import ctypes
import functools
import multiprocessing
import numpy as np
import time

from multiprocessing import Pipe, Array

from openpilot.tools.sim.bridge.common import QueueMessage, QueueMessageType
from openpilot.tools.sim.bridge.metadrive.metadrive_process import (metadrive_process, metadrive_simulation_state,
                                                                    metadrive_vehicle_state)
from openpilot.tools.sim.lib.common import SimulatorState, World
from openpilot.tools.sim.lib.camerad import W, H


class MetaDriveWorld(World):
  def __init__(self, status_q, config, test_duration, test_run, dual_camera=False):
    super().__init__(dual_camera)
    self.status_q = status_q
    self.camera_array = Array(ctypes.c_uint8, W*H*3)
    self.road_image = np.frombuffer(self.camera_array.get_obj(), dtype=np.uint8).reshape((H, W, 3))
    self.wide_camera_array = None
    if dual_camera:
      self.wide_camera_array = Array(ctypes.c_uint8, W*H*3)
      self.wide_road_image = np.frombuffer(self.wide_camera_array.get_obj(), dtype=np.uint8).reshape((H, W, 3))

    self.controls_send, self.controls_recv = Pipe()
    self.simulation_state_send, self.simulation_state_recv = Pipe()
    self.vehicle_state_send, self.vehicle_state_recv = Pipe()

    self.exit_event = multiprocessing.Event()
    self.op_engaged = multiprocessing.Event()

    self.test_run = test_run

    self.first_engage = None
    self.last_check_timestamp = 0
    self.distance_moved = 0

    self.metadrive_process = multiprocessing.Process(name="metadrive process", target=
                              functools.partial(metadrive_process, dual_camera, config,
                                                self.camera_array, self.wide_camera_array, self.image_lock,
                                                self.controls_recv, self.simulation_state_send,
                                                self.vehicle_state_send, self.exit_event, self.op_engaged, test_duration, self.test_run))

    self.metadrive_process.start()
    self.status_q.put(QueueMessage(QueueMessageType.START_STATUS, "starting"))

    print("----------------------------------------------------------")
    print("---- Spawning Metadrive world, this might take awhile ----")
    print("----------------------------------------------------------")

    self.vehicle_last_pos = self.vehicle_state_recv.recv().position # wait for a state message to ensure metadrive is launched
    self.status_q.put(QueueMessage(QueueMessageType.START_STATUS, "started"))

    self.steer_ratio = 15
    self.vc = [0.0,0.0]
    self.reset_time = 0
    self.should_reset = False

  def apply_controls(self, steer_angle, throttle_out, brake_out):
    if (time.monotonic() - self.reset_time) > 2:
      self.vc[0] = steer_angle

      if throttle_out:
        self.vc[1] = throttle_out
      else:
        self.vc[1] = -brake_out
    else:
      self.vc[0] = 0
      self.vc[1] = 0

    self.controls_send.send([*self.vc, self.should_reset])
    self.should_reset = False

  def read_state(self):
    while self.simulation_state_recv.poll(0):
      md_state: metadrive_simulation_state = self.simulation_state_recv.recv()
      if md_state.done:
        self.status_q.put(QueueMessage(QueueMessageType.TERMINATION_INFO, md_state.done_info))
        self.exit_event.set()

  def read_sensors(self, state: SimulatorState):
    while self.vehicle_state_recv.poll(0):
      md_vehicle: metadrive_vehicle_state = self.vehicle_state_recv.recv()
      curr_pos = md_vehicle.position

      state.velocity = md_vehicle.velocity
      state.bearing = md_vehicle.bearing
      state.steering_angle = md_vehicle.steering_angle
      state.gps.from_xy(curr_pos)
      state.valid = True

      is_engaged = state.is_engaged
      if is_engaged and self.first_engage is None:
        self.first_engage = time.monotonic()
        self.op_engaged.set()

      # check moving 5 seconds after engaged, doesn't move right away
      after_engaged_check = is_engaged and time.monotonic() - self.first_engage >= 5 and self.test_run

      x_dist = abs(curr_pos[0] - self.vehicle_last_pos[0])
      y_dist = abs(curr_pos[1] - self.vehicle_last_pos[1])
      dist_threshold = 1
      if x_dist >= dist_threshold or y_dist >= dist_threshold: # position not the same during staying still, > threshold is considered moving
        self.distance_moved += x_dist + y_dist

      time_check_threshold = 15
      current_time = time.monotonic()
      since_last_check = current_time - self.last_check_timestamp
      if since_last_check >= time_check_threshold:
        if after_engaged_check and self.distance_moved == 0:
          self.status_q.put(QueueMessage(QueueMessageType.TERMINATION_INFO, {"vehicle_not_moving" : True}))
          self.exit_event.set()

        self.last_check_timestamp = current_time
        self.distance_moved = 0
        self.vehicle_last_pos = curr_pos

  def read_cameras(self):
    pass

  def tick(self):
    pass

  def reset(self):
    self.should_reset = True

  def close(self, reason: str):
    self.status_q.put(QueueMessage(QueueMessageType.CLOSE_STATUS, reason))
    self.exit_event.set()
    self.metadrive_process.join()