// Copyright 2013 The Flutter Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

#include "flutter/shell/platform/linux/fl_view_accessible.h"
#include "flutter/shell/platform/linux/fl_accessible_node.h"
#include "flutter/shell/platform/linux/public/flutter_linux/fl_view.h"

struct _FlViewAccessible {
  GtkWidgetAccessible parent_instance;

  // Semantics nodes keyed by ID
  GHashTable* semantics_nodes_by_id;
};

G_DEFINE_TYPE(FlViewAccessible, fl_view_accessible, GTK_TYPE_WIDGET_ACCESSIBLE)

// Gets the ATK node for the given id.
// If the node doesn't exist it will be created.
static FlAccessibleNode* get_node(FlViewAccessible* self, int32_t id) {
  FlAccessibleNode* node = FL_ACCESSIBLE_NODE(
      g_hash_table_lookup(self->semantics_nodes_by_id, GINT_TO_POINTER(id)));
  if (node != nullptr) {
    return node;
  }

  FlView* view = FL_VIEW(gtk_accessible_get_widget(GTK_ACCESSIBLE(self)));
  node = fl_accessible_node_new(fl_view_get_engine(view), id);
  if (id == 0) {
    fl_accessible_node_set_parent(node, ATK_OBJECT(self));
  }
  g_hash_table_insert(self->semantics_nodes_by_id, GINT_TO_POINTER(id),
                      reinterpret_cast<gpointer>(node));

  return node;
}

// Implements AtkObject::get_n_children
static gint fl_view_accessible_get_n_children(AtkObject* accessible) {
  return 1;
}

// Implements AtkObject::ref_child
static AtkObject* fl_view_accessible_ref_child(AtkObject* accessible, gint i) {
  FlViewAccessible* self = FL_VIEW_ACCESSIBLE(accessible);

  if (i != 0) {
    return nullptr;
  }

  FlAccessibleNode* node = get_node(self, 0);
  return ATK_OBJECT(g_object_ref(node));
}

// Implements AtkObject::get_role
static AtkRole fl_view_accessible_get_role(AtkObject* accessible) {
  return ATK_ROLE_FRAME;
}

static void fl_view_accessible_class_init(FlViewAccessibleClass* klass) {
  ATK_OBJECT_CLASS(klass)->get_n_children = fl_view_accessible_get_n_children;
  ATK_OBJECT_CLASS(klass)->ref_child = fl_view_accessible_ref_child;
  ATK_OBJECT_CLASS(klass)->get_role = fl_view_accessible_get_role;
}

static void fl_view_accessible_init(FlViewAccessible* self) {
  self->semantics_nodes_by_id = g_hash_table_new_full(
      g_direct_hash, g_direct_equal, nullptr, g_object_unref);
}

void fl_view_accessible_handle_update_semantics_node(
    FlViewAccessible* self,
    const FlutterSemanticsNode* node) {
  if (node->id == kFlutterSemanticsCustomActionIdBatchEnd) {
    return;
  }

  FlAccessibleNode* atk_node = get_node(self, node->id);

  fl_accessible_node_set_flags(atk_node, node->flags);
  fl_accessible_node_set_actions(atk_node, node->actions);
  fl_accessible_node_set_name(atk_node, node->label);
  fl_accessible_node_set_extents(
      atk_node, node->rect.left + node->transform.transX,
      node->rect.top + node->transform.transY,
      node->rect.right - node->rect.left, node->rect.bottom - node->rect.top);

  g_autoptr(GPtrArray) children = g_ptr_array_new();
  for (size_t i = 0; i < node->child_count; i++) {
    FlAccessibleNode* child =
        get_node(self, node->children_in_traversal_order[i]);
    fl_accessible_node_set_parent(child, ATK_OBJECT(atk_node));
    g_ptr_array_add(children, child);
  }
  fl_accessible_node_set_children(atk_node, children);
}