# Copyright (C) 2022 Yuchen Pei.
#
# This file is part of ptvtt.
#
# ptvtt 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.

# ptvtt 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 ptvtt.  If not, see <https://www.gnu.org/licenses/>.

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

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


def get_url(req):
    key = str.encode(os.environ.get('PTVKEY'))
    dev_id = os.environ.get('PTVID')
    req = parse.quote(req) + ('&' if ('?' in req) else '?')
    raw = req + 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:
        with request.urlopen(url) as opened:
            document = opened.read().decode()
            return json.loads(document)
    except error.HTTPError:
        print("http error!")


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}'
                f'/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]