import network
import urequests
import dht
from machine import Pin, ADC
import time

# Configuration
SSID = "Wokwi-GUEST"  # Change to your WiFi name
PASSWORD = ""         # Change to your WiFi password
THINGSPEAK_API_KEY = "ZP9ZJJOBXNTPT57S"  # Replace with your actual API key

# Hardware setup
sensor = dht.DHT22(Pin(4))       # DHT22 connected to GPIO 4
mq2_aout = ADC(Pin(34))          # MQ2 analog output (AOUT) -> GPIO34
mq2_aout.atten(ADC.ATTN_11DB)    # Full range: 0 - 3.3V
mq2_aout.width(ADC.WIDTH_12BIT)  # 12-bit resolution (0-4095)

# WiFi connection
def connect_wifi():
    wlan = network.WLAN(network.STA_IF)
    wlan.active(True)
    wlan.connect(SSID, PASSWORD)
    
    print("Connecting to WiFi...")
    while not wlan.isconnected():
        print(".", end="")
        time.sleep(1)
    
    print("\nConnected to WiFi successfully!")
    print("IP Address:", wlan.ifconfig()[0])
    return wlan

# Send data to ThingSpeak
def send_to_thingspeak(temp, hum, gas):
    try:
        url = f"https://api.thingspeak.com/update?api_key={THINGSPEAK_API_KEY}&field1={temp}&field2={hum}&field3={gas}"
        
        print(f"Sending to ThingSpeak: Temp={temp}°C, Humidity={hum}%, MQ2={gas}")
        response = urequests.get(url)
        
        if response.status_code == 200:
            entry_id = response.text
            print(f"✅ Data sent successfully! Entry ID: {entry_id}")
            response.close()
            return True
        else:
            print(f"❌ ThingSpeak error: HTTP {response.status_code}")
            response.close()
            return False
            
    except Exception as e:
        print(f"❌ Error sending to ThingSpeak: {e}")
        return False

# Read sensor data
def read_sensors():
    try:
        sensor.measure()
        temperature = sensor.temperature()
        humidity = sensor.humidity()
        gas_analog = mq2_aout.read()   # Analog value (0–4095)
        
        # Validation
        if temperature is None or humidity is None:
            print("⚠️ Invalid DHT22 reading")
            return None, None, None
        
        if temperature < -40 or temperature > 80:
            print("⚠️ Temperature out of range")
            return None, None, None
            
        if humidity < 0 or humidity > 100:
            print("⚠️ Humidity out of range")
            return None, None, None
        
        return temperature, humidity, gas_analog
    
    except Exception as e:
        print(f"❌ Sensor error: {e}")
        return None, None, None

# Main program
print("🌡️ DHT22 + MQ2 (Analog) ThingSpeak Data Logger")
print("=" * 50)

wlan = connect_wifi()

print("\n📡 Starting data logging to ThingSpeak...")
print(f"🔑 API Key: {THINGSPEAK_API_KEY}")
print("=" * 50)

reading_count = 0

while True:
    try:
        if not wlan.isconnected():
            print("📶 WiFi disconnected, reconnecting...")
            wlan = connect_wifi()
        
        temperature, humidity, gas_analog = read_sensors()
        
        if temperature is not None and humidity is not None and gas_analog is not None:
            reading_count += 1
            print(f"\n📊 Reading #{reading_count}")
            print(f"🌡️ Temperature: {temperature}°C")
            print(f"💧 Humidity: {humidity}%")
            print(f"📈 MQ2 Gas Level (AOUT): {gas_analog} (0–4095)")
            
            if send_to_thingspeak(temperature, humidity, gas_analog):
                print("✅ Data logged successfully!")
            else:
                print("❌ Failed to log data")
        else:
            print("⚠️ Skipping invalid sensor reading")
        
        print("-" * 40)
        print("⏳ Waiting 20 seconds for next reading...")
        time.sleep(20)
        
    except KeyboardInterrupt:
        print("\n🛑 Program stopped by user")
        break
    except Exception as e:
        print(f"❌ Main loop error: {e}")
        time.sleep(5)