import urllib.request
import json
import logging
from datetime import datetime, timedelta

from django.conf import settings

from infoscreen.models import HSLDataModel


class HSLFetcher:

    last_fetched = datetime.fromtimestamp(0)  # epoch
    INTERVAL = 1  # minutes
    logging.info("Set up scheduled HSL API fetch every {} minutes".format(INTERVAL))

    def fetch_if_needed(self):
        if datetime.now() - HSLFetcher.last_fetched > timedelta(minutes=HSLFetcher.INTERVAL):
            self.fetch()

    def fetch(self):
        location_coords = (2545565, 6675319)
        src = urllib.request.urlopen(
            "https://api.reittiopas.fi/hsl/prod/?userhash={}&request=stops_area&center_coordinate={},{}"
            .format(settings.HSL_USERHASH, location_coords[0], location_coords[1]))\
            .read().decode("utf-8")

        data = json.loads(src)

        arr = []

        time = datetime.now() + timedelta(minutes=settings.HSL_DEPARTURE_THRESHOLD)
        time = "{0:02d}{0:02d}".format(time.hour, time.minute)
        for element in data:
            src = urllib.request.urlopen(
                "https://api.reittiopas.fi/hsl/prod/?userhash={}&request=stop&code={}&dep_limit=20&time={}"
                .format(settings.HSL_USERHASH, element['code'], time)).read().decode("utf-8")

            parsed = json.loads(src)[0]
            arr.append({"name": parsed['name_fi'], "lines": parsed['lines'],
                        "dist": element['dist'], "departures": parsed['departures']})

        model_arr = HSLDataModel.objects.all()
        count = len(model_arr)
        json_dump = json.dumps(arr)

        if count == 0:
            HSLDataModel.objects.create(data=json_dump)
        else:
            obj = model_arr[count - 1]
            obj.data = json_dump
            obj.save()
        now = datetime.now()
        HSLFetcher.last_fetched = now

        logging.info("Fetched HSL timetable data with size {} bytes.".format(len(src)))