import dht
import utime
import ujson

from machine import Pin
from umqtt.simple import MQTTClient

# MQTT Server Parameters
MQTT_BROKER    = "broker.hivemq.com"
MQTT_CLIENT_ID = f"USK-IoT-RD-{utime.time_ns()}"

# Broker has no Username and Password
MQTT_USER      = ""
MQTT_PASSWORD  = ""

# Topic
MQTT_TOPIC     = "usk/iot/mqtt/contoh"

# DHT22 Configuration
DHT22_PIN = 15
dht22 = dht.DHT22(Pin(DHT22_PIN))


# Callback function when message is received
def mqttCallback(topic, msg):
    print("\n===== MESSAGE RECEIVED =====")
    print("Topic :", topic.decode())

    try:
        # Convert JSON message into dictionary
        data = ujson.loads(msg)

        print("Temperature :", data["temp"], "C")
        print("Humidity    :", data["humidity"], "%")
    except:
        print("Message :", msg.decode())

    print("============================\n")


# Create MQTT Client
print("Creating MQTT object...")
client = MQTTClient(
    MQTT_CLIENT_ID,
    MQTT_BROKER,
    port=1883,
    user=MQTT_USER,
    password=MQTT_PASSWORD
)

# Set callback
print("Setting callback...")
client.set_callback(mqttCallback)

# Connect to MQTT Broker
try:
    print("Connecting to server...", end="")
    client.connect()
except:
    while True:
        utime.sleep(0.1)
        print(".", end="")
        try:
            client.reconnect()
            break
        except:
            pass

print("\nConnected to MQTT server!")

# Subscribe to topic
print("Subscribing to topic:", MQTT_TOPIC)
client.subscribe(MQTT_TOPIC)

print("System ready!\n")

while True:
    try:
        print("===== READING SENSOR =====")

        # Read DHT22 data
        dht22.measure()
        temperature = dht22.temperature()
        humidity = dht22.humidity()

        # Display sensor values on Serial Monitor
        print("Temperature :", temperature, "C")
        print("Humidity    :", humidity, "%")

        # Create JSON payload
        msg = ujson.dumps({
            "temp": temperature,
            "humidity": humidity
        })

        # Publish data to MQTT Broker
        print("Publishing data...")
        print("Topic   :", MQTT_TOPIC)
        print("Message :", msg)

        client.publish(MQTT_TOPIC, msg)

        print("Data published successfully!")

        # Check if there is incoming message
        client.check_msg()

        print("Waiting for next reading...\n")
        utime.sleep(5)

    except Exception as e:
        print("Error:", e)
        utime.sleep(2)