"""
ESP32 IoT Project with MQTT
- publishes data from 2 DHT22 sensors and an ultrasonic sensor
- controls 3 LEDs (orange, pink, blue) via MQTT subscription
- uses EMQX broker for MQTT communication
- designed for Wokwi ESP32 simulation

created by: bhagaskara rafael w/ ❤
"""

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

# pin setup for sensors and leds
PINS = {
    'trig': 18,
    'echo': 19,
    'dht1': 32,
    'dht2': 33,
    'led_orange': 25,
    'led_pink': 26,
    'led_blue': 27
}

# mqtt settings
MQTT = {
    'client_id': "glitchhunters-esp32",
    'broker': "broker.hivemq.com",
    'user': "",
    'password': "",
    'topic_sensor': "/glitchhunters/bhagaskara/data_sensor",
    'topic_led': "/glitchhunters/bhagaskara/aktuasi_led"
}

# initialize our hardware
trig = Pin(PINS['trig'], Pin.OUT)
echo = Pin(PINS['echo'], Pin.IN)
dht1 = dht.DHT22(Pin(PINS['dht1']))
dht2 = dht.DHT22(Pin(PINS['dht2']))
led_orange = Pin(PINS['led_orange'], Pin.OUT)
led_pink = Pin(PINS['led_pink'], Pin.OUT)
led_blue = Pin(PINS['led_blue'], Pin.OUT)

def connect_wifi():
    """connects esp32 to wifi network"""
    print("connecting to wifi", end="")
    sta_if = network.WLAN(network.STA_IF)
    sta_if.active(True)
    sta_if.connect('Wokwi-GUEST', '')
    
    # wait until connected
    while not sta_if.isconnected():
        print(".", end="")
        time.sleep(0.1)
    print(" connected!")

def measure_distance():
    """gets distance reading from ultrasonic sensor"""
    # trigger the ultrasonic pulse
    trig.value(0)
    time.sleep_us(2)
    trig.value(1)
    time.sleep_us(10)
    trig.value(0)
    
    # measure the return pulse
    duration = time_pulse_us(echo, 1)
    return duration / 58.0  # convert to centimeters

def handle_led_message(topic, msg):
    """processes incoming mqtt messages for led control"""
    topic = topic.decode('utf-8')
    msg = msg.decode('utf-8')
    print(f"got message on {topic}: {msg}")
    
    try:
        # parse the json message
        data = ujson.loads(msg)
        
        # update led states
        if "orange" in data:
            led_orange.value(data["orange"])
        if "pink" in data:
            led_pink.value(data["pink"])
        if "blue" in data:
            led_blue.value(data["blue"])
    except:
        print("couldn't process the message")

def read_sensors():
    """gets readings from all sensors"""
    try:
        dht1.measure()
        dht2.measure()
        return {
            "temp1": dht1.temperature(),
            "humidity1": dht1.humidity(),
            "temp2": dht2.temperature(),
            "humidity2": dht2.humidity(),
            "distance": measure_distance()
        }
    except:
        print("sensor reading failed")
        return None

def main():
    """main program loop"""
    # setup wifi
    connect_wifi()
    
    # connect to mqtt broker
    print("connecting to mqtt broker...", end="")
    client = MQTTClient(MQTT['client_id'], MQTT['broker'], 
                       user=MQTT['user'], password=MQTT['password'])
    client.set_callback(handle_led_message)
    client.connect()
    print(" connected!")
    
    # subscribe to led control topic
    client.subscribe(MQTT['topic_led'])
    
    # keep track of last readings to avoid duplicate publishing
    prev_data = ""
    
    # main loop
    while True:
        try:
            # get sensor readings
            sensor_data = read_sensors()
            if sensor_data:
                message = ujson.dumps(sensor_data)
                
                # publish only if readings changed
                if message != prev_data:
                    print(f"publishing: {message}")
                    client.publish(MQTT['topic_sensor'], message)
                    prev_data = message
            
            # check for new led control messages
            client.check_msg()
            
            # wait a bit before next reading
            time.sleep(1)
            
        except Exception as e:
            print(f"oops! something went wrong: {e}")
            time.sleep(1)

# kick things off
if __name__ == "__main__":
    main()