME | _WS_MINIMIZEBOX | _WS_MAXIMIZEBOX)
	_WS_POPUP = 0x80000000
	_WS_POPUPWINDOW = (_WS_POPUP | _WS_BORDER | _WS_SYSMENU)
	_WS_SIZEBOX = 0x00040000
	_WS_SYSMENU = 0x00080000
	_WS_TABSTOP = 0x00010000
	_WS_THICKFRAME = 0x00040000
	_WS_TILED = 0x00000000
	_WS_TILEDWINDOW = (_WS_OVERLAPPED | _WS_CAPTION | _WS_SYSMENU | _WS_THICKFRAME | _WS_MINIMIZEBOX | _WS_MAXIMIZEBOX)
	_WS_VISIBLE = 0x10000000
	_WS_VSCROLL = 0x00200000
)

// Extended window styles.
const (
	_WS_EX_ACCEPTFILES = 0x00000010
	_WS_EX_APPWINDOW = 0x00040000
	_WS_EX_CLIENTEDGE = 0x00000200
//	_WS_EX_COMPOSITED = 0x02000000	// [Windows 2000:This style is not supported.]
	_WS_EX_CONTEXTHELP = 0x00000400
	_WS_EX_CONTROLPARENT = 0x00010000
	_WS_EX_DLGMODALFRAME = 0x00000001
	_WS_EX_LAYERED = 0x00080000
	_WS_EX_LAYOUTRTL = 0x00400000
	_WS_EX_LEFT = 0x00000000
	_WS_EX_LEFTSCROLLBAR = 0x00004000
	_WS_EX_LTRREADING = 0x00000000
	_WS_EX_MDICHILD = 0x00000040
	_WS_EX_NOACTIVATE = 0x08000000
	_WS_EX_NOINHERITLAYOUT = 0x00100000
	_WS_EX_NOPARENTNOTIFY = 0x00000004
	_WS_EX_OVERLAPPEDWINDOW = (_WS_EX_WINDOWEDGE | _WS_EX_CLIENTEDGE)
	_WS_EX_PALETTEWINDOW = (_WS_EX_WINDOWEDGE | _WS_EX_TOOLWINDOW | _WS_EX_TOPMOST)
	_WS_EX_RIGHT = 0x00001000
	_WS_EX_RIGHTSCROLLBAR = 0x00000000
	_WS_EX_RTLREADING = 0x00002000
	_WS_EX_STATICEDGE = 0x00020000
	_WS_EX_TOOLWINDOW = 0x00000080
	_WS_EX_TOPMOST = 0x00000008
	_WS_EX_TRANSPARENT = 0x00000020
	_WS_EX_WINDOWEDGE = 0x00000100
)

// bizarrely, this value is given on the page for CreateMDIWindow, but not CreateWindow or CreateWindowEx
// I do it this way because Go won't let me shove the exact value into an int
var (
	__CW_USEDEFAULT uint = 0x80000000
	_CW_USEDEFAULT = int(__CW_USEDEFAULT)
)

// GetSysColor values. These can be cast to HBRUSH (after adding 1) for WNDCLASS as well.
const (
	_COLOR_3DDKSHADOW = 21
	_COLOR_3DFACE = 15
	_COLOR_3DHIGHLIGHT = 20
	_COLOR_3DHILIGHT = 20
	_COLOR_3DLIGHT = 22
	_COLOR_3DSHADOW = 16
	_COLOR_ACTIVEBORDER = 10
	_COLOR_ACTIVECAPTION = 2
	_COLOR_APPWORKSPACE = 12
	_COLOR_BACKGROUND = 1
	_COLOR_BTNFACE = 15
	_COLOR_BTNHIGHLIGHT = 20
	_COLOR_BTNHILIGHT = 20
	_COLOR_BTNSHADOW = 16
	_COLOR_BTNTEXT = 18
	_COLOR_CAPTIONTEXT = 9
	_COLOR_DESKTOP = 1
	_COLOR_GRADIENTACTIVECAPTION = 27
	_COLOR_GRADIENTINACTIVECAPTION = 28
	_COLOR_GRAYTEXT = 17
	_COLOR_HIGHLIGHT = 13
	_COLOR_HIGHLIGHTTEXT = 14
	_COLOR_HOTLIGHT = 26
	_COLOR_INACTIVEBORDER = 11
	_COLOR_INACTIVECAPTION = 3
	_COLOR_INACTIVECAPTIONTEXT = 19
	_COLOR_INFOBK = 24
	_COLOR_INFOTEXT = 23
	_COLOR_MENU = 4
//	COLOR_MENUHILIGHT = 29	// [Windows 2000:This value is not supported.]
//	COLOR_MENUBAR = 30		// [Windows 2000:This value is not supported.]
	_COLOR_MENUTEXT = 7
	_COLOR_SCROLLBAR = 0
	_COLOR_WINDOW = 5
	_COLOR_WINDOWFRAME = 6
	_COLOR_WINDOWTEXT = 8
)

// SetWindowPos hWndInsertAfter values.
const (
	_HWND_BOTTOM = _HWND(1)
	_HWND_TOP = _HWND(0)
)

// SetWindowPos hWndInsertAfter values that Go won't allow as constants.
var (
	__HWND_NOTOPMOST = -2
	_HWND_NOTOPMOST = _HWND(__HWND_NOTOPMOST)
	__HWND_TOPMOST = -1
	_HWND_TOPMOST = _HWND(__HWND_TOPMOST)
)

// SetWindowPos uFlags values.
const (
	_SWP_DRAWFRAME = 0x0020
	_SWP_FRAMECHANGED = 0x0020
	_SWP_HIDEWINDOW = 0x0080
	_SWP_NOACTIVATE = 0x0010
	_SWP_NOCOPYBITS = 0x0100
	_SWP_NOMOVE = 0x0002
	_SWP_NOOWNERZORDER = 0x0200
	_SWP_NOREDRAW = 0x0008
	_SWP_NOREPOSITION = 0x0200
	_SWP_NOSENDCHANGING = 0x0400
	_SWP_NOSIZE = 0x0001
	_SWP_NOZORDER = 0x0004
	_SWP_SHOWWINDOW = 0x0040
	_SWP_ASYNCWINDOWPOS = 0x4000
	_SWP_DEFERERASE = 0x2000
)

// ShowWindow settings.
const (
	_SW_FORCEMINIMIZE = 11
	_SW_HIDE = 0
	_SW_MAXIMIZE = 3
	_SW_MINIMIZE = 6
	_SW_RESTORE = 9
	_SW_SHOW = 5
	_SW_SHOWDEFAULT = 10
	_SW_SHOWMAXIMIZED = 3
	_SW_SHOWMINIMIZED = 2
	_SW_SHOWMINNOACTIVE = 7
	_SW_SHOWNA = 8
	_SW_SHOWNOACTIVATE = 4
	_SW_SHOWNORMAL = 1
)

var (
	_createWindowEx = user32.NewProc("CreateWindowExW")
	_destroyWindow = user32.NewProc("DestroyWindow")
	_getClientRect = user32.NewProc("GetClientRect")
	_enumChildWindows = user32.NewProc("EnumChildWindows")
	_setWindowPos = user32.NewProc("SetWindowPos")
	_setWindowText = user32.NewProc("SetWindowTextW")
	_showWindow = user32.NewProc("ShowWindow")
)

/*
func DestroyWindow(hWnd HWND) (err error) {
	r1, _, err := destroyWindow.Call(uintptr(hWnd))
	if r1 == 0 {		// failure
		return err
	}
	return nil
}

type WNDENUMPROC func(hwnd HWND, lParam LPARAM) (cont bool)
type _WNDENUMPROC func(hwnd HWND, lParam LPARAM) int

func enumChildProc(p WNDENUMPROC) _WNDENUMPROC {
	return func(hwnd HWND, lParam LPARAM) int {
		if p(hwnd, lParam) {
			return TRUE
		}
		return FALSE
	}
}

// TODO figure out how to handle errors
func EnumChildWindows(hWndParent HWND, lpEnumFunc WNDENUMPROC, lParam LPARAM) (err error) {
	enumChildWindows.Call(
		uintptr(hWndParent),
		syscall.NewCallback(enumChildProc(lpEnumFunc)),
		uintptr(lParam))
	return nil
}

// TODO return the rect itself?
func GetClientRect(hWnd HWND) (lpRect *RECT, err error) {
	lpRect = new(RECT)
	r1, _, err := getClientRect.Call(
		uintptr(hWnd),
		uintptr(unsafe.Pointer(lpRect)))
	if r1 == 0 {		// failure
		return nil, err
	}
	return lpRect, nil
}

func SetWindowPos(hWnd HWND, hWndInsertAfter HWND, X int, Y int, cx int, cy int, uFlags uint32) (err error) {
	r1, _, err := setWindowPos.Call(
		uintptr(hWnd),
		uintptr(hWndInsertAfter),
		uintptr(X),
		uintptr(Y),
		uintptr(cx),
		uintptr(cy),
		uintptr(uFlags))
	if r1 == 0 {		// failure
		return err
	}
	return nil
}
*/

// WM_SETICON and WM_GETICON values.
const (
	_ICON_BIG = 1
	_ICON_SMALL = 0
	_ICON_SMALL2 = 2		// WM_GETICON only?
)

// Window messages.
const (
	_MN_GETHMENU = 0x01E1
	_WM_ERASEBKGND = 0x0014
	_WM_GETFONT = 0x0031
	_WM_GETTEXT = 0x000D
	_WM_GETTEXTLENGTH = 0x000E
	_WM_SETFONT = 0x0030
	_WM_SETICON = 0x0080
	_WM_SETTEXT = 0x000C
)

// WM_INPUTLANGCHANGEREQUEST values.
const (
	_INPUTLANGCHANGE_BACKWARD = 0x0004
	_INPUTLANGCHANGE_FORWARD = 0x0002
	_INPUTLANGCHANGE_SYSCHARSET = 0x0001
)

// WM_NCCALCSIZE return values.
const (
	_WVR_ALIGNTOP = 0x0010
	_WVR_ALIGNRIGHT = 0x0080
	_WVR_ALIGNLEFT = 0x0020
	_WVR_ALIGNBOTTOM = 0x0040
	_WVR_HREDRAW = 0x0100
	_WVR_VREDRAW = 0x0200
	_WVR_REDRAW = 0x0300
	_WVR_VALIDRECTS = 0x0400
)

// WM_SHOWWINDOW reasons (lParam).
const (
	_SW_OTHERUNZOOM = 4
	_SW_OTHERZOOM = 2
	_SW_PARENTCLOSING = 1
	_SW_PARENTOPENING = 3
)

// WM_SIZE values.
const (
	_SIZE_MAXHIDE = 4
	_SIZE_MAXIMIZED = 2
	_SIZE_MAXSHOW = 3
	_SIZE_MINIMIZED = 1
	_SIZE_RESTORED = 0
)

// WM_SIZING edge values (wParam).
const (
	_WMSZ_BOTTOM = 6
	_WMSZ_BOTTOMLEFT = 7
	_WMSZ_BOTTOMRIGHT = 8
	_WMSZ_LEFT = 1
	_WMSZ_RIGHT = 2
	_WMSZ_TOP = 3
	_WMSZ_TOPLEFT = 4
	_WMSZ_TOPRIGHT = 5
)

// WM_STYLECHANGED and WM_STYLECHANGING values (wParam).
const (
	_GWL_EXSTYLE = -20
	_GWL_STYLE = -16
)

// Window notifications.
const (
	_WM_ACTIVATEAPP = 0x001C
	_WM_CANCELMODE = 0x001F
	_WM_CHILDACTIVATE = 0x0022
	_WM_CLOSE = 0x0010
	_WM_COMPACTING = 0x0041
	_WM_CREATE = 0x0001
	_WM_DESTROY = 0x0002
//	_WM_DPICHANGED = 0x02E0		// Windows 8.1 and newer only
	_WM_ENABLE = 0x000A
	_WM_ENTERSIZEMOVE = 0x0231
	_WM_EXITSIZEMOVE = 0x0232
	_WM_GETICON = 0x007F
	_WM_GETMINMAXINFO = 0x0024
	_WM_INPUTLANGCHANGE = 0x0051
	_WM_INPUTLANGCHANGEREQUEST = 0x0050
	_WM_MOVE = 0x0003
	_WM_MOVING = 0x0216
	_WM_NCACTIVATE = 0x0086
	_WM_NCCALCSIZE = 0x0083
	_WM_NCCREATE = 0x0081
	_WM_NCDESTROY = 0x0082
	_WM_NULL = 0x0000
	_WM_QUERYDRAGICON = 0x0037
	_WM_QUERYOPEN = 0x0013
	_WM_QUIT = 0x0012
	_WM_SHOWWINDOW = 0x0018
	_WM_SIZE = 0x0005
	_WM_SIZING = 0x0214
	_WM_STYLECHANGED = 0x007D
	_WM_STYLECHANGING = 0x007C
//	_WM_THEMECHANGED = 0x031A		// Windows XP and newer only
//	_WM_USERCHANGED = 0x0054			// Windows XP only: [Note  This message is not supported as of Windows Vista.; also listed as not supported by server Windows]
	_WM_WINDOWPOSCHANGED = 0x0047
	_WM_WINDOWPOSCHANGING = 0x0046
)

type _MINMAXINFO struct {
	PtReserved		_POINT
	PtMaxSize			_POINT
	PtMaxPosition		_POINT
	PtMinTrackSize		_POINT
	PtMaxTrackSize	_POINT
}

func (l _LPARAM) MINMAXINFO() *_MINMAXINFO {
	return (*_MINMAXINFO)(unsafe.Pointer(l))
}