import os
import re

import Adafruit_DHT

from .base import Sensor, sensor


@sensor
class DS18B20(Sensor):
    sensor_class = 'pi-ds18b20'

    def __init__(self, **sensor_conf):
        super(DS18B20, self).__init__(**sensor_conf)

        self._sensor_id = None
        if 'hw_id' in sensor_conf:
            self._sensor_id = sensor_conf['hw_id']
        else:
            self._find_sensor()

    def _find_sensor(self):
        basepath = "/sys/bus/w1/devices"
        for d in os.listdir(basepath):
            if 'master' not in d and '-' in d and \
                    os.path.exists(os.path.join(basepath, d, 'w1_slave')):
                self._sensor_id = d
                break
        else:
            raise ValueError("No sensor found in filesystem")

    def get_data(self):
        temp = None
        try:
            path = "/sys/bus/w1/devices/{}/w1_slave".format(self._sensor_id)
            with open(path) as f:
                data = f.read()
                m = re.search(r".* t=(?P<temp>\d+)$", data)
                if m:
                    temp = int(m.group('temp')) / 1000.0
        except IOError:
            # log?
            pass

        return dict(temp=temp)


@sensor
class DHT(Sensor):
    sensor_class = 'pi-dht'

    def __init__(self, **sensor_conf):
        super(DHT, self).__init__(**sensor_conf)

        if sensor_conf['dht_type'] == 'dht11':
            self._dht_type = Adafruit_DHT.DHT11
        elif sensor_conf['dht_type'] == 'dht22':
            self._dht_type = Adafruit_DHT.DHT22
        else:
            raise ValueError("Unknown DHT")

    def get_data(self):
        data = Adafruit_DHT.read_retry(self._dht_type, self.pin)
        return dict(humidity=data[0], temp=data[1])