#ADRIANA SARAH // INDIVIDUAL PROJECT

import network
import time
import ujson
import ubinascii
import machine
from machine import Pin, I2C
from umqtt.simple import MQTTClient
from ssd1306 import SSD1306_I2C  # OLED library

# MQTT Server Parameters
MQTT_CLIENT_ID = ubinascii.hexlify(machine.unique_id()).decode()
MQTT_BROKER = "broker.mqtt.cool"
MQTT_TOPIC_SEAT = "teddy/bus/seats"

# WiFi Setup
SSID = "Wokwi-GUEST"
PASSWORD = ""

# Connect to WiFi
print("Connecting to WiFi...", end="")
sta_if = network.WLAN(network.STA_IF)
sta_if.active(True)
sta_if.connect(SSID, PASSWORD)

while not sta_if.isconnected():
    print(".", end="")
    time.sleep(0.1)
print(" Connected!")

# Add delay for stability
time.sleep(2)

# Connect to MQTT Broker with error handling
print("Connecting to MQTT server...", end="")
try:
    client = MQTTClient(MQTT_CLIENT_ID, MQTT_BROKER)  # Removed authentication
    client.connect()
    print(" Connected!")
except Exception as e:
    print("MQTT Connection Failed:", str(e))

# GPIO Setup
btn_board = Pin(18, Pin.IN, Pin.PULL_UP)  # Boarding button
btn_exit = Pin(19, Pin.IN, Pin.PULL_UP)  # Exiting button
led_reserved = Pin(5, Pin.OUT)  # Red LED (Reserved seat)
led_available = Pin(4, Pin.OUT)  # Green LED (Available seat)
buzzer = Pin(13, Pin.OUT)  # Buzzer

# I2C & OLED Display Setup
i2c = I2C(0, scl=Pin(22), sda=Pin(21))
oled = SSD1306_I2C(128, 64, i2c)

seats_available = 10  # Number of available seats

# Function to Update OLED Display
def update_oled():
    oled.fill(0)  # Clear screen
    oled.text("Seats Available:", 0, 10)
    oled.text(f"{seats_available}", 40, 30)
    oled.show()

update_oled()  # Initial screen display

# Function: Reserve a Seat
def reserve_seat(pin):
    global seats_available
    if seats_available > 0:
        seats_available -= 1
        led_reserved.on()
        led_available.off()
        buzzer.on()
        time.sleep(0.5)
        buzzer.off()
        print("Seat Reserved!")
        message = ujson.dumps({"status": "Reserved", "available_seats": seats_available})
        client.publish(MQTT_TOPIC_SEAT, message)
        update_oled()

# Function: Free a Seat
def free_seat(pin):
    global seats_available
    if seats_available < 10:
        seats_available += 1
        led_reserved.off()
        led_available.on()
        buzzer.on()
        time.sleep(0.5)
        buzzer.off()
        print("Seat Freed!")
        message = ujson.dumps({"status": "Available", "available_seats": seats_available})
        client.publish(MQTT_TOPIC_SEAT, message)
        update_oled()

# Attach Interrupts to Buttons
btn_board.irq(trigger=Pin.IRQ_FALLING, handler=reserve_seat)
btn_exit.irq(trigger=Pin.IRQ_FALLING, handler=free_seat)

# Keep Script Running
while True:
    time.sleep(1)