import time
import json
import network
from machine import Pin, ADC, I2C, PWM
import ssd1306

# --------------------
# WiFi Setup
# --------------------
def connect_wifi():
    print("Connecting to WiFi...")
    wlan = network.WLAN(network.STA_IF)
    wlan.active(True)
    wlan.connect("Wokwi-GUEST", "")
    while not wlan.isconnected():
        print(".", end="")
        time.sleep(0.5)
    print("\nWiFi connected:", wlan.ifconfig())

connect_wifi()

# --------------------
# MQTT Setup
# --------------------
from umqtt.simple import MQTTClient

MQTT_BROKER = "broker.hivemq.com"
MQTT_PORT = 1883
MQTT_TOPIC = "52227124091/GasSensor"
CLIENT_ID = "clientId-533ZcZwoJp"

mqtt_client = MQTTClient(CLIENT_ID, MQTT_BROKER, port=MQTT_PORT)
mqtt_client.connect()
print("MQTT connected!")

last_mqtt = 0
MQTT_INTERVAL = 1   # seconds


def mqtt_publish(gas_value, alarm_state):
    global last_mqtt
    now = time.time()

    if now - last_mqtt >= MQTT_INTERVAL:
        payload = {
            "gas_value": gas_value,
            "alarm": alarm_state,
            "timestamp": now
        }
        mqtt_client.publish(MQTT_TOPIC, json.dumps(payload))
        print("MQTT Sent:", payload)
        last_mqtt = now


# --------------------
# Pin Definitions
# --------------------
MQ2_PIN = 34
BUZZER_PIN = 15
BUTTON_PIN = 4
SERVO_PIN = 18       # Servo pin
SCL_PIN = 22
SDA_PIN = 21

# --------------------
# Hardware Setup
# --------------------
mq2 = ADC(Pin(MQ2_PIN))
mq2.atten(ADC.ATTN_11DB)

buzzer = Pin(BUZZER_PIN, Pin.OUT)
button = Pin(BUTTON_PIN, Pin.IN, Pin.PULL_UP)

# --- Servo Motor Setup ---
servo = PWM(Pin(SERVO_PIN), freq=50)

def servo_angle(angle):
    duty = int((angle / 180) * 102 + 26)  # Convert angle to duty cycle
    servo.duty(duty)

servo_angle(0)  # Start closed

# OLED Setup
i2c = I2C(0, scl=Pin(SCL_PIN), sda=Pin(SDA_PIN))
oled = ssd1306.SSD1306_I2C(128, 64, i2c)

GAS_THRESHOLD = 1800
reset_flag = False


def show_oled(line1, line2=""):
    oled.fill(0)
    oled.text(line1, 0, 10)
    oled.text(line2, 0, 30)
    oled.show()


# --------------------
# Main Loop
# --------------------
while True:
    gas_value = mq2.read()
    alarm_state = "OFF"

    # --- Button only resets buzzer ---
    if button.value() == 0:
        reset_flag = True
        buzzer.off()  # Stop buzzer only
        show_oled("RESET DONE", "Buzzer Off")
        time.sleep(1)

    # --- Gas detection ---
    if gas_value > GAS_THRESHOLD:
        if not reset_flag:
            alarm_state = "ON"

            servo_angle(90)   # Open servo
            buzzer.on()

            show_oled("!!! GAS ALERT !!!", f"Gas: {gas_value}")
            time.sleep(0.3)

            buzzer.off()
            time.sleep(0.3)

        else:
            alarm_state = "MUTED"
            servo_angle(90)  # Keep OPEN
            show_oled("GAS STILL HIGH", "Alarm Muted")
            time.sleep(0.3)

    else:
        reset_flag = False
        alarm_state = "SAFE"

        buzzer.off()
        servo_angle(0)    # Close when safe
        show_oled("Kitchen SAFE", f"Gas: {gas_value}")
        time.sleep(0.3)

    # Send MQTT
    mqtt_publish(gas_value, alarm_state)