main_read_only.py

from gpiozero import LED, LightSensor
from time import sleep
from signal import pause
import paho.mqtt.client as mqtt
import socket

class Venue:
    def __init__(self, capacity, space=True):
        self._capacity = capacity
        self._space = True
        self._count = 0
    def person_entered(self):
        self._count += 1
    def person_left(self):
        self._count -= 1
    def get_count(self):
        return self._count
    def get_capacity(self):
        return self._capacity
    def get_space(self):
        return self._space
    def is_full(self):
        self._space = False
    def not_full(self):
        self._space = True
    def print_cur_visitors(self):
        print("there are ", self._count, " people at the venue")

ldr = LightSensor(4)
led = LED(2)
Hall = Venue(capacity=60) # create venue object and set venue capacity
broker_ip = "192.168.178.56"
own_name = socket.gethostname() # get hostname as ID for publishing
entrance_topic = "entrance/+/people"
exit_topic = "exit/+/people"

def on_msg_entered(client, userdata, message):
    print("one person has entered the venue")
    Hall.person_entered()
    Hall.print_cur_visitors()
    if Hall.get_count() >= Hall.get_capacity():
        Hall.is_full()
def on_msg_left(client, userdata, message):
    print("one person has left the venue")
    Hall.person_left()
    Hall.print_cur_visitors()
    if Hall.get_count() == Hall.get_capacity():
        Hall.not_full()

def on_connect(client, userdata, flags, rc):
    if rc==0:
        client.connected_flag = True
        print("connected OK Returned code = ",rc)
    else:
        print("Bad connection Returned code = ",rc)
        client.bad_connection_flag = True

def on_message(client, userdata, msg):
    print(msg.topic+" "+str(msg.payload)+"person entered")
def on_publish(client, userdata, topic):
    print("value published succesfully to: "+topic)
def on_log(client, userdata, level, buf):
    print("log: ",buf)

client = mqtt.Client(client_id=own_name, clean_session=False)
client.connected_flag = False
client.bad_connection_flag = False
client.on_connect = on_connect
client.on_message = on_message
client.on_log = on_log

client.message_callback_add(entrance_topic, on_msg_entered)
client.message_callback_add(exit_topic, on_msg_left)

client.connect(host=broker_ip)
client.loop_start()
client.subscribe(topic=entrance_topic)
while not client.connected_flag: #wait in loop
    print("waiting for connection ...")
    sleep(1)
if client.bad_connection_flag:
    client.loop_stop()    #Stop loop
    sys.exit()


# led.off()
interrupt = False


while True:
    # led.off()
    begin_full = True
    while not Hall.get_space():
        if begin_full:
            print("Die Halle ist derzeit voll.")
            print("Bitte haben sie Geduld.")
            # led.on()
            begin_full = False

sleep(5)
client.loop_stop()
pause()