Module aws_lambda_powertools.utilities.parser.envelopes

class BaseEnvelope(ABC):
    """ABC implementation for creating a supported Envelope"""

    @staticmethod
    def _parse(data: Optional[Union[Dict[str, Any], Any]], model: Type[Model]) -> Union[Model, None]:
        """Parses envelope data against model provided

        Parameters
        ----------
        data : Dict
            Data to be parsed and validated
        model : Type[Model]
            Data model to parse and validate data against

        Returns
        -------
        Any
            Parsed data
        """
        if data is None:
            logger.debug("Skipping parsing as event is None")
            return data

        logger.debug("parsing event against model")
        if isinstance(data, str):
            logger.debug("parsing event as string")
            return model.parse_raw(data)

        return model.parse_obj(data)

    @abstractmethod
    def parse(self, data: Optional[Union[Dict[str, Any], Any]], model: Type[Model]):
        """Implementation to parse data against envelope model, then against the data model

        NOTE: Call `_parse` method to fully parse data with model provided.

        Example
        -------

        **EventBridge envelope implementation example**

        def parse(...):
            # 1. parses data against envelope model
            parsed_envelope = EventBridgeModel(**data)

            # 2. parses portion of data within the envelope against model
            return self._parse(data=parsed_envelope.detail, model=data_model)
        """
        return NotImplemented  # pragma: no cover

class CloudWatchLogsEnvelope(BaseEnvelope):
    """CloudWatch Envelope to extract a List of log records.

    The record's body parameter is a string (after being base64 decoded and gzipped),
    though it can also be a JSON encoded string.
    Regardless of its type it'll be parsed into a BaseModel object.

    Note: The record will be parsed the same way so if model is str
    """

    def parse(self, data: Optional[Union[Dict[str, Any], Any]], model: Type[Model]) -> List[Optional[Model]]:
        """Parses records found with model provided

        Parameters
        ----------
        data : Dict
            Lambda event to be parsed
        model : Type[Model]
            Data model provided to parse after extracting data using envelope

        Returns
        -------
        List
            List of records parsed with model provided
        """
        logger.debug(f"Parsing incoming data with SNS model {CloudWatchLogsModel}")
        parsed_envelope = CloudWatchLogsModel.parse_obj(data)
        logger.debug(f"Parsing CloudWatch records in `body` with {model}")
        return [
            self._parse(data=record.message, model=model) for record in parsed_envelope.awslogs.decoded_data.logEvents
        ]

class DynamoDBStreamEnvelope(BaseEnvelope):
    """DynamoDB Stream Envelope to extract data within NewImage/OldImage

    Note: Values are the parsed models. Images' values can also be None, and
    length of the list is the record's amount in the original event.
    """

    def parse(self, data: Optional[Union[Dict[str, Any], Any]], model: Type[Model]) -> List[Dict[str, Optional[Model]]]:
        """Parses DynamoDB Stream records found in either NewImage and OldImage with model provided

        Parameters
        ----------
        data : Dict
            Lambda event to be parsed
        model : Type[Model]
            Data model provided to parse after extracting data using envelope

        Returns
        -------
        List
            List of dictionaries with NewImage and OldImage records parsed with model provided
        """
        logger.debug(f"Parsing incoming data with DynamoDB Stream model {DynamoDBStreamModel}")
        parsed_envelope = DynamoDBStreamModel.parse_obj(data)
        logger.debug(f"Parsing DynamoDB Stream new and old records with {model}")
        return [
            {
                "NewImage": self._parse(data=record.dynamodb.NewImage, model=model),
                "OldImage": self._parse(data=record.dynamodb.OldImage, model=model),
            }
            for record in parsed_envelope.Records
        ]

class EventBridgeEnvelope(BaseEnvelope):
    """EventBridge envelope to extract data within detail key"""

    def parse(self, data: Optional[Union[Dict[str, Any], Any]], model: Type[Model]) -> Optional[Model]:
        """Parses data found with model provided

        Parameters
        ----------
        data : Dict
            Lambda event to be parsed
        model : Type[Model]
            Data model provided to parse after extracting data using envelope

        Returns
        -------
        Any
            Parsed detail payload with model provided
        """
        logger.debug(f"Parsing incoming data with EventBridge model {EventBridgeModel}")
        parsed_envelope = EventBridgeModel.parse_obj(data)
        logger.debug(f"Parsing event payload in `detail` with {model}")
        return self._parse(data=parsed_envelope.detail, model=model)

class KinesisDataStreamEnvelope(BaseEnvelope):
    """Kinesis Data Stream Envelope to extract array of Records

    The record's data parameter is a base64 encoded string which is parsed into a bytes array,
    though it can also be a JSON encoded string.
    Regardless of its type it'll be parsed into a BaseModel object.

    Note: Records will be parsed the same way so if model is str,
    all items in the list will be parsed as str and npt as JSON (and vice versa)
    """

    def parse(self, data: Optional[Union[Dict[str, Any], Any]], model: Type[Model]) -> List[Optional[Model]]:
        """Parses records found with model provided

        Parameters
        ----------
        data : Dict
            Lambda event to be parsed
        model : Type[Model]
            Data model provided to parse after extracting data using envelope

        Returns
        -------
        List
            List of records parsed with model provided
        """
        logger.debug(f"Parsing incoming data with Kinesis model {KinesisDataStreamModel}")
        parsed_envelope: KinesisDataStreamModel = KinesisDataStreamModel.parse_obj(data)
        logger.debug(f"Parsing Kinesis records in `body` with {model}")
        return [
            self._parse(data=record.kinesis.data.decode("utf-8"), model=model) for record in parsed_envelope.Records
        ]

class SnsEnvelope(BaseEnvelope):
    """SNS Envelope to extract array of Records

    The record's body parameter is a string, though it can also be a JSON encoded string.
    Regardless of its type it'll be parsed into a BaseModel object.

    Note: Records will be parsed the same way so if model is str,
    all items in the list will be parsed as str and npt as JSON (and vice versa)
    """

    def parse(self, data: Optional[Union[Dict[str, Any], Any]], model: Type[Model]) -> List[Optional[Model]]:
        """Parses records found with model provided

        Parameters
        ----------
        data : Dict
            Lambda event to be parsed
        model : Type[Model]
            Data model provided to parse after extracting data using envelope

        Returns
        -------
        List
            List of records parsed with model provided
        """
        logger.debug(f"Parsing incoming data with SNS model {SnsModel}")
        parsed_envelope = SnsModel.parse_obj(data)
        logger.debug(f"Parsing SNS records in `body` with {model}")
        return [self._parse(data=record.Sns.Message, model=model) for record in parsed_envelope.Records]

class SnsSqsEnvelope(BaseEnvelope):
    """SNS plus SQS Envelope to extract array of Records

    Published messages from SNS to SQS has a slightly different payload.
    Since SNS payload is marshalled into `Record` key in SQS, we have to:

    1. Parse SQS schema with incoming data
    2. Unmarshall SNS payload and parse against SNS Notification model not SNS/SNS Record
    3. Finally, parse provided model against payload extracted
    """

    def parse(self, data: Optional[Union[Dict[str, Any], Any]], model: Type[Model]) -> List[Optional[Model]]:
        """Parses records found with model provided

        Parameters
        ----------
        data : Dict
            Lambda event to be parsed
        model : Type[Model]
            Data model provided to parse after extracting data using envelope

        Returns
        -------
        List
            List of records parsed with model provided
        """
        logger.debug(f"Parsing incoming data with SQS model {SqsModel}")
        parsed_envelope = SqsModel.parse_obj(data)
        output = []
        for record in parsed_envelope.Records:
            sns_notification = SnsNotificationModel.parse_raw(record.body)
            output.append(self._parse(data=sns_notification.Message, model=model))
        return output

class SqsEnvelope(BaseEnvelope):
    """SQS Envelope to extract array of Records

    The record's body parameter is a string, though it can also be a JSON encoded string.
    Regardless of its type it'll be parsed into a BaseModel object.

    Note: Records will be parsed the same way so if model is str,
    all items in the list will be parsed as str and npt as JSON (and vice versa)
    """

    def parse(self, data: Optional[Union[Dict[str, Any], Any]], model: Type[Model]) -> List[Optional[Model]]:
        """Parses records found with model provided

        Parameters
        ----------
        data : Dict
            Lambda event to be parsed
        model : Type[Model]
            Data model provided to parse after extracting data using envelope

        Returns
        -------
        List
            List of records parsed with model provided
        """
        logger.debug(f"Parsing incoming data with SQS model {SqsModel}")
        parsed_envelope = SqsModel.parse_obj(data)
        logger.debug(f"Parsing SQS records in `body` with {model}")
        return [self._parse(data=record.body, model=model) for record in parsed_envelope.Records]