# ==========================================
# Semester 1 Project: Smart Entry System
# ESP32 Board 1: Sensor Reading & Servo Control
# ==========================================

# --- Importing Libraries ---
import dht
from machine import Pin, UART, ADC, time_pulse_us, PWM
import time
import network
import BlynkLib

# --- WiFi & Blynk Configuration ---
BLYNK_TEMPLATE_ID = "TMPL2NokFB3pV"
BLYNK_TEMPLATE_NAME = "Semester 1 Project"
BLYNK_AUTH_TOKEN = "HbMWKl1LSSoHtIDc8Oa6pgVtcNlh7NEX"
WIFI_SSID = "Wokwi-GUEST"
WIFI_PASS = ""

# --- Network Initialization ---
wifi = network.WLAN(network.STA_IF)
wifi.active(True)
wifi.connect(WIFI_SSID, WIFI_PASS)

print("Connecting to WiFi...")
while not wifi.isconnected():
    time.sleep(0.1)

print("WiFi Connected!")

# --- Blynk Initialization ---
blynk = BlynkLib.Blynk(BLYNK_AUTH_TOKEN, insecure=True)

@blynk.on("connected")
def on_blynk_connected():
    print("Successfully connected to Blynk server")

# --- Hardware Setup & Pin Assignments ---

# 1. DHT22 Sensor (Temperature & Humidity)
dht_sensor = dht.DHT22(Pin(32)) 

# 2. UART Communication (To ESP32 Board 2)
# Using UART 1, TX on Pin 17, RX on Pin 16
uart_conn = UART(1, baudrate=9600, tx=Pin(17), rx=Pin(16), timeout=1000, timeout_char=100)

# 3. MQ-2 Gas Sensor
gas_sensor_digital = Pin(25, Pin.IN) # Optional: if using digital output
gas_sensor_analog = ADC(Pin(34))
gas_sensor_analog.atten(ADC.ATTN_11DB) # Read full range up to 3.3V

# 4. HC-SR04 Ultrasonic Sensor
ultrasonic_echo = Pin(14, Pin.IN)
ultrasonic_trig = Pin(12, Pin.OUT)

# 5. Alert LED
alert_led = Pin(4, Pin.OUT)

# 6. Servo Motors (Lock and Door)
servo_lock = PWM(Pin(2), freq=50)
servo_door = PWM(Pin(18), freq=50)

# --- System Thresholds ---
DISTANCE_THRESHOLD_CM = 30
GAS_THRESHOLD_VALUE = 2500
TEMP_THRESHOLD_C = 30 # Currently unused in logic, but good to have
HUMIDITY_THRESHOLD_PCT = 40 # Currently unused in logic, but good to have

# --- Helper Functions ---

def set_lock_servo(angle):
    """Controls the lock servo motor angle (0-180 degrees)."""
    duty_cycle = int((angle / 180) * 102 + 26)
    servo_lock.duty(duty_cycle)

def set_door_servo(angle):
    """Controls the door servo motor angle (0-180 degrees)."""
    duty_cycle = int((angle / 180) * 102 + 26)
    servo_door.duty(duty_cycle)

def measure_distance_cm():
    """Triggers the ultrasonic sensor and returns distance in cm."""
    ultrasonic_trig.value(0)
    time.sleep_us(2)
    ultrasonic_trig.value(1)
    time.sleep_us(10)
    ultrasonic_trig.value(0)
    
    # Calculate duration of the echo pulse
    duration_us = time_pulse_us(ultrasonic_echo, 1)
    
    # Speed of sound is approx 343 m/s or 0.034 cm/us
    distance_cm = (duration_us * 0.034) / 2
    return distance_cm

# Initialize servos to closed position (0 degrees)
set_lock_servo(0)
set_door_servo(0)

# Track the last time sensors were read to avoid flooding
last_reading_time = time.ticks_ms()

# ==========================================
# --- Main Control Loop ---
# ==========================================

print("Starting main loop...")

while True:
    blynk.run()
    
    # Execute sensor readings every 250 ms
    current_time = time.ticks_ms()
    if time.ticks_diff(current_time, last_reading_time) >= 250:
        last_reading_time = current_time
        
        try:
            # --- 1. Read Sensors ---
            current_distance = measure_distance_cm()
            current_gas_level = gas_sensor_analog.read()
            
            dht_sensor.measure()
            current_temp = dht_sensor.temperature()
            current_humidity = dht_sensor.humidity()
            
            # --- 2. Process Logic & Determine States ---
            
            # Initialize state variables
            is_door_open = False
            door_status_text = "Closed"
            numeric_door_state = 0
            
            numeric_gas_leak_state = 0
            
            numeric_object_near_state = 0
            
            # Gas Leak Logic
            if current_gas_level > GAS_THRESHOLD_VALUE:
                alert_led.on()
                numeric_gas_leak_state = 1
            else:
                alert_led.off()
                numeric_gas_leak_state = 0
                
            # Object Proximity Logic
            if current_distance < DISTANCE_THRESHOLD_CM:
                numeric_object_near_state = 1
            else:
                numeric_object_near_state = 0

            # Door Opening Logic (Opens if object is near OR gas leak detected)
            if numeric_object_near_state == 1 or numeric_gas_leak_state == 1:
                is_door_open = True
            
            # Actuate Servos based on Door State
            if is_door_open:
                set_lock_servo(80)
                set_door_servo(80)
                numeric_door_state = 1
                door_status_text = "Open"
            else:
                set_lock_servo(0)
                set_door_servo(0)
                numeric_door_state = 0
                door_status_text = "Closed"

            # --- 3. Communication & Debugging ---
            
            # Print readings to console
            print("Temp: {:.1f}C | Hum: {:.1f}% | Dist: {:.1f}cm | Gas: {}".format(
                current_temp, current_humidity, current_distance, current_gas_level))
            print("Door Open:", is_door_open)
            
            # Send Data via UART to ESP32 Board 2 (CSV Format)
            # Format: Temp, Humidity, ObjectNear(0/1), DoorState(0/1), GasLeak(0/1)
            uart_msg = "{:.1f},{:.1f},{},{},{}\n".format(
                current_temp,
                current_humidity,
                numeric_object_near_state,
                numeric_door_state,
                numeric_gas_leak_state
            )
            uart_conn.write(uart_msg)
            print("UART Sent:", uart_msg.strip())
            print("-" * 30)

            # Send Data to Blynk Dashboard
            blynk.virtual_write(0, door_status_text)
            blynk.virtual_write(1, current_gas_level)
            blynk.virtual_write(2, numeric_gas_leak_state)
            blynk.virtual_write(3, current_temp)
            blynk.virtual_write(4, current_humidity)

        except Exception as e:
            print("Error reading sensors or sending data:", e)