import paho.mqtt.client as mqtt
import uuid
import time
import threading
import socket

class MqttClient:
    """
    Handles the connection and message processing for a single MQTT station.
    This is a standard Python class, with no GUI dependencies.
    """
    def __init__(self, broker, port, user, password, station_id, on_message_callback):
        self.broker = broker
        self.port = port
        self.user = user
        self.password = password
        self.station_id = station_id
        self.on_message_callback = on_message_callback

        unique_id = str(uuid.uuid4())
        self.client_id = f"WebApp-Backend-{self.station_id}-{unique_id}"

        self.client = mqtt.Client(mqtt.CallbackAPIVersion.VERSION2, self.client_id)
        
        # Assign callback functions
        self.client.on_connect = self.on_connect
        self.client.on_message = self.on_message
        self.client.on_disconnect = self.on_disconnect

        if self.user and self.password:
            self.client.username_pw_set(self.user, self.password)

        self.is_connected = False
        self.reconnect_delay = 1
        self.max_reconnect_delay = 60
        self.stop_thread = False

    # --- CORRECTED CALLBACK SIGNATURES ---
    def on_connect(self, client, userdata, flags, reason_code, properties):
        """Callback for when the client connects to the broker."""
        if reason_code == 0:
            self.is_connected = True
            self.reconnect_delay = 1
            print(f"Successfully connected to MQTT broker for station: {self.station_id}")
            topic_base = f"VEC/batterySmartStation/v100/{self.station_id}/#"
            # topic_base = f"VEC/batterySmartStation/v100/+/+"
            self.client.subscribe(topic_base)
            print(f"Subscribed to: {topic_base}")
        else:
            print(f"Failed to connect to MQTT for station {self.station_id}, return code {reason_code}")

    def on_disconnect(self, client, userdata, disconnect_flags, reason_code, properties):
        """Callback for when the client disconnects."""
        print(f"Disconnected from MQTT for station {self.station_id}. Will attempt to reconnect...")

    def on_message(self, client, userdata, msg):
        """Callback for when a message is received from the broker."""
        try:
            self.on_message_callback(self.station_id, msg.topic, msg.payload)
        except Exception as e:
            print(f"Error processing message in callback for topic {msg.topic}: {e}")

    def connect(self):
        """Connects the client to the MQTT broker."""
        print(f"Attempting to connect to {self.broker}:{self.port} with client ID: {self.client_id}")
        try:
            self.client.connect(self.broker, self.port, 60)
        except Exception as e:
            print(f"Error connecting to MQTT for station {self.station_id}: {e}")

    def start(self):
        """Starts the MQTT client's network loop in a separate thread."""
        self.connect()
        self.client.loop_start()

    def stop(self):
        """Stops the MQTT client's network loop."""
        print(f"Stopping MQTT client for station: {self.station_id}")
        self.client.loop_stop()