"""Lambda av_scan function module.

you can run locally with something like:
CLAMSCAN_PATH='/usr/local/Cellar/clamav/0.102.2/bin/clamscan' \
PYTHONPATH=. env/bin/python3.8 index.py
"""

import src.av_scan as av_scan
from src.handle_result.handle_result import handle_result
from lambdacommon.common_config import logger
import src.s3 as s3


def extract_triggered_key(event):
    """Get S3 bucket and key from CloudWatch or Eventbridge event.

    Args:
        event (dict): AWS CloudWatch or Eventbridge event data object.
    Returns:
         (str, str): Tuple of bucket and key names.

    """
    if not event.get('detail'):
        raise Exception('Invalid event. Cannot scan this file.')

    if event['detail'].get('requestParameters'):
        # this is cloudwatch event
        request_params = event['detail']['requestParameters']
        bucket_name = request_params.get('bucketName')
        key = request_params.get('key')
        return bucket_name, key
    if event['detail'].get('bucket') and event['detail'].get('object'):
        # this is Eventbridge event
        bucket_name = event['detail']['bucket']['name']
        key = event['detail']['object']['key']
        return bucket_name, key


def handler(event, context):
    """Lambda entry point."""
    try:
        bucket, key = extract_triggered_key(event)
        s3_obj = s3.get_object(bucket=bucket, key=key)
        file_contents = s3_obj['Body'].read()
        file_metadata = s3_obj['Metadata']
        result = av_scan.scan_string_for_virus(file_contents)
        if result == 1 and event.get('delete', True) is True:
            s3.delete_object(bucket=bucket, key=key)
        handle_result(bucket, key, result, file_metadata)
        return {'has_virus': False if result == 0 else True}
    except Exception as e:
        logger.exception(str(e))
        raise e


if __name__ == '__main__':
    handler({
        'detail': {
            'requestParameters': {
                'bucketName': 'dev-orcd-podcast-output-assets',
                'key': 'copies/safe.pdf'
            }
        }
    }, None)

    handler({
        'detail': {
            'requestParameters': {
                'bucketName': 'dev-orcd-podcast-output-assets',
                'key': 'copies/eicar.pdf'
            }
        },
        'delete': False
    }, None)

    handler({
        'detail': {
            'requestParameters': {
                'bucketName': 'test-orcd-bucket',
                'key': 'nr-ingestion/valid_test1.csv'
            }
        }
    }, None)