import json
import boto3

s3 = boto3.client('s3')

# Below Lambda function will help to retrieve S3 objects that was deleted in a versioning-enabled bucket.
# Note: This function will only retrieve S3 Objects which has Delete Marker as Latest Version

# Specify the S3 Bucket Name
bucket = 'bucket-name'

# Specify the prefix to limit the search to the key name prefix
# Example with Prefix Value: prefixValue = 'folder1/folder2/filename.jpg'
# Or leave it empty with quotes to restore the whole S3 Bucket
# Example with Empty Value: prefixValue = ''
prefixValue = 'folder1/folder2/filename.jpg'
prefixStr = f'with prefix value "{prefixValue}"' if len(prefixValue) > 0 else f''


def lambda_handler(event, context):
    # Get the bucket name and prefix from the S3 event
    # bucket = event['Records'][0]['s3']['bucket']['name']
    # prefixValue = event['Records'][0]['s3']['object']['key']

    try:
        versions = s3.list_object_versions(Bucket=bucket, Prefix=prefixValue)
        objectWithLatestDeleteMarker = []
        if 'DeleteMarkers' in versions:
            for version in versions['DeleteMarkers']:
                if version['IsLatest']:
                    objectWithLatestDeleteMarker.append({
                        'Key': version['Key'],
                        'VersionId': version['VersionId']
                    })

            if len(objectWithLatestDeleteMarker) > 0:
                # Performs Single Delete Request with all the identified S3 Objects with latest DeleteMarker; Max 1000 Objects per request.
                s3.delete_objects(
                    Bucket=bucket,
                    Delete={
                        'Objects': objectWithLatestDeleteMarker,
                        'Quiet': True
                    }
                )
                return {
                    'statusCode': 200,
                    'body': json.dumps(
                        f'Success: retrieved "{len(objectWithLatestDeleteMarker)}" S3 object(s) from bucket "{bucket}" {prefixStr}')
                }
            else:
                return {
                    'statusCode': 200,
                    'body': json.dumps(
                        f'There is no S3 object(s) with Delete Marker as Latest Version in your bucket "{bucket}" {prefixStr}')
                }
        else:
            return {
                'statusCode': 200,
                'body': json.dumps(
                    f'There is no S3 object(s) with Delete Marker as Latest Version in your bucket "{bucket}" {prefixStr}')
            }
    except Exception as e:
        print(e)
        print(
            f'Error: while retrieving the S3 object(s) from bucket "{bucket}" {prefixStr}')
        raise e