Add event sign-ups to a sheet and send a confirmation

import base64
from email.message import EmailMessage
from google.oauth2.credentials import Credentials
from googleapiclient.discovery import build
from clickruntime import on_event, credentials, state

SHEET_ID = "your-spreadsheet-id"

@on_event
def handle(event):
    if state.get(event.event_id):
        return {"skipped": "duplicate"}
    p = event.json
    creds = Credentials(credentials.connection("google", "work"))
    build("sheets", "v4", credentials=creds, cache_discovery=False).spreadsheets().values().append(
        spreadsheetId=SHEET_ID, range="Attendees!A:C", valueInputOption="USER_ENTERED",
        body={"values": [[p["name"], p["email"], event.received_at]]}).execute()
    msg = EmailMessage()
    msg["To"], msg["Subject"] = p["email"], "You're booked for the Spring Workshop"
    msg.set_content(f"Hi {p['name']},\n\nYour place is confirmed for 14 May, 6pm at Northwind Hall.\n\nSee you there.")
    raw = base64.urlsafe_b64encode(msg.as_bytes()).decode()
    build("gmail", "v1", credentials=creds, cache_discovery=False).users().messages().send(userId="me", body={"raw": raw}).execute()
    state.set(event.event_id, True)
    return {"registered": p["email"]}