import datetime
import json
import time

from services.mqtt_service import MQTTService

class MQTTForwarder:

    _client_id : str
    _local_broker : MQTTService
    _central_broker : MQTTService
    _qos : int

    def __init__(self, client_id : str, src_mqtt: MQTTService, dst_mqtt: MQTTService, qos : int):
        self._client_id = client_id
        self._local_broker = src_mqtt
        self._central_broker = dst_mqtt
        self._qos = qos

    def start(self, src_topic: str, dst_topic: str, sensor_type: str):
        try:
            def forward_handler(topic: str, msg: str):
                forwarded_msg = self.__wrap_data(msg, sensor_type)
                self._central_broker.publish(dst_topic, forwarded_msg, self._qos)

            self._local_broker.subscribe(src_topic, forward_handler)
        except Exception as e:
            print(f"An error occurred while forwarding from {src_topic} to {dst_topic}: {e}")

    def __wrap_data(self, msg : str, sensor_type: str):
        print(repr(msg))
        result = {}
        data = json.loads(msg)
        result["timestamp"] = int(time.time())
        result["systemId"] = self._client_id
        result["type"] = sensor_type
        result["data"] = {}
        for keys in data:
            result["data"][keys] = data[keys]
        return json.dumps(result)