import time
import machine
import dht
from machine import I2C, Pin

# Define GPIO pins
TRIG_PIN = machine.Pin(2, machine.Pin.OUT)
ECHO_PIN = machine.Pin(3, machine.Pin.IN)
BUZZER_PIN = machine.Pin(4, machine.Pin.OUT)
DHT_PIN = machine.Pin(5)
LED_PIN = machine.Pin(6, machine.Pin.OUT)

# I2C configuration for LCD
i2c = I2C(0, scl=Pin(1), sda=Pin(0), freq=400000)
LCD_ADDR = 0x27  # Adjust if necessary for Wokwi

# LCD Constants
LCD_CMD = 0x00
LCD_CHR = 0x01
LCD_LINE_1 = 0x80
LCD_LINE_2 = 0xC0
LCD_BACKLIGHT = 0x08
ENABLE = 0b00000100

# Initialize DHT sensor
dht_sensor = dht.DHT22(DHT_PIN)

def lcd_toggle_enable(data):
    time.sleep_us(500)
    i2c.writeto(LCD_ADDR, bytearray([data | ENABLE | LCD_BACKLIGHT]))
    time.sleep_us(500)
    i2c.writeto(LCD_ADDR, bytearray([(data & ~ENABLE) | LCD_BACKLIGHT]))
    time.sleep_us(500)

def lcd_byte(bits, mode):
    # Send byte to data pins
    high_bits = mode | (bits & 0xF0) | LCD_BACKLIGHT
    low_bits = mode | ((bits << 4) & 0xF0) | LCD_BACKLIGHT
    i2c.writeto(LCD_ADDR, bytearray([high_bits]))
    lcd_toggle_enable(high_bits)
    i2c.writeto(LCD_ADDR, bytearray([low_bits]))
    lcd_toggle_enable(low_bits)

def lcd_init():
    # Initialize display
    lcd_byte(0x33, LCD_CMD)  # Initialize
    lcd_byte(0x32, LCD_CMD)  # Set to 4-bit mode
    lcd_byte(0x06, LCD_CMD)  # Cursor move direction
    lcd_byte(0x0C, LCD_CMD)  # Turn on display
    lcd_byte(0x28, LCD_CMD)  # 2 line display
    lcd_byte(0x01, LCD_CMD)  # Clear display
    time.sleep_ms(2)

def lcd_string(message, line):
    # Send string to display
    lcd_byte(line, LCD_CMD)
    for char in message:
        lcd_byte(ord(char), LCD_CHR)

# Initialize LCD
lcd_init()

def distance_measurement():
    # Trigger ultrasonic sensor
    TRIG_PIN.on()
    time.sleep_us(10)
    TRIG_PIN.off()

    # Wait for echo to be HIGH (start time)
    while not ECHO_PIN.value():
        pass
    pulse_start = time.ticks_us()

    # Wait for echo to be LOW (end time)
    while ECHO_PIN.value():
        pass
    pulse_end = time.ticks_us()

    # Calculate distance
    pulse_duration = time.ticks_diff(pulse_end, pulse_start)
    distance = pulse_duration / 58  # Speed of sound (343 m/s) divided by 2

    return distance

def read_dht_sensor():
    dht_sensor.measure()
    return dht_sensor.temperature(), dht_sensor.humidity()

while True:
    dist = distance_measurement()
    temp, humidity = read_dht_sensor()

    # Check if the distance is less than a threshold (e.g., 50 cm)
    if dist < 50:
        # Turn on the buzzer and LED
        BUZZER_PIN.off()
        LED_PIN.off()
        status = "Flooding Detected"
    else:
        # Turn off buzzer and LED if distance is above threshold
        BUZZER_PIN.on()
        LED_PIN.on()
        status = "No Flooding Detected"

    # Update LCD with measurements
    lcd_string(f"Dist:{dist:.1f} cm", LCD_LINE_1)
    lcd_string(f"Temp:{temp:.1f}C Hum:{humidity:.1f}%", LCD_LINE_2)

    # Print to console for debugging
    print(f"Distance: {dist:.2f} cm")
    print(f"Temperature: {temp:.2f}°C, Humidity: {humidity:.2f}%")
    print("Status:", status)

    # Short delay before next loop
    time.sleep(2)