"""Shared utility helpers."""

import json
import os


def load_json(path: str) -> dict | list:
    with open(path, "r", encoding="utf-8") as f:
        return json.load(f)


def save_json(data: dict | list, path: str) -> None:
    os.makedirs(os.path.dirname(path), exist_ok=True)
    with open(path, "w", encoding="utf-8") as f:
        json.dump(data, f, ensure_ascii=False, indent=2)


def file_exists(path: str) -> bool:
    return os.path.exists(path)


def list_files(directory: str, extension: str = ".txt") -> list[str]:
    if not os.path.isdir(directory):
        return []
    return [
        os.path.join(directory, f)
        for f in os.listdir(directory)
        if f.endswith(extension)
    ]