ConfiguratorTemplate.h

//================================================================================
// Name        : ConfiguratorTemplate.h
// Author      : Micha Mueller, Carla Guillen
// Copyright   : Leibniz Supercomputing Centre
// Description : Interface template for plugin configurators.
//================================================================================

//================================================================================
// This file is part of DCDB (DataCenter DataBase)
// Copyright (C) 2018-2019 Leibniz Supercomputing Centre
//
// This program is free software; you can redistribute it and/or
// modify it under the terms of the GNU General Public License
// as published by the Free Software Foundation; either version 2
// of the License, or (at your option) any later version.
//
// This program is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
// GNU General Public License for more details.
//
// You should have received a copy of the GNU General Public License
// along with this program; if not, write to the Free Software
// Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
//================================================================================

#ifndef SRC_CONFIGURATORTEMPLATE_H_
#define SRC_CONFIGURATORTEMPLATE_H_

#include <map>
#include <set>

#include <boost/foreach.hpp>
#include <boost/algorithm/string.hpp>
#include <boost/property_tree/ptree.hpp>
#include <boost/property_tree/info_parser.hpp>
#include "ConfiguratorInterface.h"
#include "sensorbase.h"
#include "SensorGroupTemplate.h"
#include "EntityInterface.h"

#include <algorithm>
#include <iostream>
#include <sstream>
#include <iomanip>

/**
 * @brief Interface template for plugin configurator implementations with
 *        entities.
 *
 * @details There is a partial template specialization for SEntity = nullptr_t,
 *          i.e. for plugins without entities, see
 *          ConfiguratorTemplate<SBase, SGroup, nullptr_t>. Common code is moved
 *          to ConfiguratorInterface if possible. If not, common code has to be
 *          duplicated and maintained twice here and in
 *          ConfiguratorTemplate<SBase, SGroup, nullptr_t>. However, having two
 *          templates for cases with and without entities allows for simplified
 *          derived plugin configurators.
 *
 * @ingroup pusherplugins
 */
template <class SBase, class SGroup, class SEntity = nullptr_t>
class ConfiguratorTemplate : public ConfiguratorInterface {
	//the template shall only be instantiated for classes which derive from SensorBase/SensorGroup
	static_assert(std::is_base_of<SensorBase, SBase>::value, "SBase must derive from SensorBase!");
	static_assert(std::is_base_of<SensorGroupInterface, SGroup>::value, "SGroup must derive from SensorGroupInterface!");
	static_assert(std::is_base_of<EntityInterface, SEntity>::value, "SEntity must derive from EntityInterface!");

protected:
	//TODO use smart pointers
	typedef std::map<std::string, SBase*> sBaseMap_t;
	typedef std::map<std::string, SGroup*> sGroupMap_t;
	typedef std::map<std::string, SEntity*> sEntityMap_t;

	using SB_Ptr = std::shared_ptr<SBase>;
	using SG_Ptr = std::shared_ptr<SGroup>;
	
public:
	ConfiguratorTemplate() :
	    ConfiguratorInterface(),
		_entityName("INVALID"),
		_groupName("INVALID"),
		_baseName("INVALID"){}

	virtual ~ConfiguratorTemplate() {
		for (auto e : _sensorEntitys) {
			delete e;
		}
		for (auto tb : _templateSensorBases) {
			delete tb.second;
		}
		for (auto tg : _templateSensorGroups) {
			delete tg.second;
		}
		for (auto te : _templateSensorEntitys) {
			delete te.second;
		}
		_sensorGroups.clear();
		_sensorEntitys.clear();
		_templateSensorBases.clear();
		_templateSensorGroups.clear();
		_templateSensorEntitys.clear();
	}

	/**
	 * @brief Read in the given configuration
	 *
	 * @details Overwriting this method is only required if a custom logic is really necessary!
	 *
	 * @param	cfgPath Path to the config-file
	 *
	 * @return	True on success, false otherwise
	 */
	bool readConfig(std::string cfgPath) {
		_cfgPath = cfgPath;

		boost::property_tree::iptree cfg;
		boost::property_tree::read_info(cfgPath, cfg);

		//read global variables (if present overwrite those from global.conf)
		readGlobal(cfg);

		//read groups and templates for groups. If present also entity/-template stuff
		BOOST_FOREACH(boost::property_tree::iptree::value_type &val, cfg) {
			//template entity
			if (boost::iequals(val.first, "template_" + _entityName)) {
				LOG(debug) << "Template " << _entityName << " \"" << val.second.data() << "\"";
				if (!val.second.empty()) {
					//name of an entity is only used to identify templates and is not stored otherwise
					SEntity* entity = new SEntity(val.second.data());
					if (readSensorEntity(*entity, val.second, true)) {
						auto ret = _templateSensorEntitys.insert(std::pair<std::string, SEntity*>(val.second.data(), entity));
						if(!ret.second) {
							LOG(warning) << "Template " << _entityName << " "
							             << val.second.data() << " already exists! Omitting...";
							delete entity;
						}
					} else {
						LOG(warning) << "Template " << _entityName << " \""
						             << val.second.data() << "\" has bad values! Ignoring...";
						delete entity;
					}
				}
			//template group
			} else if (boost::iequals(val.first, "template_" + _groupName)) {
				LOG(debug) << "Template " << _groupName << " \"" << val.second.data() << "\"";
				if (!val.second.empty()) {
					SGroup* group = new SGroup(val.second.data());
					if (readSensorGroup(*group, val.second, true)) {
						auto ret = _templateSensorGroups.insert(std::pair<std::string, SGroup*>(val.second.data(), group));
						if(!ret.second) {
							LOG(warning) << "Template " << _groupName << " "
							             << val.second.data() << " already exists! Omitting...";
							delete group;
						}
					} else {
						LOG(warning) << "Template " << _groupName << " \""
						             << val.second.data() << "\" has bad values! Ignoring...";
						delete group;
					}
				}
			//template base
			} else if (boost::iequals(val.first, "template_" + _baseName)) {
				LOG(debug) << "Template " << _baseName << " \"" << val.second.data() << "\"";
				if (!val.second.empty()) {
					SBase* base = new SBase(val.second.data());
					if (readSensorBase(*base, val.second, true)) {
						auto ret = _templateSensorBases.insert(std::pair<std::string, SBase*>(val.second.data(), base));
						if(!ret.second) {
							LOG(warning) << "Template " << _baseName << " "
							             << val.second.data() << " already exists! Omitting...";
							delete base;
						}
					} else {
						LOG(warning) << "Template " << _baseName << " \""
						             << val.second.data() << "\" has bad values! Ignoring...";
						delete base;
					}
				}
			//template single sensor
			} else if (boost::iequals(val.first, "template_single_" + _baseName)) {
				LOG(debug) << "Template single " << _baseName << " \"" << val.second.data() << "\"";
				if (!val.second.empty()) {
					SGroup* group = new SGroup(val.second.data());
					if (readSensorGroup(*group, val.second, true)) {
						//group which consists of only one sensor
						SB_Ptr sensor = std::make_shared<SBase>(val.second.data());
						if (readSensorBase(*sensor, val.second, true)) {
							group->pushBackSensor(sensor);
							auto ret = _templateSensorGroups.insert(std::pair<std::string, SGroup*>(val.second.data(), group));
							if(!ret.second) {
								LOG(warning) << "Template single " << _baseName << " "
								             << val.second.data() << " already exists! Omitting...";
								delete group;
							}
						} else {
							LOG(warning) << "Template single " << _baseName << " "
							             << val.second.data() << " could not be read! Omitting";
							delete group;
						}
					} else {
						LOG(warning) << "Template single " << _baseName << " \""
						             << val.second.data() << "\" has bad values! Ignoring...";
						delete group;
					}
				}
			//entity
			} else if (boost::iequals(val.first, _entityName)) {
				LOG(debug) << _entityName << " \"" << val.second.data() << "\"";
				if (!val.second.empty()) {
					SEntity* entity = new SEntity(val.second.data());
					if (readSensorEntity(*entity, val.second)) {
						_sensorEntitys.push_back(entity);
					} else {
						LOG(warning) << _entityName << " \""
						             << val.second.data() << "\" has bad values! Ignoring...";
						delete entity;
					}
				}
			//group
			} else if (boost::iequals(val.first, _groupName)) {
				LOG(debug) << _groupName << " \"" << val.second.data() << "\"";
				if (!val.second.empty()) {
					SG_Ptr group = std::make_shared<SGroup>(val.second.data());
					if (readSensorGroup(*group, val.second)) {
						storeSensorGroup(group);
					} else {
						LOG(warning) << _groupName << " \""
						             << val.second.data() << "\" has bad values! Ignoring...";
					}
				}
			//single sensor
			} else if (boost::iequals(val.first, "single_" + _baseName)) {
				LOG(debug) << "Single " << _baseName << " \"" << val.second.data() << "\"";
				if (!val.second.empty()) {
					SG_Ptr group = std::make_shared<SGroup>(val.second.data());
					if (readSensorGroup(*group, val.second)) {
						//group which consists of only one sensor
						SB_Ptr sensor;
						//perhaps one sensor is already present because it was copied from the template group
						if (group->acquireSensors().size() != 0) {
						    group->releaseSensors();
							sensor = std::dynamic_pointer_cast<SBase>(group->acquireSensors()[0]);
							group->releaseSensors();
							//check if cast was successful (sensor != nullptr)
							if (sensor) {
								sensor->setName(val.second.data());
								if (readSensorBase(*sensor, val.second)) {
									storeSensorGroup(group);
								} else {
									LOG(warning) << "Single " << _baseName << " "
									             << val.second.data() << " could not be read! Omitting";
								}
							} else {
								LOG(warning) << "Single " << _baseName << " "
								             << val.second.data() << " had a type mismatch when casting! Omitting";
							}
						} else {
						    group->releaseSensors();
							sensor = std::make_shared<SBase>(val.second.data());
							if (readSensorBase(*sensor, val.second)) {
								group->pushBackSensor(sensor);
								storeSensorGroup(group);
							} else {
								LOG(warning) << "Single " << _baseName << " "
								             << val.second.data() << " could not be read! Omitting";
							}
						}
					} else {
						LOG(warning) << "Single " << _baseName << " \""
						             << val.second.data() << "\" has bad values! Ignoring...";
					}
				}
			} else if( !boost::iequals(val.first, "global") ) {
			    LOG(error) << "\"" << val.first << "\": unknown construct!";
			    return false;
			}
		}
		//read of config finished. Now we build the mqtt-topic for every sensor
		return constructSensorTopics();
	}

	/**
	 * @brief Clear internal storage and return plugin in unconfigured state.
	 */
	void clearConfig() final {
	    ConfiguratorInterface::clearConfig();
		//bring everything to a halt
		for(auto g : _sensorGroups) {
			g->stop();
		}

		//clean up sensors/groups/entitys and templates
		for(auto e : _sensorEntitys) {
			delete e;
		}
		for (auto tb : _templateSensorBases) {
			delete tb.second;
		}
		for (auto tg : _templateSensorGroups) {
			delete tg.second;
		}
		for (auto te : _templateSensorEntitys) {
			delete te.second;
		}
		_sensorGroups.clear();
		_sensorEntitys.clear();
		_templateSensorBases.clear();
		_templateSensorGroups.clear();
		_templateSensorEntitys.clear();
	}

	/**
     * @brief Print configuration.
     *
     * @param ll Log severity level to be used from logger.
     */
	void printConfig(LOG_LEVEL ll) final {
        ConfiguratorInterface::printConfig(ll);

        //prints plugin specific configurator attributes and entities if present
        printConfiguratorConfig(ll);

        LOG_VAR(ll) << " " << _entityName << "s:";
        if (_sensorEntitys.size() != 0) {
            for(auto e : _sensorEntitys) {
                e->printConfig(ll);
            }
        } else {
            LOG_VAR(ll) << "  No " << _entityName << "s present!";
        }

        LOG_VAR(ll) << "    " << _groupName << "s:";
        for(auto g : _sensorGroups) {
            g->printConfig(ll);
        }
	}

protected:

	///@name Template-internal use only
	///@{
	/**
	 * @brief Read common values of a sensorbase.
	 *
	 * @details Reads and sets the common base values of a sensor base
	 *          (currently none), then calls sensorBase() to read plugin
	 *          specific values.
	 *
	 * @param sBase		 The sensor base for which to set the values.
	 * @param config	 A boost property (sub-)tree containing the values.
	 * @param isTemplate Are we parsing a template or a regular sensor?
	 *
	 * @return	True on success, false otherwise
	 */
	bool readSensorBase(SBase& sBase, CFG_VAL config, bool isTemplate=false) {
		sBase.setCacheInterval(_cacheInterval);
		if (!isTemplate) {
			boost::optional<boost::property_tree::iptree&> def = config.get_child_optional("default");
			if(def) {
				//we copy all values from default
				LOG(debug) << "  Using \"" << def.get().data() << "\" as default.";
				auto it = _templateSensorBases.find(def.get().data());
				if(it != _templateSensorBases.end()) {
					sBase = *(it->second);
					sBase.setName(config.data());
				} else {
					LOG(warning) << "Template " << _baseName << "\" "
					             << def.get().data() << "\" not found! Using standard values.";
				}
			}
		}
		
		BOOST_FOREACH(boost::property_tree::iptree::value_type &val, config) {
			if (boost::iequals(val.first, "mqttsuffix")) {
				sBase.setMqtt(val.second.data());
			} else if (boost::iequals(val.first, "skipConstVal")) {
				sBase.setSkipConstVal(to_bool(val.second.data()));
			} else if (boost::iequals(val.first, "delta")) {
				sBase.setDelta(to_bool(val.second.data()));
			} else if (boost::iequals(val.first, "sink")) {
				sBase.setSinkPath( val.second.data() );
			} else if (boost::iequals(val.first, "subSampling")) {
				sBase.setSubsampling(std::stoul(val.second.data()));
			}
		}
		sensorBase(sBase, config);
		return true;
	}

	/**
     * @brief Read common values of a sensorGroup.
     *
     * @details Reads and sets the common base values of a sensor group
     *          (currently none), then calls sensorGroup() to read plugin
     *          specific values.
     *
     * @param sGroup     The sensor group for which to set the values.
     * @param config     A boost property (sub-)tree containing the values.
     * @param isTemplate Are we parsing a template or a regular group?
     *
     * @return  True on success, false otherwise
     */
	bool readSensorGroup(SGroup& sGroup, CFG_VAL config, bool isTemplate=false) {
		//first check if default group is given, unless we are reading a template already
		if (!isTemplate) {
			boost::optional<boost::property_tree::iptree&> def = config.get_child_optional("default");
			if(def) {
				//we copy all values from default (including copy constructing its sensors)
				//if own sensors are specified they are appended
				LOG(debug) << "  Using \"" << def.get().data() << "\" as default.";
				auto it = _templateSensorGroups.find(def.get().data());
				if(it != _templateSensorGroups.end()) {
					sGroup = *(it->second);
					sGroup.setGroupName(config.data());
				} else {
					LOG(warning) << "Template " << _groupName << "\" "
					             << def.get().data() << "\" not found! Using standard values.";
				}
			}
		}

		//read in values inherited from SensorGroupInterface
		BOOST_FOREACH(boost::property_tree::iptree::value_type &val, config) {
			if (boost::iequals(val.first, "interval")) {
				sGroup.setInterval(stoull(val.second.data()));
			} else if (boost::iequals(val.first, "minValues")) {
				sGroup.setMinValues(stoull(val.second.data()));
			} else if (boost::iequals(val.first, "mqttPart")) {
				sGroup.setMqttPart(val.second.data());
			} else if (boost::iequals(val.first, "sync")) {
				if (val.second.data() == "off") {
					sGroup.setSync(false);
				} else {
					sGroup.setSync(true);
				}
			} else if (boost::iequals(val.first, _baseName)) {
				if (!isTemplate) {
					LOG(debug) << "  " << _baseName << " " << val.second.data();
				}
				SB_Ptr sensor = std::make_shared<SBase>(val.second.data());
				if (readSensorBase(*sensor, val.second, isTemplate)) {
					sGroup.pushBackSensor(sensor);
				} else if (!isTemplate) {
					LOG(warning) << _baseName << " " << sGroup.getGroupName() << "::"
					             << sensor->getName() << " could not be read! Omitting";
				}
			}
		}

		sensorGroup(sGroup, config);
		return true;
	}

	/**
     * @brief Read common values of a sensor entity.
     *
     * @details Reads and sets the common base values of a sensor entity
     *          (currently none), then calls sensorEntity() to read plugin
     *          specific values.
     *
     * @param sEntity    The aggregating entity for which to set the values.
     * @param config     A boost property (sub-)tree containing the values.
     * @param isTemplate Indicate if sEntity is a template. If so, also store
     *                   the corresponding sGroups in the template map.
     *
     * @return  True on success, false otherwise
     */
	bool readSensorEntity(SEntity& sEntity, CFG_VAL config, bool isTemplate=false) {
		//first check if default entity is given
		boost::optional<boost::property_tree::iptree&> def = config.get_child_optional("default");
		if(def) {
			//we copy all values from default
			LOG(debug) << "  Using \"" << def.get().data() << "\" as default.";
			auto it = _templateSensorEntitys.find(def.get().data());
			if(it != _templateSensorEntitys.end()) {
				sEntity = *(it->second);
				for(auto g : _templateSensorGroups) {
					if (it->second == g.second->getEntity()) {
						SG_Ptr group = std::make_shared<SGroup>(*(g.second));
						group->setEntity(&sEntity);
						storeSensorGroup(group);
					}
				}
			} else {
				LOG(warning) << "Template " << _entityName << "\""
				             << def.get().data() << "\" not found! Using standard values.";
			}
		}

        //read in values inherited from EntityInterface
        BOOST_FOREACH(boost::property_tree::iptree::value_type &val, config) {
            if (boost::iequals(val.first, "mqttPart")) {
                sEntity.setMqttPart(val.second.data());
            }
        }

		sensorEntity(sEntity, config);

		BOOST_FOREACH(boost::property_tree::iptree::value_type &val, config) {
			if (boost::iequals(val.first, _groupName)) {
				LOG(debug) << "  " << _groupName << " " << val.second.data();
				if (!val.second.empty()) {
					if (isTemplate) {
						SGroup* group = new SGroup(val.second.data());
						if(readSensorGroup(*group, val.second)) {
						    group->setEntity(&sEntity);
							auto ret = _templateSensorGroups.insert(std::pair<std::string, SGroup*>(val.second.data(), group));
							if(!ret.second) {
								LOG(warning) << "Template " << _groupName << " "
								             << val.second.data() << " already exists! Omitting...";
								delete group;
							}
						} else {
							LOG(warning) << _groupName << " " << group->getGroupName()
							             << " could not be read! Omitting";
							delete group;
						}
					} else {
						SG_Ptr group = std::make_shared<SGroup>(val.second.data());
						if(readSensorGroup(*group, val.second)) {
						    group->setEntity(&sEntity);
							storeSensorGroup(group);
						} else {
							LOG(warning) << _groupName << " " << group->getGroupName()
							             << " could not be read! Omitting";
						}
					}
				}
			} else if (boost::iequals(val.first, "single_" + _baseName)) {
				LOG(debug) << "Single " << _baseName << " \"" << val.second.data() << "\"";
				if (!val.second.empty()) {
					if (isTemplate) {
						SGroup* group = new SGroup(val.second.data());
						//group which consists of only one sensor
						if (readSensorGroup(*group, val.second)) {
						    group->setEntity(&sEntity);
							SB_Ptr sensor = std::make_shared<SBase>(val.second.data());
							if (readSensorBase(*sensor, val.second)) {
								group->pushBackSensor(sensor);
								auto ret = _templateSensorGroups.insert(std::pair<std::string, SGroup*>(val.second.data(), group));
								if(!ret.second) {
									LOG(warning) << "Template single " << _baseName << " "
									             << val.second.data() << " already exists! Omitting...";
									delete group;
								}
							} else {
								LOG(warning) << "Template single " << _baseName << " "
								             << val.second.data() << " could not be read! Omitting";
								delete group;
							}
						} else {
							LOG(warning) << "Single " << _baseName << " \""
							             << val.second.data() << "\" has bad values! Ignoring...";
							delete group;
						}
					} else {
						SG_Ptr group = std::make_shared<SGroup>(val.second.data());
						//group which consists of only one sensor
						if (readSensorGroup(*group, val.second)) {
						    group->setEntity(&sEntity);
							SB_Ptr sensor;
							//perhaps one sensor is already present because it was copied from the template group
							if (group->aquireSensors().size() != 0) {
							    group->releaseSensors();
								sensor = std::dynamic_pointer_cast<SBase>(group->acquireSensors()[0]);
								group->releaseSensors();
								//check if cast was successful (sensor != nullptr)
								if (sensor) {
									sensor->setName(val.second.data());
									if (readSensorBase(*sensor, val.second)) {
										storeSensorGroup(group);
									} else {
										LOG(warning) << "Single " << _baseName << " "
										             << val.second.data() << " could not be read! Omitting";
									}
								} else {
									LOG(warning) << "Single " << _baseName << " "
									             << val.second.data() << " had a type mismatch when casting! Omitting";
								}
							} else {
								sensor = std::make_shared<SBase>(val.second.data());
								if (readSensorBase(*sensor, val.second)) {
									group->pushBackSensor(sensor);
									storeSensorGroup(group);
								} else {
									LOG(warning) << "Single " << _baseName << " "
									             << val.second.data() << " could not be read! Omitting";
								}
							}
						} else {
							LOG(warning) << "Single " << _baseName << " \""
							             << val.second.data() << "\" has bad values! Ignoring...";
						}
					}
				}
			}
		}

		return true;
	}
	///@}

	///@name Overwrite in plugin
	///@{
	/**
	 * Method responsible for reading plugin-specific sensor base values.
	 *
	 * @param s			The sensor base for which to set the values
	 * @param config	A boost property (sub-)tree containing the sensor values
	 */
	virtual void sensorBase(SBase& s, CFG_VAL config) = 0;

	/**
	 * Method responsible for reading plugin-specific sensor group values.
	 *
	 * @param s			The sensor group for which to set the values
	 * @param config	A boost property (sub-)tree containing the group values
	 */
	virtual void sensorGroup(SGroup& s, CFG_VAL config) = 0;

	/**
	 * Method responsible for reading plugin-specific sensor entity values.
	 *
	 * @param s			The sensor entity for which to set the values
	 * @param config	A boost property (sub-)tree containing the entity values
	 */
	virtual void sensorEntity(SEntity& s, CFG_VAL config) = 0;
	///@}

	///@name Utility
	///@{
    /**
     * @brief Store a sensor group internally.
     *
     * @param sGroup Group to store.
     */
    void storeSensorGroup(SG_Ptr sGroup) {
        _sensorGroups.push_back(sGroup);
        _sensorGroupInterfaces.push_back(sGroup);
    }

	/**
	 * @brief Adjusts the names of the sensors in generated groups.
	 *
	 * @return True if successful, false otherwise.
	 */
	bool constructSensorTopics() {
		// Sensor names are adjusted according to the respective MQTT topics
		for(auto& g: _sensorGroups) {
			for(auto& s: g->acquireSensors()) {
				s->setMqtt(MQTTChecker::formatTopic(_mqttPrefix) +
				           MQTTChecker::formatTopic(g->getEntity()->getMqttPart()) +
				           MQTTChecker::formatTopic(g->getMqttPart()) +
				           MQTTChecker::formatTopic(s->getMqtt()));
				s->setName(s->getMqtt());
				if(s->getSinkPath()!="")
					s->setSinkPath(MQTTChecker::topicToFile(s->getMqtt(), s->getSinkPath()));
			}
			g->releaseSensors();
		}
		return true;
	}
	///@}

	std::string		_entityName;
	std::string		_groupName;
	std::string		_baseName;

	std::vector<SG_Ptr>		_sensorGroups;
	std::vector<SEntity*>	_sensorEntitys;
	sBaseMap_t		_templateSensorBases;
	sGroupMap_t		_templateSensorGroups;
	sEntityMap_t	_templateSensorEntitys;
};


////////////////////////////////////////////////////////////////////////////////
// Partial template specialization for SEntity = nullptr_t
////////////////////////////////////////////////////////////////////////////////


/**
 * @brief Partial interface template specialization for plugin configurator
 *        implementations without entities.
 *
 * @details There is a general template for plugins with entities, see
 *          ConfiguratorTemplate. Common code is moved to ConfiguratorInterface
 *          if possible. If not, common code has to be duplicated and maintained
 *          twice here and in ConfiguratorTemplate. However, having two
 *          templates for cases with and without entities allows for simplified
 *          derived plugin configurators.
 *
 * @ingroup pusherplugins
 */
template <class SBase, class SGroup>
class ConfiguratorTemplate<SBase, SGroup, nullptr_t> : public ConfiguratorInterface {
    //the template shall only be instantiated for classes which derive from SensorBase/SensorGroup
    static_assert(std::is_base_of<SensorBase, SBase>::value, "SBase must derive from SensorBase!");
    static_assert(std::is_base_of<SensorGroupInterface, SGroup>::value, "SGroup must derive from SensorGroupInterface!");

protected:
    //TODO use smart pointers
    typedef std::map<std::string, SBase*> sBaseMap_t;
    typedef std::map<std::string, SGroup*> sGroupMap_t;

    using SB_Ptr = std::shared_ptr<SBase>;
    using SG_Ptr = std::shared_ptr<SGroup>;

public:
    ConfiguratorTemplate() :
        ConfiguratorInterface(),
        _groupName("INVALID"),
        _baseName("INVALID"){}

    virtual ~ConfiguratorTemplate() {
        for (auto tb : _templateSensorBases) {
            delete tb.second;
        }
        for (auto tg : _templateSensorGroups) {
            delete tg.second;
        }
        _sensorGroups.clear();
        _templateSensorBases.clear();
        _templateSensorGroups.clear();
    }

    /**
     * @brief Read in the given configuration
     *
     * @details Overwriting this method is only required if a custom logic is really necessary!
     *
     * @param   cfgPath Path to the config-file
     *
     * @return  True on success, false otherwise
     */
    bool readConfig(std::string cfgPath) {
        _cfgPath = cfgPath;

        boost::property_tree::iptree cfg;
        boost::property_tree::read_info(cfgPath, cfg);

        //read global variables (if present overwrite those from global.conf)
        readGlobal(cfg);

        //read groups and templates for groups. If present also entity/-template stuff
        BOOST_FOREACH(boost::property_tree::iptree::value_type &val, cfg) {
            //template group
            if (boost::iequals(val.first, "template_" + _groupName)) {
                LOG(debug) << "Template " << _groupName << " \"" << val.second.data() << "\"";
                if (!val.second.empty()) {
                    SGroup* group = new SGroup(val.second.data());
                    if (readSensorGroup(*group, val.second, true)) {
                        auto ret = _templateSensorGroups.insert(std::pair<std::string, SGroup*>(val.second.data(), group));
                        if(!ret.second) {
                            LOG(warning) << "Template " << _groupName << " "
                                         << val.second.data() << " already exists! Omitting...";
                            delete group;
                        }
                    } else {
                        LOG(warning) << "Template " << _groupName << " \""
                                     << val.second.data() << "\" has bad values! Ignoring...";
                        delete group;
                    }
                }
            //template base
            } else if (boost::iequals(val.first, "template_" + _baseName)) {
                LOG(debug) << "Template " << _baseName << " \"" << val.second.data() << "\"";
                if (!val.second.empty()) {
                    SBase* base = new SBase(val.second.data());
                    if (readSensorBase(*base, val.second, true)) {
                        auto ret = _templateSensorBases.insert(std::pair<std::string, SBase*>(val.second.data(), base));
                        if(!ret.second) {
                            LOG(warning) << "Template " << _baseName << " "
                                         << val.second.data() << " already exists! Omitting...";
                            delete base;
                        }
                    } else {
                        LOG(warning) << "Template " << _baseName << " \""
                                     << val.second.data() << "\" has bad values! Ignoring...";
                        delete base;
                    }
                }
            //template single sensor
            } else if (boost::iequals(val.first, "template_single_" + _baseName)) {
                LOG(debug) << "Template single " << _baseName << " \"" << val.second.data() << "\"";
                if (!val.second.empty()) {
                    SGroup* group = new SGroup(val.second.data());
                    if (readSensorGroup(*group, val.second, true)) {
                        //group which consists of only one sensor
                        SB_Ptr sensor = std::make_shared<SBase>(val.second.data());
                        if (readSensorBase(*sensor, val.second, true)) {
                            group->pushBackSensor(sensor);
                            auto ret = _templateSensorGroups.insert(std::pair<std::string, SGroup*>(val.second.data(), group));
                            if(!ret.second) {
                                LOG(warning) << "Template single " << _baseName << " "
                                             << val.second.data() << " already exists! Omitting...";
                                delete group;
                            }
                        } else {
                            LOG(warning) << "Template single " << _baseName << " "
                                         << val.second.data() << " could not be read! Omitting";
                            delete group;
                        }
                    } else {
                        LOG(warning) << "Template single " << _baseName << " \""
                                     << val.second.data() << "\" has bad values! Ignoring...";
                        delete group;
                    }
                }
            //group
            } else if (boost::iequals(val.first, _groupName)) {
                LOG(debug) << _groupName << " \"" << val.second.data() << "\"";
                if (!val.second.empty()) {
                    SG_Ptr group = std::make_shared<SGroup>(val.second.data());
                    if (readSensorGroup(*group, val.second)) {
                        storeSensorGroup(group);
                    } else {
                        LOG(warning) << _groupName << " \""
                                     << val.second.data() << "\" has bad values! Ignoring...";
                    }
                }
            //single sensor
            } else if (boost::iequals(val.first, "single_" + _baseName)) {
                LOG(debug) << "Single " << _baseName << " \"" << val.second.data() << "\"";
                if (!val.second.empty()) {
                    SG_Ptr group = std::make_shared<SGroup>(val.second.data());
                    if (readSensorGroup(*group, val.second)) {
                        //group which consists of only one sensor
                        SB_Ptr sensor;
                        //perhaps one sensor is already present because it was copied from the template group
                        if (group->acquireSensors().size() != 0) {
                            group->releaseSensors();
                            sensor = std::dynamic_pointer_cast<SBase>(group->acquireSensors()[0]);
                            group->releaseSensors();
                            //check if cast was successful (sensor != nullptr)
                            if (sensor) {
                                sensor->setName(val.second.data());
                                if (readSensorBase(*sensor, val.second)) {
                                    storeSensorGroup(group);
                                } else {
                                    LOG(warning) << "Single " << _baseName << " "
                                                 << val.second.data() << " could not be read! Omitting";
                                }
                            } else {
                                LOG(warning) << "Single " << _baseName << " "
                                             << val.second.data() << " had a type mismatch when casting! Omitting";
                            }
                        } else {
                            group->releaseSensors();
                            sensor = std::make_shared<SBase>(val.second.data());
                            if (readSensorBase(*sensor, val.second)) {
                                group->pushBackSensor(sensor);
                                storeSensorGroup(group);
                            } else {
                                LOG(warning) << "Single " << _baseName << " "
                                             << val.second.data() << " could not be read! Omitting";
                            }
                        }
                    } else {
                        LOG(warning) << "Single " << _baseName << " \""
                                     << val.second.data() << "\" has bad values! Ignoring...";
                    }
                }
            } else if( !boost::iequals(val.first, "global") ) {
                LOG(error) << "\"" << val.first << "\": unknown construct!";
                return false;
            }
        }
        //read of config finished. Now we build the mqtt-topic for every sensor
        return constructSensorTopics();
    }

    /**
     * @brief Clear internal storage and return plugin in unconfigured state.
     */
    void clearConfig() final {
        ConfiguratorInterface::clearConfig();
        //bring everything to a halt
        for(auto g : _sensorGroups) {
            g->stop();
        }

        //clean up sensors/groups and templates
        for (auto tb : _templateSensorBases) {
            delete tb.second;
        }
        for (auto tg : _templateSensorGroups) {
            delete tg.second;
        }
        _sensorGroups.clear();
        _templateSensorBases.clear();
        _templateSensorGroups.clear();
    }

    /**
     * @brief Print configuration.
     *
     * @param ll Log severity level to be used from logger.
     */
    void printConfig(LOG_LEVEL ll) final {
        ConfiguratorInterface::printConfig(ll);

        //prints plugin specific configurator attributes and entities if present
        printConfiguratorConfig(ll);

        LOG_VAR(ll) << "    " << _groupName << "s:";
        for(auto g : _sensorGroups) {
            g->printConfig(ll);
        }
    }

protected:

    ///@name Template-internal use only
    ///@{
    /**
     * @brief Read common values of a sensorbase.
     *
     * @details Reads and sets the common base values of a sensor base
     *          (currently none), then calls sensorBase() to read plugin
     *          specific values.
     *
     * @param sBase      The sensor base for which to set the values.
     * @param config     A boost property (sub-)tree containing the values.
     * @param isTemplate Are we parsing a template or a regular sensor?
     *
     * @return  True on success, false otherwise
     */
    bool readSensorBase(SBase& sBase, CFG_VAL config, bool isTemplate=false) {
        sBase.setCacheInterval(_cacheInterval);
        if (!isTemplate) {
            boost::optional<boost::property_tree::iptree&> def = config.get_child_optional("default");
            if(def) {
                //we copy all values from default
                LOG(debug) << "  Using \"" << def.get().data() << "\" as default.";
                auto it = _templateSensorBases.find(def.get().data());
                if(it != _templateSensorBases.end()) {
                    sBase = *(it->second);
                    sBase.setName(config.data());
                } else {
                    LOG(warning) << "Template " << _baseName << "\" "
                                 << def.get().data() << "\" not found! Using standard values.";
                }
            }
        }

        BOOST_FOREACH(boost::property_tree::iptree::value_type &val, config) {
            if (boost::iequals(val.first, "mqttsuffix")) {
                sBase.setMqtt(val.second.data());
            } else if (boost::iequals(val.first, "skipConstVal")) {
                sBase.setSkipConstVal(to_bool(val.second.data()));
            } else if (boost::iequals(val.first, "delta")) {
                sBase.setDelta(to_bool(val.second.data()));
            } else if (boost::iequals(val.first, "sink")) {
                sBase.setSinkPath( val.second.data() );
            } else if (boost::iequals(val.first, "subSampling")) {
                sBase.setSubsampling(std::stoul(val.second.data()));
            }
        }
        sensorBase(sBase, config);
        return true;
    }

    /**
     * @brief Read common values of a sensorGroup.
     *
     * @details Reads and sets the common base values of a sensor group
     *          (currently none), then calls sensorGroup() to read plugin
     *          specific values.
     *
     * @param sGroup     The sensor group for which to set the values.
     * @param config     A boost property (sub-)tree containing the values.
     * @param isTemplate Are we parsing a template or a regular group?
     *
     * @return  True on success, false otherwise
     */
    bool readSensorGroup(SGroup& sGroup, CFG_VAL config, bool isTemplate=false) {
        //first check if default group is given, unless we are reading a template already
        if (!isTemplate) {
            boost::optional<boost::property_tree::iptree&> def = config.get_child_optional("default");
            if(def) {
                //we copy all values from default (including copy constructing its sensors)
                //if own sensors are specified they are appended
                LOG(debug) << "  Using \"" << def.get().data() << "\" as default.";
                auto it = _templateSensorGroups.find(def.get().data());
                if(it != _templateSensorGroups.end()) {
                    sGroup = *(it->second);
                    sGroup.setGroupName(config.data());
                } else {
                    LOG(warning) << "Template " << _groupName << "\" "
                                 << def.get().data() << "\" not found! Using standard values.";
                }
            }
        }

        //read in values inherited from SensorGroupInterface
        BOOST_FOREACH(boost::property_tree::iptree::value_type &val, config) {
            if (boost::iequals(val.first, "interval")) {
                sGroup.setInterval(stoull(val.second.data()));
            } else if (boost::iequals(val.first, "minValues")) {
                sGroup.setMinValues(stoull(val.second.data()));
            } else if (boost::iequals(val.first, "mqttPart")) {
                sGroup.setMqttPart(val.second.data());
            } else if (boost::iequals(val.first, "sync")) {
                if (val.second.data() == "off") {
                    sGroup.setSync(false);
                } else {
                    sGroup.setSync(true);
                }
            } else if (boost::iequals(val.first, _baseName)) {
                if (!isTemplate) {
                    LOG(debug) << "  " << _baseName << " " << val.second.data();
                }
                SB_Ptr sensor = std::make_shared<SBase>(val.second.data());
                if (readSensorBase(*sensor, val.second, isTemplate)) {
                    sGroup.pushBackSensor(sensor);
                } else if (!isTemplate) {
                    LOG(warning) << _baseName << " " << sGroup.getGroupName() << "::"
                                 << sensor->getName() << " could not be read! Omitting";
                }
            }
        }

        sensorGroup(sGroup, config);
        return true;
    }
    ///@}

    ///@name Overwrite in plugin
    ///@{
    /**
     * Method responsible for reading plugin-specific sensor base values.
     *
     * @param s         The sensor base for which to set the values
     * @param config    A boost property (sub-)tree containing the sensor values
     */
    virtual void sensorBase(SBase& s, CFG_VAL config) = 0;

    /**
     * Method responsible for reading plugin-specific sensor group values.
     *
     * @param s         The sensor group for which to set the values
     * @param config    A boost property (sub-)tree containing the group values
     */
    virtual void sensorGroup(SGroup& s, CFG_VAL config) = 0;
    ///@}

    ///@name Utility
    ///@{
    /**
     * @brief Store a sensor group internally.
     *
     * @param sGroup Group to store.
     */
    void storeSensorGroup(SG_Ptr sGroup) {
        _sensorGroups.push_back(sGroup);
        _sensorGroupInterfaces.push_back(sGroup);
    }

    /**
     * @brief Adjusts the names of the sensors in generated groups.
     *
     * @return True if successful, false otherwise.
     */
    bool constructSensorTopics() {
        // Sensor names are adjusted according to the respective MQTT topics
        for(auto& g: _sensorGroups)
            for(auto& s: g->acquireSensors()) {
                s->setMqtt(MQTTChecker::formatTopic(_mqttPrefix) +
                           MQTTChecker::formatTopic(g->getMqttPart()) +
                           MQTTChecker::formatTopic(s->getMqtt()));
                s->setName(s->getMqtt());
                if(s->getSinkPath()!="")
                    s->setSinkPath(MQTTChecker::topicToFile(s->getMqtt(), s->getSinkPath()));
            }
        return true;
    }
    ///@}

    std::string     _groupName;
    std::string     _baseName;

    std::vector<SG_Ptr>     _sensorGroups;
    sBaseMap_t      _templateSensorBases;
    sGroupMap_t     _templateSensorGroups;
};

#endif /* SRC_CONFIGURATORTEMPLATE_H_ */