from __future__ import annotations

import os
import time
import random
import re
from dataclasses import dataclass
from typing import Any, Dict, Iterable, Optional

import numpy as np


def now_ts() -> float:
    return time.time()


def seed_everything(seed: int) -> None:
    random.seed(seed)
    np.random.seed(seed)
    os.environ["PYTHONHASHSEED"] = str(seed)


def ensure_dir(path: str) -> None:
    os.makedirs(path, exist_ok=True)


def clamp(x: float, lo: float, hi: float) -> float:
    return max(lo, min(hi, x))


def stable_hash(s: str) -> str:
    # Short stable tag for filenames/variants
    import hashlib
    return hashlib.sha1(s.encode("utf-8")).hexdigest()[:10]


def sanitize_variant_prefix(name: str, max_len: int = 24) -> str:
    safe = re.sub(r"[^A-Za-z0-9_]+", "_", name).strip("_")
    if not safe:
        safe = "run"
    if max_len > 0 and len(safe) > max_len:
        safe = safe[:max_len]
    return safe


@dataclass(frozen=True)
class TrialKey:
    exp_name: str
    platform: str
    design: str
    variant: str
    fidelity: str