server/backend/mlmAccess.py

import paho.mqtt.client as mqtt
from dbHelper import MaDbHelper
import random
import string

class MlmAccess:
    def __init__(self):
        self._initDb()
        self._initMqtt()

    def _initDb(self):
        self.db = MaDbHelper()
        initUsers = [
            ("backend", "backend", ["mlmAccess/#"], ["mlmAccess/#"]),
            ("pair-actor", "pair-actor", ["mlmAccess/pair/request/actor"], ["mlmAccess/pair/response/actor"])
        ]

        for username, password, publishAclPatterns, subscribeAclPatterns in initUsers:
            if not self.db.addUser(username, password, publishAclPatterns, subscribeAclPatterns):
                self.db.updateUser(username, password, publishAclPatterns, subscribeAclPatterns)

    def _initMqtt(self):
        self.mqtt = client = mqtt.Client(client_id="backend")
        self.mqtt.username_pw_set("backend", "backend")

        self.mqtt.on_connect = self._mqttOnConnect
        self.mqtt.on_message = self._mqttOnMessage

        print("connecting to broker")
        print(self.mqtt.connect("localhost", 1883, 60))

        self.mqtt.loop_forever()

    def _handleActorPairRequest(self, id):
        print(f"Pair request for type actor with ID {id}")
        if not self.db.userExists(f"actor-{id}"):
            password = ''.join(random.choices(string.ascii_uppercase + string.digits, k=10))
            self.db.addUser(f"actor-{id}", password, [f"mlmAccess/actor/{id}/status"], [f"mlmAccess/actor/{id}/action"])

            self.mqtt.publish("mlmAccess/pair/response/actor", password)
        else:
            self.mqtt.publish("mlmAccess/pair/response/actor", "")

    def _mqttOnConnect(self, client, userdata, flags, rc):
        print("Connected with result code "+str(rc))

        if rc != 0:
            print("")

        print(client.subscribe("mlmAccess/pair/request/actor"))

    def _mqttOnMessage(self, client, userdata, message):
        if message.topic == "mlmAccess/pair/request/actor":
            self._handleActorPairRequest(str(message.payload.decode("utf-8")))



if __name__ == "__main__":
    MlmAccess()