"""Python implementation for deserializing a dynamo db streams image.

This codebase and its tests should be updated prior to making
any Snowflake database PRs to update the UDF.
"""

from typing import Any

from boto3.dynamodb.types import TypeDeserializer


def _clean_dynamodb_streams_image(item: Any) -> Any:
    """Clean a DynamoDBStreams Image."""
    if isinstance(item, dict):
        if "type" in item:
            return {
                item["type"]: _clean_dynamodb_streams_image(item[item["type"].lower()])
            }
        cleaned_dict = {}
        for key, val in item.items():
            cleaned_dict[key] = _clean_dynamodb_streams_image(val)
        return cleaned_dict
    elif isinstance(item, list):
        cleaned_list = []
        for li in item:
            cleaned_list.append(_clean_dynamodb_streams_image(li))
        return cleaned_list

    return item


def udf_entrypoint(obj: Any) -> Any:
    """Deserializes a DynamoDBStreams Image into a Python Dict."""
    dynamo_item = _clean_dynamodb_streams_image(obj)
    return TypeDeserializer().deserialize({"M": dynamo_item})