"""File containing Infoscreen HSL data fetcher classes."""

import requests
import json
import logging
import os
import pytz

from datetime import timedelta, datetime
from django.utils import timezone, dateparse
from django.utils.dateformat import format

from django.conf import settings


with open(os.path.join(settings.BASE_DIR, 'infoscreen', 'hsl_stops.graphql')) as stops_file:
    STOPS_QUERY = stops_file.read()

with open(os.path.join(settings.BASE_DIR, 'infoscreen', 'hsl_stops_variables.json')) as vars_file:
    STOPS_VARS = json.loads(vars_file.read())

API_URL = 'https://api.digitransit.fi/routing/v1/routers/hsl/index/graphql'
API_HEADERS = {'Content-Type': 'application/json'}


def fetch():
    """Fetch data from HSL API."""

    query_vars = STOPS_VARS.copy()
    query_vars['startTime_6'] = format(timezone.now(), 'U')

    post_data = json.dumps({
        'operationName': 'NearestRoutesContainer',
        'query': STOPS_QUERY,
        'variables': query_vars,
    })

    resp = requests.post(API_URL, data=post_data, headers=API_HEADERS)

    data = resp.json()

    items = data['data']['viewer']['_nearest']['edges']
    places = map(lambda item: item['node']['place'], items)

    schedule = []
    for place in places:
        route = place['pattern']['route']['shortName']
        stop_times = place['_stoptimes']
        for stop_time in stop_times:
            timestamp = time_utc = stop_time['serviceDay'] + stop_time['realtimeArrival']
            headsign = stop_time['stopHeadsign']
            stop_name = stop_time['stop']['name']
            time_diff = (timestamp - timezone.now().timestamp()) / 60  # minutes

            if time_diff < settings.HSL_DEPARTURE_THRESHOLD:
                continue
            elif time_diff < settings.HSL_HURRY_THRESHOLD:
                time = '{} min'.format(int(time_diff))
            else:
                time = pytz.utc.localize(datetime.fromtimestamp(timestamp)).strftime('%H:%M')

            schedule.append({
                'route': route,
                'headsign': headsign,
                'timestamp': time,
                'stop': stop_name,
                'utc': time_utc,
            })

    return schedule