"""Load test: N parallel WebSocket sessions for a while, mixing solved episodes, heavy Python and quick exits.

Usage: .venv/bin/python scripts/load_test.py --url http://localhost:8011 --workers 8 --seconds 180
"""

import argparse
import random
import statistics
import sys
import threading
import time
from pathlib import Path

sys.path.insert(0, str(Path(__file__).resolve().parents[1]))
sys.path.insert(0, str(Path(__file__).resolve().parent))

from diligence.environment import TASK_IDS, build  # noqa: E402
from wsclient import Session  # noqa: E402

HEAVY = "x = bytearray(450 * 1024 * 1024)\nimport hashlib\nprint(hashlib.sha256(x).hexdigest()[:8])"
SPIN = "import time\nt = time.time()\nwhile time.time() - t < 4: pass\nprint('spun')"


def worker(url, until, rng, stats, lock):
    while time.time() < until:
        task_id = rng.choice(TASK_IDS)
        seed = rng.randrange(10 ** 9)
        mode = rng.choices(["oracle", "heavy", "quick"], [0.5, 0.3, 0.2])[0]
        try:
            with Session(url, timeout=120) as s:
                t0 = time.time()
                data = s.reset(task_id=task_id, seed=seed)
                lat = [time.time() - t0]
                tools = data["observation"]["output"]
                if mode == "oracle":
                    actions = build(task_id, seed).oracle()
                elif mode == "heavy" and '- python {"code"' in tools:
                    actions = [{"tool": "python", "args": {"code": rng.choice([HEAVY, SPIN])}}, {"tool": "submit", "args": {}}]
                else:
                    actions = [{"tool": "list_files" if "list_files" in tools else "nope", "args": {}},
                               {"tool": "submit", "args": {}}]
                for action in actions:
                    t0 = time.time()
                    data = s.step(action)
                    lat.append(time.time() - t0)
                    if data["done"]:
                        break
                ok = data["done"] and (mode != "oracle" or data["reward"] == 1.0)
                with lock:
                    stats["episodes"] += 1
                    stats["latency"] += lat
                    if not ok:
                        stats["bad"].append((task_id, seed, mode, data.get("reward")))
        except Exception as exc:  # noqa: BLE001
            with lock:
                stats["errors"].append(f"{task_id} {mode}: {type(exc).__name__}: {exc}"[:200])


def main():
    ap = argparse.ArgumentParser()
    ap.add_argument("--url", default="http://localhost:8011")
    ap.add_argument("--workers", type=int, default=8)
    ap.add_argument("--seconds", type=int, default=180)
    args = ap.parse_args()
    stats = {"episodes": 0, "latency": [], "bad": [], "errors": []}
    lock = threading.Lock()
    until = time.time() + args.seconds
    threads = [threading.Thread(target=worker, args=(args.url, until, random.Random(i), stats, lock))
               for i in range(args.workers)]
    for t in threads:
        t.start()
    for t in threads:
        t.join()
    lat = sorted(stats["latency"]) or [0.0]
    print(f"episodes {stats['episodes']}, calls {len(lat)}, errors {len(stats['errors'])}, "
          f"wrong results {len(stats['bad'])}")
    print(f"latency p50 {statistics.median(lat):.2f}s p95 {lat[int(0.95 * len(lat))]:.2f}s max {lat[-1]:.2f}s")
    for e in stats["errors"][:10] + [str(b) for b in stats["bad"][:10]]:
        print(" ", e)
    sys.exit(1 if stats["errors"] or stats["bad"] else 0)


if __name__ == "__main__":
    main()