import machine
import time
import json
from machine import Pin


# --- Configuration ----
adc = machine.ADC(Pin(26))   # Potentiometer wiper on GP26
THRESHOLD = 500              # Significant change threshold
last_sent_value = 0


def simulate_cloud_processing(packet):
    """
    Simulates what a Cloud Server does once it receives the JSON.
    """
    data = json.loads(packet)
    val = data["raw_value"]

    # Cloud-side 'Heavy' Logic
    if val > 60000:
        print(f">>> [CLOUD ALERT] Critical pressure at {val}! Shutting down system.")
    else:
        print(f">>> [CLOUD LOG] Normal operation recorded for {data['id']}")


print("Experiment 4.2: Edge Filtering with Potentiometer Started...")
print("-" * 50)

while True:
    # 1. READ (Perception Layer)
    current_value = adc.read_u16()  # 0 → 65535
    diff = abs(current_value - last_sent_value)

    # 2. EDGE LOGIC (Processing Layer)
    if diff > THRESHOLD:
        # 3. PACKAGING (Network Layer)
        packet = json.dumps({
            "id": "VALVE_01",
            "raw_value": current_value,
            "event": "Significant Change"
        })

        print(f"EDGE: Pot moved! Change = {diff}. Sending to Cloud...")

        # 4. SEND (Application Layer)
        simulate_cloud_processing(packet)

        last_sent_value = current_value
    else:
        print(f"EDGE: Minor pot movement ({diff}). Data filtered locally.")

    time.sleep(2)