MqttClient.h

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/*
==============================================================================
MIT License
 
Copyright 2022 Institute for Automotive Engineering of RWTH Aachen University.
 
Permission is hereby granted, free of charge, to any person obtaining a copy
of this software and associated documentation files (the "Software"), to deal
in the Software without restriction, including without limitation the rights
to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
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furnished to do so, subject to the following conditions:
 
The above copyright notice and this permission notice shall be included in all
copies or substantial portions of the Software.
 
THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
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OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
SOFTWARE.
==============================================================================
*/
 
 
#pragma once
 
#include <filesystem>
#include <map>
#include <memory>
#include <string>
 
#include <mqtt_client_interfaces/IsConnected.h>
#include <mqtt/async_client.h>
#include <nodelet/nodelet.h>
#include <ros/ros.h>
#include <rosfmt/full.h> // fmt::format, fmt::join
#include <topic_tools/shape_shifter.h>
 
 
namespace mqtt_client {
 
 
class MqttClient : public nodelet::Nodelet,
                   public virtual mqtt::callback,
                   public virtual mqtt::iaction_listener {
 
 protected:
  virtual void onInit() override;
 
  void loadParameters();
 
  bool loadParameter(const std::string& key, std::string& value);
 
  bool loadParameter(const std::string& key, std::string& value,
                     const std::string& default_value);
 
  template <typename T>
  bool loadParameter(const std::string& key, T& value);
 
  template <typename T>
  bool loadParameter(const std::string& key, T& value, const T& default_value);
 
  template <typename T>
  bool loadParameter(const std::string& key, std::vector<T>& value);
 
  template <typename T>
  bool loadParameter(const std::string& key, std::vector<T>& value, const std::vector<T>& default_value);
 
  std::filesystem::path resolvePath(const std::string& path_string);
 
  void setup();
 
  void setupClient();
 
  void connect();
 
  void ros2mqtt(const topic_tools::ShapeShifter::ConstPtr& ros_msg,
                const std::string& ros_topic);
 
  void mqtt2ros(mqtt::const_message_ptr mqtt_msg,
                const ros::WallTime& arrival_stamp = ros::WallTime::now());
 
  void mqtt2primitive(mqtt::const_message_ptr mqtt_msg);
 
  void connected(const std::string& cause) override;
 
  void connection_lost(const std::string& cause) override;
 
  bool isConnected();
 
  bool isConnectedService(
    mqtt_client_interfaces::IsConnected::Request& request,
    mqtt_client_interfaces::IsConnected::Response& response);
 
  void message_arrived(mqtt::const_message_ptr mqtt_msg) override;
 
  void delivery_complete(mqtt::delivery_token_ptr token) override;
 
  void on_success(const mqtt::token& token) override;
 
  void on_failure(const mqtt::token& token) override;
 
 protected:
  struct BrokerConfig {
    std::string host;  
    int port;          
    std::string user;  
    std::string pass;  
    struct {
      bool enabled;  
      std::filesystem::path
        ca_certificate;  
    } tls;               
  };
 
  struct ClientConfig {
    std::string id;  
    struct {
      bool enabled;                     
      int size;                         
      std::filesystem::path directory;  
    } buffer;                           
    struct {
      std::string topic;         
      std::string message;       
      int qos;                   
      bool retained;             
    } last_will;                 
    bool clean_session;          
    double keep_alive_interval;  
    int max_inflight;            
    struct {
      std::filesystem::path certificate;    
      std::filesystem::path key;            
      std::string password;                 
      int version;                          
      bool verify;                          
      std::vector<std::string> alpn_protos; 
    } tls;                   
  };
 
  struct Ros2MqttInterface {
    struct {
      ros::Subscriber subscriber;  
      int queue_size = 1;          
    } ros;                         
    struct {
      std::string topic;      
      int qos = 0;            
      bool retained = false;  
    } mqtt;                   
    bool primitive = false;   
    bool stamped = false;     
  };
 
  struct Mqtt2RosInterface {
    struct {
      int qos = 0;  
    } mqtt;         
    struct {
      std::string topic;                        
      ros::Publisher publisher;                 
      topic_tools::ShapeShifter shape_shifter;  
      ros::Publisher latency_publisher;         
      int queue_size = 1;                       
      bool latched = false;  
    } ros;                   
    bool primitive = false;  
    bool stamped = false;    
  };
 
 protected:
  static const std::string kRosMsgTypeMqttTopicPrefix;
 
  static const std::string kLatencyRosTopicPrefix;
 
  ros::NodeHandle node_handle_;
 
  ros::NodeHandle private_node_handle_;
 
  ros::ServiceServer is_connected_service_;
 
  bool is_connected_ = false;
 
  BrokerConfig broker_config_;
 
  ClientConfig client_config_;
 
  std::shared_ptr<mqtt::async_client> client_;
 
  mqtt::connect_options connect_options_;
 
  std::map<std::string, Ros2MqttInterface> ros2mqtt_;
 
  std::map<std::string, Mqtt2RosInterface> mqtt2ros_;
};
 
 
template <typename T>
bool MqttClient::loadParameter(const std::string& key, T& value) {
  bool found = private_node_handle_.getParam(key, value);
  if (found)
    NODELET_DEBUG("Retrieved parameter '%s' = '%s'", key.c_str(),
                  std::to_string(value).c_str());
  return found;
}
 
 
template <typename T>
bool MqttClient::loadParameter(const std::string& key, T& value,
                               const T& default_value) {
  bool found = private_node_handle_.param<T>(key, value, default_value);
  if (!found) {
    if (private_node_handle_.hasParam(key))
      NODELET_ERROR("Parameter '%s' has wrong data type", key.c_str());
    NODELET_WARN("Parameter '%s' not set, defaulting to '%s'", key.c_str(),
                 std::to_string(default_value).c_str());
  }
  if (found)
    NODELET_DEBUG("Retrieved parameter '%s' = '%s'", key.c_str(),
                  std::to_string(value).c_str());
  return found;
}
 
 
template <typename T>
bool MqttClient::loadParameter(const std::string& key, std::vector<T>& value)
{
  const bool found = private_node_handle_.getParam(key, value);
  if (found)
    NODELET_DEBUG("Retrieved parameter '%s' = '[%s]'", key.c_str(),
                  fmt::format("{}", fmt::join(value, ", ")).c_str());
  return found;
}
 
 
template <typename T>
bool MqttClient::loadParameter(const std::string& key, std::vector<T>& value,
                               const std::vector<T>& default_value)
{
  const bool found = private_node_handle_.param<T>(key, value, default_value);
  if (!found)
    NODELET_WARN("Parameter '%s' not set, defaulting to '%s'", key.c_str(),
                  fmt::format("{}", fmt::join(value, ", ")).c_str());
  if (found)
    NODELET_DEBUG("Retrieved parameter '%s' = '%s'", key.c_str(),
                  fmt::format("{}", fmt::join(value, ", ")).c_str());
  return found;
}
 
 
template <typename T>
void serializeRosMessage(const T& msg, std::vector<uint8_t>& buffer) {
 
  const uint32_t length = ros::serialization::serializationLength(msg);
  buffer.resize(length);
  ros::serialization::OStream stream(buffer.data(), length);
  ros::serialization::serialize(stream, msg);
}
 
}  // namespace mqtt_client