#ifndef THIRD_PARTY_MILOTIC_EXTERNAL_CC_TLBMC_SENSORS_VIRTUAL_SENSOR_H_
#define THIRD_PARTY_MILOTIC_EXTERNAL_CC_TLBMC_SENSORS_VIRTUAL_SENSOR_H_

#include <memory>
#include <optional>
#include <string>

#include "absl/container/flat_hash_map.h"
#include "absl/functional/any_invocable.h"
#include "absl/status/statusor.h"
#include "boost/asio.hpp"  //NOLINT: boost::asio is commonly used in BMC
#include "virtual_sensor_config.pb.h"
#include "tlbmc/expression/expression.h"
#include "sensor.pb.h"
#include "tlbmc/sensors/sensor.h"

namespace milotic_tlbmc {

class VirtualSensor : public Sensor,
                      public std::enable_shared_from_this<VirtualSensor> {
 private:
  class Token;

 public:
  static absl::StatusOr<std::shared_ptr<VirtualSensor>> Create(
      const VirtualSensorConfig& config,
      const std::shared_ptr<boost::asio::io_context>& io_context,
      const absl::flat_hash_map<std::string, std::shared_ptr<Sensor>>&
          sensors_map,
      std::unique_ptr<Expression> expression,
      std::optional<NotificationCb> on_batch_notify = std::nullopt);

  VirtualSensor(Token token, const std::string& sensor_name,
                SensorUnit sensor_unit,
                const EntityCommonConfig& entity_common_config,
                const ThresholdConfigs& threshold_configs,
                const ReadingRangeConfigs& reading_range_configs,
                const absl::flat_hash_map<std::string, std::shared_ptr<Sensor>>&
                    sensors_map,
                std::unique_ptr<Expression> expression,
                const std::shared_ptr<boost::asio::io_context>& io_context,
                std::optional<NotificationCb> on_batch_notify = std::nullopt);

  ~VirtualSensor() override = default;

  void RefreshOnceAsync(
      absl::AnyInvocable<void(const std::shared_ptr<const SensorValue>&)>
          callback) override;

 protected:
  absl::StatusOr<double> GetSensorValue();

 private:
  class Token {
   private:
    explicit Token() = default;
    friend VirtualSensor;
  };

  std::shared_ptr<boost::asio::io_context> io_context_;
  // The sensors that are used to calculate the virtual sensor value.
  absl::flat_hash_map<std::string, std::shared_ptr<Sensor>> sensors_map_;
  std::unique_ptr<Expression> expression_;
  const std::string sensor_name_;
};

}  // namespace milotic_tlbmc

#endif  // THIRD_PARTY_MILOTIC_EXTERNAL_CC_TLBMC_SENSORS_VIRTUAL_SENSOR_H_