app.py

import threading
from collections import deque
import gradio as gr
import paho.mqtt.client as mqtt
import json
import pandas as pd
from datetime import datetime
import plotly.express as px

# Data buffer to store received weight data
data_buffer = deque(maxlen=100)

# MQTT client and configuration variables
client = mqtt.Client()
MQTT_BROKER = ""
MQTT_PORT = 8883
MQTT_TOPIC = "FX-120i/e6613008e3659f2f"
MQTT_USERNAME = ""
MQTT_PASSWORD = ""

# Global variables to track connection and data status
connection_status = "❌ Not connected"
data_status = "⌛ Waiting for data..."

# Mutex for thread-safe status updates
status_lock = threading.Lock()

def get_status():
    """
    Returns the current status of the MQTT connection and data reception.
    """
    with status_lock:
        return f"**MQTT Connection:** {connection_status}\n**Data Status:** {data_status}"

def update_data_status(new_status):
    """
    Safely updates the data reception status.
    """
    global data_status
    with status_lock:
        data_status = new_status

def on_connect(client, userdata, flags, rc):
    """
    Callback for MQTT connection events.
    """
    global connection_status
    if rc == 0:
        client.subscribe(MQTT_TOPIC)
        connection_status = "✅ Connected"
    else:
        connection_status = f"❌ Connection failed (code {rc})"

def on_message(client, userdata, msg):
    """
    Callback for processing incoming MQTT messages.
    """
    global data_status
    try:
        payload = json.loads(msg.payload.decode())
        weight = float(payload["Current Weight"].replace('g', '').strip().replace('+', ''))
        timestamp = f"{payload['Date']} {payload['Time']}"
        dt = datetime.strptime(timestamp, "%Y-%m-%d %H:%M:%S")
        data_buffer.append({'timestamp': dt, 'weight': weight})
        update_data_status("✅ Receiving data")
        
        # Reset the inactivity timer
        reset_inactivity_timer()
    except Exception as e:
        print(f"Error processing message: {e}")

def connect_mqtt(hivemq_host, username, password):
    """
    Connects to the MQTT broker with the provided credentials.
    """
    global MQTT_BROKER, MQTT_USERNAME, MQTT_PASSWORD, connection_status
    
    try:
        MQTT_BROKER = hivemq_host
        MQTT_USERNAME = username
        MQTT_PASSWORD = password
        
        client.username_pw_set(MQTT_USERNAME, MQTT_PASSWORD)
        if not client._ssl:
            client.tls_set()
        
        client.on_connect = on_connect
        client.on_message = on_message
        client.connect(MQTT_BROKER, MQTT_PORT, 60)
        client.loop_start()

    except Exception as e:
        connection_status = f"❌ Connection error: {str(e)}"
        return f"Connection error: {str(e)}"

# Inactivity timer
inactivity_timer = None

def reset_inactivity_timer():
    """
    Resets the inactivity timer to monitor data reception.
    """
    global inactivity_timer
    if inactivity_timer is not None:
        inactivity_timer.cancel()
    inactivity_timer = threading.Timer(5.0, on_inactivity)
    inactivity_timer.start()

def on_inactivity():
    """
    Callback for when no data is received within the timeout period.
    """
    update_data_status("⌛ Waiting for data...")

def update_graph():
    """
    Updates the Plotly graph with the latest data from the data buffer.
    """
    if not data_buffer:
        fig = px.line(title="Waiting for Data...")
    else:
        df = pd.DataFrame(list(data_buffer))
        fig = px.line(df, x='timestamp', y='weight', title="Weight Over Time")
        fig.update_layout(
            xaxis=dict(
                type="date",
                tickformat="%H:%M:%S",
                title="Time"
            ),
            yaxis=dict(title="Weight (g)")
        )
    return fig

# Gradio application interface
with gr.Blocks() as app:
    gr.Markdown("# Weight Monitor")
    gr.Markdown("## Connect to MQTT")
    
    # Input fields for HiveMQ connection
    with gr.Row():
        hivemq_host = gr.Textbox(
            label="HiveMQ Host:",
            value="248cc294c37642359297f75b7b023374.s2.eu.hivemq.cloud"
        )
        mqtt_username = gr.Textbox(
            label="HiveMQ Username:",
            value="sgbaird"
        )
        mqtt_password = gr.Textbox(
            label="HiveMQ Password:",
            value="D.Pq5gYtejYbU#L",
            type="password"
        )
    
    # Connect button
    connect_button = gr.Button("Connect")
    
    # Status indicator
    status_md = gr.Markdown(
        get_status,
        every = 10  # Update status every 10 seconds
    )
    
    # Graph display with auto-refresh
    plot = gr.Plot(
        update_graph,
        every = 2.5  # Updates every 2.5 seconds
    )
    
    # Connect button action
    connect_button.click(
        fn=connect_mqtt,
        inputs=[hivemq_host, mqtt_username, mqtt_password],
        outputs=gr.Markdown()  # Show connection result
    )

if __name__ == "__main__":
    app.launch()