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

# ----------------------------------------------------------------------------
# Network & Cloud Configuration Parameters
# ----------------------------------------------------------------------------
WIFI_SSID = "Wokwi-GUEST"
WIFI_PASSWORD = "" 

MQTT_BROKER = "test.mosquitto.org"
TOPIC = b"school/esp32/weather"
CLIENT_ID = "ESP32SecurityDemo"

# Initialize DHT22 Sensor on GPIO 15
sensor = dht.DHT22(Pin(15))

def connect_wifi():
    wlan = network.WLAN(network.STA_IF)
    wlan.active(True)
    wlan.connect(WIFI_SSID, WIFI_PASSWORD)
    
    print("Connecting WiFi...")
    while not wlan.isconnected():
        print("Waiting...")
        time.sleep(1)
        
    print("WiFi Connected\n")
    return wlan

def connect_mqtt():
    client = MQTTClient(CLIENT_ID, MQTT_BROKER)
    client.connect()
    print("MQTT Connected\n")
    return client

def read_sensor():
    sensor.measure()
    t = sensor.temperature()
    h = sensor.humidity()
    return t, h

# ----------------------------------------------------------------------------
# Updated Validation Logic (Strict Bounds for Testing)
# ----------------------------------------------------------------------------
def validate(t, h):
    """
    Checks if values breach safe operating ranges.
    Using <= and >= flags extreme values (-40 and 0) as errors for testing.
    """
    if t <= -40:
        print("Validation Fault: Temperature is too low! (<= -40°C)")
        return False
    if t >= 80:
        print("Validation Fault: Temperature is too high! (>= 80°C)")
        return False
    if h <= 0:
        print("Validation Fault: Humidity is too low! (<= 0%)")
        return False
    if h >= 100:
        print("Validation Fault: Humidity is too high! (>= 100%)")
        return False
        
    return True

# ============================================================================
# Main Program Boot & Telemetry Lifecycle
# ============================================================================
print("\nStarting System\n")

wifi = connect_wifi()
mqtt = connect_mqtt()

while True:
    try:
        # Capture current climate numbers from hardware
        temperature, humidity = read_sensor()

        print("------------------------")
        print("Raw Sensor Data -> Temp: {:.1f}°C, Humid: {:.1f}%".format(temperature, humidity))

        # Validate data integrity before publishing
        if validate(temperature, humidity):
            msg = "Temp={:.1f} Humidity={:.1f}".format(temperature, humidity)
            
            # Broadcast message payload out to the cloud channel topic
            mqtt.publish(TOPIC, msg)
            print("Status: Published Successfully")
        else:
            # Caught an intentional boundary anomaly
            print("Status: Invalid Sensor Reading (Data Suppressed)")

    except Exception as e:
        print("\n[Runtime Exception Handled]:", e)
        print("Retrying connection in next cycle...")

    # Wait 5 seconds before repeating
    time.sleep(5)