"""
mdb    :  Lecturas de sensor permanentes
Revisar: https://forums.raspberrypi.com/viewtopic.php?t=342045

"""

from time import sleep
from machine import Pin, I2C, Timer
import _thread

BME280 = False
BMP085 = False
DHT22  = True
"""
assert not (BME280 and BMP085) 
assert (BME280 or BMP085) 
"""

if BME280:
    print("importar BME280")
    import bme280
if BMP085:
    print("importar BMP085")
    # https://github.com/robert-hh/BMP085_BMP180
    import bmp085
if DHT22:
    print("importar DHT22")
    import dht

#initialize I2C
print("agregar la inicializacion de i2c")



class Sensor:
    #periodically read sensor data#
    
    def __init__(self, period=5000, callback = None):
        
        if BME280:
            self.bme = bme280.BME280()
        if BMP085:
            self.bmp = bmp085.BMP085()
        if DHT22:
            self.DHT = dht.DHT22(Pin(15))
            timerDHT = Timer(1)
            timerDHT.init(period=period, mode=Timer.PERIODIC, callback=self._process_sensor)
        self.callback = callback
  
    def _process_sensor( self, t):
        self._read_sensor()
        if self.callback != None:
            self.callback( temp = self.temp, pressure=self.pressure, humidity=self.humidity)
            
    def _read_sensor(self):
        global temp, pressure, humidity
        if BME280:
            values = self.bme.values
            self.temp     = values[0]
            self.pressure = values[1]
            self.humidity = values[2]

        if BMP085:
            self.temp     = self.bmp.temperature
            self.pressure = self.bmp.pressure
            self.humidity = 0.0
        
        if DHT22:
            self.temp     = self.DHT.temperature()
            self.pressure = 0.9
            self.humidity = self.DHT.humidity()


#ensure that writing, reading of 'reading'-variable are synchronized by a lock

reading = "undefined"
lock = _thread.allocate_lock()

def get_reading():
    #synchronized with a lock#
    with lock:
        return reading  # here a clone operation would be perfect. 

def callback(temp, pressure, humidity):
    #synchronized with a lock, partially
    print('Temperatura=',temp, 'Presion=',pressure, 'Humedad=',humidity)
    global reading
    
    with lock:
        reading = f"Temperature: { temp }, Humidity: {humidity}, Pressure: {pressure}"
    
    #
    # display on ssd1306
    #
    # ...
    # ...
print('Instancia Sensor')
sensor = Sensor(period=3_333, callback=callback)