import json
import requests
import sys
import os
import subprocess

# See github project: https://github.com/mpolden/atb
ATB_API_URL = "https://mpolden.no/atb/v2/departures/"
# Stop place codes found through https://stoppested.entur.org/
STOP_PLACES = {
    "gløshaugen": "44085",
    "høgskoleringen": "42029",
    "hesthagen": "41620"
}

def format_departure(departure_dict: dict) -> str:
    """Formats the json supplied by mpolden's atb api to a single line of text
    quickly summarizing the scheduled bus.
    """
    line = departure_dict["line"]
    departure_time = departure_dict["scheduledDepartureTime"].split("T")[1].split(".")[0]
    destination = departure_dict["destination"]
    is_real_time = departure_dict["isRealtimeData"]
    towards_city_center = departure_dict["isGoingTowardsCentrum"]

    # return f"{departure_time}: {line}\t({'R' if is_real_time else 'S'}, {'I' if towards_city_center else 'O'}) {destination}"
    return f"{departure_time}: {line}\t{destination}\t ({'realtime' if is_real_time else 'aimed'},\t{'til Midtbyen' if towards_city_center else 'fra Midtbyen'})"


def write_to_socket(s: str, mpv_socket) -> None:
    """Writes the string s to the mpv on screen display through
    the open mpv ipc socket located at the path `mpv_socket`.
    """
    cmd_dict = {"command": ["show-text", f"{s}", 10000]}
    mpv_cmd = json.dumps(cmd_dict)
    cmd = f'echo \'{mpv_cmd}\' | socat - ./{mpv_socket}'
    subprocess.Popen(cmd, shell=True, stdout=subprocess.PIPE, stderr=subprocess.STDOUT)
    return None


if __name__ == "__main__":
    input_stop_place = sys.argv[1]
    if input_stop_place in STOP_PLACES.keys():
        active_stop_place = STOP_PLACES[input_stop_place]
    else:
        active_stop_place = STOP_PLACES["gløshaugen"]

    r = requests.get(ATB_API_URL + active_stop_place)
    departures = r.json()["departures"]
    sorted_departures = sorted(departures, key = lambda d: d["scheduledDepartureTime"])

    # ensure mpv is running with the ipc-server socket set in MPV_SOCKET
    MPV_SOCKET = "mpv_ipc.socket"
    if os.path.exists(MPV_SOCKET):
        write_to_socket(
            f"{'\n'.join([
                format_departure(sorted_departures[i]) 
                for i in range(len(sorted_departures))
            ])}", MPV_SOCKET)
    else:
        for dep in sorted_departures:
            print(format_departure(dep))