"""Lambda function module."""
from typing import Dict
import uuid

import boto3
from botocore.errorfactory import ClientError
import config
from ddex_ingester_common.logging import utils as logging_utils
from ddex_ingester_common.schemas.state_machine_schema import (
    StateMachineSchema
)

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


def handler(event: Dict, context: Dict) -> Dict:
    """Lambda entrypoint."""
    state_machine_data = StateMachineSchema().load(event)
    correlation_id = state_machine_data.correlation_id or str(uuid.uuid4())
    state_machine_data.correlation_id = correlation_id

    logging_utils.update_logger_correlation_id(logger, correlation_id)
    logging_utils.update_logger_with_message_ids(
        logger,
        state_machine_data.message_id,
        state_machine_data.message_thread_id,
        state_machine_data.execution_name
    )

    upc = state_machine_data.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)
        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
        )

    return StateMachineSchema().dump(state_machine_data)


class LockfileExistsException(Exception):
    """Lockfile exists exception."""