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import machine, time
from machine import Pin
from machine import UART
import urequests as requests
import gc

def debug_log(message):
    print(message) #for now

def error_log(message):
    debug_log(message)

def push_sensor_value(server, dbname, username, password, measurement, co2val):
    try:
        led(0)
        if not sta_if.isconnected():
            do_connect()

        url = "{server}/write?db={dbname}".format(server=server, dbname=dbname)
        if username and password:
            url += "&u={username}&p={password}".format(username=username, password=password)

        debug_log("Posting to %s" % url)

        linedata = "{measurement},station=co2 CO2={value}".format(measurement=measurement, value=co2val)

        debug_log("Data: %s" % linedata)

        r = requests.post(url, data=linedata)
        debug_log("Response: %s" % r)
        r.close()
        led(1)
    except Exception as err:
        error_log(err)


def get_sensor_value():
    """Get value from MHZ19B CO2 sensor.
    :returns: CO2 integer value
    """
    debug_log("Getting sensor val")
    try:
        led(0)
        result = u.write(b'\xff\x01\x86\x00\x00\x00\x00\x00\x79')
        time.sleep(0.2)
        s = u.read(9)
        if s:
            if s[0] == 255 and s[1] == 134:
                co2value = int(s[2]*256) + int(s[3])
                debug_log("CO2: %s" % co2value)
                led(1)
                return co2value
            else:
                debug_log("No sensor value %s" % s)
        return -1
    except Exception as err:
        error_log(err)
        return -1


if __name__=="__main__":
    # setup sensor comms
    u = UART(1, baudrate=9600)
    u.init(9600, bits=8, parity=None, stop=1, tx=17, rx=16)
    gc.collect()

    while True:
        val = get_sensor_value()
        if val > 0:
            push_sensor_value("http://0.0.0.0:8086", "luftdata", "username", "*****", "home", val)

        # Wait until next measurement
        for i in range(30):
            led(1)
            debug_log("Sleeping %s" % i)
            time.sleep(1)
            led(0)
        led(1)
        gc.collect()