Get a monthly Stripe tax summary in Slack

import stripe
from clickruntime import on_trigger, credentials, notify
import time
from datetime import date

@on_trigger
def run(event):
    stripe.api_key = credentials.secret("STRIPE_API_KEY")
    first = date.today().replace(day=1)
    start = first.replace(year=first.year - 1, month=12) if first.month == 1 else first.replace(month=first.month - 1)
    period = {"gte": int(time.mktime(start.timetuple())), "lt": int(time.mktime(first.timetuple()))}
    totals = {}
    for inv in stripe.Invoice.list(status="paid", created=period, limit=100, expand=["data.total_tax_amounts.tax_rate"]).auto_paging_iter():
        for t in inv.total_tax_amounts:
            rate = t.tax_rate
            key = (rate.display_name, rate.country or rate.jurisdiction or "-", f"{rate.percentage}%", inv.currency.upper())
            totals[key] = totals.get(key, 0) + t.amount / 100
    lines = [f"{name} {region} {pct}: {amount:,.2f} {cur}" for (name, region, pct, cur), amount in sorted(totals.items())]
    text = f"Tax collected {start:%B %Y}\n" + ("\n".join(lines) or "No tax on paid invoices")
    notify.slack(text, channel="#finance")
    notify.email_me(f"Stripe tax summary {start:%B %Y}", text)
    return {"lines": len(lines)}