#!/usr/bin/env python

# Copyright (c) 2019 Computer Vision Center (CVC) at the Universitat Autonoma de
# Barcelona (UAB).
#
# This work is licensed under the terms of the MIT license.
# For a copy, see <https://opensource.org/licenses/MIT>.

import glob
import os
import sys

try:
    sys.path.append(glob.glob('../carla/dist/carla-*%d.%d-%s.egg' % (
        sys.version_info.major,
        sys.version_info.minor,
        'win-amd64' if os.name == 'nt' else 'linux-x86_64'))[0])
except IndexError:
    pass

import carla

import argparse
import math
import random
import time

red = carla.Color(255, 0, 0)
green = carla.Color(0, 255, 0)
blue = carla.Color(47, 210, 231)
cyan = carla.Color(0, 255, 255)
yellow = carla.Color(255, 255, 0)
orange = carla.Color(255, 162, 0)
white = carla.Color(255, 255, 255)

trail_life_time = 10
waypoint_separation = 4


def draw_transform(debug, trans, col=carla.Color(255, 0, 0), lt=-1):
    yaw_in_rad = math.radians(trans.rotation.yaw)
    pitch_in_rad = math.radians(trans.rotation.pitch)
    p1 = carla.Location(
        x=trans.location.x + math.cos(pitch_in_rad) * math.cos(yaw_in_rad),
        y=trans.location.y + math.cos(pitch_in_rad) * math.sin(yaw_in_rad),
        z=trans.location.z + math.sin(pitch_in_rad))
    debug.draw_arrow(trans.location, p1, thickness=0.05, arrow_size=1.0, color=col, life_time=lt)


def draw_waypoint_union(debug, w0, w1, color=carla.Color(255, 0, 0), lt=5):
    debug.draw_line(
        w0.transform.location + carla.Location(z=0.25),
        w1.transform.location + carla.Location(z=0.25),
        thickness=0.1, color=color, life_time=lt, persistent_lines=False)
    debug.draw_point(w1.transform.location + carla.Location(z=0.25), 0.1, color, lt, False)


def draw_waypoint_info(debug, w, lt=5):
    w_loc = w.transform.location
    debug.draw_string(w_loc + carla.Location(z=0.5), "lane: " + str(w.lane_id), False, yellow, lt)
    debug.draw_string(w_loc + carla.Location(z=1.0), "road: " + str(w.road_id), False, blue, lt)
    debug.draw_string(w_loc + carla.Location(z=-.5), str(w.lane_change), False, red, lt)


def main():
    argparser = argparse.ArgumentParser()
    argparser.add_argument(
        '--host',
        metavar='H',
        default='127.0.0.1',
        help='IP of the host server (default: 127.0.0.1)')
    argparser.add_argument(
        '-p', '--port',
        metavar='P',
        default=2000,
        type=int,
        help='TCP port to listen to (default: 2000)')
    argparser.add_argument(
        '-x',
        default=0.0,
        type=float,
        help='X start position (default: 0.0)')
    argparser.add_argument(
        '-y',
        default=0.0,
        type=float,
        help='Y start position (default: 0.0)')
    argparser.add_argument(
        '-z',
        default=0.0,
        type=float,
        help='Z start position (default: 0.0)')
    argparser.add_argument(
        '-s', '--seed',
        metavar='S',
        default=os.getpid(),
        type=int,
        help='Seed for the random path (default: program pid)')
    argparser.add_argument(
        '-t', '--tick-time',
        metavar='T',
        default=0.2,
        type=float,
        help='Tick time between updates (forward velocity) (default: 0.2)')
    args = argparser.parse_args()

    try:
        client = carla.Client(args.host, args.port)
        client.set_timeout(2.0)

        world = client.get_world()
        m = world.get_map()
        debug = world.debug

        random.seed(args.seed)
        print("Seed: ", args.seed)

        loc = carla.Location(args.x, args.y, args.z)
        print("Initial location: ", loc)

        current_w = m.get_waypoint(loc)

        # main loop
        while True:
            # list of potential next waypoints
            potential_w = list(current_w.next(waypoint_separation))

            # check for available right driving lanes
            if current_w.lane_change & carla.LaneChange.Right:
                right_w = current_w.get_right_lane()
                if right_w and right_w.lane_type == carla.LaneType.Driving:
                    potential_w += list(right_w.next(waypoint_separation))

            # check for available left driving lanes
            if current_w.lane_change & carla.LaneChange.Left:
                left_w = current_w.get_left_lane()
                if left_w and left_w.lane_type == carla.LaneType.Driving:
                    potential_w += list(left_w.next(waypoint_separation))

            # choose a random waypoint to be the next
            next_w = random.choice(potential_w)
            potential_w.remove(next_w)

            # Render some nice information, notice that you can't see the strings if you are using an editor camera
            draw_waypoint_info(debug, current_w, trail_life_time)
            draw_waypoint_union(debug, current_w, next_w, cyan if current_w.is_junction else green, trail_life_time)
            draw_transform(debug, current_w.transform, white, trail_life_time)

            # print the remaining waypoints
            for p in potential_w:
                debug.draw_string(p.transform.location, str(p.lane_id), False, orange, trail_life_time)
                draw_waypoint_union(debug, current_w, p, red, trail_life_time)
                draw_transform(debug, p.transform, white, trail_life_time)

            # update the current waypoint and sleep for some time
            current_w = next_w
            time.sleep(args.tick_time)

    finally:
        pass


if __name__ == '__main__':
    try:
        main()
    except KeyboardInterrupt:
        print('\nExit by user.')
    finally:
        print('\nExit.')