#!/usr/bin/env python3
"""Small dependency-free concurrency gate for the persisted read paths."""

from __future__ import annotations

import argparse
import json
import math
import time
import urllib.error
import urllib.request
from concurrent.futures import ThreadPoolExecutor, as_completed

PATHS = (
    "/api/v1/dashboard",
    "/api/v1/vehicles?page=1&page_size=25",
    "/api/v1/bookings?page=1&page_size=25&sort=operational",
    "/api/v1/data-quality/issues?status=open&page=1&page_size=25",
    "/api/v1/audit?page=1&page_size=25",
    "/api/v1/system/status",
)


def request(url: str, cookie: str, timeout: float) -> tuple[float, int]:
    started = time.perf_counter()
    try:
        with urllib.request.urlopen(
            urllib.request.Request(url, headers={"Cookie": cookie}), timeout=timeout
        ) as response:
            response.read()
            status = response.status
    except urllib.error.HTTPError as error:
        status = error.code
    return (time.perf_counter() - started) * 1000, status


def main() -> None:
    parser = argparse.ArgumentParser()
    parser.add_argument("--base-url", default="http://localhost:1228")
    parser.add_argument("--requests", type=int, default=240)
    parser.add_argument("--concurrency", type=int, default=12)
    parser.add_argument("--timeout", type=float, default=5.0)
    parser.add_argument("--max-p95-ms", type=float, default=1500.0)
    args = parser.parse_args()
    if args.requests < 1 or args.concurrency < 1:
        raise SystemExit("requests and concurrency must be positive")

    login = urllib.request.Request(
        f"{args.base_url.rstrip('/')}/api/v1/demo/login",
        data=json.dumps({"role": "operations_manager"}).encode(),
        headers={"Content-Type": "application/json"},
        method="POST",
    )
    with urllib.request.urlopen(login, timeout=args.timeout) as response:
        cookie = response.headers.get("Set-Cookie", "").split(";", 1)[0]
    if not cookie:
        raise SystemExit("demo login returned no session cookie")

    base = args.base_url.rstrip("/")
    work = [f"{base}{PATHS[index % len(PATHS)]}" for index in range(args.requests)]
    results: list[tuple[float, int]] = []
    with ThreadPoolExecutor(max_workers=args.concurrency) as executor:
        futures = [executor.submit(request, url, cookie, args.timeout) for url in work]
        results.extend(future.result() for future in as_completed(futures))

    failures = [status for _, status in results if status != 200]
    durations = sorted(duration for duration, _ in results)
    p95 = durations[max(0, math.ceil(len(durations) * 0.95) - 1)]
    print(
        f"read-only load smoke: requests={len(results)} concurrency={args.concurrency} "
        f"failures={len(failures)} p95_ms={p95:.1f} max_ms={durations[-1]:.1f}"
    )
    if failures:
        raise SystemExit(f"read-only load smoke returned non-200 statuses: {sorted(set(failures))}")
    if p95 > args.max_p95_ms:
        raise SystemExit(f"p95 {p95:.1f} ms exceeds {args.max_p95_ms:.1f} ms")


if __name__ == "__main__":
    main()