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

from hcsr04 import HCSR04
from time import sleep

from servo import Servo

motor=Servo(pin=12) 

# MQTT Server Parameters
MQTT_CLIENT_ID = "2023pj16001"
MQTT_BROKER    = "test.mosquitto.org"
MQTT_USER      = ""
MQTT_PASSWORD  = ""
MQTT_TOPIC_DISTANCE = "/IOT/SmartCarParking"   # Original topic for distance status
MQTT_TOPIC_STATUS   = "/IOT/parkingStatus"     # New topic for textual status

# Initialize the HC-SR04 Sensor
sensor1 = HCSR04(trigger_pin=5, echo_pin=18, echo_timeout_us=100000)

# Connecting to WiFi
print("Connecting to WiFi", end="")
sta_if = network.WLAN(network.STA_IF)
sta_if.active(True)
sta_if.connect('Wokwi-GUEST', '')  # Change the Wi-Fi credentials if needed
while not sta_if.isconnected():
    print(".", end="")
    time.sleep(0.1)
print(" Connected!")

# Connecting to MQTT Server
print("Connecting to MQTT server... ", end="")
client = MQTTClient(MQTT_CLIENT_ID, MQTT_BROKER, user=MQTT_USER, password=MQTT_PASSWORD)
client.connect()
print("Connected!")

# Main loop to read and publish sensor data
prev_message = ""
prev_status = ""
while True:
    # Read the distance from the sensor
    distance = sensor1.distance_cm()

    # Determine if the distance is less than 40 cm and set the corresponding messages
    if distance < 40:
        message = ujson.dumps(0)  # Numeric value for Car Slot Occupied
        status_message = "Car slot occupied"  # Text status for GUI display
        print("Car slot occupied")  # Print to serial monitor
        motor.move(90)
    else:
        message = ujson.dumps(1)  # Numeric value for Car Slot Empty
        status_message = "Car slot empty"  # Text status for GUI display
        print("Car slot empty")  # Print to serial monitor
        motor.move(0)

    # Publish distance status to the original topic
    if message != prev_message:
        print("Reporting distance status to MQTT topic {}: {}".format(MQTT_TOPIC_DISTANCE, message))
        client.publish(MQTT_TOPIC_DISTANCE, message)
        prev_message = message

    # Publish the textual status to the new topic
    if status_message != prev_status:
        print("Reporting status to MQTT topic {}: {}".format(MQTT_TOPIC_STATUS, status_message))
        client.publish(MQTT_TOPIC_STATUS, status_message)
        prev_status = status_message

    # Delay before the next reading
    time.sleep(1)