function_app.py

import logging
logging.basicConfig(level=logging.INFO)
import azure.functions as func
import requests
import os
import datetime
import pytz
import time

app = func.FunctionApp()

@app.function_name(name="mytimer")
@app.timer_trigger(schedule="0 0 6-20 1-31 6-8 *", arg_name="mytimer", run_on_startup=False) 
def main(mytimer: func.TimerRequest) -> None:
    #list of all devices/blinds/switches and there orientation regarding the sun relative to the house
    all_device_ids = [
        ['fcb467a615c0', 'East', 'Küche'],
        ['fcb467a5c794', 'East', 'Klavier'],
        ['fcb467a59c88', 'South', 'Essen'],
        ['fcb467a5d358', 'South', 'Wohnen'],
        ['fcb467a5b4f0', 'West', 'Terrasse'],
        ['fcb467a683c8', 'West', 'Gästebad']
    ]

    #list of all hours of the day when the sun shines mapped to the direction from where it shines
    sun_direction = {
        6: 'East',
        7: 'East',
        8: 'East',
        9: 'East',
        10: 'South',
        11: 'South',
        12: 'South',
        13: 'South',
        14: 'South',
        15: 'West',
        16: 'West',
        17: 'West',
        18: 'West',
        19: 'West',
        20: 'West'
    }

    # prepare weather forecast request
    berlin_tz = pytz.timezone('Europe/Berlin')
    current_time = datetime.datetime.now(tz=berlin_tz)
    current_hour = current_time.hour
    city = 'Schmölln-Putzkau, DE'
    logging.info(f'Checking sunshine forecast for {city} at {current_hour}.')

    # get the weather forecast for the current hour, to see whether the sun will shine
    api_key = os.getenv('OPENWEATHERMAP_API_KEY')
    response = requests.get(f'http://api.openweathermap.org/data/2.5/weather?q={city}&appid={api_key}')
    weather_data = response.json()

    if 'weather' in weather_data:
        sunrise_time = datetime.datetime.fromtimestamp(weather_data['sys']['sunrise'], tz=berlin_tz)
        sunset_time = datetime.datetime.fromtimestamp(weather_data['sys']['sunset'], tz=berlin_tz)
        weather_condition = weather_data['weather'][0]['main']
        temperature_kelvin = weather_data['main']['temp']
        temperature_celsius = temperature_kelvin - 273.15
        shelly_auth = os.getenv('SHELLY_AUTH_TOKEN')
        #iterate over the devices and check whether the sun will shine at the current hour and the window is impacted
        #if so, tell it to close, if not, tell it to open
        for device_id, device_direction, device_name in all_device_ids:
            if (device_direction == sun_direction[current_hour] and 
                sunrise_time.hour <= current_hour <= sunset_time.hour and 
                weather_condition == 'Clear' and
                temperature_celsius >= 15):
                logging.info(f'The sun will shine at {current_hour}:00 for {device_name} with a weather condition of {weather_condition} at {temperature_celsius} °C, closing the blind.')
                channel = "1"
            else:
                logging.info(f'The sun will not shine at {current_hour}:00 for {device_name}, opening the blind.')
                channel = "0"

            # prepare device payload
            payload_str = f"channel={channel}&turn=on&id={device_id}&auth_key={shelly_auth}"

            headers = {'content-type': 'application/x-www-form-urlencoded'}
            response = requests.post(f'https://shelly-27-eu.shelly.cloud/device/relay/control', data=payload_str, headers=headers)

            if response.status_code == 200:
                logging.info(f'Request sent successfully for {device_name}.')
            else:
                logging.error(f'Failed to control {device_name}. Error: {response.text}')
            
            time.sleep(10) #wait for 10 second before sending the next request to avoid rate limit
        
        logging.info('All blinds set according to forecast, see you next hour.')

    else:
        logging.error('Failed to fetch or read weather data - mission abort.')    

    #TODO: send a mail on error via https://sendgrid.com/en-us/pricing