from machine import Pin, I2C, ADC, PWM
import time
import dht
import network

# LCD2004 I2C 
class I2cLcd:
    LCD_CLR = 0x01
    LCD_SET_DDRAM = 0x80

    def __init__(self, i2c, addr):
        self.i2c = i2c
        self.addr = addr
        self.backlight = 0x08
        self.EN = 0x04
        self.RS = 0x01

        time.sleep_ms(50)
        self._write_init()
        self.command(0x28)
        self.command(0x0C)
        self.command(0x06)
        self.clear()

    def _i2c_write(self, data):
        self.i2c.writeto(self.addr, bytes([data | self.backlight]))

    def _pulse_enable(self, data):
        self._i2c_write(data | self.EN)
        time.sleep_us(1)
        self._i2c_write(data & ~self.EN)
        time.sleep_us(50)

    def _write4(self, nibble, mode=0):
        data = (nibble & 0xF0) | mode
        self._i2c_write(data)
        self._pulse_enable(data)

    def _write_init(self):
        self._write4(0x30)
        time.sleep_ms(5)
        self._write4(0x30)
        time.sleep_us(150)
        self._write4(0x30)
        self._write4(0x20)

    def command(self, cmd):
        self._write4(cmd & 0xF0, 0)
        self._write4((cmd << 4) & 0xF0, 0)

    def write_char(self, ch):
        self._write4(ord(ch) & 0xF0, self.RS)
        self._write4((ord(ch) << 4) & 0xF0, self.RS)

    def putstr(self, s):
        for ch in s:
            self.write_char(ch)

    def clear(self):
        self.command(self.LCD_CLR)
        time.sleep_ms(2)

    def move_to(self, col, row):
        offsets = [0x00, 0x40, 0x14, 0x54]
        self.command(self.LCD_SET_DDRAM | (col + offsets[row]))


# PIN SETUP

i2c = I2C(0, sda=Pin(0), scl=Pin(1), freq=400000)
devices = i2c.scan()
if not devices:
    raise RuntimeError("LCD not found!")
lcd = I2cLcd(i2c, devices[0])

dht_sensor = dht.DHT22(Pin(15))
ldr = ADC(Pin(26))
pir = Pin(17, Pin.IN)

relay = Pin(16, Pin.OUT)

btn_mode = Pin(7, Pin.IN, Pin.PULL_UP)
btn_on = Pin(8, Pin.IN, Pin.PULL_UP)
btn_off = Pin(6, Pin.IN, Pin.PULL_UP)

led_temp = Pin(10, Pin.OUT)
led_motion = Pin(11, Pin.OUT)
led_relay = Pin(12, Pin.OUT)

buzzer = PWM(Pin(13))
buzzer.freq(2000)
buzzer.duty_u16(0)

# WIFI CONNECT (WOKWI)

WIFI_SSID = "Wokwi-GUEST"
WIFI_PASS = ""

wlan = network.WLAN(network.STA_IF)
wlan.active(True)

print("Connecting to WiFi...")
wlan.connect(WIFI_SSID, WIFI_PASS)

timeout = 10
start = time.time()

while not wlan.isconnected():
    if time.time() - start > timeout:
        print("WiFi Failed!")
        break
    time.sleep(0.5)

if wlan.isconnected():
    ip = wlan.ifconfig()[0]
    print("WiFi Connected! IP:", ip)
else:
    print("Not connected.")

# SYSTEM VARIABLES

auto_mode = False
manual_state = False
light_threshold = 25000
temp_threshold = 35
last_motion = time.ticks_ms()

# FUNCTIONS

def beep(freq=2000, ms=120):
    buzzer.freq(freq)
    buzzer.duty_u16(30000)
    time.sleep_ms(ms)
    buzzer.duty_u16(0)

# MAIN LOOP

while True:

    # Button control
    if btn_mode.value() == 0:
        auto_mode = not auto_mode
        beep(2200, 80)
        time.sleep(0.3)

    if btn_on.value() == 0:
        auto_mode = False
        manual_state = True
        beep(2400, 80)
        time.sleep(0.3)

    if btn_off.value() == 0:
        auto_mode = False
        manual_state = False
        beep(1800, 80)
        time.sleep(0.3)

    # Read sensors
    try:
        dht_sensor.measure()
        t = dht_sensor.temperature()
        h = dht_sensor.humidity()
    except:
        t = 0
        h = 0

    light = ldr.read_u16()
    motion = pir.value()

    if motion:
        last_motion = time.ticks_ms()

    is_dark = light < light_threshold

    # Relay logic
    if auto_mode:
        if is_dark and motion:
            relay.value(1)
        else:
            idle = time.ticks_diff(time.ticks_ms(), last_motion) / 1000
            if idle > 30:
                relay.value(0)
    else:
        relay.value(1 if manual_state else 0)

    # LEDs
    led_temp.value(1 if t >= temp_threshold else 0)
    led_motion.value(motion)
    led_relay.value(relay.value())

    # Alarm
    if t >= temp_threshold:
        beep(1800, 150)

    # LCD display
    lcd.clear()
    lcd.move_to(0, 0)
    lcd.putstr("Smart Home WiFi")
    lcd.move_to(0, 1)
    lcd.putstr("T:{:.1f}C H:{:.1f}%".format(t, h))
    lcd.move_to(0, 2)
    lcd.putstr("Light:{} PIR:{}".format(light, motion))
    lcd.move_to(0, 3)
    lcd.putstr("Relay:{} Auto:{}".format(
        "ON" if relay.value() else "OFF",
        "ON" if auto_mode else "OFF"
    ))

    time.sleep(1)