import hassapi as hass
import json
import urllib.request
import datetime as dt


def calcAQI(Cp, Ih, Il, BPh, BPl):
    """
    The calcs AQI using the varibles passed in. I'm not sure what they are exactly.
    this function is from purpleair's docs. converted from JS to python.

    """
    a = (Ih - Il)
    b = (BPh - BPl)
    c = (Cp - BPl)
    return round((a / b) * c + Il)

def aqiFromPM(pm):
    """
    Pass in the pm 2.5 value and returns AQI.

    this function is from purpleair's docs. converted from JS to python.
    JS call : var AQI = aqiFromPM(pm25value);


    Good                              0 - 50         0.0 - 15.0         0.0 – 12.0
    Moderate                         51 - 100           >15.0 - 40        12.1 – 35.4
    Unhealthy for Sensitive Groups  101 – 150     >40 – 65          35.5 – 55.4
    Unhealthy                       151 – 200         > 65 – 150       55.5 – 150.4
    Very Unhealthy                  201 – 300 > 150 – 250     150.5 – 250.4
    Hazardous                       301 – 400         > 250 – 350     250.5 – 350.4
    Hazardous                       401 – 500         > 350 – 500     350.5 – 500
    """

    # this is error checking. convert to python?
    # if (isNaN(pm)) return "-"; // isNaN means "is number"
    # if (pm == undefined) return "-";
    # if (pm < 0) return pm;
    # if (pm > 1000) return "-";

    if (pm > 350.5):
        return calcAQI(pm, 500, 401, 500, 350.5)
    elif (pm > 250.5):
        return calcAQI(pm, 400, 301, 350.4, 250.5)
    elif (pm > 150.5):
        return calcAQI(pm, 300, 201, 250.4, 150.5)
    elif (pm > 55.5):
        return calcAQI(pm, 200, 151, 150.4, 55.5)
    elif (pm > 35.5):
        return calcAQI(pm, 150, 101, 55.4, 35.5)
    elif (pm > 12.1):
        return calcAQI(pm, 100, 51, 35.4, 12.1)
    elif (pm >= 0):
        return calcAQI(pm, 50, 0, 12, 0)
    else:
        return undefined

class AirQuality(hass.Hass):
    def initialize(self):
        #self.get_set_purpleair(self)

        starttime = dt.datetime.now() + dt.timedelta(seconds=5)
        self.run_every(self.get_set_purpleair, starttime, 300)
        self.listen_state(self.sensorNodePmChange, "sensor.sensornode_airquality_pm_2_5")




    def sensorNodePmChange(self, entity, attribute, old, new, kwargs):
        # pm2.5 value changed. Update AQI.
        if new == "unavailable":
            return

        self.set_state(
            "sensor.inside_air_aqi",
            state = aqiFromPM(float(new)),
            attributes={
                "unit_of_measurement": "AQI",

            },
        )