#ifndef THIRD_PARTY_MILOTIC_EXTERNAL_CC_TLBMC_THERMAL_DFF_CONTROLLER_H_
#define THIRD_PARTY_MILOTIC_EXTERNAL_CC_TLBMC_THERMAL_DFF_CONTROLLER_H_

#include <memory>
#include <string>
#include <utility>
#include <vector>

#include "absl/base/attributes.h"
#include "absl/base/nullability.h"
#include "absl/status/statusor.h"
#include "absl/strings/string_view.h"
#include <nlohmann/json_fwd.hpp>
#include "thermal_config.pb.h"
#include "thermal_controller_specification.pb.h"
#include "tlbmc/thermal/controller/algorithm/dff.h"
#include "tlbmc/thermal/controller/controller.h"
#include "tlbmc/thermal/zone_manager.h"

namespace milotic_tlbmc::thermal {

struct DffControllerParameters {
  std::string id;
  ZoneManager* absl_nonnull zone_manager ABSL_REQUIRE_EXPLICIT_INIT;
  std::unique_ptr<DffThermalLoop> absl_nonnull dff_loop
      ABSL_REQUIRE_EXPLICIT_INIT;
  std::vector<std::string> input_sensors;
  std::vector<std::string> affected_controller_ids;
};

/**
 * `DffController` reads a number of, usually, power sensors
 * and provides additive setpoints for the fan controllers such as PID fan
 * controllers.
 *
 * Since this type of controllers reads from non-temperature sensors, it picks
 * the maximum of all inputs, and performs the DFF thermal loop to derive a
 * setpoint.
 *
 * This class is not thread-safe.
 */
class DffController : public ThermalController {
 public:
  ~DffController() final = default;

  static absl::StatusOr<std::unique_ptr<DffController>> Create(
      DffControllerParameters params);

  void ProcessThermalLoop() final;
  double ProcessInput() final;
  void ProcessOutput(double output) final;

  ZoneManager* GetZoneManager() const { return zone_owner_; }

  DffThermalLoop* GetDffLoop() const { return dff_loop_.get(); }

  std::string GetId() const final { return id_; }
  bool IsFanController() const final { return false; }
  bool IsSupportiveController() const final { return true; }
  const std::vector<std::string>& GetAffectedControllerIds() const final {
    return affected_controller_ids_;
  }
  // DFF controller has no setpoint to be adjusted.
  void AdjustSetpoint([[maybe_unused]] double offset) final {}

  double GetLastOutput() const { return dff_loop_->GetLastOutput(); }

  nlohmann::json ToJson() const;

  // Setters of DFF coefficients for tuning purposes.
  void SetCoeffH1(double coeff_h1) { dff_loop_->SetCoeffH1(coeff_h1); }
  void SetCoeffH2(double coeff_h2) { dff_loop_->SetCoeffH2(coeff_h2); }
  void SetCoeffH3(double coeff_h3) { dff_loop_->SetCoeffH3(coeff_h3); }
  void SetCoeffF1(double coeff_f1) { dff_loop_->SetCoeffF1(coeff_f1); }
  void SetCoeffF2(double coeff_f2) { dff_loop_->SetCoeffF2(coeff_f2); }
  void SetCoeffF3(double coeff_f3) { dff_loop_->SetCoeffF3(coeff_f3); }
  void SetReferencePower(double reference_power) {
    dff_loop_->SetReferencePower(reference_power);
  }

 protected:
  explicit DffController(absl::string_view id, ZoneManager* zone_manager,
                         std::unique_ptr<DffThermalLoop> absl_nonnull dff_loop,
                         std::vector<std::string> input_sensors,
                         std::vector<std::string> affected_controller_ids)
      : ThermalController(),
        id_(id),
        zone_owner_(zone_manager),
        dff_loop_(std::move(dff_loop)),
        input_sensors_(std::move(input_sensors)),
        affected_controller_ids_(std::move(affected_controller_ids)) {}

 private:
  const std::string id_;

  // Use a raw pointer here to avoid circular dependency, as `ZoneManager`
  // depends on `DffController` with `std::unique_ptr`.
  // Every `ZoneManager` will be owned by the thermal control collector of
  // tlBMC, and will live as long as the thermal control service is on.
  ZoneManager* zone_owner_ = nullptr;

  // Every `DffThermalLoop` will be owned by its thermal controller, and will
  // live as long as the thermal control service is on.
  std::unique_ptr<DffThermalLoop> dff_loop_;
  std::vector<std::string> input_sensors_;
  std::vector<std::string> affected_controller_ids_;

  double last_output_ = 0.0;
};

}  // namespace milotic_tlbmc::thermal

#endif  // THIRD_PARTY_MILOTIC_EXTERNAL_CC_TLBMC_THERMAL_DFF_CONTROLLER_H_