Get an email when a PagerDuty incident changes

from datetime import datetime, timedelta, timezone
from clickruntime import on_trigger, credentials, http, notify, state, report_fetched

PD = "https://api.pagerduty.com"

def pd(path, **params):
    resp = http.get(f"{PD}{path}", params=params, headers={"Authorization": f"Token token={credentials.secret('PAGERDUTY_API_KEY')}",
                    "Accept": "application/json"})
    resp.raise_for_status()
    return resp.json()

@on_trigger
def run(event):
    since = (datetime.now(timezone.utc) - timedelta(days=2)).isoformat()
    incidents = pd("/incidents", since=since, limit=100)["incidents"]
    known = state.get("statuses") or {}
    changed = [i for i in incidents if known.get(i["id"]) != i["status"]]
    report_fetched(len(changed))
    if not changed:
        return {"changed": 0}
    for i in changed:
        who = ", ".join(a["assignee"]["summary"] for a in i.get("assignments", [])) or "unassigned"
        notify.email_me(f"[{i['status']}] {i['title']}", f"Service: {i['service']['summary']}\nUrgency: {i['urgency']}\n"
                        f"Assigned: {who}\n{i['html_url']}")
        known[i["id"]] = i["status"]
    state.set("statuses", {i["id"]: known[i["id"]] for i in incidents if i["id"] in known})
    return {"changed": len(changed)}