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# SPDX-License-Identifier: MIT-0
#
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import json
import traceback
import logging
import sys
from time import time


import dragino_lht65

# Setup  logging
logger = logging.getLogger("PayloadDecoder")
logger.setLevel(logging.INFO)


def lambda_handler(event, context):
    """ Transforms a binary payload by invoking "decode_{event.type}" function
        Parameters
        ----------
        DeviceId : str
            Device Id
        ApplicationId : int
            LoRaWAN Application Id / Port number
        PayloadData : str
            Base64 encoded input payload


        Returns
        -------
        This function returns a JSON object with the following keys:

        - status: 200 or 500
        - transformed_payload: result of calling "{PayloadDecoderName}.dict_from_payload"      (only if status == 200)
        - lns_payload: a representation of payload as received from an LNS
        - error_type                                                        (only if status == 500)
        - error_message                                                     (only if status == 500)
        - stackTrace                                                        (only if status == 500)


    """

    logger.info("Received event: %s" % json.dumps(event))

    input_base64 = event.get("PayloadData")
    device_id = event.get("WirelessDeviceId")
    metadata = event.get("WirelessMetadata")["LoRaWAN"]

    try:

        # Invoke a payload conversion function
        decoded_payload = dragino_lht65.dict_from_payload(
            event.get("PayloadData"))

        # Define the output of AWS Lambda function in case of successful decoding
        result = {
            "status": 200,
            "LNSData": {
                "PayloadData": input_base64,
                "WirelessDeviceId": device_id,
                "WirelessMetadata": {"LoRaWAN": metadata}
            },
            "TransformedPayloadData": decoded_payload
        }
        logger.info(result)
        return result

    except Exception as exp:

        logger.error(f"Exception {exp} during binary decoding")

        raise exp