cached/weather_forecast.py

   1 #!/usr/bin/env python3
   2
   3 from dataclasses import dataclass
   4 import datetime
   5 import logging
   6 import os
   7 import urllib.request
   8
   9 import astral  # type: ignore
  10 from astral.sun import sun  # type: ignore
  11 from bs4 import BeautifulSoup  # type: ignore
  12 from overrides import overrides
  13 import pytz
  14
  15 import argparse_utils
  16 import config
  17 import datetime_utils
  18 import dateparse.dateparse_utils as dp
  19 import persistent
  20 import text_utils
  21
  22 logger = logging.getLogger(__name__)
  23
  24 cfg = config.add_commandline_args(
  25     f'Cached Weather Forecast ({__file__})',
  26     'Arguments controlling detailed weather rendering'
  27 )
  28 cfg.add_argument(
  29     '--weather_forecast_cachefile',
  30     type=str,
  31     default=f'{os.environ["HOME"]}/cache/.weather_forecast_cache',
  32     metavar='FILENAME',
  33     help='File in which to cache weather data'
  34 )
  35 cfg.add_argument(
  36     '--weather_forecast_stalest_acceptable',
  37     type=argparse_utils.valid_duration,
  38     default=datetime.timedelta(seconds=7200),   # 2 hours
  39     metavar='DURATION',
  40     help='Maximum acceptable age of cached data.  If zero, forces a refetch'
  41 )
  42
  43
  44 @dataclass
  45 class WeatherForecast:
  46     date: datetime.date                # The date
  47     sunrise: datetime.datetime         # Sunrise datetime
  48     sunset: datetime.datetime          # Sunset datetime
  49     description: str                   # Textual description of weather
  50
  51
  52 @persistent.persistent_autoloaded_singleton()
  53 class CachedDetailedWeatherForecast(object):
  54     def __init__(self, forecasts = None):
  55         if forecasts is not None:
  56             self.forecasts = forecasts
  57             return
  58
  59         now = datetime_utils.now_pacific()
  60         self.forecasts = {}
  61
  62         # Ask the raspberry pi about the outside temperature.
  63         www = None
  64         try:
  65             www = urllib.request.urlopen(
  66                 "http://10.0.0.75/~pi/outside_temp",
  67                 timeout=2,
  68             )
  69             current_temp = www.read().decode("utf-8")
  70             current_temp = float(current_temp)
  71             current_temp *= (9/5)
  72             current_temp += 32.0
  73             current_temp = round(current_temp)
  74         except Exception:
  75             logger.warning('Timed out reading 10.0.0.75/~pi/outside_temp?!')
  76             current_temp = None
  77         finally:
  78             if www is not None:
  79                 www.close()
  80
  81         # Get a weather forecast for Bellevue.
  82         www = urllib.request.urlopen(
  83             "https://forecast.weather.gov/MapClick.php?lat=47.652775&lon=-122.170716"
  84         )
  85         forecast_response = www.read()
  86         www.close()
  87
  88         soup = BeautifulSoup(forecast_response, "html.parser")
  89         forecast = soup.find(id='detailed-forecast-body')
  90         parser = dp.DateParser()
  91
  92         said_temp = False
  93         last_dt = now
  94         dt = now
  95         for (day, txt) in zip(
  96                 forecast.find_all('b'),
  97                 forecast.find_all(class_='col-sm-10 forecast-text')
  98         ):
  99             last_dt = dt
 100             try:
 101                 dt = parser.parse(day.get_text())
 102             except Exception:
 103                 dt = last_dt
 104             assert dt is not None
 105
 106             # Compute sunrise/sunset times on dt.
 107             city = astral.LocationInfo(
 108                 "Bellevue", "USA", "US/Pacific", 47.653, -122.171
 109             )
 110             s = sun(city.observer, date=dt, tzinfo=pytz.timezone("US/Pacific"))
 111             sunrise = s['sunrise']
 112             sunset = s['sunset']
 113
 114             if dt.date() == now.date() and not said_temp and current_temp is not None:
 115                 blurb = f'{day.get_text()}: The current outside tempterature is {current_temp}. '
 116                 blurb += txt.get_text()
 117                 said_temp = True
 118             else:
 119                 blurb = f'{day.get_text()}: {txt.get_text()}'
 120             blurb = text_utils.wrap_string(blurb, 80)
 121
 122             if dt.date() in self.forecasts:
 123                 self.forecasts[dt.date()].description += '\n' + blurb
 124             else:
 125                 self.forecasts[dt.date()] = WeatherForecast(
 126                     date = dt,
 127                     sunrise = sunrise,
 128                     sunset = sunset,
 129                     description = blurb,
 130                 )
 131
 132     @classmethod
 133     @overrides
 134     def load(cls):
 135         if persistent.was_file_written_within_n_seconds(
 136                 config.config['weather_forecast_cachefile'],
 137                 config.config['weather_forecast_stalest_acceptable'].total_seconds(),
 138         ):
 139             import pickle
 140             with open(config.config['weather_forecast_cachefile'], 'rb') as rf:
 141                 weather_data = pickle.load(rf)
 142                 return cls(weather_data)
 143         return None
 144
 145     @overrides
 146     def save(self):
 147         import pickle
 148         with open(config.config['weather_forecast_cachefile'], 'wb') as wf:
 149             pickle.dump(
 150                 self.forecasts,
 151                 wf,
 152                 pickle.HIGHEST_PROTOCOL,
 153             )