from machine import Pin, PWM
import time
import json


# --- Configuration ---
adc = machine.ADC(Pin(26))
THRESHOLD = 500  # "Significant change" threshold for Edge Filtering
last_sent_value = 0


def simulate_cloud_processing(packet):
   """
   Simulates what a Cloud Server does once it receives the JSON.
   In a real scenario, this would involve a database and AI.
   """
   data = json.loads(packet)
   val = data["raw_value"]
  
   # Cloud-side 'Heavy' Logic: Predictive analysis
   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 Simulation Started...")


while True:
   # 1. READ (Perception Layer)
   current_value = adc.read_u16()
  
   # 2. EDGE LOGIC (Processing Layer)
   # Check if the value has changed significantly since the last 'Cloud' update
   diff = abs(current_value - last_sent_value)
  
   if diff > THRESHOLD:
       # 3. PACKAGING (Network Layer)
       packet = json.dumps({
           "id": "VALVE_01",
           "raw_value": current_value,
           "event": "Significant Change"
       })
      
       print(f"EDGE: Change detected ({diff}). Sending to Cloud...")
      
       # 4. SEND (Application Layer)
       simulate_cloud_processing(packet)
      
       # Update our 'last sent' baseline
       last_sent_value = current_value
   else:
       # We process this locally, but do NOT send it to the cloud
       print(f"EDGE: Minimal change ({diff}). Dropping packet to save bandwidth.")
  
   time.sleep(2)