"""One call to an OpenAI-compatible chat endpoint. Used only for summaries, and only when a switch is on."""
import json
import os
import urllib.request


def complete(cfg, system, user):
    c = cfg["llm"]
    if not c["endpoint"]:
        raise SystemExit("a summary switch is on but llm.endpoint is empty in settings.yaml")
    headers = {"Content-Type": "application/json"}
    if c.get("api_key_env"):
        headers["Authorization"] = "Bearer " + os.environ[c["api_key_env"]]
    body = {"model": c["model"], "temperature": 0,
            "messages": [{"role": "system", "content": system}, {"role": "user", "content": user}]}
    req = urllib.request.Request(c["endpoint"], json.dumps(body).encode(), headers)
    with urllib.request.urlopen(req, timeout=c["timeout_s"]) as r:
        return json.load(r)["choices"][0]["message"]["content"].strip()