from common.numpy_fast import interp
import numpy as np
from selfdrive.controls.lib.latcontrol_helpers import model_polyfit, calc_desired_path, compute_path_pinv

CAMERA_OFFSET = 0.06  # m from center car to camera


class ModelParser(object):
  def __init__(self):
    self.d_poly = [0., 0., 0., 0.]
    self.c_poly = [0., 0., 0., 0.]
    self.c_prob = 0.
    self.last_model = 0.
    self.lead_dist, self.lead_prob, self.lead_var = 0, 0, 1
    self._path_pinv = compute_path_pinv()

    self.lane_width_estimate = 3.7
    self.lane_width_certainty = 1.0
    self.lane_width = 3.7
    self.l_prob = 0.
    self.r_prob = 0.
    self.x_points = np.arange(50)

  def update(self, v_ego, md):
    if len(md.leftLane.poly):
      l_poly = np.array(md.leftLane.poly)
      r_poly = np.array(md.rightLane.poly)
      p_poly = np.array(md.path.poly)
    else:
      l_poly = model_polyfit(md.leftLane.points, self._path_pinv)  # left line
      r_poly = model_polyfit(md.rightLane.points, self._path_pinv)  # right line
      p_poly = model_polyfit(md.path.points, self._path_pinv)  # predicted path

    # only offset left and right lane lines; offsetting p_poly does not make sense
    l_poly[3] += CAMERA_OFFSET
    r_poly[3] += CAMERA_OFFSET

    p_prob = 1.  # model does not tell this probability yet, so set to 1 for now
    l_prob = md.leftLane.prob  # left line prob
    r_prob = md.rightLane.prob  # right line prob

    # Find current lanewidth
    lr_prob = l_prob * r_prob
    self.lane_width_certainty += 0.05 * (lr_prob - self.lane_width_certainty)
    current_lane_width = abs(l_poly[3] - r_poly[3])
    self.lane_width_estimate += 0.005 * (current_lane_width - self.lane_width_estimate)
    speed_lane_width = interp(v_ego, [0., 31.], [2.8, 3.5])
    self.lane_width = self.lane_width_certainty * self.lane_width_estimate + \
                      (1 - self.lane_width_certainty) * speed_lane_width

    self.lead_dist = md.lead.dist
    self.lead_prob = md.lead.prob
    self.lead_var = md.lead.std**2

    # compute target path
    self.d_poly, self.c_poly, self.c_prob = calc_desired_path(
      l_poly, r_poly, p_poly, l_prob, r_prob, p_prob, v_ego, self.lane_width)

    self.r_poly = r_poly
    self.r_prob = r_prob

    self.l_poly = l_poly
    self.l_prob = l_prob

    self.p_poly = p_poly
    self.p_prob = p_prob