import json
import boto3

from datetime import datetime, timedelta

scheduler_client = boto3.client('scheduler')

#schedule the EventBridge Schedule to run 5 min from now
schedule_time = datetime.now() + timedelta(minutes=5)

#these values come from the EventBridge schedule itself
event_scheduler_name = 'MY_EVENT_NAME'
target_arn = 'MY_TARGET_ARN'
role_arn = 'MY_ROLE_ARN'

def lambda_handler(event, context):

    scheduler_client.update_schedule(Name=event_scheduler_name,
                                     ScheduleExpression=f'cron({schedule_time.minute} {schedule_time.hour} {schedule_time.day} {schedule_time.month} ? {schedule_time.year})',
                                     FlexibleTimeWindow={
                                        'MaximumWindowInMinutes': 1,
                                        'Mode': 'FLEXIBLE'
                                     },
                                     Target={
                                         'Arn': target_arn,
                                         'RoleArn': role_arn
                                     })

    return {
        'statusCode': 200,
        'body': json.dumps('Working!')
    }