import machine
import utime
import azure.iot.device

# Define Azure IoT Hub connection string and device ID
CONNECTION_STRING = "HostName=TrafficManagement.azure-devices.net;DeviceId=RaspPi;SharedAccessKey=7ryCImqSUWqhp5ChKRrkZxNCwpjqtJHL2AIoTGkwJBs="
DEVICE_ID = "RaspPi"

# Initialize the IoT Hub client
from azure.iot.device import IoTHubDeviceClient, Message
client = IoTHubDeviceClient.create_from_connection_string(CONNECTION_STRING)

# GPIO pins for the HC-SR04 sensor
trigger_pin = machine.Pin(2, machine.Pin.OUT)
echo_pin = machine.Pin(3, machine.Pin.IN)

# Traffic light control pins (simulated)
red_light = machine.Pin(10, machine.Pin.OUT)
yellow_light = machine.Pin(11, machine.Pin.OUT)
green_light = machine.Pin(12, machine.Pin.OUT)

def measure_distance():
    trigger_pin.value(0)
    utime.sleep_us(2)
    trigger_pin.value(1)
    utime.sleep_us(10)
    trigger_pin.value(0)

    while echo_pin.value() == 0:
        pulse_start = utime.ticks_us()

    while echo_pin.value() == 1:
        pulse_end = utime.ticks_us()

    pulse_duration = utime.ticks_diff(pulse_end, pulse_start)
    distance = (pulse_duration * 0.0343) / 2  # Speed of sound is approximately 343 meters per second

    return distance

def control_traffic_lights(distance):
    if distance < 10:
        red_light.value(0)
        yellow_light.value(1)
        green_light.value(0)
    elif 10 <= distance < 20:
        red_light.value(1)
        yellow_light.value(0)
        green_light.value(0)
    else:
        red_light.value(0)
        yellow_light.value(0)
        green_light.value(1)

while True:
    distance = measure_distance()
    control_traffic_lights(distance)

    # For simulation purposes, print the distance and the traffic light state
    print("Distance: {:.2f} cm".format(distance))

    # Send distance data to IoT Hub
    telemetry_data = {"distance_cm": distance}
    message = Message(telemetry_data)
    client.send_message(message)

    utime.sleep(2)  # Adjust the sleep duration as needed