# import MicroPython modules
from umqtt.simple import MQTTClient
import machine
import network
import ujson
import time
import dht
import random

# message callback function
def callback_function(topic, msg):
  print('Data transmission successful!')
  print('Topic:', topic, '\nMessage:', msg)
  print('\n')

# setup (i.e., void setup() in Arduino)
# initialize random number generator
random.seed(random.randint(0, 100))

# Initialize MQTT
client = MQTTClient(client_id = '649e372cfce65253e2c96e8f', 
                    server = 'mqtt.things.ph', 
                    port = 1883,
                    user = '6151c9b3061687fc9ec66686',
                    password = 'IwqOSc5BXlDgxNtoM9eNpEEz',
                    keepalive = 60,
                    ssl = False)

client.set_callback(callback_function)

# Try connecting to Wi-Fi Wokwi Gateway ("Wokwi-GUEST")
print("Connecting to WiFi", end="")
sta_if = network.WLAN(network.STA_IF)
sta_if.active(True)
sta_if.connect('Wokwi-GUEST', '')
  
while not sta_if.isconnected():
  print(".", end="")
  time.sleep(0.1)
print("Connected!")
print('')
  
# define GPIO pin for DHT22 sensor
DHTsensor = dht.DHT22(machine.Pin(4))

# define GPIO pin for potentiometer
adc = machine.ADC(machine.Pin(32))

# Create JSON document object
doc = {}

# main loop (i.e., void loop() in Arduino)
while(True):
  # read ADC value from potentiometer
  adc_raw = adc.read()

  #volts = (adc_raw / 4096) * 3.3

  # get DHT measurements parameters
  DHTsensor.measure()

  # get temperature (degrees Celsius) and humidity (%) value
  #tempC = DHTsensor.temperature()
  #humid = DHTsensor.humidity()

  # generate random float values for sensors
  tempC = round(random.uniform(15.99, 39.99), 2)
  humid = round(random.uniform(49.99, 99.99), 2)
  volts = round(random.uniform(9.99, 12.99), 2)

  # Define JSON dictionary Things PH payload
  doc["hardware_serial"] = "Soil Nutrient"
  doc["payload_fields"] =  {"temperature": tempC, "humidity": humid, "battery": volts}
  time.sleep(5)

  # Serialized JSON content as Things PH payload
  thingsph_payload = ujson.dumps(doc)

  # Print values
  print(thingsph_payload)
  print('')
  
  # Covert topics and payload into bytes data type
  mqtt_topic = bytes('Soil Nutrient', 'utf-8')
  mqtt_msg = bytes(thingsph_payload, 'utf-8')

  # Connecting to Things PH IoT platform
  client.connect()

  # Subscribe a topic to Things PH IoT platform
  client.subscribe(mqtt_topic, qos = 1)

  # Publish message to Things PH IoT platform
  client.publish(mqtt_topic, mqtt_msg)

  # Wait a message from server (Things PH) and print the reponse using callback function
  client.wait_msg()

  # time delay every 30 seconds
  time.sleep(30)