import board
import busio
from adafruit_bme280 import basic as adafruit_bme280

class BME280():
    mqtt_state_topic = "homeassistant/sensor/balcony_weather_station/bme_280_001/state"
    mqtt_config_topic_temperature = "homeassistant/sensor/balcony_weather_station/bme_280_001_temp/config"
    mqtt_config_topic_humidity    = "homeassistant/sensor/balcony_weather_station/bme_280_001_humi/config"
    mqtt_config_topic_pressure    = "homeassistant/sensor/balcony_weather_station/bme_280_001_pres/config"
    config_msg_temperature = """{
    "name": "BEM 280 Temperature",
    "device_class": "temperature",
    "unit_of_measurement": "°C",
    "value_template": "{{ value_json.temperature}}",
    "state_topic": "homeassistant/sensor/balcony_weather_station/bme_280_001/state",
    "unique_id": "balcony_weather_station_bme_280_001_temperature",
    "device": {
        "identifiers": "balcony_weather_station_001",
        "name": "Balcony Weather Station"
    }
    }"""
    config_msg_pressure = """{
    "name": "BEM 280 Pressure",
    "device_class": "pressure",
    "unit_of_measurement": "hPa",
    "value_template": "{{ value_json.pressure}}",
    "state_topic": "homeassistant/sensor/balcony_weather_station/bme_280_001/state",
    "unique_id": "balcony_weather_station_bme_280_001_pressure",
    "device": {
        "identifiers": "balcony_weather_station_001",
        "name": "Balcony Weather Station"
    }
    }"""
    config_msg_humidity = """{
    "name": "BEM 280 Humidity",
    "device_class": "humidity",
    "unit_of_measurement": "%",
    "value_template": "{{ value_json.humidity}}",
    "state_topic": "homeassistant/sensor/balcony_weather_station/bme_280_001/state",
    "unique_id": "balcony_weather_station_bme_280_001_humidity",
    "device": {
        "identifiers": "balcony_weather_station_001",
        "name": "Balcony Weather Station"
    }
    }"""

    def __init__(self, pubsub):
        self.pubsub = pubsub
        i2c = busio.I2C(scl=board.GP15, sda=board.GP14)
        self.bme280 = adafruit_bme280.Adafruit_BME280_I2C(i2c, 0x76)
        self.bme280.sea_level_pressure = 1016 # value from https://metar-taf.com/EDDM
        self.pubsub.publish('mqtt_pub', { 
            'topic': self.mqtt_config_topic_temperature,
            'msg': self.config_msg_temperature
        })
        self.pubsub.publish('mqtt_pub', {
            'topic': self.mqtt_config_topic_humidity, 
            'msg': self.config_msg_humidity
        })
        self.pubsub.publish('mqtt_pub', {
            'topic': self.mqtt_config_topic_pressure,
            'msg': self.config_msg_pressure
        })
        self.pubsub.subscribe('tick 120', self._send)

    def _send(self, _):
        msg = f"""{{
            "temperature": {self.bme280.temperature:.1f},
            "humidity": {self.bme280.relative_humidity:.1f},
            "pressure": {self.bme280.pressure:.1f}
        }}"""
        self.pubsub.publish('mqtt_pub', {'topic': self.mqtt_state_topic, 'msg': msg})