"""Lambda function module."""

import json

from constants import common
import common_config
from constants import general
from constants import statuses
import dynamodb
import sentry


def prepare_dynamodb_item(event, s3_event, attachment_attrs):
    """Prepare item suitable for DynamoDB table.

    Args:
         event (dict): original SNS event
         s3_event (dict): original S3 event
         attachment_attrs (dict): parsed attachment attributes

    Returns:
        dict: item suitable for DynamoDB

    """
    s3_object = s3_event['Records'][0]['s3']['object']
    s3_bucket = s3_event['Records'][0]['s3']['bucket']
    key = s3_object.get('key')
    principal_id = s3_event['Records'][0]['userIdentity']['principalId']
    status = statuses.STATUS_FAIL
    principalId_status = '{}_{}'.format(principal_id, status)
    item = {
        'principalId_status': principalId_status,
        'file_key': key,
        'file_name': attachment_attrs.get('filename', key),
        'etag': s3_object['eTag'],
        'file_version': s3_object.get('versionId', 'No versionId.'),
        'file_size': s3_object['size'],
        'bucket_name': s3_bucket['name'],
        'principalId': principal_id,
        'status': status,
        'message': event,
        'event_time': s3_event['Records'][0]['eventTime'],
        'ttl': dynamodb.get_ttl_value_for_item(
            general.DYNAMODB_ERROR_RECORD_TTL),
    }
    return item


@sentry.sentry_capture_exception
def handler(event, context):
    """Lambda entry point."""
    if common_config.IGNORE_ALL_EVENTS is not None:
        common_config.logger.warning(common.IGNORE_MESSAGE)
        return
    common_config.logger.info('Starting to process SNS message')
    message = json.loads(event['Records'][0]['Sns']['Message'])
    s3_event = message.get('s3_event')
    # event by DLQ, ignore it
    if s3_event is None:
        common_config.logger.info('Ignoring DLQ event.')
        return

    attachment_attrs = message.get('attachment_attrs')
    item = prepare_dynamodb_item(event, s3_event, attachment_attrs)
    common_config.logger.info('Storing item in dynamodb.')
    dynamodb.put_item(common_config.DYNAMODB_TABLE_ERROR, item)
    common_config.logger.info('Done.')