namespace phoenix {

static gboolean Canvas_expose(GtkWidget* widget, GdkEvent* event, pCanvas* self) {
  cairo_t* context = gdk_cairo_create(gtk_widget_get_window(widget));
  cairo_set_source_surface(context, self->surface, 0, 0);
  cairo_paint(context);
  cairo_destroy(context);
  return true;
}

static void Canvas_dropEvent(GtkWidget* widget, GdkDragContext* context, gint x, gint y,
GtkSelectionData* data, guint type, guint timestamp, Canvas* canvas) {
  if(canvas->state.droppable == false) return;
  lstring paths = DropPaths(data);
  if(paths.empty()) return;
  if(canvas->onDrop) canvas->onDrop(paths);
}

static gboolean Canvas_mouseLeave(GtkWidget* widget, GdkEventButton* event, pCanvas* self) {
  if(self->canvas.onMouseLeave) self->canvas.onMouseLeave();
  return true;
}

static gboolean Canvas_mouseMove(GtkWidget* widget, GdkEventButton* event, pCanvas* self) {
  if(self->canvas.onMouseMove) self->canvas.onMouseMove({(signed)event->x, (signed)event->y});
  return true;
}

static gboolean Canvas_mousePress(GtkWidget* widget, GdkEventButton* event, pCanvas* self) {
  if(self->canvas.onMousePress) switch(event->button) {
  case 1: self->canvas.onMousePress(Mouse::Button::Left); break;
  case 2: self->canvas.onMousePress(Mouse::Button::Middle); break;
  case 3: self->canvas.onMousePress(Mouse::Button::Right); break;
  }
  return true;
}

static gboolean Canvas_mouseRelease(GtkWidget* widget, GdkEventButton* event, pCanvas* self) {
  if(self->canvas.onMouseRelease) switch(event->button) {
  case 1: self->canvas.onMouseRelease(Mouse::Button::Left); break;
  case 2: self->canvas.onMouseRelease(Mouse::Button::Middle); break;
  case 3: self->canvas.onMouseRelease(Mouse::Button::Right); break;
  }
  return true;
}

void pCanvas::setDroppable(bool droppable) {
  gtk_drag_dest_set(gtkWidget, GTK_DEST_DEFAULT_ALL, nullptr, 0, GDK_ACTION_COPY);
  if(droppable) gtk_drag_dest_add_uri_targets(gtkWidget);
}

void pCanvas::setSize(Size size) {
  cairo_surface_destroy(surface);
  surface = cairo_image_surface_create(CAIRO_FORMAT_RGB24, canvas.state.width, canvas.state.height);
}

void pCanvas::update() {
  memcpy(cairo_image_surface_get_data(surface), canvas.state.data, canvas.state.width * canvas.state.height * sizeof(uint32_t));
  if(gtk_widget_get_realized(gtkWidget) == false) return;
  gdk_window_invalidate_rect(gtk_widget_get_window(gtkWidget), nullptr, true);
}

void pCanvas::constructor() {
  surface = cairo_image_surface_create(CAIRO_FORMAT_RGB24, canvas.state.width, canvas.state.height);
  memcpy(cairo_image_surface_get_data(surface), canvas.state.data, canvas.state.width * canvas.state.height * sizeof(uint32_t));
  gtkWidget = gtk_drawing_area_new();
  gtk_widget_set_double_buffered(gtkWidget, false);
  gtk_widget_add_events(gtkWidget,
    GDK_BUTTON_PRESS_MASK | GDK_BUTTON_RELEASE_MASK | GDK_EXPOSURE_MASK | GDK_LEAVE_NOTIFY_MASK | GDK_POINTER_MOTION_MASK);
  g_signal_connect(G_OBJECT(gtkWidget), "drag-data-received", G_CALLBACK(Canvas_dropEvent), (gpointer)&canvas);
  g_signal_connect(G_OBJECT(gtkWidget), "button_press_event", G_CALLBACK(Canvas_mousePress), (gpointer)this);
  g_signal_connect(G_OBJECT(gtkWidget), "button_release_event", G_CALLBACK(Canvas_mouseRelease), (gpointer)this);
  g_signal_connect(G_OBJECT(gtkWidget), "expose_event", G_CALLBACK(Canvas_expose), (gpointer)this);
  g_signal_connect(G_OBJECT(gtkWidget), "leave_notify_event", G_CALLBACK(Canvas_mouseLeave), (gpointer)this);
  g_signal_connect(G_OBJECT(gtkWidget), "motion_notify_event", G_CALLBACK(Canvas_mouseMove), (gpointer)this);
}

void pCanvas::destructor() {
  gtk_widget_destroy(gtkWidget);
  cairo_surface_destroy(surface);
}

void pCanvas::orphan() {
  destructor();
  constructor();
}

}