import network
import time
import socket
import struct
import random

BROKER = "broker.hivemq.com"
PORT = 1883
CLIENT_ID = b"bridge_node1_final"

client = None

def connect_wifi():
    wlan = network.WLAN(network.STA_IF)
    wlan.active(True)
    
    if not wlan.isconnected():
        print("Connecting to WiFi...")
        wlan.connect("Wokwi-GUEST", "")
        
        while not wlan.isconnected():
            time.sleep(1)
            
    print("WiFi Connected!")

def connect_mqtt():
    global client

    client = socket.socket()
    client.settimeout(10)

    address = socket.getaddrinfo(BROKER, PORT)[0][-1]
    client.connect(address)

    packet = b"\x10" + bytes([12 + len(CLIENT_ID)])
    packet += b"\x00\x04MQTT\x04\x02\x00\x3c"
    packet += bytes([0, len(CLIENT_ID)]) + CLIENT_ID

    client.send(packet)
    response = client.recv(4)

    if response[0] == 0x20 and response[3] == 0:
        print("MQTT Connected Successfully!")
    else:
        raise Exception("MQTT connection failed")

def publish(topic, message):
    topic_bytes = topic.encode()
    msg_bytes = str(message).encode()

    length = 2 + len(topic_bytes) + len(msg_bytes)
    packet = b"\x30" + bytes([length])
    packet += struct.pack("!H", len(topic_bytes))
    packet += topic_bytes + msg_bytes

    client.send(packet)
    print(f"Published [{topic}]: {message}")

# ---------------- MAIN PROGRAM ----------------
print("SMART BRIDGE - NODE 1 (ALL SENSORS)")

while True:
    try:
        connect_wifi()
        
        if client is None:
            connect_mqtt()

        # Read/Simulate all three sensors on Node 1
        vibration = random.randint(10, 100)
        temperature = random.randint(25, 60)
        strain = random.randint(100, 800)

        # Publish each sensor reading to its respective topic
        publish("bridge/node1/vibration", vibration)
        publish("bridge/node1/temperature", temperature)
        publish("bridge/node1/strain", strain)

        print("----------------------")
        time.sleep(5)

    except Exception as error:
        print("Connection Error:", error)

        if client is not None:
            try:
                client.close()
            except:
                pass
            client = None

        print("Reconnecting in 3 seconds...")
        time.sleep(3)