#! /usr/bin/python3
# ===================================================================
# IoT MQTT Test Subscriber
# This simulates MQTT subscribing IoT devices 
# ===================================================================

import user_interface as ui
import paho.mqtt.client as mqtt
import sys

broker = '192.168.1.77'
topic  = 'test/wifi/iot-01'


# -------------------------------------------------------------------
# ---- callbacks
# -------------------------------------------------------------------

# ---- callback when the client connects to the broker
# ----
# ---- 0: Connection successful
# ---- 1: Connection refused – incorrect protocol version
# ---- 2: Connection refused – invalid client identifier
# ---- 3: Connection refused – server unavailable
# ---- 4: Connection refused – bad username or password
# ---- 5: Connection refused – not authorised
# ---- 6-255: Currently unused.
# ----
# ---- also subscribe to the topic

def on_connect(client, userdata, flags, rc):
    print(f'Connected with result code {str(rc)}')
    client.subscribe(topic)

# ---- callback when a topic message is received from the broker

def on_message(client, userdata, msg):
    m = str(msg.payload.decode('utf-8'))
    print(f'received topic:{msg.topic}  msg:{m}')


# -------------------------------------------------------------------
# ---- main
# -------------------------------------------------------------------

# ---- running Python3

if not ui.running_python3():
    print()
    print('Must run Python3 - program exit')
    print()
    sys.exit()


print()
print('==================================================')
print(f'broker: {broker}')
print(f'topic : {topic}')
print('==================================================')
print()


# Create instance of client with client ID 'iot_mqtt_test'
client = mqtt.Client('iot_mqtt_test_sub')

# Define callback function for successful connection
client.on_connect = on_connect

# Define callback function for receipt of messages
# client.connect(broker, 1883, 60)
# Connect to (broker, port, keepalive-time)
client.on_message = on_message

client.connect(broker)

# Start networking daemon
client.loop_forever()

print('Disconnect ...')
client.disconnect()