"""Lambda handler for proxying request from SNS to StepFunction."""

import os
import json

import boto3

STATEMACHINE_ARN = os.environ.get('STATEMACHINE_ARN')
sfn_client = boto3.client('stepfunctions')


def index(event, context):
    """Lambda entry point.

    Args:
        event (dict): Information about uploaded image.
        context (dict): Environment state.

    Returns:
        dict: Dict with start execution results
    """

    response = sfn_client.start_execution(
        stateMachineArn=STATEMACHINE_ARN,
        input=json.dumps(event)
    )

    return {
        "statusCode": 200,
        "executionArn": response['executionArn']
    }