# === Wokwi-Compatible MicroPython Code ===
from machine import Pin, I2C
from time import sleep, sleep_us, ticks_us, ticks_diff
from pico_i2c_lcd import I2cLcd

# === Setup I2C LCD ===
i2c = I2C(0, scl=Pin(1), sda=Pin(0), freq=400000)
lcd = I2cLcd(i2c, 0x27, 2, 16)

# === LEDs ===
led_green = Pin(12, Pin.OUT)
led_red = Pin(13, Pin.OUT)

# === Buzzer ===
buzzer = Pin(15, Pin.OUT)

# === Push Buttons ===
door_button = Pin(9, Pin.IN, Pin.PULL_UP)
emergency_button = Pin(10, Pin.IN, Pin.PULL_UP)
weight_button = Pin(11, Pin.IN, Pin.PULL_UP)

# === Ultrasonic Sensor (HC-SR04) ===
ultra_trig = Pin(14, Pin.OUT)
ultra_echo = Pin(28, Pin.IN)

# === Keypad ===
row_pins = [Pin(16, Pin.OUT), Pin(17, Pin.OUT), Pin(18, Pin.OUT), Pin(19, Pin.OUT)]
col_pins = [Pin(20, Pin.IN, Pin.PULL_DOWN), Pin(21, Pin.IN, Pin.PULL_DOWN), Pin(22, Pin.IN, Pin.PULL_DOWN)]

keys = [
    ['1', '2', '3'],
    ['4', '5', '6'],
    ['7', '8', '9'],
    ['*', '0', '#']
]

# === 7-Segment Display (Common Anode with DP) ===
seg_pins = [Pin(2, Pin.OUT), Pin(3, Pin.OUT), Pin(4, Pin.OUT), Pin(5, Pin.OUT), Pin(6, Pin.OUT), Pin(7, Pin.OUT), Pin(8, Pin.OUT)]
dp = Pin(11, Pin.OUT)

segments = {
    '0': [0,0,0,0,0,0,1],
    '1': [1,0,0,1,1,1,1],
    '2': [0,0,1,0,0,1,0],
    '3': [0,0,0,0,1,1,0],
    '4': [1,0,0,1,1,0,0],
    '5': [0,1,0,0,1,0,0],
    '6': [0,1,0,0,0,0,0],
    '7': [0,0,0,1,1,1,1],
    '8': [0,0,0,0,0,0,0],
    '9': [0,0,0,0,1,0,0],
    ' ': [1,1,1,1,1,1,1]
}

def display_digit(digit, dot=False):
    pattern = segments.get(digit, segments[' '])
    for seg, val in zip(seg_pins, pattern):
        seg.value(val)
    dp.value(dot)

def clear_7seg():
    for seg in seg_pins:
        seg.value(1)
    dp.value(1)

def read_distance():
    ultra_trig.value(0)
    sleep_us(2)
    ultra_trig.value(1)
    sleep_us(10)
    ultra_trig.value(0)

    while ultra_echo.value() == 0:
        pass
    start = ticks_us()
    while ultra_echo.value() == 1:
        pass
    end = ticks_us()

    duration = ticks_diff(end, start)
    return (duration / 2) / 29.1

def scan_keypad():
    for i, row in enumerate(row_pins):
        for r in row_pins:
            r.value(0)
        row.value(1)
        for j, col in enumerate(col_pins):
            if col.value():
                sleep(0.2)
                return keys[i][j]
    return None

def buzzer_on(duration=0.5):
    buzzer.value(1)
    sleep(duration)
    buzzer.value(0)

def open_then_auto_close_door(duration=5):
    led_green.value(1)
    led_red.value(0)
    lcd.clear()
    lcd.putstr("Door Opening")
    buzzer_on(0.5)
    for sec in range(duration, 0, -1):
        display_digit(str(sec))
        sleep(1)
    clear_7seg()
    led_green.value(0)
    led_red.value(1)
    lcd.clear()
    lcd.putstr("Door Closing")
    sleep(2)

def go_to_floor(floor):
    global current_floor
    lcd.clear()
    lcd.putstr(f"Going to {floor}")
    sleep(1)
    current_floor = floor
    lcd.clear()
    lcd.putstr(f"Arrived at {current_floor}")
    buzzer_on(0.5)
    sleep(1)
    open_then_auto_close_door()

def handle_emergency():
    lcd.clear()
    lcd.putstr("!!! EMERGENCY !!!")
    led_green.value(0)
    led_red.value(1)
    clear_7seg()
    while emergency_button.value() == 0:
        sleep(0.1)
    lcd.clear()
    lcd.putstr("Hold to Reset...")
    hold_time = 0
    while emergency_button.value():
        sleep(0.1)
    while emergency_button.value() == 0:
        hold_time += 0.1
        sleep(0.1)
        if hold_time >= 3:
            lcd.clear()
            lcd.putstr("Reset Complete")
            sleep(1)
            lcd.clear()
            lcd.putstr(f"At Floor {current_floor}")
            return

def handle_weight():
    global buzzer_active
    if weight_button.value() == 0:
        if not buzzer_active:
            buzzer_active = True
            buzzer.value(1)
            lcd.clear()
            lcd.putstr("Full Load Detected!")
        else:
            buzzer_active = False
            buzzer.value(0)
            lcd.clear()
            lcd.putstr("Load Reset!")
        sleep(0.5)

# === Initial State ===
current_floor = '0'
buzzer_active = False
last_button = 1
led_red.value(1)
led_green.value(0)
lcd.clear()
lcd.putstr("At Ground Floor")
clear_7seg()

# === Main Loop ===
while True:
    if emergency_button.value() == 0:
        handle_emergency()
        continue

    handle_weight()

    distance = read_distance()
    if distance and distance < 30:
        lcd.clear()
        lcd.putstr("Object Detected!")
        open_then_auto_close_door()
        sleep(2)

    key = scan_keypad()
    if key and key.isdigit():
        go_to_floor(key)

    current_button = door_button.value()
    if last_button and not current_button:
        open_then_auto_close_door()
    last_button = current_button

    sleep(0.05)