import network
import time
import ujson
import dht
from machine import Pin
from umqtt.simple import MQTTClient

# =====================================================
# MQTT Parameters
# =====================================================
MQTT_CLIENT_ID = "vent-dht-publisher"
MQTT_BROKER = "broker.hivemq.com"
MQTT_TOPIC = "smart/vent/system"

# =====================================================
# Sensor Setup
# =====================================================
sensor = dht.DHT22(Pin(15))

# =====================================================
# WiFi Connection
# =====================================================
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!")

# 1
# =====================================================
# MQTT Connection
# =====================================================
print("MQTT Connecting....")
client = MQTT_CLIENT_ID(MQTT_CLIENT_ID, MQTT_BROKER)
client.connect()
print("MQTT Connected")
# 2
# =====================================================
# Main Loop
# =====================================================
prev_msg = ""

while True:
    print("reading value....")
    sensor.measure()
    temp = sensor.temperature()
    hum = sensor.humidity()
    # =================================================
    # Decision Logic
    # =================================================
    if temp > 30:
        state = "OPEN"
    elif temp < 20:
        state = "CLOSE"
    else:
        state = "HALF"
    msg = ujson.dumps({
        "state ":state,
        "temp ": temp,
        "humidity ": hum 
    })
    # Publish only if changed
    if msg != prev_msg:
        client.publish(MQTT_TOPIC, msg)
        print("publish: ", msg)
        prev_msg = msg

    time.sleep(2)