import boto3
import json
import logging
import os

from base64 import b64decode
import requests

# The base-64 encoded, encrypted key (CiphertextBlob) stored in the kmsEncryptedHookUrl environment variable
ENCRYPTED_HOOK_URL = os.environ['kmsEncryptedHookUrl']
# The Slack channel to send a message to stored in the slackChannel environment variable
SLACK_CHANNEL = os.environ['slackChannel']

slack_url = boto3.client('kms').decrypt(CiphertextBlob=b64decode(ENCRYPTED_HOOK_URL))['Plaintext']
HOOK_URL = "https://" + slack_url.decode('utf-8')

logger = logging.getLogger()
logger.setLevel(logging.INFO)

def lambda_handler(event, context):
    for record in event['Records']:
      payload=b64decode(record["kinesis"]["data"])
      db_event = json.loads(payload.decode('utf-8'))
      logger.info("Decoded payload: " + payload.decode('utf-8'))
      
      # Send Maxwell event to Slack
      slack_message = {
        'channel': SLACK_CHANNEL,
        'text': "`" + payload.decode('utf-8') + "` TABLE: `" + db_event["table"] + "` VALUE: `" + db_event["data"]["value"] + "`"
      }
      
      r = requests.post(HOOK_URL, data=json.dumps(slack_message))
      r.raise_for_status()
      logger.info("Message posted to %s", slack_message['channel'])