# Copyright (C) 2022 Yuchen Pei.
#
# ptv.py is free software: you can redistribute it and/or modify it
# under the terms of the GNU Affero General Public License as
# published by the Free Software Foundation, either version 3 of the
# License, or (at your option) any later version.

# ptv.py is distributed in the hope that it will be useful, but
# WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
# Affero General Public License for more details.

# You should have received a copy of the GNU Affero General Public
# License along with ptv.py.  If not, see
# <https://www.gnu.org/licenses/>.

from hashlib import sha1
from urllib import request, error, parse
import hmac
import json
import pprint
import itertools
import os

_ROUTE_TYPE = ["Train", "Tram", "Bus", "Vline", "Night Bus"]

def get_url(request):
    key = str.encode(os.environ.get('PTVKEY'))
    dev_id = os.environ.get('PTVID')
    request = parse.quote(request) + ('&' if ('?' in request) else '?')
    raw = request + f'devid={dev_id}'
    hashed = hmac.new(key, raw.encode('utf-8'), sha1)
    signature = hashed.hexdigest().upper()
    return f'http://timetableapi.ptv.vic.gov.au{raw}&signature={signature}'

def get_json(url):
    try:
        document = request.urlopen(url).read().decode()
    except error.HTTPError:
        print("http error!")
        return
    return json.loads(document)

def get_stops(search_result):
    return [{'routes': stop['routes'],
             'stop_name': stop['stop_name'],
             'stop_id': stop['stop_id']} for stop in search_result(stops)]

def get_stop_and_routes(search_result):
    return itertools.chain.from_iterable(
        [[(stop, route) for route in stop['routes']]
            for stop in search_result['stops']])

def search(keyword):
    return get_json(get_url(f'/v3/search/{keyword}'))

def get_departures(route_type, stop_id, route_id):
    return get_json(get_url(
        f'/v3/departures/route_type/{route_type}/stop/{stop_id}/route/{route_id}'))

def get_departures_from_stop_and_route(stop, route):
    return get_departures(route['route_type'], stop['stop_id'],
                          route['route_id'])

def get_directions(route_id):
    return get_json(get_url(f'/v3/directions/route/{route_id}'))

def get_direction_names(route_id):
    return {dir['direction_id']: dir['direction_name'] for dir in
            get_directions(route_id)['directions']}

def get_route_type(idx):
    return _ROUTE_TYPE[idx]