/* GTK - The GIMP Toolkit
 * Copyright (C) 2010 Carlos Garnacho <carlosg@gnome.org>
 * Copyright (C) 2011 Red Hat, Inc.
 *
 * Authors: Carlos Garnacho <carlosg@gnome.org>
 *          Cosimo Cecchi <cosimoc@gnome.org>
 *
 * This library is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public
 * License as published by the Free Software Foundation; either
 * version 2 of the License, or (at your option) any later version.
 *
 * This library is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public
 * License along with this library; if not, write to the
 * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
 * Boston, MA 02111-1307, USA.
 */

#include <config.h>

#include "gtkwin32themeprivate.h"

#ifdef G_OS_WIN32

#include <windows.h>
#include <cairo-win32.h>

typedef HANDLE HTHEME;

#define UXTHEME_DLL "uxtheme.dll"

static HINSTANCE uxtheme_dll = NULL;
static gboolean use_xp_theme = FALSE;

typedef HRESULT (FAR PASCAL *GetThemeSysFontFunc)           (HTHEME hTheme, int iFontID, OUT LOGFONTW *plf);
typedef int (FAR PASCAL *GetThemeSysSizeFunc)               (HTHEME hTheme, int iSizeId);
typedef COLORREF (FAR PASCAL *GetThemeSysColorFunc)         (HTHEME hTheme,
							     int iColorID);
typedef HTHEME (FAR PASCAL *OpenThemeDataFunc)              (HWND hwnd,
							     LPCWSTR pszClassList);
typedef HRESULT (FAR PASCAL *CloseThemeDataFunc)            (HTHEME theme);
typedef HRESULT (FAR PASCAL *DrawThemeBackgroundFunc)       (HTHEME hTheme, HDC hdc, int iPartId, int iStateId,
							     const RECT *pRect, const RECT *pClipRect);
typedef HRESULT (FAR PASCAL *EnableThemeDialogTextureFunc)  (HWND hwnd,
							     DWORD dwFlags);
typedef BOOL (FAR PASCAL *IsThemeActiveFunc)                (VOID);
typedef BOOL (FAR PASCAL *IsAppThemedFunc)                  (VOID);
typedef BOOL (FAR PASCAL *IsThemeBackgroundPartiallyTransparentFunc) (HTHEME hTheme,
								      int iPartId,
								      int iStateId);
typedef HRESULT (FAR PASCAL *DrawThemeParentBackgroundFunc) (HWND hwnd,
							     HDC hdc,
							     RECT *prc);
typedef HRESULT (FAR PASCAL *GetThemePartSizeFunc)          (HTHEME hTheme,
							     HDC hdc,
							     int iPartId,
							     int iStateId,
							     RECT *prc,
							     int eSize,
							     SIZE *psz);

static GetThemeSysFontFunc get_theme_sys_font = NULL;
static GetThemeSysColorFunc get_theme_sys_color = NULL;
static GetThemeSysSizeFunc get_theme_sys_metric = NULL;
static OpenThemeDataFunc open_theme_data = NULL;
static CloseThemeDataFunc close_theme_data = NULL;
static DrawThemeBackgroundFunc draw_theme_background = NULL;
static EnableThemeDialogTextureFunc enable_theme_dialog_texture = NULL;
static IsThemeActiveFunc is_theme_active = NULL;
static IsAppThemedFunc is_app_themed = NULL;
static IsThemeBackgroundPartiallyTransparentFunc is_theme_partially_transparent = NULL;
static DrawThemeParentBackgroundFunc draw_theme_parent_background = NULL;
static GetThemePartSizeFunc get_theme_part_size = NULL;

static GHashTable *hthemes_by_class = NULL;

static void
_gtk_win32_theme_init (void)
{
  char *buf;
  char dummy;
  int n, k;

  if (uxtheme_dll)
    return;

  n = GetSystemDirectory (&dummy, 0);
  if (n <= 0)
    return;

  buf = g_malloc (n + 1 + strlen (UXTHEME_DLL));
  k = GetSystemDirectory (buf, n);
  if (k == 0 || k > n)
    {
      g_free (buf);
      return;
    }

  if (!G_IS_DIR_SEPARATOR (buf[strlen (buf) -1]))
    strcat (buf, G_DIR_SEPARATOR_S);
  strcat (buf, UXTHEME_DLL);

  uxtheme_dll = LoadLibrary (buf);
  g_free (buf);

  if (!uxtheme_dll)
    return;

  is_app_themed = (IsAppThemedFunc) GetProcAddress (uxtheme_dll, "IsAppThemed");
  if (is_app_themed)
    {
      is_theme_active = (IsThemeActiveFunc) GetProcAddress (uxtheme_dll, "IsThemeActive");
      open_theme_data = (OpenThemeDataFunc) GetProcAddress (uxtheme_dll, "OpenThemeData");
      close_theme_data = (CloseThemeDataFunc) GetProcAddress (uxtheme_dll, "CloseThemeData");
      draw_theme_background = (DrawThemeBackgroundFunc) GetProcAddress (uxtheme_dll, "DrawThemeBackground");
      enable_theme_dialog_texture = (EnableThemeDialogTextureFunc) GetProcAddress (uxtheme_dll, "EnableThemeDialogTexture");
      get_theme_sys_font = (GetThemeSysFontFunc) GetProcAddress (uxtheme_dll, "GetThemeSysFont");
      get_theme_sys_color = (GetThemeSysColorFunc) GetProcAddress (uxtheme_dll, "GetThemeSysColor");
      get_theme_sys_metric = (GetThemeSysSizeFunc) GetProcAddress (uxtheme_dll, "GetThemeSysSize");
      is_theme_partially_transparent = (IsThemeBackgroundPartiallyTransparentFunc) GetProcAddress (uxtheme_dll, "IsThemeBackgroundPartiallyTransparent");
      draw_theme_parent_background = (DrawThemeParentBackgroundFunc) GetProcAddress (uxtheme_dll, "DrawThemeParentBackground");
      get_theme_part_size = (GetThemePartSizeFunc) GetProcAddress (uxtheme_dll, "GetThemePartSize");
    }

  if (is_app_themed && is_theme_active)
    {
      use_xp_theme = (is_app_themed () && is_theme_active ());
    }
  else
    {
      use_xp_theme = FALSE;
    }

  hthemes_by_class = g_hash_table_new (g_str_hash, g_str_equal);
}

static HTHEME
lookup_htheme_by_classname (const char *class)
{
  HTHEME theme;
  guint16 *wclass;
  char *lower;
  
  lower = g_ascii_strdown (class, -1);

  theme = (HTHEME)  g_hash_table_lookup (hthemes_by_class, lower);
  if (theme)
    {
      g_free (lower);
      return theme;
    }

  wclass = g_utf8_to_utf16 (lower, -1, NULL, NULL, NULL);
  theme  = open_theme_data (NULL, wclass);
  g_free (wclass);

  if (theme == NULL)
    {
      g_free (lower);
      return NULL;
    }

  /* Takes ownership of lower: */
  g_hash_table_insert (hthemes_by_class, lower, theme);

  return theme;
}

#else

typedef void * HTHEME;

static void
_gtk_win32_theme_init (void)
{
}

static HTHEME
lookup_htheme_by_classname (const char *class)
{
  return NULL;
}

#endif /* G_OS_WIN32 */

G_DEFINE_BOXED_TYPE_WITH_CODE (GtkWin32ThemePart, _gtk_win32_theme_part,
			       _gtk_win32_theme_part_ref, _gtk_win32_theme_part_unref, 
			       _gtk_win32_theme_init() )

struct _GtkWin32ThemePart {
  HTHEME theme;
  int part;
  int state;

  double over_alpha;
  int part2;
  int state2;

  gint ref_count;
};

GtkWin32ThemePart *
_gtk_win32_theme_part_new (const char *class, 
			   int xp_part, int state, 
			   int xp_part2, int state2, 
			   double over_alpha)
{
  GtkWin32ThemePart *part;

  part = g_slice_new0 (GtkWin32ThemePart);
  part->ref_count = 1;

  part->theme = lookup_htheme_by_classname (class);
  part->part = xp_part;
  part->state = state;
  part->part2 = xp_part2;
  part->state2 = state2;
  part->over_alpha = over_alpha;

  return part;
}

GtkWin32ThemePart *
_gtk_win32_theme_part_ref (GtkWin32ThemePart *part)
{
  g_return_val_if_fail (part != NULL, NULL);

  part->ref_count++;

  return part;
}

void
_gtk_win32_theme_part_unref (GtkWin32ThemePart *part)
{
  g_return_if_fail (part != NULL);

  part->ref_count--;

  if (part->ref_count == 0)
    {
      g_slice_free (GtkWin32ThemePart, part);
    }
}

int
_gtk_win32_theme_part_parse (GtkCssParser *parser, 
			     GFile *base, 
			     GValue *value)
{
  char *class;
  int xp_part, state, xp_part2, state2;
  double over_alpha;
  GtkWin32ThemePart *theme_part;

  if (!_gtk_css_parser_try (parser, "-gtk-win32-theme-part", TRUE))
    {
      return -1;
    }
  
  g_value_unset (value);
  g_value_init (value, GTK_TYPE_WIN32_THEME_PART);

  if (!_gtk_css_parser_try (parser, "(", TRUE))
    {
      _gtk_css_parser_error (parser,
                             "Expected '(' after '-gtk-win32-theme-part'");
      return 0;
    }
  
  class = _gtk_css_parser_try_name (parser, TRUE);
  if (class == NULL)
    {
      _gtk_css_parser_error (parser,
                             "Expected name as first argument to  '-gtk-win32-theme-part'");
      return 0;
    }

  if (! _gtk_css_parser_try (parser, ",", TRUE))
    {
      g_free (class);
      _gtk_css_parser_error (parser,
			     "Expected ','");
      return 0;
    }

  if (!_gtk_css_parser_try_int (parser, &xp_part))
    {
      g_free (class);
      _gtk_css_parser_error (parser, "Expected a valid integer value");
      return 0;
    }

  if (!_gtk_css_parser_try_int (parser, &state))
    {
      g_free (class);
      _gtk_css_parser_error (parser, "Expected a valid integer value");
      return 0;
    }


  over_alpha = 1.0;
  xp_part2 = -1;
  state2 = -1;

  if ( _gtk_css_parser_try (parser, ",", TRUE))
    {

      if ( _gtk_css_parser_try (parser, "over", TRUE))
	{
	  if (!_gtk_css_parser_try (parser, "(", TRUE))
	    {
	      _gtk_css_parser_error (parser,
				     "Expected '(' after 'over'");
	      return 0;
	    }

	  if (!_gtk_css_parser_try_int (parser, &xp_part2))
	    {
	      g_free (class);
	      _gtk_css_parser_error (parser, "Expected a valid integer value");
	      return 0;
	    }

	  if (!_gtk_css_parser_try_int (parser, &state2))
	    {
	      g_free (class);
	      _gtk_css_parser_error (parser, "Expected a valid integer value");
	      return 0;
	    }

	  if ( _gtk_css_parser_try (parser, ",", TRUE))
	    {
	      if (!_gtk_css_parser_try_double (parser, &over_alpha))
		{
		  g_free (class);
		  _gtk_css_parser_error (parser, "Expected a valid double value");
		  return 0;
		}
	    }

	  if (!_gtk_css_parser_try (parser, ")", TRUE))
	    {
	      _gtk_css_parser_error (parser,
				     "Expected ')' at end of 'over'");
	      return 0;
	    }
	}
    }


  if (!_gtk_css_parser_try (parser, ")", TRUE))
    {
      g_free (class);
      _gtk_css_parser_error (parser,
			     "Expected ')'");
      return 0;
    }
  
  theme_part = _gtk_win32_theme_part_new (class, 
					  xp_part, state, 
					  xp_part2, state2,
					  over_alpha);
  g_free (class);
  
  g_value_take_boxed (value, theme_part);
  return 1;
}

#ifdef G_OS_WIN32
cairo_surface_t *
_gtk_win32_theme_part_create_surface  (GtkWin32ThemePart  *part,
				       int                 xp_part,
				       int                 state,
				       int                 width,
				       int                 height)
{
  cairo_surface_t *surface;
  HDC hdc;
  RECT rect;
  HRESULT res;

  surface = cairo_win32_surface_create_with_dib (CAIRO_FORMAT_ARGB32, width, height);
  hdc = cairo_win32_surface_get_dc (surface);
  
  rect.left = 0;
  rect.top = 0;
  rect.right = width;
  rect.bottom = height;

  res = draw_theme_background (part->theme, hdc, xp_part, state, &rect, &rect);
  return surface;
}
#endif


cairo_pattern_t *
_gtk_win32_theme_part_render  (GtkWin32ThemePart  *part,
			       int                 width,
			       int                 height)
{
#ifdef G_OS_WIN32
  cairo_surface_t *surface, *surface2, *image;
  cairo_pattern_t *pattern;
  cairo_t *cr;
  cairo_matrix_t matrix;
  cairo_user_data_key_t key;

  surface = _gtk_win32_theme_part_create_surface  (part, part->part, part->state, 
						   width, height);
  
  if (part->state2 >= 0)
    {
      surface2 = _gtk_win32_theme_part_create_surface  (part, part->part2, part->state2, 
							width, height);


      cr = cairo_create (surface);

      pattern = cairo_pattern_create_for_surface (surface2);
      cairo_set_source (cr, pattern);
      cairo_set_operator (cr, CAIRO_OPERATOR_OVER);
      cairo_paint_with_alpha (cr, part->over_alpha);
      
      cairo_destroy (cr);
      cairo_pattern_destroy (pattern);

      cairo_surface_destroy (surface2);
    }

  /* We need to return an image surface, as that is what the code expects in order
     to get the size */
  image = cairo_win32_surface_get_image (surface);
  pattern = cairo_pattern_create_for_surface (cairo_surface_reference (image));

  cairo_matrix_init_scale (&matrix,
			   width,
			   height);
  cairo_pattern_set_matrix (pattern, &matrix);

  /* We can't immediately destroy the surface, because that would free the data
     the image surface refers too. Instead we destroy it with the pattern. */
  cairo_pattern_set_user_data (pattern,
			       &key,
			       surface, (cairo_destroy_func_t) cairo_surface_destroy);

  return pattern;
#else
  GdkRGBA color;
  
  gdk_rgba_parse (&color, "pink");

  return cairo_pattern_create_rgb (color.red, color.green, color.blue);
#endif
}

int
_gtk_win32_theme_int_parse (GtkCssParser      *parser,
			    GFile             *base,
			    int               *value)
{
  char *class;
  int arg;

  if (_gtk_css_parser_try (parser,
			   "-gtk-win32-size",
			   TRUE))
    {
      if (!_gtk_css_parser_try (parser, "(", TRUE))
	{
	  _gtk_css_parser_error (parser,
				 "Expected '(' after '-gtk-win32-size'");
	  return 0;
	}

      class = _gtk_css_parser_try_name (parser, TRUE);
      if (class == NULL)
	{
	  _gtk_css_parser_error (parser,
				 "Expected name as first argument to  '-gtk-win32-size'");
	  return 0;
	}

      if (! _gtk_css_parser_try (parser, ",", TRUE))
	{
	  g_free (class);
	  _gtk_css_parser_error (parser,
				 "Expected ','");
	  return 0;
	}

      if (!_gtk_css_parser_try_int (parser, &arg))
	{
	  g_free (class);
	  _gtk_css_parser_error (parser, "Expected a valid integer value");
	  return 0;
	}

      if (!_gtk_css_parser_try (parser, ")", TRUE))
	{
	  _gtk_css_parser_error (parser,
				 "Expected ')'");
	  return 0;
	}

#ifdef G_OS_WIN32
      if (use_xp_theme && get_theme_sys_metric != NULL)
	{
	  HTHEME theme = lookup_htheme_by_classname (class);

	  /* If theme is NULL it will just return the GetSystemMetrics value */
	  *value = get_theme_sys_metric (theme, arg);
	}
      else
	*value = GetSystemMetrics (arg);
#else
      *value = 1;
#endif

      g_free (class);

      return 1;
    }

  return -1;
}

GtkSymbolicColor *
_gtk_win32_theme_color_parse (GtkCssParser *parser)
{
  GtkSymbolicColor *color;
  char *class;
  int id;

  class = _gtk_css_parser_try_name (parser, TRUE);
  if (class == NULL)
    {
      _gtk_css_parser_error (parser,
			     "Expected name as first argument to  '-gtk-win32-color'");
      return NULL;
    }

  if (! _gtk_css_parser_try (parser, ",", TRUE))
    {
      g_free (class);
      _gtk_css_parser_error (parser,
			     "Expected ','");
      return NULL;
    }

  if (!_gtk_css_parser_try_int (parser, &id))
    {
      g_free (class);
      _gtk_css_parser_error (parser, "Expected a valid integer value");
      return NULL;
    }

  color = gtk_symbolic_color_new_win32 (class, id);
  g_free (class);
  return color;
}

gboolean
_gtk_win32_theme_color_resolve (const char *theme_class,
				gint id,
				GdkRGBA *color)
{
#ifdef G_OS_WIN32
  DWORD dcolor;

  if (use_xp_theme && get_theme_sys_color != NULL)
    {
      HTHEME theme = lookup_htheme_by_classname (theme_class);

      /* if theme is NULL, it will just return the GetSystemColor()
         value */
      dcolor = get_theme_sys_color (theme, id);
    }
  else
    dcolor = GetSysColor (id);

  color->alpha = 1.0;
  color->red = GetRValue (dcolor) / 255.0;
  color->green = GetGValue (dcolor) / 255.0;
  color->blue = GetBValue (dcolor) / 255.0;
#else
  gdk_rgba_parse (color, "pink");
#endif
  return TRUE;
}