// Copyright 2016 Open Source Robotics Foundation, Inc.
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
//     http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.

#include "rclcpp/rclcpp.hpp"
#include "std_msgs/msg/string.hpp"

rclcpp::Node::SharedPtr g_node = nullptr;

/* We do not recommend this style anymore, because composition of multiple
 * nodes in the same executable is not possible. Please see one of the subclass
 * examples for the "new" recommended styles. This example is only included
 * for completeness because it is similar to "classic" standalone ROS nodes. */

void topic_callback(const std_msgs::msg::String & msg)
{
  RCLCPP_INFO(g_node->get_logger(), "I heard: '%s'", msg.data.c_str());
}

int main(int argc, char * argv[])
{
  rclcpp::init(argc, argv);
  g_node = rclcpp::Node::make_shared("minimal_subscriber");
  auto subscription =
    g_node->create_subscription<std_msgs::msg::String>("topic", 10, topic_callback);
  rclcpp::spin(g_node);
  rclcpp::shutdown();
  return 0;
}