#include <errno.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>

#include "config.h"

#include <gtk/gtk.h>
#include <glib/gstdio.h>

#include "award.h"
#include "demos.h"

static GtkWidget *info_view;
static GtkWidget *source_view;

static gchar *current_file = NULL;

static GtkWidget *notebook;
static GtkSingleSelection *selection;
static GtkWidget *toplevel;

typedef struct _GtkDemo GtkDemo;
struct _GtkDemo
{
  GObject parent_instance;

  const char *name;
  const char *title;
  const char *filename;
  GDoDemoFunc func;
  GListModel *children_model;
};

enum {
  PROP_0,
  PROP_FILENAME,
  PROP_NAME,
  PROP_TITLE,

  N_PROPS
};

# define GTK_TYPE_DEMO (gtk_demo_get_type ())
G_DECLARE_FINAL_TYPE (GtkDemo, gtk_demo, GTK, DEMO, GObject);

G_DEFINE_TYPE (GtkDemo, gtk_demo, G_TYPE_OBJECT);
static GParamSpec *properties[N_PROPS] = { NULL, };

static void
gtk_demo_get_property (GObject    *object,
                       guint       property_id,
                       GValue     *value,
                       GParamSpec *pspec)
{
  GtkDemo *self = GTK_DEMO (object);

  switch (property_id)
    {
    case PROP_FILENAME:
      g_value_set_string (value, self->filename);
      break;

    case PROP_NAME:
      g_value_set_string (value, self->name);
      break;

    case PROP_TITLE:
      g_value_set_string (value, self->title);
      break;

    default:
      G_OBJECT_WARN_INVALID_PROPERTY_ID (object, property_id, pspec);
      break;
    }
}

static void gtk_demo_class_init (GtkDemoClass *klass)
{
  GObjectClass *gobject_class = G_OBJECT_CLASS (klass);

  gobject_class->get_property = gtk_demo_get_property;

  properties[PROP_FILENAME] =
    g_param_spec_string ("filename",
                         "filename",
                         "filename",
                         NULL,
                         G_PARAM_READABLE);
  properties[PROP_NAME] =
    g_param_spec_string ("name",
                         "name",
                         "name",
                         NULL,
                         G_PARAM_READABLE);
  properties[PROP_TITLE] =
    g_param_spec_string ("title",
                         "title",
                         "title",
                         NULL,
                         G_PARAM_READABLE);

  g_object_class_install_properties (gobject_class, N_PROPS, properties);
}

static void gtk_demo_init (GtkDemo *self)
{
}

typedef struct _CallbackData CallbackData;
struct _CallbackData
{
  GtkTreeModel *model;
  GtkTreePath *path;
};

static gboolean
gtk_demo_run (GtkDemo   *self,
              GtkWidget *window)
{
  GtkWidget *result;

  if (!self->func)
    return FALSE;

  result = self->func (window);
  if (result == NULL)
    return FALSE;

  if (GTK_IS_WINDOW (result))
    {
      gtk_window_set_transient_for (GTK_WINDOW (result), GTK_WINDOW (window));
      gtk_window_set_modal (GTK_WINDOW (result), TRUE);
    }
  return TRUE;
}
              
static void
activate_about (GSimpleAction *action,
                GVariant      *parameter,
                gpointer       user_data)
{
  GtkApplication *app = user_data;
  const gchar *authors[] = {
    "The GTK Team",
    NULL
  };
  char *version;
  GString *s;

  s = g_string_new ("");

  g_string_append (s, "System libraries\n");
  g_string_append_printf (s, "\tGLib\t%d.%d.%d\n",
                          glib_major_version,
                          glib_minor_version,
                          glib_micro_version);
  g_string_append_printf (s, "\tPango\t%s\n",
                          pango_version_string ());
  g_string_append_printf (s, "\tGTK\t%d.%d.%d\n",
                          gtk_get_major_version (),
                          gtk_get_minor_version (),
                          gtk_get_micro_version ());
  g_string_append_printf (s, "\nA link can appear here: <http://www.gtk.org>");

  version = g_strdup_printf ("%s\nRunning against GTK %d.%d.%d",
                             PACKAGE_VERSION,
                             gtk_get_major_version (),
                             gtk_get_minor_version (),
                             gtk_get_micro_version ());

  gtk_show_about_dialog (GTK_WINDOW (gtk_application_get_active_window (app)),
                         "program-name", "GTK Demo",
                         "version", version,
                         "copyright", "© 1997—2020 The GTK Team",
                         "license-type", GTK_LICENSE_LGPL_2_1,
                         "website", "http://www.gtk.org",
                         "comments", "Program to demonstrate GTK widgets",
                         "authors", authors,
                         "logo-icon-name", "org.gtk.Demo4",
                         "title", "About GTK Demo",
                         "system-information", s->str,
                         NULL);

  g_string_free (s, TRUE);
  g_free (version);
}

static void
activate_quit (GSimpleAction *action,
               GVariant      *parameter,
               gpointer       user_data)
{
  GtkApplication *app = user_data;
  GtkWidget *win;
  GList *list, *next;

  list = gtk_application_get_windows (app);
  while (list)
    {
      win = list->data;
      next = list->next;

      gtk_window_destroy (GTK_WINDOW (win));

      list = next;
    }
}

static void
activate_inspector (GSimpleAction *action,
                    GVariant      *parameter,
                    gpointer       user_data)
{
  gtk_window_set_interactive_debugging (TRUE);
  award ("demo-inspector");
}

static void
activate_run (GSimpleAction *action,
              GVariant      *parameter,
              gpointer       window)
{
  GtkTreeListRow *row = gtk_single_selection_get_selected_item (selection);
  GtkDemo *demo = gtk_tree_list_row_get_item (row);

  gtk_demo_run (demo, window);
}

/* Stupid syntax highlighting.
 *
 * No regex was used in the making of this highlighting.
 * It should only work for simple cases.  This is good, as
 * that's all we should have in the demos.
 */
/* This code should not be used elsewhere, except perhaps as an example of how
 * to iterate through a text buffer.
 */
enum {
  STATE_NORMAL,
  STATE_IN_COMMENT
};

static const char *tokens[] =
{
  "/*",
  "\"",
  NULL
};

static const char *types[] =
{
  "static",
  "const ",
  "void",
  "gint",
  " int ",
  " char ",
  "gchar ",
  "gfloat",
  "float",
  "double",
  "gint8",
  "gint16",
  "gint32",
  "guint",
  "guint8",
  "guint16",
  "guint32",
  "guchar",
  "glong",
  "gboolean" ,
  "gshort",
  "gushort",
  "gulong",
  "gdouble",
  "gldouble",
  "gpointer",
  "NULL",
  "GList",
  "GSList",
  "FALSE",
  "TRUE",
  "FILE ",
  "GtkColorSelection ",
  "GtkWidget ",
  "GtkButton ",
  "GdkColor ",
  "GdkRectangle ",
  "GdkEventExpose ",
  "GdkGC ",
  "GdkPixbufLoader ",
  "GdkPixbuf ",
  "GError",
  "size_t",
  "GtkAboutDialog ",
  "GtkAction ",
  "GtkActionEntry ",
  "GtkRadioActionEntry ",
  "GtkIconFactory ",
  "GtkTextBuffer ",
  "GtkStatusbar ",
  "GtkTextIter ",
  "GtkTextMark ",
  "GdkEventWindowState ",
  "GtkActionGroup ",
  "GtkUIManager ",
  "GtkRadioAction ",
  "GtkActionClass ",
  "GtkToggleActionEntry ",
  "GtkAssistant ",
  "GtkBuilder ",
  "GtkSizeGroup ",
  "GtkTreeModel ",
  "GtkTreeSelection ",
  "GdkDisplay ",
  "GdkScreen ",
  "GdkSurface ",
  "GdkEventButton ",
  "GdkCursor ",
  "GtkTreeIter ",
  "GtkTreeViewColumn ",
  "GdkDisplayManager ",
  "GdkClipboard ",
  "GtkIconSize ",
  "GtkImage ",
  "GdkDragContext ",
  "GtkSelectionData ",
  "GtkDialog ",
  "GtkMenuItem ",
  "GtkListStore ",
  "GtkCellLayout ",
  "GtkCellRenderer ",
  "GtkTreePath ",
  "GtkTreeStore ",
  "GtkEntry ",
  "GtkEditable ",
  "GtkEditableInterface ",
  "GdkPixmap ",
  "GdkEventConfigure ",
  "GdkEventMotion ",
  "GdkModifierType ",
  "GtkEntryCompletion ",
  "GtkToolItem ",
  "GDir ",
  "GtkIconView ",
  "GtkCellRendererText ",
  "GtkContainer ",
  "GtkPaned ",
  "GtkPrintOperation ",
  "GtkPrintContext ",
  "cairo_t ",
  "PangoLayout "
  "PangoFontDescription ",
  "PangoRenderer ",
  "PangoMatrix ",
  "PangoContext ",
  "PangoLayout ",
  "GtkToggleButton ",
  "GString ",
  "GtkIconSize ",
  "GtkTreeView ",
  "GtkTextTag ",
  "GdkEvent ",
  "GdkEventKey ",
  "GtkTextView ",
  "GdkBitmap ",
  "GtkTextChildAnchor ",
  "GArray ",
  "GtkCellEditable ",
  "GtkCellRendererToggle ",
  NULL
};

static const char *control[] =
{
  " if ",
  " while ",
  " else",
  " do ",
  " for ",
  "?",
  ":",
  "return ",
  "goto ",
  NULL
};
void
parse_chars (gchar       *text,
             gchar      **end_ptr,
             gint        *state,
             const char **tag,
             gboolean     start)
{
  gint i;
  gchar *next_token;

  /* Handle comments first */
  if (*state == STATE_IN_COMMENT)
    {
      *end_ptr = strstr (text, "*/");
      if (*end_ptr)
        {
          *end_ptr += 2;
          *state = STATE_NORMAL;
          *tag = "comment";
        }
      return;
    }

  *tag = NULL;
  *end_ptr = NULL;

  /* check for comment */
  if (!strncmp (text, "/*", 2))
    {
      *end_ptr = strstr (text, "*/");
      if (*end_ptr)
        *end_ptr += 2;
      else
        *state = STATE_IN_COMMENT;
      *tag = "comment";
      return;
    }

  /* check for preprocessor defines */
  if (*text == '#' && start)
    {
      *end_ptr = NULL;
      *tag = "preprocessor";
      return;
    }

  /* functions */
  if (start && * text != '\t' && *text != ' ' && *text != '{' && *text != '}')
    {
      if (strstr (text, "("))
        {
          *end_ptr = strstr (text, "(");
          *tag = "function";
          return;
        }
    }
  /* check for types */
  for (i = 0; types[i] != NULL; i++)
    if (!strncmp (text, types[i], strlen (types[i])) ||
        (start && types[i][0] == ' ' && !strncmp (text, types[i] + 1, strlen (types[i]) - 1)))
      {
        *end_ptr = text + strlen (types[i]);
        *tag = "type";
        return;
      }

  /* check for control */
  for (i = 0; control[i] != NULL; i++)
    if (!strncmp (text, control[i], strlen (control[i])))
      {
        *end_ptr = text + strlen (control[i]);
        *tag = "control";
        return;
      }

  /* check for string */
  if (text[0] == '"')
    {
      gint maybe_escape = FALSE;

      *end_ptr = text + 1;
      *tag = "string";
      while (**end_ptr != '\000')
        {
          if (**end_ptr == '\"' && !maybe_escape)
            {
              *end_ptr += 1;
              return;
            }
          if (**end_ptr == '\\')
            maybe_escape = TRUE;
          else
            maybe_escape = FALSE;
          *end_ptr += 1;
        }
      return;
    }

  /* not at the start of a tag.  Find the next one. */
  for (i = 0; tokens[i] != NULL; i++)
    {
      next_token = strstr (text, tokens[i]);
      if (next_token)
        {
          if (*end_ptr)
            *end_ptr = (*end_ptr<next_token)?*end_ptr:next_token;
          else
            *end_ptr = next_token;
        }
    }

  for (i = 0; types[i] != NULL; i++)
    {
      next_token = strstr (text, types[i]);
      if (next_token)
        {
          if (*end_ptr)
            *end_ptr = (*end_ptr<next_token)?*end_ptr:next_token;
          else
            *end_ptr = next_token;
        }
    }

  for (i = 0; control[i] != NULL; i++)
    {
      next_token = strstr (text, control[i]);
      if (next_token)
        {
          if (*end_ptr)
            *end_ptr = (*end_ptr<next_token)?*end_ptr:next_token;
          else
            *end_ptr = next_token;
        }
    }
}

/* While not as cool as c-mode, this will do as a quick attempt at highlighting */
void
fontify (GtkTextBuffer *source_buffer)
{
  GtkTextIter start_iter, next_iter, tmp_iter;
  gint state;
  gchar *text;
  gchar *start_ptr, *end_ptr;
  const char *tag;

  gtk_text_buffer_create_tag (source_buffer, "source",
                              "font", "monospace",
                              NULL);
  gtk_text_buffer_create_tag (source_buffer, "comment",
                              "foreground", "DodgerBlue",
                              NULL);
  gtk_text_buffer_create_tag (source_buffer, "type",
                              "foreground", "ForestGreen",
                              NULL);
  gtk_text_buffer_create_tag (source_buffer, "string",
                              "foreground", "RosyBrown",
                              "weight", PANGO_WEIGHT_BOLD,
                              NULL);
  gtk_text_buffer_create_tag (source_buffer, "control",
                              "foreground", "purple",
                              NULL);
  gtk_text_buffer_create_tag (source_buffer, "preprocessor",
                              "style", PANGO_STYLE_OBLIQUE,
                              "foreground", "burlywood4",
                              NULL);
  gtk_text_buffer_create_tag (source_buffer, "function",
                              "weight", PANGO_WEIGHT_BOLD,
                              "foreground", "DarkGoldenrod4",
                              NULL);

  gtk_text_buffer_get_bounds (source_buffer, &start_iter, &tmp_iter);
  gtk_text_buffer_apply_tag_by_name (source_buffer, "source", &start_iter, &tmp_iter);

  state = STATE_NORMAL;

  gtk_text_buffer_get_iter_at_offset (source_buffer, &start_iter, 0);

  next_iter = start_iter;
  while (gtk_text_iter_forward_line (&next_iter))
    {
      gboolean start = TRUE;
      start_ptr = text = gtk_text_iter_get_text (&start_iter, &next_iter);

      do
        {
          parse_chars (start_ptr, &end_ptr, &state, &tag, start);

          start = FALSE;
          if (end_ptr)
            {
              tmp_iter = start_iter;
              gtk_text_iter_forward_chars (&tmp_iter, end_ptr - start_ptr);
            }
          else
            {
              tmp_iter = next_iter;
            }
          if (tag)
            gtk_text_buffer_apply_tag_by_name (source_buffer, tag, &start_iter, &tmp_iter);

          start_iter = tmp_iter;
          start_ptr = end_ptr;
        }
      while (end_ptr);

      g_free (text);
      start_iter = next_iter;
    }
}

static GtkWidget *
display_image (const char *resource)
{
  GtkWidget *sw, *image;

  image = gtk_image_new_from_resource (resource);
  gtk_widget_set_halign (image, GTK_ALIGN_CENTER);
  gtk_widget_set_valign (image, GTK_ALIGN_CENTER);
  sw = gtk_scrolled_window_new (NULL, NULL);
  gtk_scrolled_window_set_child (GTK_SCROLLED_WINDOW (sw), image);

  return sw;
}

static GtkWidget *
display_text (const char *resource)
{
  GtkTextBuffer *buffer;
  GtkWidget *textview, *sw;
  GBytes *bytes;

  bytes = g_resources_lookup_data (resource, 0, NULL);
  g_assert (bytes);

  g_assert (g_utf8_validate (g_bytes_get_data (bytes, NULL), g_bytes_get_size (bytes), NULL));

  textview = gtk_text_view_new ();
  g_object_set (textview,
                "left-margin", 20,
                "right-margin", 20,
                "top-margin", 20,
                "bottom-margin", 20,
                NULL);
  gtk_text_view_set_editable (GTK_TEXT_VIEW (textview), FALSE);
  gtk_text_view_set_cursor_visible (GTK_TEXT_VIEW (textview), FALSE);
  /* Make it a bit nicer for text. */
  gtk_text_view_set_wrap_mode (GTK_TEXT_VIEW (textview), GTK_WRAP_WORD);
  gtk_text_view_set_pixels_above_lines (GTK_TEXT_VIEW (textview), 2);
  gtk_text_view_set_pixels_below_lines (GTK_TEXT_VIEW (textview), 2);

  buffer = gtk_text_buffer_new (NULL);
  gtk_text_buffer_set_text (buffer, g_bytes_get_data (bytes, NULL), g_bytes_get_size (bytes));
  if (g_str_has_suffix (resource, ".c"))
    fontify (buffer);
  gtk_text_view_set_buffer (GTK_TEXT_VIEW (textview), buffer);

  g_bytes_unref (bytes);

  sw = gtk_scrolled_window_new (NULL, NULL);
  gtk_scrolled_window_set_policy (GTK_SCROLLED_WINDOW (sw),
                                  GTK_POLICY_AUTOMATIC,
                                  GTK_POLICY_AUTOMATIC);
  gtk_scrolled_window_set_child (GTK_SCROLLED_WINDOW (sw), textview);

  return sw;
}

static GtkWidget *
display_video (const char *resource)
{
  GtkWidget *video;

  video = gtk_video_new_for_resource (resource);
  gtk_video_set_loop (GTK_VIDEO (video), TRUE);

  return video;
}

static GtkWidget *
display_nothing (const char *resource)
{
  GtkWidget *widget;
  char *str;

  str = g_strdup_printf ("The lazy GTK developers forgot to add a way to display the resource '%s'", resource);
  widget = gtk_label_new (str);
  gtk_label_set_wrap (GTK_LABEL (widget), TRUE);

  g_free (str);

  return widget;
}

static struct {
  const char *extension;
  GtkWidget * (* display_func) (const char *resource);
} display_funcs[] = {
  { ".gif", display_image },
  { ".jpg", display_image },
  { ".png", display_image },
  { ".c", display_text },
  { ".css", display_text },
  { ".glsl", display_text },
  { ".h", display_text },
  { ".txt", display_text },
  { ".ui", display_text },
  { ".webm", display_video }
};

static void
add_data_tab (const gchar *demoname)
{
  gchar *resource_dir, *resource_name;
  gchar **resources;
  GtkWidget *widget, *label;
  guint i, j;

  resource_dir = g_strconcat ("/", demoname, NULL);
  resources = g_resources_enumerate_children (resource_dir, 0, NULL);
  if (resources == NULL)
    {
      g_free (resource_dir);
      return;
    }

  for (i = 0; resources[i]; i++)
    {
      resource_name = g_strconcat (resource_dir, "/", resources[i], NULL);

      for (j = 0; j < G_N_ELEMENTS(display_funcs); j++)
        {
          if (g_str_has_suffix (resource_name, display_funcs[j].extension))
            break;
        }

      if (j < G_N_ELEMENTS(display_funcs))
        widget = display_funcs[j].display_func (resource_name);
      else
        widget = display_nothing (resource_name);

      label = gtk_label_new (resources[i]);
      gtk_widget_show (label);
      gtk_notebook_append_page (GTK_NOTEBOOK (notebook), widget, label);
      g_object_set (gtk_notebook_get_page (GTK_NOTEBOOK (notebook), widget),
                    "tab-expand", FALSE,
                    NULL);

      g_free (resource_name);
    }

  g_strfreev (resources);
  g_free (resource_dir);
}

static void
remove_data_tabs (void)
{
  gint i;

  for (i = gtk_notebook_get_n_pages (GTK_NOTEBOOK (notebook)) - 1; i > 1; i--)
    gtk_notebook_remove_page (GTK_NOTEBOOK (notebook), i);
}

void
load_file (const gchar *demoname,
           const gchar *filename)
{
  GtkTextBuffer *info_buffer, *source_buffer;
  GtkTextIter start, end;
  char *resource_filename;
  GError *err = NULL;
  int state = 0;
  gboolean in_para = 0;
  gchar **lines;
  GBytes *bytes;
  gint i;

  if (!g_strcmp0 (current_file, filename))
    return;

  remove_data_tabs ();

  add_data_tab (demoname);

  g_free (current_file);
  current_file = g_strdup (filename);

  info_buffer = gtk_text_buffer_new (NULL);
  gtk_text_buffer_create_tag (info_buffer, "title",
                              "font", "Sans 18",
                              "pixels-below-lines", 10,
                              NULL);

  source_buffer = gtk_text_buffer_new (NULL);

  gtk_text_buffer_begin_irreversible_action (info_buffer);
  gtk_text_buffer_begin_irreversible_action (source_buffer);

  resource_filename = g_strconcat ("/sources/", filename, NULL);
  bytes = g_resources_lookup_data (resource_filename, 0, &err);
  g_free (resource_filename);

  if (bytes == NULL)
    {
      g_warning ("Cannot open source for %s: %s", filename, err->message);
      g_error_free (err);
      return;
    }

  lines = g_strsplit (g_bytes_get_data (bytes, NULL), "\n", -1);
  g_bytes_unref (bytes);

  gtk_text_buffer_get_iter_at_offset (info_buffer, &start, 0);
  for (i = 0; lines[i] != NULL; i++)
    {
      gchar *p;
      gchar *q;
      gchar *r;

      /* Make sure \r is stripped at the end for the poor windows people */
      lines[i] = g_strchomp (lines[i]);

      p = lines[i];
      switch (state)
        {
        case 0:
          /* Reading title */
          while (*p == '/' || *p == '*' || g_ascii_isspace (*p))
            p++;
          r = p;
          while (*r != '\0')
            {
              while (*r != '/' && *r != ':' && *r != '\0')
                r++;
              if (*r == '/')
                {
                  r++;
                  p = r;
                }
              if (r[0] == ':' && r[1] == ':')
                *r = '\0';
            }
          q = p + strlen (p);
          while (q > p && g_ascii_isspace (*(q - 1)))
            q--;


          if (q > p)
            {
              int len_chars = g_utf8_pointer_to_offset (p, q);

              end = start;

              g_assert (strlen (p) >= q - p);
              gtk_text_buffer_insert (info_buffer, &end, p, q - p);
              start = end;

              gtk_text_iter_backward_chars (&start, len_chars);
              gtk_text_buffer_apply_tag_by_name (info_buffer, "title", &start, &end);

              start = end;

              while (*p && *p != '\n') p++;

              state++;
            }
          break;

        case 1:
          /* Reading body of info section */
          while (g_ascii_isspace (*p))
            p++;
          if (*p == '*' && *(p + 1) == '/')
            {
              gtk_text_buffer_get_iter_at_offset (source_buffer, &start, 0);
              state++;
            }
          else
            {
              int len;

              while (*p == '*' || g_ascii_isspace (*p))
                p++;

              len = strlen (p);
              while (g_ascii_isspace (*(p + len - 1)))
                len--;

              if (len > 0)
                {
                  if (in_para)
                    gtk_text_buffer_insert (info_buffer, &start, " ", 1);

                  g_assert (strlen (p) >= len);
                  gtk_text_buffer_insert (info_buffer, &start, p, len);
                  in_para = 1;
                }
              else
                {
                  gtk_text_buffer_insert (info_buffer, &start, "\n", 1);
                  in_para = 0;
                }
            }
          break;

        case 2:
          /* Skipping blank lines */
          while (g_ascii_isspace (*p))
            p++;

          if (!*p)
            break;

          p = lines[i];
          state++;
          G_GNUC_FALLTHROUGH;

        case 3:
          /* Reading program body */
          gtk_text_buffer_insert (source_buffer, &start, p, -1);
          if (lines[i+1] != NULL)
            gtk_text_buffer_insert (source_buffer, &start, "\n", 1);
          break;

        default:
          g_assert_not_reached ();
        }
    }

  g_strfreev (lines);

  fontify (source_buffer);

  gtk_text_buffer_end_irreversible_action (source_buffer);
  gtk_text_view_set_buffer (GTK_TEXT_VIEW (source_view), source_buffer);
  g_object_unref (source_buffer);

  gtk_text_buffer_end_irreversible_action (info_buffer);
  gtk_text_view_set_buffer (GTK_TEXT_VIEW (info_view), info_buffer);
  g_object_unref (info_buffer);
}

static void
activate_cb (GtkWidget *widget,
             guint      position,
             gpointer   window)
{
  GtkTreeListRow *row = g_list_model_get_item (gtk_list_view_get_model (GTK_LIST_VIEW (widget)), position);
  GtkDemo *demo = gtk_tree_list_row_get_item (row);

  gtk_demo_run (demo, window);

  g_object_unref (row);
}

static void
selection_cb (GtkSingleSelection *sel,
              GParamSpec         *pspec,
              gpointer            user_data)
{
  GtkTreeListRow *row = gtk_single_selection_get_selected_item (sel);
  GtkDemo *demo = gtk_tree_list_row_get_item (row);

  if (demo->filename)
    load_file (demo->name, demo->filename);

  gtk_window_set_title (GTK_WINDOW (toplevel), demo->title);
}

static GListModel *
create_demo_model (void)
{
  GListStore *store = g_list_store_new (GTK_TYPE_DEMO);
  DemoData *demo = gtk_demos;

  while (demo->title)
    {
      GtkDemo *d = GTK_DEMO (g_object_new (GTK_TYPE_DEMO, NULL));
      DemoData *children = demo->children;

      d->name = demo->name;
      d->title = demo->title;
      d->filename = demo->filename;
      d->func = demo->func;

      g_list_store_append (store, d);

      if (children)
        {
          d->children_model = G_LIST_MODEL (g_list_store_new (GTK_TYPE_DEMO));

          while (children->title)
            {
              GtkDemo *child = GTK_DEMO (g_object_new (GTK_TYPE_DEMO, NULL));

              child->name = children->name;
              child->title = children->title;
              child->filename = children->filename;
              child->func = children->func;

              g_list_store_append (G_LIST_STORE (d->children_model), child);
              children++;
            }
        }

      demo++;
    }

  return G_LIST_MODEL (store);
}

static GListModel *
get_child_model (gpointer item,
                 gpointer user_data)
{
  GtkDemo *demo = item;

  if (demo->children_model)
    return g_object_ref (G_LIST_MODEL (demo->children_model));

  return NULL;
}

static void
activate (GApplication *app)
{
  GtkBuilder *builder;
  GListModel *listmodel;
  GtkTreeListModel *treemodel;
  GtkWidget *window, *listview;

  static GActionEntry win_entries[] = {
    { "run", activate_run, NULL, NULL, NULL }
  };

  builder = gtk_builder_new_from_resource ("/ui/main.ui");

  window = (GtkWidget *)gtk_builder_get_object (builder, "window");
  gtk_application_add_window (GTK_APPLICATION (app), GTK_WINDOW (window));
  g_action_map_add_action_entries (G_ACTION_MAP (window),
                                   win_entries, G_N_ELEMENTS (win_entries),
                                   window);

  notebook = GTK_WIDGET (gtk_builder_get_object (builder, "notebook"));

  info_view = GTK_WIDGET (gtk_builder_get_object (builder, "info-textview"));
  source_view = GTK_WIDGET (gtk_builder_get_object (builder, "source-textview"));
  toplevel = GTK_WIDGET (window);
  listview = GTK_WIDGET (gtk_builder_get_object (builder, "listview"));
  g_signal_connect (listview, "activate", G_CALLBACK (activate_cb), window);

  load_file (gtk_demos[0].name, gtk_demos[0].filename);

  listmodel = create_demo_model ();
  treemodel = gtk_tree_list_model_new (FALSE,
                                       G_LIST_MODEL (listmodel),
                                       FALSE,
                                       get_child_model,
                                       NULL,
                                       NULL);
  selection = gtk_single_selection_new (G_LIST_MODEL (treemodel));
  g_signal_connect (selection, "notify::selected-item", G_CALLBACK (selection_cb), NULL);
  gtk_list_view_set_model (GTK_LIST_VIEW (listview),
                           G_LIST_MODEL (selection));

  award ("demo-start");

  gtk_widget_show (GTK_WIDGET (window));

  g_object_unref (builder);
}

static gboolean
auto_quit (gpointer data)
{
  g_application_quit (G_APPLICATION (data));
  return G_SOURCE_REMOVE;
}

static void
list_demos (void)
{
  DemoData *d, *c;

  d = gtk_demos;

  while (d->title)
    {
      c = d->children;
      if (d->name)
        g_print ("%s\n", d->name);
      d++;
      while (c && c->title)
        {
          if (c->name)
            g_print ("%s\n", c->name);
          c++;
        }
    }
}

static gint
command_line (GApplication            *app,
              GApplicationCommandLine *cmdline)
{
  GVariantDict *options;
  const gchar *name = NULL;
  gboolean autoquit = FALSE;
  gboolean list = FALSE;
  DemoData *d, *c;
  GDoDemoFunc func = 0;
  GtkWidget *window, *demo;

  activate (app);

  options = g_application_command_line_get_options_dict (cmdline);
  g_variant_dict_lookup (options, "run", "&s", &name);
  g_variant_dict_lookup (options, "autoquit", "b", &autoquit);
  g_variant_dict_lookup (options, "list", "b", &list);

  if (list)
    {
      list_demos ();
      g_application_quit (app);
      return 0;
    }

  if (name == NULL)
    goto out;

  window = gtk_application_get_windows (GTK_APPLICATION (app))->data;

  d = gtk_demos;

  while (d->title)
    {
      c = d->children;
      if (g_strcmp0 (d->name, name) == 0)
        {
          func = d->func;
          goto out;
        }
      d++;
      while (c && c->title)
        {
          if (g_strcmp0 (c->name, name) == 0)
            {
              func = c->func;
              goto out;
            }
          c++;
        }
    }

out:
  if (func)
    {
      demo = (func) (window);

      gtk_window_set_transient_for (GTK_WINDOW (demo), GTK_WINDOW (window));
      gtk_window_set_modal (GTK_WINDOW (demo), TRUE);
    }

  if (autoquit)
    g_timeout_add_seconds (1, auto_quit, app);

  return 0;
}

static void
print_version (void)
{
  g_print ("gtk3-demo %d.%d.%d\n",
           gtk_get_major_version (),
           gtk_get_minor_version (),
           gtk_get_micro_version ());
}

static int
local_options (GApplication *app,
               GVariantDict *options,
               gpointer      data)
{
  gboolean version = FALSE;

  g_variant_dict_lookup (options, "version", "b", &version);

  if (version)
    {
      print_version ();
      return 0;
    }

  return -1;
}

int
main (int argc, char **argv)
{
  GtkApplication *app;
  static GActionEntry app_entries[] = {
    { "about", activate_about, NULL, NULL, NULL },
    { "quit", activate_quit, NULL, NULL, NULL },
    { "inspector", activate_inspector, NULL, NULL, NULL },
  };
  struct {
    const gchar *action_and_target;
    const gchar *accelerators[2];
  } accels[] = {
    { "app.about", { "F1", NULL } },
    { "app.quit", { "<Control>q", NULL } },
  };
  int i;

  /* Most code in gtk-demo is intended to be exemplary, but not
   * these few lines, which are just a hack so gtk-demo will work
   * in the GTK tree without installing it.
   */
  if (g_file_test ("../../modules/input/immodules.cache", G_FILE_TEST_EXISTS))
    {
      g_setenv ("GTK_IM_MODULE_FILE", "../../modules/input/immodules.cache", TRUE);
    }
  /* -- End of hack -- */

  app = gtk_application_new ("org.gtk.Demo4", G_APPLICATION_NON_UNIQUE|G_APPLICATION_HANDLES_COMMAND_LINE);

  g_action_map_add_action_entries (G_ACTION_MAP (app),
                                   app_entries, G_N_ELEMENTS (app_entries),
                                   app);

  for (i = 0; i < G_N_ELEMENTS (accels); i++)
    gtk_application_set_accels_for_action (app, accels[i].action_and_target, accels[i].accelerators);

  g_application_add_main_option (G_APPLICATION (app), "version", 0, 0, G_OPTION_ARG_NONE, "Show program version", NULL);
  g_application_add_main_option (G_APPLICATION (app), "run", 0, 0, G_OPTION_ARG_STRING, "Run an example", "EXAMPLE");
  g_application_add_main_option (G_APPLICATION (app), "list", 0, 0, G_OPTION_ARG_NONE, "List examples", NULL);
  g_application_add_main_option (G_APPLICATION (app), "autoquit", 0, 0, G_OPTION_ARG_NONE, "Quit after a delay", NULL);

  g_signal_connect (app, "activate", G_CALLBACK (activate), NULL);
  g_signal_connect (app, "command-line", G_CALLBACK (command_line), NULL);
  g_signal_connect (app, "handle-local-options", G_CALLBACK (local_options), NULL);

  g_application_run (G_APPLICATION (app), argc, argv);

  return 0;
}