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 from typing import Any
   8 import urllib.request
   9
  10 import astral  # type: ignore
  11 from astral.sun import sun  # type: ignore
  12 from bs4 import BeautifulSoup  # type: ignore
  13 from overrides import overrides
  14 import pytz
  15
  16 import argparse_utils
  17 import config
  18 import datetime_utils
  19 import dateparse.dateparse_utils as dp
  20 import persistent
  21 import text_utils
  22
  23 logger = logging.getLogger(__name__)
  24
  25 cfg = config.add_commandline_args(
  26     f'Cached Weather Forecast ({__file__})',
  27     'Arguments controlling detailed weather rendering'
  28 )
  29 cfg.add_argument(
  30     '--weather_forecast_cachefile',
  31     type=str,
  32     default=f'{os.environ["HOME"]}/cache/.weather_forecast_cache',
  33     metavar='FILENAME',
  34     help='File in which to cache weather data'
  35 )
  36 cfg.add_argument(
  37     '--weather_forecast_stalest_acceptable',
  38     type=argparse_utils.valid_duration,
  39     default=datetime.timedelta(seconds=7200),   # 2 hours
  40     metavar='DURATION',
  41     help='Maximum acceptable age of cached data.  If zero, forces a refetch'
  42 )
  43
  44
  45 @dataclass
  46 class WeatherForecast:
  47     date: datetime.date                # The date
  48     sunrise: datetime.datetime         # Sunrise datetime
  49     sunset: datetime.datetime          # Sunset datetime
  50     description: str                   # Textual description of weather
  51
  52
  53 @persistent.persistent_autoloaded_singleton()
  54 class CachedDetailedWeatherForecast(persistent.Persistent):
  55     def __init__(self, forecasts = None):
  56         if forecasts is not None:
  57             self.forecasts = forecasts
  58             return
  59
  60         now = datetime_utils.now_pacific()
  61         self.forecasts = {}
  62
  63         # Ask the raspberry pi about the outside temperature.
  64         www = None
  65         try:
  66             www = urllib.request.urlopen(
  67                 "http://10.0.0.75/~pi/outside_temp",
  68                 timeout=2,
  69             )
  70             current_temp = www.read().decode("utf-8")
  71             current_temp = float(current_temp)
  72             current_temp *= (9/5)
  73             current_temp += 32.0
  74             current_temp = round(current_temp)
  75         except Exception:
  76             logger.warning('Timed out reading 10.0.0.75/~pi/outside_temp?!')
  77             current_temp = None
  78         finally:
  79             if www is not None:
  80                 www.close()
  81
  82         # Get a weather forecast for Bellevue.
  83         www = urllib.request.urlopen(
  84             "https://forecast.weather.gov/MapClick.php?lat=47.652775&lon=-122.170716"
  85         )
  86         forecast_response = www.read()
  87         www.close()
  88
  89         soup = BeautifulSoup(forecast_response, "html.parser")
  90         forecast = soup.find(id='detailed-forecast-body')
  91         parser = dp.DateParser()
  92
  93         said_temp = False
  94         last_dt = now
  95         dt = now
  96         for (day, txt) in zip(
  97                 forecast.find_all('b'),
  98                 forecast.find_all(class_='col-sm-10 forecast-text')
  99         ):
 100             last_dt = dt
 101             try:
 102                 dt = parser.parse(day.get_text())
 103             except Exception:
 104                 dt = last_dt
 105             assert dt is not None
 106
 107             # Compute sunrise/sunset times on dt.
 108             city = astral.LocationInfo(
 109                 "Bellevue", "USA", "US/Pacific", 47.653, -122.171
 110             )
 111             s = sun(city.observer, date=dt, tzinfo=pytz.timezone("US/Pacific"))
 112             sunrise = s['sunrise']
 113             sunset = s['sunset']
 114
 115             if dt.date() == now.date() and not said_temp and current_temp is not None:
 116                 blurb = f'{day.get_text()}: The current outside tempterature is {current_temp}. '
 117                 blurb += txt.get_text()
 118                 said_temp = True
 119             else:
 120                 blurb = f'{day.get_text()}: {txt.get_text()}'
 121             blurb = text_utils.wrap_string(blurb, 80)
 122
 123             if dt.date() in self.forecasts:
 124                 self.forecasts[dt.date()].description += '\n' + blurb
 125             else:
 126                 self.forecasts[dt.date()] = WeatherForecast(
 127                     date = dt,
 128                     sunrise = sunrise,
 129                     sunset = sunset,
 130                     description = blurb,
 131                 )
 132
 133     @classmethod
 134     @overrides
 135     def load(cls) -> Any:
 136         if persistent.was_file_written_within_n_seconds(
 137                 config.config['weather_forecast_cachefile'],
 138                 config.config['weather_forecast_stalest_acceptable'].total_seconds(),
 139         ):
 140             import pickle
 141             with open(config.config['weather_forecast_cachefile'], 'rb') as rf:
 142                 weather_data = pickle.load(rf)
 143                 return cls(weather_data)
 144         return None
 145
 146     @overrides
 147     def save(self) -> bool:
 148         import pickle
 149         with open(config.config['weather_forecast_cachefile'], 'wb') as wf:
 150             pickle.dump(
 151                 self.forecasts,
 152                 wf,
 153                 pickle.HIGHEST_PROTOCOL,
 154             )
 155         return True