cached/weather_forecast.py

   1 #!/usr/bin/env python3
   2
   3 # © Copyright 2021-2022, Scott Gasch
   4
   5 """How's the weather going to be tomorrow?"""
   6
   7 import datetime
   8 import logging
   9 import os
  10 import urllib.request
  11 from dataclasses import dataclass
  12 from typing import Any
  13
  14 import astral  # type: ignore
  15 import pytz
  16 from astral.sun import sun  # type: ignore
  17 from bs4 import BeautifulSoup  # type: ignore
  18 from overrides import overrides
  19
  20 import argparse_utils
  21 import config
  22 import dateparse.dateparse_utils as dp
  23 import datetime_utils
  24 import persistent
  25 import smart_home.thermometers as temps
  26 import text_utils
  27
  28 logger = logging.getLogger(__name__)
  29
  30 cfg = config.add_commandline_args(
  31     f'Cached Weather Forecast ({__file__})',
  32     'Arguments controlling detailed weather rendering',
  33 )
  34 cfg.add_argument(
  35     '--weather_forecast_cachefile',
  36     type=str,
  37     default=f'{os.environ["HOME"]}/cache/.weather_forecast_cache',
  38     metavar='FILENAME',
  39     help='File in which to cache weather data',
  40 )
  41 cfg.add_argument(
  42     '--weather_forecast_stalest_acceptable',
  43     type=argparse_utils.valid_duration,
  44     default=datetime.timedelta(seconds=7200),  # 2 hours
  45     metavar='DURATION',
  46     help='Maximum acceptable age of cached data.  If zero, forces a refetch',
  47 )
  48
  49
  50 @dataclass
  51 class WeatherForecast:
  52     date: datetime.date  # The date
  53     sunrise: datetime.datetime  # Sunrise datetime
  54     sunset: datetime.datetime  # Sunset datetime
  55     description: str  # Textual description of weather
  56
  57
  58 @persistent.persistent_autoloaded_singleton()  # type: ignore
  59 class CachedDetailedWeatherForecast(persistent.Persistent):
  60     def __init__(self, forecasts=None):
  61         if forecasts is not None:
  62             self.forecasts = forecasts
  63             return
  64
  65         now = datetime_utils.now_pacific()
  66         self.forecasts = {}
  67
  68         # Ask the raspberry pi about the outside temperature.
  69         current_temp = temps.ThermometerRegistry().read_temperature(
  70             'house_outside', convert_to_fahrenheit=True
  71         )
  72
  73         # Get a weather forecast for Bellevue.
  74         www = urllib.request.urlopen(
  75             "https://forecast.weather.gov/MapClick.php?lat=47.652775&lon=-122.170716"
  76         )
  77         forecast_response = www.read()
  78         www.close()
  79
  80         soup = BeautifulSoup(forecast_response, "html.parser")
  81         forecast = soup.find(id='detailed-forecast-body')
  82         parser = dp.DateParser()
  83
  84         said_temp = False
  85         last_dt = now
  86         dt = now
  87         for (day, txt) in zip(
  88             forecast.find_all('b'),
  89             forecast.find_all(class_='col-sm-10 forecast-text'),
  90         ):
  91             last_dt = dt
  92             try:
  93                 dt = parser.parse(day.get_text())
  94             except Exception:
  95                 dt = last_dt
  96             assert dt is not None
  97
  98             # Compute sunrise/sunset times on dt.
  99             city = astral.LocationInfo("Bellevue", "USA", "US/Pacific", 47.653, -122.171)
 100             s = sun(city.observer, date=dt, tzinfo=pytz.timezone("US/Pacific"))
 101             sunrise = s['sunrise']
 102             sunset = s['sunset']
 103
 104             if dt.date() == now.date() and not said_temp and current_temp is not None:
 105                 blurb = f'{day.get_text()}: The current outside tempterature is {current_temp}. '
 106                 blurb += txt.get_text()
 107                 said_temp = True
 108             else:
 109                 blurb = f'{day.get_text()}: {txt.get_text()}'
 110             blurb = text_utils.wrap_string(blurb, 80)
 111
 112             if dt.date() in self.forecasts:
 113                 self.forecasts[dt.date()].description += '\n' + blurb
 114             else:
 115                 self.forecasts[dt.date()] = WeatherForecast(
 116                     date=dt,
 117                     sunrise=sunrise,
 118                     sunset=sunset,
 119                     description=blurb,
 120                 )
 121
 122     @classmethod
 123     @overrides
 124     def load(cls) -> Any:
 125         if persistent.was_file_written_within_n_seconds(
 126             config.config['weather_forecast_cachefile'],
 127             config.config['weather_forecast_stalest_acceptable'].total_seconds(),
 128         ):
 129             import pickle
 130
 131             with open(config.config['weather_forecast_cachefile'], 'rb') as rf:
 132                 weather_data = pickle.load(rf)
 133                 return cls(weather_data)
 134         return None
 135
 136     @overrides
 137     def save(self) -> bool:
 138         import pickle
 139
 140         with open(config.config['weather_forecast_cachefile'], 'wb') as wf:
 141             pickle.dump(
 142                 self.forecasts,
 143                 wf,
 144                 pickle.HIGHEST_PROTOCOL,
 145             )
 146         return True