"""Original torque-bar utilization from caller-qualified observations."""

from dataclasses import dataclass
import math
from typing import Any, Literal


GRAVITY = 9.81
DEFAULT_MAX_LATERAL_ACCELERATION = 3.0
LATERAL_STATES = frozenset(("pidState", "angleState", "debugState", "torqueState", "curvatureState",
                            "lqrStateDEPRECATED", "indiStateDEPRECATED"))


@dataclass(frozen=True)
class TorqueFeedback:
  utilization: float | None = None
  source: Literal["unavailable", "actuator_output", "lateral_acceleration_estimate"] = "unavailable"
  reason: str = "car_state_unavailable"


def _finite(value: Any) -> float | None:
  if type(value) not in (int, float):
    return None
  try:
    result = float(value)
    return result if math.isfinite(result) else None
  except (OverflowError, ValueError):
    return None


def observe_torque_feedback(car_state: Any, car_control: Any, controls_state: Any, car_output: Any,
                            vehicle_parameters: Any, car_params: Any) -> TorqueFeedback:
  """Pass None for invalid, stale, offroad or pre-drive messages; no IPC or writes."""
  car, controls, output, control = car_state, controls_state, car_output, car_control
  if (car is None or getattr(car, "canValid", None) is not True or getattr(car, "canTimeout", None) is not False):
    return TorqueFeedback(reason="car_state_unavailable")
  try:
    state = controls.lateralControlState.which()
  except (AttributeError, TypeError, ValueError):
    state = None
  if type(state) is not str or state not in LATERAL_STATES:
    return TorqueFeedback(reason="lateral_state_unavailable")

  angle = state == "angleState"
  if getattr(car_params, "brand", None) == "rivian" and not angle:
    if output is None:
      return TorqueFeedback(reason="actuator_output_unavailable")
    mode = getattr(getattr(output, "actuatorsOutput", None), "lateralControlMode", None)
    if mode is not None:
      mode = str(mode)
      if mode not in ("inactive", "angle", "torque", "torqueRecovering"):
        return TorqueFeedback(reason="output_mode_invalid")
      if control is None or type(getattr(control, "latActive", None)) is not bool:
        return TorqueFeedback(reason="lateral_activity_unavailable")
      angle = mode == "angle" and control.latActive

  if not angle:
    torque = _finite(getattr(getattr(output, "actuatorsOutput", None), "torque", None))
    if torque is None or not -1 <= torque <= 1:
      return TorqueFeedback(reason="actuator_output_unavailable")
    return TorqueFeedback(-torque, "actuator_output", "observed")

  if control is None or type(getattr(control, "latActive", None)) is not bool:
    return TorqueFeedback(reason="lateral_activity_unavailable")
  if not control.latActive:
    return TorqueFeedback(0.0, "lateral_acceleration_estimate", "lateral_inactive")
  parameters = vehicle_parameters
  if parameters is None or getattr(parameters, "valid", None) is not True:
    return TorqueFeedback(reason="vehicle_parameters_unavailable")
  speed = _finite(getattr(car, "vEgo", None))
  curvature = _finite(getattr(controls, "curvature", None))
  desired_curvature = _finite(getattr(controls, "desiredCurvature", None))
  roll = _finite(getattr(parameters, "roll", None))
  maximum = DEFAULT_MAX_LATERAL_ACCELERATION if car_params is None else _finite(getattr(car_params, "maxLateralAccel", None))
  if (speed is None or speed < 0 or curvature is None or desired_curvature is None or roll is None or
      maximum is None or maximum <= 0):
    return TorqueFeedback(reason="estimate_inputs_invalid")
  speed_squared = speed * speed
  actual_acceleration = curvature * speed_squared
  desired_acceleration = desired_curvature * speed_squared
  acceleration_error = desired_acceleration - actual_acceleration
  roll_compensation = roll * GRAVITY * max(0.0, min(1.0, (speed - 5) / 10))
  utilization = ((actual_acceleration - roll_compensation) + acceleration_error) / maximum
  if not math.isfinite(utilization):
    return TorqueFeedback(reason="estimate_inputs_invalid")
  return TorqueFeedback(max(-1.0, min(1.0, utilization)), "lateral_acceleration_estimate", "estimated")