"""usage of the hosted server from Horizon's records: calls, errors, latency, clients.

    HORIZON_API_KEY=… uv run --no-project python scripts/usage.py [--days 7]
"""

from __future__ import annotations

import argparse
import json
import os
import sys
import urllib.parse
import urllib.request
from collections import Counter
from datetime import UTC, datetime, timedelta

API = "https://horizon.prefect.io/api/v0"
ORG = "ead2665d-917e-495b-94cf-29e4918382c3"
PROJECT = "1ffb780e-002f-45e4-8e37-ea3a28cf78e5"


def api(path: str, **params) -> dict:
    url = f"{API}{path}?{urllib.parse.urlencode({k: v for k, v in params.items() if v is not None})}"
    req = urllib.request.Request(url, headers={"authorization": f"Bearer {os.environ['HORIZON_API_KEY']}"})
    with urllib.request.urlopen(req, timeout=60) as r:
        return json.loads(r.read())


def main() -> int:
    ap = argparse.ArgumentParser()
    ap.add_argument("--days", type=int, default=7)
    args = ap.parse_args()
    if "HORIZON_API_KEY" not in os.environ:
        sys.exit("HORIZON_API_KEY is not set")
    end = datetime.now(UTC)
    start = end - timedelta(days=args.days)
    s, e = start.isoformat(timespec="seconds"), end.isoformat(timespec="seconds")
    base = f"/organizations/{ORG}/projects/{PROJECT}/targets"
    target = api(base)["items"][0]["id"]

    summary = api(f"{base}/{target}/usage/summary", start=s, end=e)
    print(f"last {args.days}d: {summary['calls']} calls, error rate {summary['errorRate']:.1%}, p95 {summary['p95Ms'] / 1000:.1f}s")
    for t in api(f"{base}/{target}/usage/tools", start=s, end=e)["items"]:
        print(f"  {t['name']:<16} {t['calls']:>5} calls  errors {t['errorRate']:.0%}  p95 {t['p95Ms'] / 1000:.1f}s")

    clients: Counter = Counter()
    cursor = None
    while True:
        page = api(f"{base}/{target}/logs", startDate=s, endDate=e, limit=200, cursor=cursor)
        for item in page.get("items", []):
            if (item.get("mcp") or {}).get("method") != "tools/call":
                continue
            client = (item.get("mcp") or {}).get("client") or {}
            clients[client.get("name") or (item.get("http") or {}).get("request", {}).get("userAgent") or "unknown"] += 1
        cursor = page.get("cursor") or page.get("nextCursor")
        if not cursor:
            break
    if clients:
        print("tool calls by client:")
        for name, n in clients.most_common(15):
            print(f"  {name:<40} {n}")
    return 0


if __name__ == "__main__":
    sys.exit(main())