This service should know in which state the relay currently is and also implement a function to switch to another state.

Implementation should look something like this:

class RelayService:
    def __init__(self, pin):
        # implementation

    def get_state():
        # implementation

    def switch():
        # implementation

Usage

relayService = RelayService(16)

current_state = relayService.get_state()
relayService.switch()

For the GPIO interaction this library should be used.

Create a service for reading temperature of DHT11 sensor.

Adafruit Python DHT library should be used for the basic operations.

Configuration service should be able to read in config.json and serve values contained there to rest of the program.

Example of config.json, where threshold is on switch temperature in Celsius and is switch
so called cooldown period in minutes

{
  "threshold": 24,
  "cooldown": 60
}

Usage of this service should look something like this

from configuration import ConfigService

configService = ConfigService()

config = configService.getConfig()

threshold = config['threshold']
cooldown = config['cooldown']

One MUST HAVE aspect of the config service is that it must be live reloaded. Meaning that program must adapt changes is config without being restarted. Threads must be used for this, one option is to declare setInterval method like this.