#ifndef THIRD_PARTY_MILOTIC_EXTERNAL_CC_TLBMC_SENSORS_FAN_TACH_H_
#define THIRD_PARTY_MILOTIC_EXTERNAL_CC_TLBMC_SENSORS_FAN_TACH_H_

#include <cstddef>
#include <memory>
#include <optional>
#include <string>
#include <vector>

#include "absl/base/thread_annotations.h"
#include "absl/status/statusor.h"
#include "absl/synchronization/mutex.h"
#include "boost/asio.hpp"  //NOLINT: boost::asio is commonly used in BMC
#include "boost/circular_buffer.hpp"  //NOLINT: boost is commonly used in BMC
#include "entity_common_config.pb.h"
#include "fan_tach_config.pb.h"
#include "i2c_common_config.pb.h"
#include "reading_range_config.pb.h"
#include "threshold_config.pb.h"
#include "tlbmc/hal/sysfs/i2c.h"
#include "sensor.pb.h"
#include "tlbmc/sensors/fan_controller.h"
#include "tlbmc/sensors/i2c_hwmon_based_sensor.h"
#include "tlbmc/sensors/sensor.h"

namespace milotic_tlbmc {

class FanTachometer : public I2cHwmonBasedSensor {
 private:
  class Token;

 public:
  // Enables the PWM if not already enabled and returns a sensor that can be
  // used to read the PWM from the device.
  // Note:
  // 1. The `io_context` must run only on a single thread.
  static absl::StatusOr<std::shared_ptr<Sensor>> Create(
      const FanTachConfig& config, const FanController& fan_controller,
      const std::shared_ptr<boost::asio::io_context>& io_context,
      const I2cSysfs& i2c_sysfs,
      std::optional<NotificationCb> on_batch_notify = std::nullopt);

  FanTachometer(Token token, FanTachType sensor_type,
                const std::string& input_dev_path,
                const std::string& sensor_name,
                const I2cCommonConfig& i2c_common_config,
                const ThresholdConfigs& threshold_configs,
                const ReadingRangeConfigs& reading_range_configs,
                const EntityCommonConfig& entity_common_config,
                const std::shared_ptr<boost::asio::io_context>& io_context,
                std::optional<NotificationCb> on_batch_notify);

  ~FanTachometer() override = default;

  void HandleRefreshResult(const boost::system::error_code& error,
                           size_t bytes_read) override
      ABSL_LOCKS_EXCLUDED(sensor_data_mutex_);

 protected:
  FanTachometer() = default;

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

  const FanTachType sensor_type_ = TACH_SENSOR_TYPE_UNKNOWN;
  const std::string sensor_name_;
  const std::string board_config_name_;
};

}  // namespace milotic_tlbmc

#endif  // THIRD_PARTY_MILOTIC_EXTERNAL_CC_TLBMC_SENSORS_FAN_TACH_H_