"""Lambda function module for create_ingestion_lock."""
import boto3
from botocore.exceptions import ClientError
from common.schemas.state_machine_schema import StateMachineSchema

import config
from src.exceptions import LockfileExistsException

logger = config.app_logger
s3_client = boto3.client('s3')


def handler(event, context):
    """Create ingestion lock file."""
    logger.info(f'Triggered create_ingestion_lock: {event}')

    sm_context = StateMachineSchema().load(event)

    upc = sm_context.product.upc
    lockfile_key = f'{config.INGESTION_LOCK_S3_PATH}{upc}.lock'

    # Check if lockfile exists
    try:
        logger.info('Checking if lock exists')
        s3_client.head_object(
            Bucket=config.INGESTION_LOCK_S3_BUCKET,
            Key=lockfile_key,
            ExpectedBucketOwner=config.INGESTION_S3_EXPECTED_OWNER)
        msg = f'Lockfile exists: {lockfile_key}'
        logger.warn(msg)
        raise LockfileExistsException(msg)
    except ClientError:
        # Lockfile does not exist
        logger.info(f'Creating lockfile: {lockfile_key}')
        s3_client.put_object(
            Bucket=config.INGESTION_LOCK_S3_BUCKET,
            Key=lockfile_key,
            ExpectedBucketOwner=config.INGESTION_S3_EXPECTED_OWNER
        )

    return StateMachineSchema().dump(sm_context)