from collections import defaultdict
from datetime import datetime
from hashlib import sha1
import hmac
import httpx
import os

dev_id = os.environ['PTV_USER_ID']
api_key = os.environ['PTV_API_KEY']

def sign(request):
    request += '&' if ('?' in request) else '?'
    request += 'devid='
    request += dev_id
    hashed = hmac.new(api_key.encode(), request.encode(), sha1)
    return f'https://timetableapi.ptv.vic.gov.au{request}&signature={hashed.hexdigest().upper()}'

def fetch(path):
    res = httpx.get(sign(path))
    res.raise_for_status()
    return res.json()

# Lilydale route 9 (type 0) (dir 1 in, 8 out) (stop 1229)
# Belgrave route 2 (type 0) (dir 1 in, 2 out) (stop 1229)
# 109 route 722 (type 1) (dir 2 E, 3 W) (stop 2415 E, 2460 W)
# 70 route 940 (type 1) (dir 28 E, 29 W) (stop 2161 E, 2162 W)
# 766 route 15800 (type 2) (dir 13 N, 207 S) (stop 17861)
# 612 route 13024 (type 2) (dir 13 N, 158 S) (stop 17861)

class Route:
    def __init__(self, name, route_id, route_type_id, directions, stops):
        self.name = name
        self.route_id = route_id
        self.route_type_id = route_type_id
        self.directions = directions
        self.stops = stops

local_routes = [
    Route('Lilydale', 9    , 0, [(1, 'in'), (8, 'out')]   , [1229]      ),
    Route('Belgrave', 2    , 0, [(1, 'in'), (2, 'out')]   , [1229]      ),
    Route('109'     , 722  , 1, [(2, 'E'), (3, 'W')]      , [2415, 2460]),
    Route('70'      , 940  , 1, [(28, 'E'), (29, 'W')]    , [2162, 2161]),
    Route('766'     , 15800, 2, [(13, 'N'), (188, 'S')]   , [17861]     ),
    Route('612'     , 13024, 2, [(13, 'N'), (139, 'S')]   , [17861]     ),
]
# exp 951624
# non-exp 951826

def fetch_departures(stop_id, route_type_id):
    return fetch(f'/v3/departures/route_type/{route_type_id}/stop/{stop_id}')['departures']

def fetch_run(run_ref):
    return fetch(f'/v3/runs/{run_ref}')['runs']

def departure_time(dep):
    return datetime.fromisoformat(dep['estimated_departure_utc'] or dep['scheduled_departure_utc'])

def get_departure_data():
    bus = fetch_departures(17861, 2)
    train = fetch_departures(1229, 0)
    tram_109w = fetch_departures(2460, 1)
    tram_70w = fetch_departures(2161, 1)

    next_express_dep = None
    train.sort(key=departure_time)
    for dep in train:
        if dep['direction_id'] == 1:
            match fetch_run(dep['run_ref']):
                case [run]:
                    if run['express_stop_count'] > 1: # Ignore East Richmond
                        next_express_dep = dep
                        break

    def earliest(deps):
        return min((departure_time(dep) for dep in deps), default=None)

    return {
        '612 S': earliest(dep for dep in bus if dep['route_id'] == 13024 and dep['direction_id'] == 139),
        '612 N': earliest(dep for dep in bus if dep['route_id'] == 13024 and dep['direction_id'] == 13),
        '766 N': earliest(dep for dep in bus if dep['route_id'] == 15800 and dep['direction_id'] == 13),

        'Union W': earliest(dep for dep in train if dep['direction_id'] == 1 and dep is not next_express_dep),
        'Union W Express': departure_time(next_express_dep) if next_express_dep else None,
        'Union E': earliest(dep for dep in train if dep['direction_id'] in {2, 8}),

        '109 W': earliest(tram_109w),
        '70 W': earliest(tram_70w),
    }