action_wrapper.hpp

// Copyright 2024 Robin Müller
//
// 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
//
//      https://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.
 
#pragma once
 
#include <chrono>
 
#include "auto_apms_util/action_context.hpp"
#include "auto_apms_util/action_wrapper_params.hpp"
#include "auto_apms_util/logging.hpp"
#include "rclcpp/rclcpp.hpp"
#include "rclcpp_action/rclcpp_action.hpp"
 
namespace auto_apms_util
{

enum class ActionStatus : uint8_t
{
  RUNNING,
  SUCCESS,
  FAILURE
};
 
extern const std::string ACTION_WRAPPER_PARAM_NAME_LOOP_RATE;
extern const std::string ACTION_WRAPPER_PARAM_NAME_FEEDBACK_RATE;

template <typename ActionT>
class ActionWrapper
{
public:
  using Params = action_wrapper_params::Params;
  using ParamListener = action_wrapper_params::ParamListener;
  using Status = ActionStatus;
  using ActionContextType = ActionContext<ActionT>;
  using Goal = typename ActionContextType::Goal;
  using Feedback = typename ActionContextType::Feedback;
  using Result = typename ActionContextType::Result;
  using GoalHandle = typename ActionContextType::GoalHandle;

  explicit ActionWrapper(
    const std::string & action_name, rclcpp::Node::SharedPtr node_ptr,
    std::shared_ptr<ActionContextType> action_context_ptr);

  explicit ActionWrapper(const std::string & action_name, rclcpp::Node::SharedPtr node_ptr);

  explicit ActionWrapper(const std::string & action_name, const rclcpp::NodeOptions & options);
 
private:

  virtual bool onGoalRequest(std::shared_ptr<const Goal> goal_ptr);

  virtual void setInitialResult(std::shared_ptr<const Goal> goal_ptr, std::shared_ptr<Result> result_ptr);

  virtual bool onCancelRequest(std::shared_ptr<const Goal> goal_ptr, std::shared_ptr<Result> result_ptr);

  virtual Status cancelGoal(std::shared_ptr<const Goal> goal_ptr, std::shared_ptr<Result> result_ptr);

  virtual Status executeGoal(
    std::shared_ptr<const Goal> goal_ptr, std::shared_ptr<Feedback> feedback_ptr,
    std::shared_ptr<Result> result_ptr) = 0;

 
  rclcpp_action::GoalResponse handle_goal_(const rclcpp_action::GoalUUID & uuid, std::shared_ptr<const Goal> goal_ptr);
  rclcpp_action::CancelResponse handle_cancel_(std::shared_ptr<GoalHandle> goal_handle_ptr);
  void handle_accepted_(std::shared_ptr<GoalHandle> goal_handle_ptr);
 
  void execution_timer_callback_(std::shared_ptr<const Goal> goal_ptr);
 
public:
  rclcpp::node_interfaces::NodeBaseInterface::SharedPtr get_node_base_interface() const;
 
protected:
  rclcpp::Node::SharedPtr node_ptr_;
  std::shared_ptr<ActionContextType> action_context_ptr_;
  const ParamListener param_listener_;
 
private:
  typename rclcpp_action::Server<ActionT>::SharedPtr action_server_ptr_;
  rclcpp::TimerBase::SharedPtr execution_timer_ptr_;
  rclcpp::Time last_feedback_ts_;
};
 
template <class ActionT>
ActionWrapper<ActionT>::ActionWrapper(
  const std::string & action_name, rclcpp::Node::SharedPtr node_ptr,
  std::shared_ptr<ActionContextType> action_context_ptr)
: node_ptr_(node_ptr), action_context_ptr_(action_context_ptr), param_listener_(node_ptr)
{
  using namespace std::placeholders;
  action_server_ptr_ = rclcpp_action::create_server<ActionT>(
    node_ptr_, action_name, std::bind(&ActionWrapper<ActionT>::handle_goal_, this, _1, _2),
    std::bind(&ActionWrapper<ActionT>::handle_cancel_, this, _1),
    std::bind(&ActionWrapper<ActionT>::handle_accepted_, this, _1));
}
 
template <class ActionT>
ActionWrapper<ActionT>::ActionWrapper(const std::string & action_name, rclcpp::Node::SharedPtr node_ptr)
: ActionWrapper(action_name, node_ptr, std::make_shared<ActionContextType>(node_ptr->get_logger()))
{
}
 
template <class ActionT>
ActionWrapper<ActionT>::ActionWrapper(const std::string & action_name, const rclcpp::NodeOptions & options)
: ActionWrapper(action_name, std::make_shared<rclcpp::Node>(action_name + "_node", options))
{
}
 
template <class ActionT>
rclcpp::node_interfaces::NodeBaseInterface::SharedPtr ActionWrapper<ActionT>::get_node_base_interface() const
{
  return node_ptr_->get_node_base_interface();
}
 
template <class ActionT>
bool ActionWrapper<ActionT>::onGoalRequest(std::shared_ptr<const Goal> /*goal_ptr*/)
{
  // Always accept goal by default
  return true;
}
 
template <class ActionT>
void ActionWrapper<ActionT>::setInitialResult(
  std::shared_ptr<const Goal> /*goal_ptr*/, std::shared_ptr<Result> /*result_ptr*/)
{
  // By default, the result is initialized using the default values specified in the action message definition.
}
 
template <class ActionT>
bool ActionWrapper<ActionT>::onCancelRequest(
  std::shared_ptr<const Goal> /*goal_ptr*/, std::shared_ptr<Result> /*result_ptr*/)
{
  // Always accept cancel request by default
  return true;
}
 
template <class ActionT>
ActionStatus ActionWrapper<ActionT>::cancelGoal(
  std::shared_ptr<const Goal> /*goal_ptr*/, std::shared_ptr<Result> /*result_ptr*/)
{
  // Do nothing by default
  return ActionStatus::SUCCESS;
}
 
template <class ActionT>
rclcpp_action::GoalResponse ActionWrapper<ActionT>::handle_goal_(
  const rclcpp_action::GoalUUID & uuid, std::shared_ptr<const Goal> goal_ptr)
{
  if (action_context_ptr_->isValid() && action_context_ptr_->getGoalHandlePtr()->is_active()) {
    RCLCPP_DEBUG(
      node_ptr_->get_logger(), "Goal %s was REJECTED: Goal %s is still executing.",
      rclcpp_action::to_string(uuid).c_str(),
      rclcpp_action::to_string(action_context_ptr_->getGoalHandlePtr()->get_goal_id()).c_str());
    return rclcpp_action::GoalResponse::REJECT;
  }
 
  if (!onGoalRequest(goal_ptr)) {
    RCLCPP_DEBUG(
      node_ptr_->get_logger(), "Goal %s was REJECTED because onGoalRequest() returned false",
      rclcpp_action::to_string(uuid).c_str());
    return rclcpp_action::GoalResponse::REJECT;
  }
 
  return rclcpp_action::GoalResponse::ACCEPT_AND_EXECUTE;
}
 
template <class ActionT>
rclcpp_action::CancelResponse ActionWrapper<ActionT>::handle_cancel_(std::shared_ptr<GoalHandle> /*goal_handle_ptr*/)
{
  return onCancelRequest(action_context_ptr_->getGoalHandlePtr()->get_goal(), action_context_ptr_->getResultPtr())
           ? rclcpp_action::CancelResponse::ACCEPT
           : rclcpp_action::CancelResponse::REJECT;
}
 
template <class ActionT>
void ActionWrapper<ActionT>::handle_accepted_(std::shared_ptr<GoalHandle> goal_handle_ptr)
{
  action_context_ptr_->setUp(goal_handle_ptr);
  std::shared_ptr<const Goal> goal_ptr = action_context_ptr_->getGoalHandlePtr()->get_goal();
  setInitialResult(goal_ptr, action_context_ptr_->getResultPtr());
  (void)goal_handle_ptr;  // action_context_ptr_ takes ownership of goal handle from now on
 
  const Params & params = param_listener_.get_params();
 
  // Ensure that feedback is published already after the first cycle
  last_feedback_ts_ = node_ptr_->now() - rclcpp::Duration::from_seconds(params.feedback_rate);
 
  // Create the timer that triggers the execution routine
  execution_timer_ptr_ = node_ptr_->create_wall_timer(
    std::chrono::duration<double>(params.loop_rate), [this, goal_ptr]() { this->execution_timer_callback_(goal_ptr); });
}
 
template <class ActionT>
void ActionWrapper<ActionT>::execution_timer_callback_(std::shared_ptr<const Goal> goal_ptr)
{
  // Cancel timer when goal has terminated
  if (!action_context_ptr_->getGoalHandlePtr()->is_active()) {
    execution_timer_ptr_->cancel();
    return;
  }
 
  // Check if canceling
  if (action_context_ptr_->getGoalHandlePtr()->is_canceling()) {
    switch (cancelGoal(goal_ptr, action_context_ptr_->getResultPtr())) {
      case ActionStatus::RUNNING:
        return;
      case ActionStatus::SUCCESS:
        action_context_ptr_->cancel();
        return;
      case ActionStatus::FAILURE:
        action_context_ptr_->abort();
        return;
    }
  } else {
    const auto ret = executeGoal(goal_ptr, action_context_ptr_->getFeedbackPtr(), action_context_ptr_->getResultPtr());
 
    // Publish feedback
    const auto feedback_rate = rclcpp::Duration::from_seconds(param_listener_.get_params().feedback_rate);
    if (node_ptr_->now() - last_feedback_ts_ > feedback_rate) {
      action_context_ptr_->publishFeedback();
      last_feedback_ts_ = node_ptr_->now();
    }
 
    switch (ret) {
      case ActionStatus::RUNNING:
        break;
      case ActionStatus::SUCCESS:
        action_context_ptr_->succeed();
        return;
      case ActionStatus::FAILURE:
        action_context_ptr_->abort();
        return;
    }
  }
}
 
}  // namespace auto_apms_util